Pulumi Blog: Alex Leventer

How to Test Infrastructure as Code

Alex Leventer — Tue, 30 Jun 2026 14:00:00 -0700

IaC testing means validating your infrastructure code the same way you test application software—unit tests with mocked cloud providers that run in milliseconds, integration tests that deploy and inspect real resources, and policy checks that enforce compliance rules on every preview and deploy. Together, these layers catch misconfigurations before they reach production.

Untested infrastructure code is a liability. A missing tag in a security group rule, an S3 bucket with public read access, a misconfigured IAM policy—any of these can slip through code review and land in production. Infrastructure bugs are often harder to debug than application bugs, because the feedback loop is slow (deploy, observe, destroy) and the blast radius is large (an outage, a security incident, a surprise AWS bill).

The good news: Pulumi is built on general-purpose programming languages, which means you can test infrastructure code with the exact same tools and frameworks you already use to test application code. No new language to learn. No separate toolchain. Just pytest, Mocha, or go test—pointing at your infrastructure program.

This guide walks through all three testing layers with complete, runnable examples.

Why should you test infrastructure as code?

The case for testing application code is well-established. The case for testing IaC is just as strong—arguably stronger, because the consequences of an undetected bug are more severe.

Catch misconfigurations before they deploy. A unit test that checks whether a security group allows SSH from 0.0.0.0/0 will catch that misconfiguration in milliseconds, before any cloud API call is made. The same test in CI catches it before the code is merged.

Prevent drift and outages. Integration tests that deploy to a staging environment and validate runtime behavior—does the HTTP endpoint return 200? does the database accept connections?—give you confidence that an infrastructure change doesn’t silently break a dependent service.

Refactor safely. Well-tested infrastructure code can be restructured, modularized, and upgraded without fear. When all your properties, tags, and security rules are asserted in tests, you know immediately if a refactor breaks a constraint.

Enforce security and compliance automatically. Policy as code lets you encode your organization’s security rules as executable tests. Mandatory policies block non-compliant deployments entirely; advisory policies surface warnings for human review. These rules run on every pulumi preview and pulumi up—not just at audit time.

Ship infrastructure at software speed. Teams that test IaC ship changes faster, with less fear. The CI pipeline becomes a confidence engine rather than a deployment gate.

The annual DORA State of DevOps research is consistently associated with a pattern among elite-performing engineering teams—those that deploy frequently and recover quickly from failures: comprehensive automated testing across the stack. Infrastructure is no longer exempt from that standard.

What types of IaC tests are there?

IaC testing mirrors the classic software test pyramid: a wide base of fast, cheap unit tests, a smaller layer of integration tests against real infrastructure, and policy checks that enforce rules throughout.

Layer	What it tests	Speed	Cost	Cloud credentials?
Unit tests	Resource properties, tags, security rules, naming conventions	Milliseconds	Free	No
Integration tests	Full stack lifecycle, runtime behavior, cross-resource dependencies	Minutes	Real cloud spend	Yes
Policy as code	Compliance rules, security baselines, organizational standards	Milliseconds	Free	No (runs at preview time)

graph TD
A["🔒 Policy as Code<br/>Compliance &amp; guardrails<br/>Runs at preview time<br/>Milliseconds · Free"] --> B
B["🧪 Integration Tests<br/>Real cloud deployments<br/>Full lifecycle validation<br/>Minutes · Cloud spend"] --> C
C["⚡ Unit Tests<br/>Mocked providers<br/>Property assertions<br/>Milliseconds · Free"]
style A fill:#8A3FFC,color:#fff,stroke:#6B2FD4
style B fill:#0EA5E9,color:#fff,stroke:#0284C7
style C fill:#10B981,color:#fff,stroke:#059669

Start with unit tests—they’re free, fast, and catch the most common mistakes. Add integration tests for critical paths (the deployment pipeline, data infrastructure, security-sensitive resources). Layer in policy as code for compliance requirements that must never regress.

How do you write unit tests for Pulumi?

Pulumi unit tests replace the communication channel between the Pulumi program and the cloud provider with mocks. When the program registers a resource (e.g., aws.ec2.SecurityGroup(...)), the mock intercepts the call, returns dummy state, and never makes a real cloud API call. Tests run in the same process, in the same language, using the same test runner you already use.

Setting up mocks

The import-order rule: You must set up mocks before importing your Pulumi program. If you import the program first, the Pulumi runtime initializes without mocks and will attempt real cloud calls.

# test_infra.py
import unittest
import pulumi

class MyMocks(pulumi.runtime.Mocks):
 def new_resource(self, args: pulumi.runtime.MockResourceArgs):
 # Return [id, state]. State keys must be camelCase.
 return [args.name + "_id", args.inputs]

 def call(self, args: pulumi.runtime.MockCallArgs):
 return {}

# Set mocks BEFORE importing the program
pulumi.runtime.set_mocks(MyMocks())
import infra # import program AFTER setting mocks

class TestInfra(unittest.TestCase):

 @pulumi.runtime.test
 def test_no_public_ssh(self):
 """Security group must not expose SSH to the public internet."""
 def check_security_group(args):
 ingress_rules = args[0]
 for rule in (ingress_rules or []):
 for cidr in (rule.get("cidrBlocks") or []):
 self.assertNotEqual(
 cidr, "0.0.0.0/0",
 "Security group must not expose port 22 to the internet."
 )
 return pulumi.Output.all(infra.group.ingress).apply(check_security_group)

 @pulumi.runtime.test
 def test_server_has_tags(self):
 """EC2 instance must have required tags."""
 def check_tags(args):
 tags = args[0]
 self.assertIn("Environment", tags, "Missing 'Environment' tag")
 self.assertIn("Name", tags, "Missing 'Name' tag")
 return pulumi.Output.all(infra.server.tags).apply(check_tags)

if __name__ == "__main__":
 unittest.main()

Run with: python -m unittest discover -v

// infra.test.ts
import * as pulumi from "@pulumi/pulumi";
import { expect } from "chai";

// Set mocks BEFORE dynamic import of the program
pulumi.runtime.setMocks(
 {
 newResource: (args: pulumi.runtime.MockResourceArgs): { id: string; state: any } => {
 // State keys must be camelCase
 return { id: `${args.name}-id`, state: args.inputs };
 },
 call: (args: pulumi.runtime.MockCallArgs) => ({ ...args.inputs }),
 },
 "my-project",
 "test",
 false // preview = false
);

describe("Infrastructure", function () {
 let infra: typeof import("./index");

 before(async function () {
 // Dynamic import AFTER setting mocks
 infra = await import("./index");
 });

 it("must not expose SSH to the internet", function (done) {
 pulumi.all([infra.group.ingress]).apply(([ingress]) => {
 for (const rule of ingress ?? []) {
 for (const cidr of rule.cidrBlocks ?? []) {
 expect(cidr).to.not.equal(
 "0.0.0.0/0",
 "Security group must not expose port 22 to the internet"
 );
 }
 }
 done();
 });
 });

 it("must have required tags", function (done) {
 pulumi.all([infra.server.tags]).apply(([tags]) => {
 expect(tags).to.include.keys("Environment", "Name");
 done();
 });
 });
});

Run with: mocha -r ts-node/register infra.test.ts

// infra_test.go
package infra_test

import (
 "testing"

 "github.com/pulumi/pulumi-aws/sdk/v6/go/aws/ec2"
 "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
 "github.com/stretchr/testify/assert"
)

// MockResourceMonitor implements pulumi.ResourceMonitor for unit tests.
func TestNoPublicSSH(t *testing.T) {
 err := pulumi.RunErr(func(ctx *pulumi.Context) error {
 infra, err := NewInfra(ctx)
 assert.NoError(t, err)

 infra.Group.Ingress.ApplyT(func(rules []ec2.SecurityGroupIngress) error {
 for _, rule := range rules {
 for _, cidr := range rule.CidrBlocks {
 assert.NotEqual(t, "0.0.0.0/0", cidr,
 "Security group must not expose port 22 to the internet")
 }
 }
 return nil
 })
 return nil
 }, pulumi.WithMocks("my-project", "test", mocks{}))
 assert.NoError(t, err)
}

type mocks struct{}

func (mocks) NewResource(args pulumi.MockResourceArgs) (string, map[string]interface{}, error) {
 return args.Name + "_id", args.Inputs, nil
}
func (mocks) Call(args pulumi.MockCallArgs) (map[string]interface{}, error) {
 return args.Args, nil
}

