Use secrets

Your service or job might need to have dependencies requiring API keys, passwords or other sensitive information. For Cloud Run, Google recommends that you store this type of sensitive information in a secret created in Secret Manager.

You can make a secret available to your containers in either of two ways:

Mount each secret as a volume, which makes the secret available to the container as files. Reading a volume always fetches the secret value from Secret Manager, so it can be used with the latest version. This method also works well with secret rotation.
Pass a secret using environment variables. Environment variables are resolved at instance startup time, so if you use this method, Google recommends that you pin the secret to a particular version rather than using latest.

For more information, refer to the Secret Manager best practices document.

How secrets are checked at deployment and runtime

During service deployment or job creation, all secrets used, whether as environment variable or mounted as a volume, are checked to ensure the service account used to run the container has access to them. If any check fails, the deployment or job creation fails.

During runtime, when instances start up:

If the secret is an environment variable, the value of the secret is retrieved prior to starting the instance, so if secret retrieval fails, the instance does not start.
If the secret is mounted as a volume, no check is performed during instance startup. However, during runtime, if a secret is inaccessible, attempts to read the mounted volume will fail.

Allow Cloud Run to access a secret

You can use an existing Secret Manager secret or create a new secret. However, in order to allow a Cloud Run service to access the secret, you must grant the Secret Manager Secret Accessor role to the Cloud Run service account:

Go to the Secret Manager page in the Google Cloud console
Select the secret and in the right side permissions tab, click Add Principal.
In the New principals textbox, enter the service account email for your Cloud Run service.
Grant it the role Secret Manager Secret Accessor.

Make a secret accessible to Cloud Run

You can make secrets available to services and to jobs.

For Cloud Run services

Any configuration change leads to the creation of a new revision. Subsequent revisions will also automatically get this configuration setting unless you make explicit updates to change it.

You can make a secret accessible to your service using the Google Cloud console, the Google Cloud CLI, or a YAML file when you deploy a new service or update an existing service and deploy a revision:

Console

Go to Cloud Run
Click Create Service if you are configuring a new service you are deploying to. If you are configuring an existing service, click on the service, then click Edit and Deploy New Revision.
If you are configuring a new service, fill out the initial service settings page as desired, then click Container, Networking, Security to expand the service configuration page.
Click the Variables & Secrets tab.
In the Variables & Secrets tab:
- Under Secrets, click Reference a Secret
- Select the secret you want to use from the Secret pulldown list.
- In the Reference method pulldown menu, select the way you want to use your secret, mounted as a volume or exposed as environment variables.
- If you are mounting the secret as a volume,
  1. Under Mount path, specify the mount path you are using for secrets.
  2. By default, the latest version is selected. You can select a specific version if you want. Under Specified paths for secret versions, specify the path to the version and the version number.
  3. Click Done.
- If you are exposing the secret as an environment variable:
  1. Supply the Name of the variable and select the secret version, or latest to always use the current secret version.
  2. Click Done.
Click Create or Deploy.

Command line

To make a secret accessible to your service, enter one of the following commands.

To mount the secret as a volume when deploying a service:
```
gcloud run deploy SERVICE --image IMAGE_URL  \
--update-secrets=PATH=SECRET_NAME:VERSION
```
Replace:
- SERVICE with the name of your service.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- PATHwith the mount path of the volume and filename of the secret. It must start with a leading slash, for example: /etc/secrets/dbconfig/password, where /etc/secrets/dbconfig/ is the mount path of the volume, and password is the filename of the secret.
- SECRET_NAME with the secret name in the same project, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.
To expose the secret as an environment variable when deploying a service:
```
gcloud run deploy SERVICE --image IMAGE_URL --update-secrets=ENV_VAR_NAME=SECRET_NAME:VERSION
```
Replace:
- SERVICE with the name of your service.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- ENV_VAR_NAME with the name of the environment variable you want to use with the secret.
- SECRET_NAME with the secret name in the same project, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.
You can update multiple secrets at the same time. To do this, separate the configuration options for each secret with a comma. The following command updates one secret mounted as a volume and another secret exposed as an environment variable.

To update existing secrets, enter the following command:
```
gcloud run deploy SERVICE --image IMAGE_URL \
--update-secrets=PATH=SECRET_NAME:VERSION,ENV_VAR_NAME=SECRET_NAME:VERSION
```
To clear existing secrets and make a new secret accessible to the service, use the --set-secrets flag:
```
gcloud run services update SERVICE \
--set-secrets="ENV_VAR_NAME=SECRET_NAME:VERSION"
```

YAML

You can download and view existing service configurations using the gcloud run services describe --format export command, which yields cleaned results in YAML format. You can then modify the fields described below and upload the modified YAML using the gcloud run services replace command. Make sure you only modify fields as documented.

