Secrets

All resource input and output values are recorded as state, and are stored in the Pulumi Service, a file, or a pluggable provider that you choose. These raw values are usually just server names, configuration settings, and so on. In some cases, however, these values contain sensitive data, such as database passwords or service tokens.

The Pulumi Service always transmits and stores entire state files securely; however, Pulumi also supports encrypting specific values as “secrets” for extra protection. Encryption ensures that these values never appear as plaintext in your state file. By default, the encryption method uses automatic, per-stack encryption keys provided by the Pulumi Service or you can use a provider of your own choosing instead.

To encrypt a configuration setting before runtime, you can use the CLI command config set command with a --secret flag. You can also set a secret during runtime. Any Output<T> value can be marked secret. If an output is a secret, any computed values derived from it—such as those derived through an apply call —will also be marked secret. All these encrypted values are stored in your state file.

An Output<T> can be marked secret in a number of ways:

As soon as an Output<T> is marked secret, the Pulumi engine will encrypt it wherever it is stored.

Programmatically Creating Secrets

There are two ways to programmatically create secret values:

  • Using config.GetSecret(key) or config.RequireSecret(key) when reading a value from config.
  • Calling pulumi.ToSecret(value) to construct a secret from an existing value.
  • Using Config.GetSecret(key) or Config.RequireSecret(key) when reading a value from config.
  • Calling Output.CreateSecret(value) to construct a secret from an existing value.

As an example, let’s create an AWS Parameter Store secure value. Parameter Store is an AWS service that stores strings. Those strings can either be secret or not. To create an encrypted value, we need to pass an argument to initialize the store’s value property. Unfortunately, the obvious thing to do —passing a raw, unencrypted value— means that the value is also stored in the Pulumi state, unencrypted so we need to ensure that the value is a secret:

const cfg = new pulumi.Config()
const param = new aws.ssm.Parameter("a-secret-param", {
    type: "SecureString",
    value: cfg.requireSecret("my-secret-value"),
});
const cfg = new pulumi.Config()
const param = new aws.ssm.Parameter("a-secret-param", {
    type: "SecureString",
    value: cfg.requireSecret("my-secret-value"),
});
cfg = pulumi.Config()
param = ssm.Parameter("a-secret-param",
    type="SecureString",
    value=cfg.require_secret("my-secret-value"))
package main

import (
    "github.com/pulumi/pulumi-aws/sdk/v4/go/aws/ssm"
    "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
    "github.com/pulumi/pulumi/sdk/v3/go/pulumi/config"
)

func main() {
    pulumi.Run(func(ctx *pulumi.Context) error {
        cfg := config.New(ctx, "")
        param, err := ssm.NewParameter(ctx, "a-secret-param", &ssm.ParameterArgs{
            Type:  "SecureString",
            Value: cfg.RequireSecret("my-secret-value"),
        })
        if err != nil {
            return err
        }
        return nil
    }
}
var cfg = new Pulumi.Config()
var param = new Aws.Ssm.Parameter("a-secret-param", new Aws.Ssm.ParameterArgs
{
    type = pulumi.String("SecureString"),
    value = cfg.RequireSecret("my-secret-value"),
});

The Parameter resource’s value property is encrypted in the Pulumi state file.

Pulumi tracks the transitive use of secrets, so that your secret won’t end up accidentally leaking into the state file. Tracking includes automatically marking data generated from secret inputs as secret themselves, as well as fully encrypting any resource properties that include secrets in them.

How Secrets Relate to Outputs

Secrets have the same type, Output<T>, as do unencrypted resource outputs. The difference is that they are marked internally as needing encryption before persisting in the state file. When you combine an existing output that is marked as a secret using apply or Output.all, the resulting output is also marked as a secret.

An apply’s callback is given the plaintext value of the underlying secret. Although Pulumi ensures that the value returned from an apply on a secret is also marked as secret, Pulumi cannot guarantee that the apply callback itself will not expose the secret value —for instance, by explicitly printing the value to the console or saving it to a file.

Explicitly Marking Resource Outputs as Secrets

It is possible to mark resource outputs as containing secrets. In this case, Pulumi will automatically treat those outputs as secrets and encrypt them in the state file and anywhere they flow to. To do so, use the additional secret outputs option.

Encrypted Secrets in Configuration Data

Some configuration data is sensitive, such as database passwords or service tokens. For such cases, passing the --secret flag to the config set command encrypts the data and stores the resulting ciphertext instead of plaintext.