Run with: go test ./... -v

// InfraTests.cs
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Pulumi;
using Pulumi.Testing;
using Xunit;

public class InfraTests
{
 [Fact]
 public async Task NoPublicSSH()
 {
 var resources = await Testing.RunAsync<MyStack>();

 var sg = resources.OfType<Pulumi.Aws.Ec2.SecurityGroup>().First();
 var ingress = await sg.Ingress.GetValueAsync();

 foreach (var rule in ingress)
 {
 foreach (var cidr in rule.CidrBlocks)
 {
 Assert.NotEqual("0.0.0.0/0", cidr);
 }
 }
 }

 [Fact]
 public async Task ServerHasRequiredTags()
 {
 var resources = await Testing.RunAsync<MyStack>();

 var server = resources.OfType<Pulumi.Aws.Ec2.Instance>().First();
 var tags = await server.Tags.GetValueAsync();

 Assert.True(tags.ContainsKey("Environment"), "Missing 'Environment' tag");
 Assert.True(tags.ContainsKey("Name"), "Missing 'Name' tag");
 }
}

Run with: dotnet test

// InfraTest.java
package myproject;

import com.pulumi.aws.ec2.Instance;
import com.pulumi.aws.ec2.SecurityGroup;
import com.pulumi.test.Mocks;
import com.pulumi.test.Mocks.CallArgs;
import com.pulumi.test.Mocks.ResourceArgs;
import com.pulumi.test.Mocks.ResourceResult;
import com.pulumi.test.PulumiTest;
import com.pulumi.test.TestOptions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import static org.junit.jupiter.api.Assertions.*;

class InfraTest {

 // Implement Mocks to intercept resource creation. State keys must be camelCase.
 static class MyMocks implements Mocks {
 @Override
 public CompletableFuture<ResourceResult> newResourceAsync(ResourceArgs args) {
 var state = new HashMap<>(args.inputs);
 return CompletableFuture.completedFuture(
 ResourceResult.of(Optional.of(args.name + "_id"), state));
 }

 @Override
 public CompletableFuture<Map<String, Object>> callAsync(CallArgs args) {
 return CompletableFuture.completedFuture(Map.of());
 }
 }

 // PulumiTest.cleanup() must run after every test to reset the runtime state.
 @AfterEach
 void cleanup() {
 PulumiTest.cleanup();
 }

 @Test
 void serverHasRequiredTags() {
 var result = PulumiTest
 .withMocks(new MyMocks())
 .withOptions(TestOptions.builder()
 .projectName("project").stackName("stack").preview(false)
 .build())
 .runTest(ctx -> new Infra());

 var instance = result.resources().stream()
 .filter(r -> r instanceof Instance)
 .map(r -> (Instance) r)
 .findFirst()
 .orElseThrow(() -> new AssertionError("EC2 instance not found"));

 var tags = PulumiTest.extractValue(instance.tags())
 .orElseThrow(() -> new AssertionError("Tags must not be null"));
 assertTrue(tags.containsKey("Environment"), "Missing 'Environment' tag");
 assertTrue(tags.containsKey("Name"), "Missing 'Name' tag");
 }

 @Test
 void noPublicSshExposed() {
 var result = PulumiTest
 .withMocks(new MyMocks())
 .withOptions(TestOptions.builder()
 .projectName("project").stackName("stack").preview(false)
 .build())
 .runTest(ctx -> new Infra());

 var group = result.resources().stream()
 .filter(r -> r instanceof SecurityGroup)
 .map(r -> (SecurityGroup) r)
 .findFirst()
 .orElseThrow(() -> new AssertionError("Security group not found"));

 var rules = PulumiTest.extractValue(group.ingress());
 for (var rule : rules) {
 for (var cidr : rule.cidrBlocks()) {
 assertNotEquals("0.0.0.0/0", cidr,
 "Security group must not expose SSH to the internet");
 }
 }
 }
}

Run with: mvn test (JUnit 5)

The program under test

Both examples above test this program:

# infra.py
import pulumi
from pulumi_aws import ec2

group = ec2.SecurityGroup("web-secgrp",
 ingress=[{
 "protocol": "tcp",
 "from_port": 80,
 "to_port": 80,
 "cidrBlocks": ["0.0.0.0/0"],
 }],
)

server = ec2.Instance("web-server",
 instance_type="t2.micro",
 ami="ami-0b0ea68c435eb488d",
 vpc_security_group_ids=[group.id],
 tags={"Name": "web-server", "Environment": "dev"},
)

// index.ts
import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

export const group = new aws.ec2.SecurityGroup("web-secgrp", {
 ingress: [{
 protocol: "tcp",
 fromPort: 80,
 toPort: 80,
 cidrBlocks: ["0.0.0.0/0"],
 }],
});

export const server = new aws.ec2.Instance("web-server", {
 instanceType: "t2.micro",
 ami: "ami-0b0ea68c435eb488d",
 vpcSecurityGroupIds: [group.id],
 tags: { Name: "web-server", Environment: "dev" },
});

// main.go
package infra_test

import (
 "github.com/pulumi/pulumi-aws/sdk/v6/go/aws/ec2"
 "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

type Infra struct {
 Group *ec2.SecurityGroup
 Server *ec2.Instance
}

func NewInfra(ctx *pulumi.Context) (*Infra, error) {
 group, err := ec2.NewSecurityGroup(ctx, "web-secgrp", &ec2.SecurityGroupArgs{
 Ingress: ec2.SecurityGroupIngressArray{
 ec2.SecurityGroupIngressArgs{
 Protocol: pulumi.String("tcp"),
 FromPort: pulumi.Int(80),
 ToPort: pulumi.Int(80),
 CidrBlocks: pulumi.StringArray{pulumi.String("0.0.0.0/0")},
 },
 },
 })
 if err != nil {
 return nil, err
 }

 server, err := ec2.NewInstance(ctx, "web-server", &ec2.InstanceArgs{
 InstanceType: pulumi.String("t2.micro"),
 Ami: pulumi.String("ami-0b0ea68c435eb488d"),
 VpcSecurityGroupIds: pulumi.StringArray{group.ID()},
 Tags: pulumi.StringMap{
 "Name": pulumi.String("web-server"),
 "Environment": pulumi.String("dev"),
 },
 })
 if err != nil {
 return nil, err
 }

 return &Infra{Group: group, Server: server}, nil
}

// MyStack.cs
using Pulumi;
using Pulumi.Aws.Ec2;
using Pulumi.Aws.Ec2.Inputs;

public class MyStack : Stack
{
 public MyStack()
 {
 var group = new SecurityGroup("web-secgrp", new SecurityGroupArgs
 {
 Ingress = new[]
 {
 new SecurityGroupIngressArgs
 {
 Protocol = "tcp", FromPort = 80, ToPort = 80,
 CidrBlocks = new[] { "0.0.0.0/0" },
 },
 },
 });

 var server = new Instance("web-server", new InstanceArgs
 {
 InstanceType = "t2.micro",
 Ami = "ami-0b0ea68c435eb488d",
 VpcSecurityGroupIds = new[] { group.Id },
 Tags = new InputMap<string>
 {
 { "Name", "web-server" },
 { "Environment", "dev" },
 },
 });
 }
}

// Infra.java
package myproject;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.aws.ec2.SecurityGroup;
import com.pulumi.aws.ec2.SecurityGroupArgs;
import com.pulumi.aws.ec2.Instance;
import com.pulumi.aws.ec2.InstanceArgs;
import com.pulumi.aws.ec2.inputs.SecurityGroupIngressArgs;
import java.util.List;
import java.util.Map;

public class Infra {
 public final SecurityGroup group;
 public final Instance server;

 public Infra() {
 this.group = new SecurityGroup("web-secgrp",
 SecurityGroupArgs.builder()
 .ingress(SecurityGroupIngressArgs.builder()
 .protocol("tcp")
 .fromPort(80)
 .toPort(80)
 .cidrBlocks("0.0.0.0/0")
 .build())
 .build());

 this.server = new Instance("web-server",
 InstanceArgs.builder()
 .instanceType("t2.micro")
 .ami("ami-0b0ea68c435eb488d")
 .vpcSecurityGroupIds(group.id().applyValue(List::of))
 .tags(Map.of("Name", "web-server", "Environment", "dev"))
 .build());
 }
}

Key detail: State property keys in the mock’s new_resource/newResource return value must be camelCase (cidrBlocks, not cidr_blocks), regardless of the language you’re writing in. This is how Pulumi serializes properties internally.