To view and download the configuration:

gcloud run services describe SERVICE --format export > service.yaml

For secrets exposed as environment variables, under env, update the ENV_VAR, VERSION, and/or SECRET_NAME as desired. If you have multiple secrets mounted as environment variables, you will have multiples of these attributes.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: SERVICE
spec:
  template:
    metadata:
      name: REVISION
    spec:
      containers:
      - image: IMAGE_URL
        env:
        - name: ENV_VAR
          valueFrom:
            secretKeyRef:
              key: VERSION
              name: SECRET_NAME

For secrets mounted as file paths, update the MOUNT_PATH, VOLUME_NAME, VERSION, FILENAME, and/or SECRET_NAME as desired. If you have multiple secrets mounted as file paths, you will have multiples of these attributes.
```
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: SERVICE
spec:
  template:
    metadata:
      name: REVISION
    spec:
      containers:
      - image: IMAGE_URL
        volumeMounts:
        - mountPath: MOUNT_PATH
          name: VOLUME_NAME
      volumes:
      - name: VOLUME_NAME
        secret:
          items:
          - key: VERSION
            path: FILENAME
          secretName: SECRET_NAME
```
Note that VOLUME_NAME can be set to any name.

Replace
- SERVICE with the name of your Cloud Run service
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- REVISION with a new revision name or delete it (if present). If you supply a new revision name, it must meet the following criteria:
  - Starts with SERVICE-
  - Contains only lowercase letters, numbers and -
  - Does not end with a -
  - Does not exceed 63 characters
Replace the service with its new configuration using the following command:
```
gcloud run services replace service.yaml
```

Referencing secrets from other projects

You can reference a secret from another project, if your project's service account has been allowed to access the secret.

Console

Go to Cloud Run
Click Create Service if you are configuring a new service you are deploying to. If you are configuring an existing service, click on the service, then click Edit and Deploy New Revision.
If you are configuring a new service, fill out the initial service settings page as desired, then click Container, Networking, Security to expand the service configuration page.
Click the Variables & Secrets tab.
In the Variables & Secrets tab:
- Under Secrets, click Reference a Secret
- Select Don't see your secret? Enter secret resource ID from the Secret pulldown list, to display the following form:
- In the Add a secret by resource ID form, enter the secret from the other project, in the format projects/PROJECT_NUMBER/secrets/SECRET_NAME. You can alternatively copy and paste the resource ID from the other project if you have access to it, by selecting the secret, clicking the Actions ellipsis at the right of the secret, and selecting Copy resource ID from the pulldown menu.
- Click Add secret.
- In the Reference method pulldown menu, select the way you want to use your secret, mounted as a volume or exposed as environment variables.
- If you are mounting the secret as a volume,
  1. Under Mount path, specify the mount path you are using for secrets.
  2. By default, the latest version is selected. You can select a specific version if you want. Under Specified paths for secret versions, specify the path to the version and the version number.
  3. Click Done.
- If you are exposing the secret as an environment variable:
  1. Supply the Name of the variable and select the secret version, or latest to always use the current secret version.
  2. Click Done.
Click Create or Deploy.

Command line

To mount a secret as a volume when deploying a service:
```
gcloud run deploy SERVICE --image IMAGE_URL  \
--update-secrets=PATH=projects/PROJECT_NUMBER/secrets/SECRET_NAME:VERSION
```
Replace:
- SERVICE with the name of your service.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- PATHwith the mount path of the volume and filename of the secret. It must start with a leading slash, for example: /etc/secrets/dbconfig/password, where /etc/secrets/dbconfig/ is the mount path of the volume, and password is the filename of the secret.
- PROJECT_NUMBER with the project number for the project the secret was created in.
- SECRET_NAME with the secret name, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.

YAML

To view and download the configuration:

gcloud run services describe SERVICE --format export > service.yaml

Due to constraints around API compatibility, the secret locations must be stored in an annotation.

For secrets exposed as environment variables:
```
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: SERVICE
spec:
  template:
    metadata:
      annotations:
        run.googleapis.com/secrets: SECRET_LOOKUP_NAME:projects/PROJECT_NUMBER/secrets/SECRET_NAME
    spec:
      containers:
      - image: IMAGE_URL
        env:
        - name: ENV_VAR
          valueFrom:
            secretKeyRef:
              key: VERSION
              name: SECRET_LOOKUP_NAME
```
Replace:
- SERVICE with the name of your service.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- ENV_VAR
- PROJECT_NUMBER with the project number for the project the secret was created in.
- SECRET_NAME with the secret name, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.
- SECRET_LOOKUP_NAME with any name that has a valid secret name syntax (e.g. my-secret), it can be the same as SECRET_NAME
For secrets mounted as file paths:
```
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: SERVICE
spec:
  template:
    metadata:
      annotations:
        run.googleapis.com/secrets: SECRET_LOOKUP_NAME:projects/PROJECT_NUMBER/secrets/SECRET_NAME
    spec:
      containers:
      - image: IMAGE_URL
        volumeMounts:
        - mountPath: MOUNT_PATH
          name: VOLUME_NAME
      volumes:
      - name: VOLUME_NAME
        secret:
          items:
          - key: VERSION
            path: FILENAME
          secretName: SECRET_LOOKUP_NAME
```
Replace:
- SERVICE with the name of your service.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/hello:latest
- PATHwith the mount path of the volume and filename of the secret. It must start with a leading slash, for example: /etc/secrets/dbconfig/password, where /etc/secrets/dbconfig/ is the mount path of the volume, and password is the filename of the secret.
- PROJECT_NUMBER with the project number for the project the secret was created in.
- SECRET_NAME with the secret name, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.
- SECRET_LOOKUP_NAME with any name that has a valid secret name syntax (e.g. my-secret), it can be the same as SECRET_NAME
- VOLUME_NAME with any name (e.g. my-volume), it can be the same as SECRET_NAME