For example, this command sets a configuration variable named dbPassword to the plaintext value S3cr37:

$ pulumi config set --secret dbPassword S3cr37

If we list the configuration for our stack, the plaintext value for dbPassword will not be printed:

$ pulumi config
KEY                        VALUE
aws:region                 us-west-1
dbPassword                 [secret]

Similarly, if our program attempts to print the value of dbPassword to the console-either intentionally or accidentally-Pulumi will mask it out:

var pulumi = require("@pulumi/pulumi");
var config = new pulumi.Config();
console.log("Password: " + config.require("dbPassword"));
import * as pulumi from "@pulumi/pulumi";
const config = new pulumi.Config();
console.log(`Password: ${config.require("dbPassword")}`);
import pulumi
config = pulumi.Config()
print('Password: {}'.format(config.require('dbPassword')))
c := config.New(ctx, "")
fmt.Println("Password: "+c.Require("dbPassword"))
var config = new Pulumi.Config();
Console.WriteLine($"Password: {config.Require("dbPassword")}");

Running this program yields the following result:

$ pulumi up
Password: [secret]

By default, configuration values are saved in plaintext. To explicitly denote a plaintext or unencrypted configuration value, pass the --plaintext flag. This flag can be used to indicate that you did not want an encrypted secret.

$ pulumi config set --plaintext aws:region us-west-2

Using Configuration and Secrets in Code

To access configuration or secret values for your package, project, or component, use the pulumi.Config type. This type offers a collection of getters and setters for retrieving configuration values of various types by their key.

To begin, allocate an instance of the pulumi.Config object. Its constructor takes an optional namespace for all configuration keys being read back. Similar rules to the CLI usage apply here, in that if you omit the namespace argument, the current project is used. This is the common case for project configuration but is not what you want for packages and components which need their own isolated configuration.

For example, assume the following configuration values have been set:

$ pulumi config set name BroomeLLC             # set a plaintext value
$ pulumi config set --secret dbPassword S3cr37 # set an encrypted secret value

Use the following code to access these configuration values in your Pulumi program:

var pulumi = require("@pulumi/pulumi");

var config = new pulumi.Config();

var name = config.require("name");
var dbPassword = config.requireSecret("dbPassword");
import * as pulumi from "@pulumi/pulumi";

const config = new pulumi.Config();

const name = config.require("name");
const dbPassword = config.requireSecret("dbPassword");
import pulumi

config = pulumi.Config()

print(config.require('name'))
print(config.require_secret('dbPassword'))
package main

import (
    "github.com/pulumi/pulumi/sdk/v3/go/pulumi"
    "github.com/pulumi/pulumi/sdk/v3/go/pulumi/config"
)
func main() {
    pulumi.Run(func(ctx *pulumi.Context) error {
        c := config.New(ctx, "")

        name := c.Require("name")
        dbPassword := c.RequireSecret("dbPassword")
    }
}
using System.Threading.Tasks;
using Pulumi;

class MyStack : Stack
{
    public MyStack()
    {
        var config = new Config();

        var name = config.Require("name");
        var dbPassword = config.RequireSecret("dbPassword");
    }
}

In this example, we have read back the name and dbPassword configuration variables programmatically. The name is just the string BroomeLLC, while the dbPassword is a secret output value that is encrypted.

Notice the keys used above have no namespaces, both in the CLI gestures and in the pulumi.Config constructor. This means they have taken our project name as the default namespace. We could have specified this explicitly, as in pulumi config set broome-proj:name BroomeLLC and new pulumi.Config("broome-proj").

Secrets within structured config are also supported. Consider a list of endpoints, each having a url and token property. The token value could be stored as a secret:

$ pulumi config set --path endpoints[0].url https://example.com
$ pulumi config set --path --secret endpoints[0].token accesstokenvalue

A Warning: Using Secrets in Code

On pulumi up, secret values are decrypted and made available in plaintext at runtime. These may be read through any of the standard pulumi.Config getters shown above. While it is possible to read a secret using the ordinary non-secret getters, this is almost certainly not what you want. Use the secret variants of the configuration APIs instead, since this ensures that all transitive uses of that secret are themselves also marked as secrets.

Configuring Secrets Encryption

The Pulumi Service automatically manages per-stack encryption keys on your behalf. Anytime you encrypt a value using --secret or by programmatically wrapping it as a secret at runtime, a secure protocol is used between the CLI and Pulumi Service that ensures secret data is encrypted in transit, at rest, and physically anywhere it gets stored. For more details about the concept of state files and backends, refer to State and Backends.