How do you run integration tests against real cloud resources?

Unit tests tell you whether your resource definitions are correct. Integration tests tell you whether your infrastructure actually works. Integration tests deploy real cloud resources, run assertions against them, and then destroy everything—giving you end-to-end confidence at the cost of actual cloud spend and time.

Using the Automation API

The Pulumi Automation API lets you drive pulumi up, pulumi destroy, and every other Pulumi CLI operation programmatically, from within a test. You define the stack inline (using a function that runs your Pulumi program) or point it at an existing project directory.

# test_integration.py
import pytest
import pulumi
import pulumi_aws as aws
from pulumi import automation as auto

def create_bucket_program():
 """The Pulumi program to deploy during the test."""
 bucket = aws.s3.Bucket("test-bucket",
 tags={"Environment": "test", "ManagedBy": "pulumi"},
 )
 pulumi.export("bucket_name", bucket.id)
 pulumi.export("bucket_arn", bucket.arn)

@pytest.fixture(scope="module")
def deployed_stack():
 """Deploy the stack for the test module and destroy it when done."""
 stack = auto.create_or_select_stack(
 stack_name="integration-test",
 project_name="bucket-test",
 program=create_bucket_program,
 )
 stack.set_config("aws:region", auto.ConfigValue(value="us-west-2"))

 # Install provider plugins
 stack.workspace.install_plugin("aws", "v7.34.0")

 # Deploy
 up_result = stack.up(on_output=print)

 yield up_result.outputs

 # Teardown: destroy everything after the test module completes
 stack.destroy(on_output=print)
 stack.workspace.remove_stack("integration-test")

def test_bucket_was_created(deployed_stack):
 """The S3 bucket should have been created with the expected name prefix."""
 bucket_name = deployed_stack["bucket_name"].value
 assert bucket_name.startswith("test-bucket"), f"Unexpected bucket name: {bucket_name}"

def test_bucket_has_tags(deployed_stack):
 """Verify the bucket was created with required tags (via AWS SDK)."""
 import boto3
 s3 = boto3.client("s3", region_name="us-west-2")
 bucket_name = deployed_stack["bucket_name"].value
 tagging = s3.get_bucket_tagging(Bucket=bucket_name)
 tag_map = {t["Key"]: t["Value"] for t in tagging["TagSet"]}
 assert tag_map.get("Environment") == "test"
 assert tag_map.get("ManagedBy") == "pulumi"

Run with: pytest test_integration.py -v

// integration.test.ts
import { LocalWorkspace, ConfigValue, UpResult } from "@pulumi/pulumi/automation";
import * as aws from "@pulumi/aws";
import * as pulumi from "@pulumi/pulumi";
import { expect } from "chai";

describe("S3 Bucket Integration", function () {
 this.timeout(300_000); // 5 min — real deploys take time

 let outputs: UpResult["outputs"];
 let stackName = "integration-test-ts";

 before(async function () {
 const stack = await LocalWorkspace.createOrSelectStack({
 stackName,
 projectName: "bucket-test",
 program: async () => {
 const bucket = new aws.s3.Bucket("test-bucket", {
 tags: { Environment: "test", ManagedBy: "pulumi" },
 });
 return {
 bucketName: bucket.id,
 bucketArn: bucket.arn,
 };
 },
 });

 await stack.setConfig("aws:region", { value: "us-west-2" });
 await stack.workspace.installPlugin("aws", "v7.34.0");

 const upResult = await stack.up({ onOutput: console.log });
 outputs = upResult.outputs;
 });

 after(async function () {
 const stack = await LocalWorkspace.selectStack({ stackName, projectName: "bucket-test", program: async () => {} });
 await stack.destroy({ onOutput: console.log });
 await stack.workspace.removeStack(stackName);
 });

 it("creates a bucket with the right name prefix", function () {
 const name = outputs["bucketName"].value as string;
 expect(name).to.match(/^test-bucket/);
 });
});

Run with: mocha -r ts-node/register integration.test.ts

// integration_test.go
package integration_test

import (
 "context"
 "fmt"
 "os"
 "testing"

 "github.com/pulumi/pulumi-aws/sdk/v6/go/aws/s3"
 "github.com/pulumi/pulumi/sdk/v3/go/auto"
 "github.com/pulumi/pulumi/sdk/v3/go/auto/optup"
 "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
 "github.com/stretchr/testify/assert"
)

func TestBucketIntegration(t *testing.T) {
 ctx := context.Background()

 stack, err := auto.NewStackInlineSource(ctx, "integration-test", "bucket-test",
 func(ctx *pulumi.Context) error {
 bucket, err := s3.NewBucket(ctx, "test-bucket", &s3.BucketArgs{
 Tags: pulumi.StringMap{
 "Environment": pulumi.String("test"),
 "ManagedBy": pulumi.String("pulumi"),
 },
 })
 if err != nil {
 return err
 }
 ctx.Export("bucketName", bucket.ID())
 return nil
 },
 )
 assert.NoError(t, err)

 _ = stack.SetConfig(ctx, "aws:region", auto.ConfigValue{Value: "us-west-2"})
 upResult, err := stack.Up(ctx, optup.ProgressStreams(os.Stdout))
 assert.NoError(t, err)

 t.Cleanup(func() {
 _, _ = stack.Destroy(ctx)
 _ = stack.Workspace().RemoveStack(ctx, "integration-test")
 })

 name := fmt.Sprintf("%v", upResult.Outputs["bucketName"].Value)
 assert.Contains(t, name, "test-bucket")
}

Run with: go test ./... -v -timeout 10m

// IntegrationTests.cs
using System;
using System.Threading.Tasks;
using Pulumi.Automation;
using Xunit;

public class IntegrationTests : IAsyncLifetime
{
 private WorkspaceStack _stack = null!;
 private UpResult _upResult = null!;

 public async Task InitializeAsync()
 {
 var program = PulumiFn.Create(() =>
 {
 var bucket = new Pulumi.Aws.S3.Bucket("test-bucket", new()
 {
 Tags = new() { ["Environment"] = "test", ["ManagedBy"] = "pulumi" },
 });
 return new System.Collections.Generic.Dictionary<string, object?>
 {
 ["bucketName"] = bucket.Id,
 };
 });

 _stack = await LocalWorkspace.CreateOrSelectStackAsync(new InlineProgramArgs(
 projectName: "bucket-test",
 stackName: "integration-test",
 program: program
 ));

 await _stack.SetConfigAsync("aws:region", new ConfigValue("us-west-2"));
 _upResult = await _stack.UpAsync(new UpOptions { OnStandardOutput = Console.WriteLine });
 }

 public async Task DisposeAsync()
 {
 await _stack.DestroyAsync(new DestroyOptions { OnStandardOutput = Console.WriteLine });
 await _stack.Workspace.RemoveStackAsync("integration-test");
 }

 [Fact]
 public void BucketNameHasExpectedPrefix()
 {
 var name = _upResult.Outputs["bucketName"].Value.ToString();
 Assert.StartsWith("test-bucket", name);
 }
}