For Cloud Run jobs

You can make a secret accessible to your job using the Google Cloud console or the Google Cloud CLI:

Console

Go to Cloud Run
If you are configuring a new job, click the Jobs tab and fill out the initial job settings page as desired. If you are configuring an existing job, click the job, then click Edit.
Click Container, variables and secrets, connections, security to expand the job properties page.
Click the Variables & Secrets tab.
In the Variables & Secrets tab:
- Under Secrets, click Reference a Secret
- Select the secret you want to use from the Secret pulldown list.
- In the Reference method pulldown menu, select the way you want to use your secret, mounted as a volume or exposed as environment variables.
- If you are mounting the secret as a volume,
  1. Under Mount path, specify the mount path you are using for secrets.
  2. By default, the latest version is selected. You can select a specific version if you want. Under Specified paths for secret versions, specify the path to the version and the version number.
  3. Click Done.
- If you are exposing the secret as an environment variable:
  1. Supply the Name of the variable and select the secret version, or latest to always use the current secret version.
  2. Click Done.
Click Create or Update.

Command line

To specify the secret in an environment variable when creating a new job:
```
gcloud beta run jobs create JOB_NAME \
--image IMAGE_URL \
--set-secrets ENV_VAR_NAME=SECRET_NAME:VERSION
```
Replace
- JOB_NAME with the name of your job.
- ENV_VAR_NAME with the name of the environment variable to use for the secret.
- SECRET_NAME with the secret name in the same project, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.
- Replace IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/job:latest.
You can specify several environment variable/secret pairs, using a comma delimited list.

To specify the secret in an environment variable when updating a job:

gcloud beta run jobs update JOB_NAME \
--set-secrets ENV_VAR_NAME=SECRET_NAME:VERSION

To mount the secret as a volume when creating a job:
```
gcloud beta run jobs create JOB_NAME \
--image IMAGE_URL \
--set-secrets=PATH=SECRET_NAME:VERSION
```
Replace:
- JOB_NAME with the name of your job.
- IMAGE_URL with a reference to the container image, for example, us-docker.pkg.dev/cloudrun/container/job:latest
- PATHwith the mount path of the volume and filename of the secret. It must start with a leading slash, for example: /etc/secrets/dbconfig/password, where /etc/secrets/dbconfig/ is the mount path of the volume, and password is the filename of the secret.
- SECRET_NAME with the secret name in the same project, e.g. mysecret.
- VERSION with the secret version. Use latest for latest version, or a number, for example, 2.

To update a secret in an existing job:

gcloud beta run jobs update JOB_NAME \
--update-secrets=PATH=SECRET_NAME:VERSION

View secrets settings

To view the current secrets settings for your Cloud Run service:

Console

Go to Cloud Run
Click the service you are interested in to open the Service details page.
Click the Revisions tab.
In the details panel at the right, the secrets setting is listed under the Variables & Secrets tab.

Command line

Use the following command:
```
gcloud run services describe SERVICE
```
Locate the secrets setting in the returned configuration.

To view the current secrets settings for your Cloud Run job:

Console

Go to Cloud Run jobs
Click the job you are interested in to open the Job details page.
Click the Configuration tab.
Locate the secrets setting in the configuration details.

Command line

Use the following command:
```
gcloud beta run jobs describe JOB_NAME
```
Locate the secrets setting in the returned configuration.

Use secrets in your code

For examples on accessing secrets in your code as environment variables, refer to the tutorial on end user authentication, particularly the section Handling sensitive configuration with Secret Manager.

Disallowed paths and limitations

Cloud Run does not allow you to mount secrets at /dev, /proc and /sys, or on their subdirectories.

If you are mounting secrets on /tmp and you are using first generation execution environment, refer to the known issue on mounting secrets on /tmp.

Cloud Run does not allow you to mount multiple secrets at the same path because two volume mounts cannot be mounted at the same location.