The default encryption mechanism may be insufficient in the following scenarios:

  1. If you are using the Pulumi CLI independent of the Pulumi Service-either in local mode, or by using one of the available backend plugins (such as those that store state in AWS S3, Azure Blob Store, or Google Object Storage).

  2. If your team already has a preferred cloud encryption provider that you would like to use.

In both cases, you can continue using secrets management as described above, but instruct Pulumi to use an alternative encryption provider.

Initializing a Stack with Alternative Encryption

To specify an alternative encryption provider, specify it at stack initialization time:

$ pulumi stack init <name> --secrets-provider="<provider>://<provider-settings>"

After doing so, all encryption operations for your stack will use the custom provider settings. The <provider> and <provider-settings> are specific to your chosen encryption provider. See below for the available providers and their options.

Pulumi uses the Go Cloud Development Kit to implement pluggable secrets providers. In the event configuration or authentication options below do not work, the Go CDK documentation can be consulted for debugging information.

Available Encryption Providers

Pulumi supports the following encryption providers:

Each provider has its own unique <provider-settings> and authentication mechanisms.

AWS Key Management Service (KMS)

The awskms provider uses an existing KMS key in your AWS account for encryption. This key can be specified using one of three approaches:

  1. By ID: awskms://1234abcd-12ab-34cd-56ef-1234567890ab?region=us-east-1.
  2. By alias: awskms://alias/ExampleAlias?region=us-east-1.
  3. By ARN: awskms:///arn:aws:kms:us-east-1:111122223333:key/1234abcd-12ab-34bc-56ef-1234567890ab?region=us-east-1.

For example, this configures a stack to use an AWS KMS key with ID 1234abcd-12ab-34cd-56ef-1234567890ab:

$ pulumi stack init my-stack \
    --secrets-provider="awskms://1234abcd-12ab-34cd-56ef-1234567890ab?region=us-east-1"

If you have previously configured the AWS CLI, the same credentials will be used. These can also be overridden using the standard AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables. For more options, refer to the AWS Go SDK documentation.

Azure Key Vault

The azurekeyvault provider uses an Azure Key Vault key for encryption. This key is specified using an Azure Key object identifier, which includes both your key vault’s name and the key to use: azurekeyvault://mykeyvaultname.vault.azure.net/keys/mykeyname.

For example, this configures a stack to use an Azure Key Vault key named payroll in vault acmecorpsec:

$ pulumi stack init my-stack \
    --secrets-provider="azurekeyvault://acmecorpsec.vault.azure.net/keys/payroll"

By default, this provider will use Azure Environment Authentication. If you wish to login using the az command for authentication instead, set AZURE_KEYVAULT_AUTH_VIA_CLI to true.

Google Cloud Key Management Service (KMS)

The gcpkms provider uses an existing GCP KMS key for encryption. Specify the key resource ID for the key to use, which is a URL including your project, location, keyring, and key name: gcpkms://projects/MYPROJECT/locations/MYLOCATION/keyRings/MYKEYRING/cryptoKeys/MYKEY.

For example, this configures a stack to use a GCP KMS key payroll in project acmecorpsec, location us-west1, and key ring named prod:

$ pulumi stack init my-stack \
    --secrets-provider="gcpkms://projects/acmecorpsec/locations/us-west1/keyRings/prod/cryptoKeys/payroll"

This provider will use your Google Cloud Application Default Credentials. If you’ve previously configured the gcloud CLI, the same credentials will be used for authentication. For alternative configuration mechanisms, refer to Authenticating as a service account.

HashiCorp Vault Transit Secrets Engine

The hashivault provider uses Vault’s Transit Secrets Engine to encrypt and decrypt information. You only need to pass a key name for the provider setting: hashivault://mykey. The Vault server endpoint and authentication token to use are provided with the VAULT_SERVER_URL and VAULT_SERVER_TOKEN, respectively.

For example, this configures a stack to use a HashiCorp Vault transit key named payroll:

$ pulumi stack init my-stack \
    --secrets-provider="hashivault://payroll"

Changing the Secrets Provider for a Stack

To change the secrets provider for an existing stack use the pulumi stack change-secrets-provider command.

$ pulumi stack change-secrets-provider "<secrets-provider>"

This will change the encrypted secrets in the provider configuration and the stack’s state file to use the new secrets provider. The supported secrets providers are:

  • default
  • passphrase
  • awskms
  • azurekeyvault
  • gcpkms
  • hashivault

After the provider has been changed, you should be able to run pulumi preview and see no proposed changes. Your configuration secrets and state files are now encrypted using the new secrets provider.