Run with: dotnet test

// IntegrationTest.java
package myproject;

import com.pulumi.Context;
import com.pulumi.automation.LocalWorkspace;
import com.pulumi.automation.UpOptions;
import com.pulumi.automation.DestroyOptions;
import com.pulumi.automation.ConfigValue;
import com.pulumi.automation.WorkspaceStack;
import org.junit.jupiter.api.*;
import java.util.Map;
import static org.junit.jupiter.api.Assertions.*;

@TestInstance(TestInstance.Lifecycle.PER_CLASS)
class IntegrationTest {

 private static final String PROJECT_NAME = "bucket_test_project";
 private static final String STACK_NAME = "integration-test";

 private WorkspaceStack stack;
 private Map<String, com.pulumi.automation.OutputValue> outputs;

 @BeforeAll
 void setUp() throws Exception {
 stack = LocalWorkspace.createOrSelectStack(PROJECT_NAME, STACK_NAME, (Context ctx) -> {
 var bucket = new com.pulumi.aws.s3.Bucket("test-bucket",
 com.pulumi.aws.s3.BucketArgs.builder()
 .tags(Map.of("Environment", "test", "ManagedBy", "pulumi"))
 .build());
 ctx.export("bucketName", bucket.id());
 });

 stack.workspace().installPlugin("aws", "v7.34.0");
 stack.setConfig("aws:region", new ConfigValue("us-west-2"));

 var upResult = stack.up(UpOptions.builder().onStandardOutput(System.out::println).build());
 outputs = upResult.outputs();
 }

 @AfterAll
 void tearDown() throws Exception {
 if (stack != null) {
 stack.destroy(DestroyOptions.builder().onStandardOutput(System.out::println).build());
 stack.workspace().removeStack(STACK_NAME);
 }
 }

 @Test
 void bucketNameHasExpectedPrefix() {
 var name = (String) outputs.get("bucketName").value();
 assertTrue(name.startsWith("test-bucket"), "Unexpected bucket name: " + name);
 }
}

Run with: mvn test

Using the Go integration framework

If you prefer Go-based integration tests, Pulumi ships a purpose-built Go test framework at github.com/pulumi/pulumi/pkg/v3/testing/integration. It handles the full create → validate → destroy lifecycle for any Pulumi program (written in any language), with an ExtraRuntimeValidation hook for assertions against deployed state.

func TestS3Website(t *testing.T) {
 integration.ProgramTest(t, &integration.ProgramTestOptions{
 Dir: path.Join("..", "my-s3-website"),
 Config: map[string]string{"aws:region": "us-west-2"},
 ExtraRuntimeValidation: func(t *testing.T, stack integration.RuntimeValidationStackInfo) {
 url := stack.Outputs["websiteUrl"].(string)
 resp, _ := http.Get("http://" + url)
 assert.Equal(t, 200, resp.StatusCode)
 },
 })
}

Best practice: Always destroy test stacks in a finally block or test teardown fixture. Leaked integration test stacks are a common cause of unexpected cloud spend.

How does policy as code complement IaC testing?

Unit and integration tests validate what your infrastructure does. Policy as code enforces what your infrastructure must conform to—security standards, tagging conventions, compliance requirements—and it runs automatically on every pulumi preview and pulumi up.

Pulumi Policies are currently supported in Python and TypeScript. You write policies in the same language as the rest of your stack, without learning a DSL. A mandatory policy blocks a deployment entirely when violated; an advisory policy surfaces a warning but allows the deploy to proceed.

# __main__.py in your policy pack directory
from pulumi_policy import (
 EnforcementLevel,
 PolicyPack,
 ReportViolation,
 ResourceValidationArgs,
 ResourceValidationPolicy,
)

REQUIRED_TAGS = {"Name", "Environment", "Owner"}

def require_tags(args: ResourceValidationArgs, report_violation: ReportViolation):
 if args.resource_type.startswith("aws:"):
 tags = args.props.get("tags") or {}
 missing = REQUIRED_TAGS - set(tags.keys())
 if missing:
 report_violation(
 f"Resource is missing required tags: {', '.join(sorted(missing))}"
 )

def no_public_s3(args: ResourceValidationArgs, report_violation: ReportViolation):
 if args.resource_type == "aws:s3/bucket:Bucket":
 if args.props.get("acl") in ("public-read", "public-read-write"):
 report_violation("S3 buckets must not have a public ACL.")

PolicyPack(
 name="aws-security-baseline",
 policies=[
 ResourceValidationPolicy(
 name="require-tags",
 description="All AWS resources must have Name, Environment, and Owner tags.",
 enforcement_level=EnforcementLevel.MANDATORY,
 validate=require_tags,
 ),
 ResourceValidationPolicy(
 name="no-public-s3",
 description="S3 buckets must not be publicly accessible via ACL.",
 enforcement_level=EnforcementLevel.MANDATORY,
 validate=no_public_s3,
 ),
 ],
)

// index.ts in your policy pack directory
import * as aws from "@pulumi/aws";
import { PolicyPack, validateResourceOfType } from "@pulumi/policy";

new PolicyPack("aws-security-baseline", {
 policies: [
 {
 name: "require-tags",
 description: "All EC2 instances must have Name, Environment, and Owner tags.",
 enforcementLevel: "mandatory",
 validateResource: validateResourceOfType(aws.ec2.Instance, (instance, args, reportViolation) => {
 const required = ["Name", "Environment", "Owner"];
 const tags = instance.tags || {};
 for (const tag of required) {
 if (!tags[tag]) {
 reportViolation(`Missing required tag: ${tag}`);
 }
 }
 }),
 },
 {
 name: "no-public-s3",
 description: "S3 buckets must not have a public ACL.",
 enforcementLevel: "mandatory",
 validateResource: validateResourceOfType(aws.s3.Bucket, (bucket, args, reportViolation) => {
 if (bucket.acl === "public-read" || bucket.acl === "public-read-write") {
 reportViolation("S3 bucket must not have a public ACL.");
 }
 }),
 },
 ],
});

Running a policy pack

# Scaffold a new policy pack from a template
mkdir my-policies && cd my-policies
pulumi policy new aws-typescript

# Run policy checks against a stack
pulumi preview --policy-pack ./my-policies
pulumi up --policy-pack ./my-policies

# Or publish to Pulumi Cloud and enforce organization-wide
pulumi policy publish

As Joe Duffy, Pulumi CEO, puts it: “The smartest agent in the world still needs guardrails, audit trails, and policy enforcement to be trusted with production systems at scale.”

Policy checks complement unit tests: unit tests verify your intent (“I wrote tags into this resource”), while policies enforce your standards (“all resources must have these tags, regardless of what any one developer intended”). For complex compliance environments, publish policies to Pulumi Cloud and assign them via policy groups to enforce them across the stacks or accounts you choose—including organization-wide.

How is testing IaC in Pulumi different from Terraform?

The fundamental difference is language cohesion. With Pulumi, you write infrastructure, tests, and policies all in the same general-purpose language. With Terraform, your infrastructure is HCL but your tests must be something else—either Go (Terratest) or a constrained HCL DSL (terraform test).

	Pulumi	Terratest	`terraform test` (≥ 1.6)
Language for tests	Same language as infra (Python, TypeScript, Go, C#, Java); YAML programs tested via Automation API from any of those languages	Always Go (regardless of infra language)	HCL DSL (`.tftest.hcl`)
Unit tests with mocks	Yes — `pulumi.runtime.set_mocks()`, no cloud credentials needed	No — no mock layer for cloud providers	Limited — `mock_provider` (v1.7+) is HCL-declarative, no programmatic logic
Integration testing	Automation API (any language) or Go framework	Full-featured but Go-only	Yes, via `command = apply` run blocks
Policy / guardrails	Pulumi Policies: Python or TypeScript, runs at preview time	External tools (checkov, tfsec, OPA/Rego — separate toolchain)	Sentinel (enterprise) or external
Execution speed	Unit: milliseconds; integration: depends on cloud	Minutes (real deployments by default)	Plan-only: fast; apply: minutes
Learning curve	Use existing language skills and test frameworks	Requires Go knowledge and understanding of `go test`	Low if you know HCL; limited expressiveness

Terratest is battle-tested and widely adopted, particularly for Terraform module testing. It offers deep integrations with AWS, GCP, Azure, and Kubernetes. Its limitation is that it has no mock layer for cloud providers, so most test suites deploy real infrastructure, which makes them slower and costlier to run on every commit.

terraform test has improved significantly in Terraform 1.6 and 1.7. The command = plan mode avoids real deployments, and mock_provider enables basic unit-like testing. But expressiveness is bounded by HCL’s declarative model—no general-purpose programming, no third-party assertion libraries, and a fixed set of run/assert test constructs.

With Pulumi, there’s no context switch. The same developer who writes the infrastructure writes the tests in the same language, using the same IDE, the same debugger, and the same CI pipeline. That cohesion is a productivity multiplier.

How to set up IaC testing with Pulumi

Follow these steps to add a complete test suite to a Pulumi project. The examples use Python, but the pattern is identical in TypeScript, Go, C#, or Java.

Step 1: Install Pulumi and choose a language SDK

# Install Pulumi CLI
curl -fsSL https://get.pulumi.com | sh

# Create a new project (or use an existing one)
pulumi new aws-python --name my-project --stack dev

Step 2: Add a test framework

# Python
pip install pytest pytest-asyncio

# TypeScript
npm install --save-dev mocha ts-node @types/mocha chai @types/chai

# Go uses the built-in testing package — no additional dependencies

Step 3: Implement the Mocks class

Create mocks.py (or equivalent) with your Mocks subclass. Keep it simple for unit tests: return [args.name + "_id", args.inputs] from new_resource.

Step 4: Write unit tests

Create test_infra.py in your project root. Import mocks first, then your program. Write test functions that use @pulumi.runtime.test and pulumi.Output.all(...).apply(...) to assert resource properties.

Step 5: Add integration tests

Create test_integration.py with a pytest fixture that creates a stack, calls stack.up(), yields outputs for assertions, and calls stack.destroy() in teardown. Point this at a dedicated test cloud account.

Step 6: Create a policy pack

mkdir policies && cd policies
pulumi policy new aws-python
# Edit __main__.py to add your rules

Step 7: Wire it all into CI

# .github/workflows/test.yml (GitHub Actions excerpt)
jobs:
 unit-tests:
 runs-on: ubuntu-latest
 steps:
 - uses: actions/checkout@v4
 - uses: pulumi/actions@v6
 - run: pip install -r requirements.txt
 - run: python -m pytest tests/unit/ -v

 integration-tests:
 runs-on: ubuntu-latest
 needs: unit-tests
 environment: staging
 steps:
 - uses: actions/checkout@v4
 - uses: pulumi/actions@v6
 - run: pip install -r requirements.txt
 - env:
 PULUMI_ACCESS_TOKEN: ${{ secrets.PULUMI_ACCESS_TOKEN }}
 AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
 AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
 run: python -m pytest tests/integration/ -v --timeout=300

Frequently asked questions

What is infrastructure as code testing?

Infrastructure as code testing is the practice of writing automated checks that validate your IaC programs before they deploy to production. Just like application testing, it includes unit tests (fast, no cloud credentials, mock the provider), integration tests (real cloud deployments in ephemeral environments), and policy checks (rules that enforce compliance standards on every preview and deploy).

Can you unit test IaC without deploying to the cloud?

Yes. Pulumi’s mocking framework intercepts all cloud API calls and replaces them with in-process stubs. Unit tests run entirely in memory—no cloud credentials, no network calls, no cost. A suite of 50 unit tests runs in under a second. This is the primary reason to write unit tests: fast, free, deterministic feedback on every commit.

Do you need real cloud credentials to test Pulumi?

Only for integration tests. Unit tests use Pulumi’s mock runtime and require no cloud credentials at all. Policy checks also run without credentials at pulumi preview time. Integration tests that use the Automation API do need credentials—they deploy real resources—so they’re typically run in a CI stage with access to a dedicated test account, not on every PR.

What’s the difference between unit and integration tests for IaC?

Unit tests validate resource properties, configurations, and relationships using mocked cloud providers—they run in milliseconds with no cloud credentials. Integration tests deploy actual resources to a real cloud environment, validate runtime behavior (does the endpoint respond? does the database accept connections?), and then destroy everything. Unit tests are cheap and frequent; integration tests are slower, cost real cloud spend, and run less often.

How do you mock cloud resources in Pulumi?

Implement pulumi.runtime.Mocks (Python) or call pulumi.runtime.setMocks() (TypeScript/JavaScript) before importing your Pulumi program. The new_resource method receives every resource registration and returns a fake [id, state] pair. The call method handles data-source lookups. Set mocks with pulumi.runtime.set_mocks(MyMocks()) and then import your program—the runtime will route all resource registrations through your mock instead of making real API calls.

What test frameworks work with Pulumi?

Any language-native test framework works. For Python: pytest (recommended) or unittest. For TypeScript/JavaScript: Mocha, Jest, or Vitest. For Go: the standard testing package. For C#: NUnit or xUnit. For Java: JUnit. The @pulumi/pulumi/automation SDK and pulumi.automation module integrate naturally with all of them. YAML is Pulumi’s declarative configuration language; because it has no control flow or executable statements, you cannot write test logic in YAML itself. YAML programs are tested by pointing the Automation API from Python, TypeScript, Go, C#, or Java at the project directory and asserting on the stack outputs.

How do you test Pulumi in CI/CD?

Split your test suite into two CI stages. Stage 1 (unit tests): runs on every PR commit, no cloud credentials required, fast. Stage 2 (integration tests): runs on merge to main or on a schedule, requires cloud credentials for a dedicated test account, uses the Automation API to deploy ephemeral stacks. The Pulumi GitHub Actions integration simplifies credential injection and stack management in both stages.

Is policy as code the same as testing?

Policy as code is complementary to—but distinct from—testing. Tests validate what your program produces (resource A has property B); policies enforce what your resources must conform to (all resources must have tag X). Policies run automatically at preview time and block non-compliant deployments at deploy time. Together, they create defense in depth: tests verify intent, policies enforce standards regardless of intent.

How is Pulumi testing different from Terratest?

Terratest typically deploys real infrastructure—it has no mock layer for cloud providers—so most test runs provision actual cloud resources, incurring real cost and taking 5–30 minutes. Tests must be written in Go regardless of what language your infrastructure uses. Pulumi’s unit testing framework runs in milliseconds with no cloud credentials, uses your existing language and test runner, and provides true mock isolation. For integration testing, Pulumi’s Automation API offers a similar model to Terratest but in any language.

How do you tear down resources after integration tests?

In Python pytest, use a module-scoped fixture that yields after stack.up() and calls stack.destroy() in the teardown. In TypeScript Mocha, call stack.destroy() in an after() hook. In Go, use defer stack.Destroy(ctx, ...). Always use a try/finally pattern (or equivalent in your language) so teardown runs even when a test assertion fails. Pulumi Cloud also has built-in stack TTL and auto-destroy features for extra safety.

Where to go next

Testing IaC is not an all-or-nothing investment. Start by adding a handful of unit tests to your most critical stack—the one that manages your production VPC, your IAM roles, or your data infrastructure. Pick three to five properties that, if wrong, would cause an outage or a security incident. Write tests for those. Run them in CI. Expand from there.

When you’re ready to go deeper:

Testing overview — Pulumi’s full testing documentation
Unit testing guide — detailed mock API reference with Go and C# examples
Automation API integration testing — advanced patterns (multi-stack tests, config injection, parallel test execution)
Policy as code authoring — writing and publishing Pulumi Policies
Pulumi vs. Terraform — a full comparison of the two platforms

If you’re migrating from Terraform, the Pulumi conversion tool translates your existing HCL to Python, TypeScript, Go, C#, and more, including your test infrastructure. Your Terratest or terraform test suites can be ported to Pulumi’s native test runner—using your existing language—as part of the migration.

Get started with Pulumi for free →

Best AI Infrastructure Tools in 2026

Alex Leventer — Mon, 25 May 2026 00:00:00 +0000

“AI infrastructure tools” covers two distinct markets: infrastructure for AI (GPU clouds like CoreWeave, MLOps platforms like Weights & Biases) and AI for infrastructure (agentic platforms like Pulumi Neo that generate, deploy, and govern cloud resources for you). Most teams need tools from both categories, and picking the wrong one wastes budget and adoption goodwill.

The pressure to get this right is real. McKinsey research puts the productivity lift from generative AI in software development at 20–45%, which is great for application teams and a problem for platform teams trying to keep up with the resulting feature flow. Infrastructure investment is climbing on both fronts: more spend on the compute that trains and serves models, more spend on AI tools that manage everything else.

This guide covers both categories: the compute and MLOps stack in Part 1, and AI-powered infrastructure management in Part 2, where the more interesting product shift is happening.

AI infrastructure tools overview

Tools for building AI infrastructure

CoreWeave: GPU cloud built for AI workloads
Lambda Labs: straightforward GPU cloud for research and startups
Modal: serverless GPU compute
Weights & Biases: ML experiment tracking and model management
MLflow: open-source ML lifecycle platform
Hyperscaler AI platforms: AWS SageMaker, Google Vertex AI, Azure ML

AI-powered infrastructure management tools

Pulumi Neo: agentic AI with policy automation
Firefly AIaC: asset codification and IaC generation
env0 Cloud Compass: multi-IaC insights and analysis
Spacelift AI: run explanation and troubleshooting
Crossplane with Upbound: Kubernetes-native infrastructure
General-purpose code assistants: Copilot, Claude Code, Cursor, Gemini
AWS Application Composer: visual serverless builder

Quick picks

If you only have two minutes:

Enterprise compliance: Pulumi Neo. Executes changes (not only suggestions), ships with policy packs for CIS, HITRUST, NIST, and PCI DSS, and works with Terraform, CloudFormation, and resources created by hand.
Serious GPU compute: CoreWeave. Purpose-built for AI workloads, deep NVIDIA partnership, and prices that generally undercut the hyperscalers.
Best developer experience for ML: Modal. Decorate a Python function, get a GPU, pay by the second.
Open-source MLOps: MLflow. No vendor lock-in, runs anywhere, plays well with everything.

What is AI infrastructure?

The term covers two distinct categories that share almost no vendors.

Infrastructure for AI is the compute, storage, and orchestration that AI workloads run on. Training a large model is not a normal cloud workload: it wants thousands of GPUs talking to each other over fat, low-latency networks for weeks at a time. Inference is different again: lower latency, smarter batching, different hardware. General-purpose cloud was not designed for either case, which is why specialized GPU clouds and MLOps platforms exist.

AI-powered infrastructure management is the inverse: AI tools that manage cloud infrastructure. They generate infrastructure as code, run deployments, detect drift, and remediate policy violations. The pitch is that modern infrastructure (multi-cloud, containers, microservices, regulated workloads) has gotten too complex for humans to manage by hand and too varied for scripted automation to keep up with.

Most organizations end up needing both: somewhere to run their ML workloads, and something to keep the rest of the cloud sane.

Part 1: Tools for building AI infrastructure

These are the platforms you run AI and ML workloads on: GPU clouds for raw compute, MLOps platforms for the lifecycle around them.

CoreWeave

CoreWeave is the GPU cloud that broke out of the AI hype cycle into a real public company. They went public in 2025, signed a multi-billion-dollar capacity deal with OpenAI, and acquired Weights & Biases. Their thesis from day one was that AI workloads deserve infrastructure designed for AI workloads, not a GPU SKU bolted onto a general-purpose cloud.

License: Proprietary
Best for: Large-scale training and high-throughput inference; teams that need dedicated GPU capacity with first access to new NVIDIA hardware
Strengths: GPU infrastructure designed for AI; Kubernetes-native; direct NVIDIA partnership; handles distributed training at scale
Watch out for: Smaller global footprint than AWS/GCP/Azure; not a general-purpose cloud, so if you need RDS, S3, and a managed Kafka in the same provider, this isn’t it

Lambda Labs

Lambda has been the approachable GPU cloud for a long time. Environments come pre-configured with PyTorch and TensorFlow, and you can be running on an H100 in about as long as it takes to copy your SSH key.

License: Proprietary
Best for: Research teams, startups, and individual practitioners who want GPUs without a configuration tax
Strengths: Straightforward to start on; pre-configured deep learning environments; competitive on-demand pricing; strong learning resources
Watch out for: Smaller scale than CoreWeave or the hyperscalers; availability gets tight during demand spikes

Modal’s pitch is that you write a Python function, decorate it, and Modal handles the GPU. No capacity planning, no idle instances burning money overnight, no Dockerfile to maintain.

License: Proprietary
Best for: Variable ML workloads where reserved capacity would sit idle; data scientists who’d rather not learn Kubernetes
Strengths: Strong developer experience; serverless GPUs with automatic scaling; pay-per-second pricing; cold starts are fast for what they are
Watch out for: You give up infrastructure control. Not ideal for long training jobs that need reserved hardware or strict configuration requirements.

Weights & Biases

Weights & Biases is the de facto standard for ML experiment tracking and model management, integrated with essentially every framework and cloud you’d plausibly use. CoreWeave acquired the company in 2025, which has accelerated the joint roadmap but raised some neutrality questions for teams that prefer their tooling cloud-agnostic.

License: Proprietary with a free tier
Best for: ML teams that need shared experiment tracking, model versioning, and reporting
Strengths: Industry-leading experiment tracking and visualization; comprehensive model registry; strong team collaboration; broad integration surface
Watch out for: Costs scale quickly past the free tier; some teams self-host alternatives for data residency reasons

MLflow

MLflow is the leading open-source MLOps platform: experiment tracking, packaging, registry, and serving, with no lock-in. Originally built at Databricks, it’s now a broad open-source ecosystem with managed offerings from multiple vendors (including Databricks and the major clouds).

License: Apache 2.0
Best for: Teams that want MLOps without a vendor; or want the option to start managed and self-host later
Strengths: Open source; covers the full ML lifecycle; runs locally, on-prem, or managed; broad framework support
Watch out for: Self-hosting carries the usual operational tax; commercial alternatives have stronger collaboration UX out of the box

Hyperscaler AI platforms

The major clouds all sell end-to-end ML platforms. Each leads on the dimensions that line up with its parent cloud (Vertex for Google’s models and TPUs, SageMaker for AWS-native data pipelines, Azure ML for Microsoft-stack integration), but the wider integration with the rest of the cloud is the deciding factor.

AWS SageMaker: end-to-end ML on AWS, deeply integrated with S3 and Glue, with first-class connections to Lambda for serverless inference and to the rest of the AWS data stack. The default pick if your data already lives in AWS.
Google Vertex AI: Google’s ML stack, including TPUs for workloads that need them, plus access to Google’s foundation models. Strongest when paired with BigQuery.
Azure Machine Learning: the natural choice when the rest of your stack is Microsoft; first-party MLOps integrations across GitHub Actions, Azure DevOps, and Microsoft Fabric for downstream reporting. The right choice if you’re already an Azure shop with Microsoft compliance requirements.

The shared tradeoff: hyperscaler GPU compute typically runs 2–3x the per-hour price of specialized providers, and the platforms work best when you commit to them top to bottom. For organizations already inside one cloud, the unified billing and single support contract usually justifies the premium. For a new ML team starting from scratch, it rarely does.

Part 2: AI-powered infrastructure management tools

This is where the more interesting product shift is happening. Instead of running AI on infrastructure, these tools point AI at your infrastructure and let it do work. They’re a newer, AI-native layer on top of the broader infrastructure as code tooling landscape.

From code generation to agentic execution

Before the tool list, one distinction matters more than any feature comparison: whether the tool generates code or executes changes.

Code generation tools like GitHub Copilot suggest infrastructure code based on context. You review it, maybe edit it, run it yourself. The AI helps, but you’re still the one doing the work.

Agentic platforms generate the code and run it, with the guardrails you define. They understand your environment, handle multi-step workflows, and enforce policies on the way through. You describe the outcome; the platform makes it happen.

Capability	Code generation	Agentic execution
Generates infrastructure code	Yes	Yes
Understands infrastructure context	Limited	Deep
Executes changes	No	Yes
Handles multi-step workflows	No	Yes
Enforces policies automatically	No	Yes
Remediates drift and violations	No	Yes

Where you want to land on this spectrum is mostly a governance question, not a productivity one.

Pulumi Neo

Pulumi Neo is Pulumi’s agentic AI for infrastructure. The distinguishing claim is execution: Neo doesn’t only suggest a Terraform snippet, it figures out the right resources, generates the code, and runs the deployment inside whatever guardrails you’ve set.

License: Proprietary (Pulumi Cloud)
Best for: Platform engineering teams that want AI automation with real policy controls, especially in regulated industries

A few things that set it apart in practice:

Policy automation and compliance. Neo is integrated with Pulumi Insights and Governance, which ships pre-built policy packs for CIS benchmarks, HITRUST CSF, NIST SP 800-53, and PCI DSS. Detection and remediation run in the same loop: Neo finds a violation, generates a fix, and (subject to approvals) applies it. You can batch-remediate across stacks and accounts with prompts like “find and fix all unencrypted S3 buckets across our AWS accounts.”

Works with infrastructure you didn’t create with Pulumi. Neo’s governance applies to Pulumi-managed resources, Terraform state, CloudFormation stacks, and resources someone clicked together in the AWS console. That matters because the realistic adoption path is to point Neo at what you have, audit it, and gradually bring it under management, not to migrate everything first.

Progressive autonomy. Trust levels are configurable. Start with human approval for everything; loosen it for well-defined, low-risk operations as confidence builds; keep production and sensitive resources behind strict approvals. This is the part that tends to determine whether enterprises actually deploy agentic AI in anger, versus letting it sit as a sandbox toy.

IDE and CI/CD integration. The Pulumi MCP Server brings Neo into Cursor, Claude Code, Claude Desktop, Windsurf, and any other MCP-compatible client. The Pulumi Cloud UI is the home base for approvals, history, and remediation status. Neo also slots into CI/CD pipelines for pre-merge policy remediation.

Case studies:

Werner Enterprises reduced infrastructure provisioning time from 3 days to 4 hours using Pulumi.
Spear AI cut their Authority to Operate (ATO) timeline from an expected 1.5 years to roughly 3 months by using policy-as-code to evidence compliance controls for auditors.

Tradeoff to be honest about: Neo gets more valuable the deeper you are in the Pulumi ecosystem. If you’re running IaC, ESC, and policy packs already, Neo has a lot of context to draw on. If you’re kicking the tires, it’s still useful, but the differentiating capability (context-aware, policy-respecting agentic execution) is harder to feel.

Firefly AIaC

Firefly is an asset management platform with AI features bolted on top of a strong core. The core capability is asset codification: it discovers cloud resources you already have and generates the IaC for them.

License: Proprietary
Best for: Teams that need to codify existing cloud footprints or generate IaC from natural language

Strengths: solid asset discovery, multi-cloud coverage, natural-language IaC generation, drift detection with remediation hooks. Caveat: AI features here are supplementary to the asset management product, not the main event, and Firefly is less focused on agentic execution than on inventory and policy.

env0 Cloud Compass

env0’s Cloud Compass adds AI to env0’s IaC automation platform, focusing on analysis rather than autonomous execution.

License: Proprietary
Best for: Multi-IaC shops that want AI-generated PR summaries, drift explanations, and cost insights

Strengths: multi-tool support across Terraform, OpenTofu, Pulumi, and Terragrunt; AI-generated PR summaries; drift cause analysis; cost estimation. Caveat: this is analysis and explanation, not action: Cloud Compass complements an agentic tool rather than replacing one.

Spacelift AI

Spacelift’s AI work is focused on the post-run experience: explaining what happened in a deployment and helping troubleshoot failures.

License: Proprietary
Best for: GitOps shops that want AI assistance reading complex runs and diagnosing failed deployments

Strengths: AI-powered run explanation; troubleshooting guidance for failures; broad IaC tool support; mature CI/CD integration. Caveat: like Spacelift as a whole, this is observation and explanation, not generation or execution. Pair with something that writes the code.

Crossplane with Upbound

Crossplane brings Kubernetes-style declarative management to cloud resources. Upbound is the company that commercializes it, and is layering AI-native control-plane capabilities into the 2.0 generation.

License: Apache 2.0 (Crossplane); proprietary (Upbound)
Best for: Teams already deep in Kubernetes that want to manage cloud resources the same way

Strengths: Kubernetes-native model; native GitOps fit; very active OSS community; AI control-plane work emerging from Upbound. Caveat: the learning curve is real if you’re not already living in Kubernetes; the commercial AI features are still maturing.

General-purpose code assistants

General-purpose AI coding assistants are the tools your developers already have open: GitHub Copilot, Claude Code, Cursor, and Google’s Gemini and Antigravity. They write Terraform HCL, Pulumi programs, and CloudFormation templates competently, about as well as they write anything else.

License: Proprietary (subscription), varies by tool
Best for: Developers who want broad code assistance, including infrastructure code, inside their existing editor

Strengths: excellent line-by-line code completion; broad language support; first-class editor integration; trained on huge corpora. Caveat: no infrastructure context. They don’t know what’s in your account, what your policies are, or which subnet you should pick. Treat their IaC suggestions as first-pass scaffolding, not production output.

AWS Application Composer

Application Composer is AWS’s visual builder for serverless applications. Drag services onto a canvas, get a CloudFormation template out, with AI suggestions for service configuration along the way.

License: Proprietary (AWS, included)
Best for: Teams building AWS serverless apps who prefer a visual workflow

Strengths: visual development for serverless; direct AWS integration; AI suggestions for service configuration; emits CloudFormation. Caveat: AWS-only, CloudFormation-only, and best suited to serverless rather than general infrastructure.

Comparison tables

Infrastructure for AI

Tool	Category	Key strength	Limitation	Pricing	Best for
CoreWeave	GPU cloud	Purpose-built GPU infra, NVIDIA partnership	Not a general-purpose cloud	Per-GPU-hour	Large-scale AI training
Lambda Labs	GPU cloud	Approachable, pre-configured environments	Smaller scale	Per-GPU-hour	Research teams, startups
Modal	Serverless GPU	Developer experience, pay-per-second	Less infrastructure control	Pay-per-use	Variable ML workloads
Weights & Biases	MLOps	Industry-standard experiment tracking	Costs scale quickly	Free tier + paid	ML team collaboration
MLflow	MLOps	Open source, no lock-in	Self-hosting overhead	Free (self-hosted)	Flexible ML lifecycle
AWS SageMaker	Hyperscaler	AWS ecosystem integration	Higher cost, lock-in	Per-use	AWS-native orgs
Google Vertex AI	Hyperscaler	Google models, TPU access	Lock-in	Per-use	Google Cloud users
Azure ML	Hyperscaler	Microsoft integration, enterprise features	Lock-in	Per-use	Microsoft ecosystem

AI-powered infrastructure management

Tool	Approach	Key strength	Limitation	Pricing	Best for
Pulumi Neo	Agentic AI	Execution + policy automation	Best within Pulumi ecosystem	Pulumi Cloud tiers	Enterprise platform teams
Firefly AIaC	Asset management	Asset codification, IaC generation	AI is supplementary	Proprietary	Codifying existing infra
env0 Cloud Compass	Multi-IaC platform	Multi-tool support, PR analysis	Analysis, not execution	Proprietary	Multi-IaC environments
Spacelift AI	CI/CD platform	Run explanation, troubleshooting	Observation, not action	Proprietary	GitOps workflows
Crossplane / Upbound	Kubernetes-native	K8s patterns for infra	Requires K8s expertise	Open source + commercial	Kubernetes-native teams
Code assistants	Code assistant	Broad language support, IDE	No infrastructure context	Subscription	General code assistance
AWS Composer	Visual builder	Visual serverless development	AWS- and CFN-only	Included with AWS	AWS serverless apps

How to choose

There’s no universal best tool. Five questions sort the field quickly:

Cloud strategy. Multi-cloud means tools like Pulumi Neo, Firefly, env0, or Crossplane. Single-cloud commitment means hyperscaler-native tools may integrate more deeply (AWS Composer, SageMaker, and so on).
Team expertise. Programmers gravitate to tools that use real languages (Pulumi Neo, Pulumi IaC). Kubernetes teams find Crossplane natural; everyone else finds it steep. Teams that prefer visual workflows should look at AWS Composer or env0’s UI.
Compliance. Regulated industries (healthcare, finance, government) get the most value from tools with pre-built compliance packs and audit trails. Pulumi Neo’s CIS/HITRUST/NIST/PCI packs are the most direct fit. If preventative policy enforcement matters, prefer tools that block non-compliant deployments rather than flag them after the fact.
Existing footprint. Greenfield projects can use anything. Brownfield is where it gets interesting: Pulumi Neo works against Terraform, CloudFormation, and manually-created resources, which lets you adopt incrementally instead of migrating first. Mixed-IaC shops should also look at env0.
Budget. Open source first: MLflow for MLOps, Crossplane for Kubernetes-native infra. Open source is not free, though: self-hosting carries a real total cost of ownership in hosting, maintenance, and the expertise to operate it. Commercial tools (Pulumi Cloud, env0, Spacelift) fold that operational cost into the price, on top of support, SLAs, and the enterprise-tier features open source can lack.

Before adopting anything, get visibility into what you have today, pilot on staging where mistakes are cheap, and define success metrics up front: time to provision, policy violation rates, mean time to remediate. The best AI infrastructure tool is the one your team will actually use, which means meeting developers where they already work.

Key trends and outlook

From copilots to agents. “AI suggests code” and “AI runs the deploy” are different products with different governance implications. The teams getting value from agentic tools have figured out which tasks to delegate fully, which to keep human-in-the-loop, and which to leave alone.

Progressive autonomy. Enterprise adoption follows a predictable shape: visibility → recommendations → human-approved execution → autonomous execution for well-understood scenarios. Tools that support that graduation will see stronger enterprise traction than tools that force an all-or-nothing choice.

Policy as the control plane. As AI takes on more infrastructure tasks, policy frameworks become the primary control plane. Done well, policy becomes an enabler (guardrails that let you safely expand automation) rather than a brake on velocity.

MCP standardization. The Model Context Protocol is becoming the integration standard between AI assistants and infrastructure tools. The practical upshot is that the IDE is increasingly a viable surface for managing infrastructure, with AI mediating between natural language and the underlying APIs.

Consolidation. CoreWeave acquiring Weights & Biases and NVIDIA acquiring Run:ai both point toward integrated platforms across the AI infrastructure stack. For tool selection today, that’s an argument for picking vendors with clear strategic direction over point solutions likely to be acquired or out-competed.

Frequently asked questions

What is the best AI agent for cloud infrastructure management?

For enterprise governance plus true agentic capability, Pulumi Neo is currently the most complete offering: it executes changes (not just suggests them), integrates with pre-built compliance frameworks, and works with infrastructure regardless of how it was provisioned. For Kubernetes-native shops, Crossplane with Upbound’s emerging AI features is worth tracking.

How can I use generative AI to manage cloud infrastructure?

Start by identifying the repetitive, time-consuming infrastructure work in your team. The highest-value early use cases tend to be:

Code generation: write IaC from natural-language descriptions, then review.
Documentation: explain unfamiliar configurations and reduce onboarding time.
Troubleshooting: analyze logs, errors, and configs to suggest likely causes.
Security and compliance: scan for violations and generate fixes.
Full automation: for shops that want it, agentic platforms like Pulumi Neo execute provisioning workflows end-to-end with governance controls intact.

What is agentic AI for infrastructure?

Agentic AI for infrastructure means AI systems that autonomously execute infrastructure tasks, not just generate code suggestions. The difference from a code assistant is action: an agent understands your environment, respects your policies, and performs multi-step work (provisioning, configuration, security controls) within the boundaries you’ve defined.

How do AI agents improve DevOps workflows?

By automating the repetitive parts (provisioning, drift remediation, policy enforcement), reducing context-switching, and catching issues earlier. Teams that have rolled out agentic tools well report faster provisioning, fewer policy violations slipping into production, and quicker compliance remediation. The compounding effect (engineers freed for higher-value work as the agent absorbs the routine) is the actual point.

What’s the difference between AI code generation and agentic execution?

Code generation suggests IaC for a human to review and run. Agentic execution generates the code and runs it, with policy and governance enforced along the way. It’s the difference between a knowledgeable colleague who suggests an approach and a knowledgeable colleague who also ships the change with appropriate oversight.

Can AI generate Terraform or Pulumi programs?

Yes. Most general-purpose AI assistants (Copilot, Claude, Gemini, ChatGPT, Cursor) can produce Terraform HCL, Pulumi programs in TypeScript / Python / Go, and CloudFormation. Quality varies. Generic assistants lack environment context and will happily emit syntactically correct but operationally wrong code. Infrastructure-specific tools like Pulumi Neo generate code that’s aware of your existing resources, policies, and provider constraints.

Can AI help with infrastructure compliance and policy automation?

Yes, and this is one of the highest-leverage uses of AI in infrastructure. Tools like Pulumi Neo detect policy violations across your footprint (including resources created outside IaC), generate compliant remediation, and apply it with the approvals you require. Pre-built frameworks for CIS, HITRUST, NIST, and PCI DSS shorten what would otherwise be a long manual compliance project.

Are AI infrastructure tools secure for enterprise use?

Enterprise-grade ones are. Look for RBAC, full audit logging of AI actions, preventative policy enforcement (not just detection), and human-in-the-loop approvals for sensitive operations. SOC 2, data residency options, and configurable autonomy levels are table stakes. The risk to avoid is wiring a consumer AI assistant directly into a production cloud account without those controls.

How do I choose between different AI infrastructure tools?

Match the tool to your context: existing clouds and IaC, team skills, compliance requirements, budget. Enterprise platform teams with governance needs should evaluate Pulumi Neo first. MLOps-focused teams should look at Weights & Biases or MLflow. For general code assistance inside the editor, a general-purpose assistant like Copilot, Cursor, or Gemini is the default. Most organizations end up with more than one: a code assistant for daily development and an agentic platform for production infrastructure.

What are the best tools for machine learning infrastructure?

For GPU compute, CoreWeave leads at scale, Modal wins for variable workloads and developer experience, and the hyperscalers are the default pick if you’re already inside one of them. For experiment tracking and model management, Weights & Biases is the leading commercial platform; MLflow is the leading open-source one. Most teams pick on the deploy model and pricing fit rather than capability gap. For the cloud infrastructure underneath the ML workloads, the same infrastructure management story applies: Pulumi Neo can provision and govern ML infrastructure the same way it handles everything else.

Conclusion

Two categories, two problems. GPU clouds and MLOps platforms (CoreWeave, Lambda, Modal, hyperscaler trio, W&B, MLflow) solve the compute and lifecycle problem for running AI workloads. AI-powered infrastructure tools (Neo, Firefly, env0, Spacelift, Crossplane, code assistants, Composer) solve the management problem for everything else.

For GPU workloads, the choice mostly comes down to scale and where you already are. For infrastructure management, the real question is how much you actually want AI to do. Code assistants help you write IaC faster, but you’re still running it. Agentic platforms like Pulumi Neo execute changes and enforce policy on the way through, with the guardrails you control.

The pattern from teams getting real value: treat AI as a force multiplier on routine work (provisioning, drift, compliance) and keep human judgment in the loop for the architecture and the edge cases.

If you want to see agentic infrastructure management running against real resources, start with Pulumi Neo.