---
title: Cloud Run
lang: en-US
meta:
  - name: keywords
    content: pomerium, identity access proxy, gcp, google, iap, serverless, cloudrun
description: >-
  This guide covers how to deploy Pomerium to Cloud Run and use it to protect
  other endpoints via Authorization Headers.
---

# Securing Cloud Run endpoints

This recipe's sources can be found [on github](https://github.com/pomerium/pomerium/tree/main/examples/cloudrun)

## Background

Services on [Cloud Run](https://cloud.google.com/run) and other Google Cloud serverless products can be restricted to only permit access with a properly signed [bearer token](https://cloud.google.com/run/docs/authenticating/service-to-service). This allows requests from other services running in GCP or elsewhere to be securely authorized despite the endpoints being public.

These bearer tokens are not easily set in a browser session and must be refreshed on a regular basis, preventing them from being useful for end user authorization. Pomerium, however, can generate compatible tokens on behalf of end users and proxy the request to these services.

## How it works

![cloudrun architecture](./img/cloud-run/architecture.svg)

- Add an IAM policy delegating `roles/run.invoker` permissions to a service account
- Run Pomerium with access to a key for the corresponding service account
- Publish DNS records for each protected application pointing to Pomerium
- Configure Pomerium with appropriate policy and `enable_google_cloud_serverless_authentication`

The protected application delegates trust to a GCP service account which Pomerium runs as, and Pomerium performs user based authorization on a per route basis. This turns Pomerium into a bridge between a user-centric and service-centric authorization models.

## Pre-requisites

This guide assumes you have Editor access to a Google Cloud project which can be used for isolated testing, and a DNS zone which you are also able to control. DNS does not need to be inside Google Cloud for the example to work.

## Set Up

To deploy Pomerium to Cloud Run securely and easily, a special [image](https://console.cloud.google.com/gcr/images/pomerium-io/GLOBAL/pomerium) is available at `gcr.io/pomerium-io/pomerium:[version]-cloudrun`. It allows sourcing configuration from GCP Secrets Manager, and sets some defaults for Cloud Run to keep configuration minimal. We will be leveraging it in this example to store IdP credentials. Our policy contains no secrets so we can place it directly in an ENV var.

[Dockerfile](https://github.com/pomerium/pomerium/blob/main/.github/Dockerfile-cloudrun) Based on [vals-entrypoint](https://github.com/pomerium/vals-entrypoint)

The image expects a config file at `/pomerium/config.yaml`. Set `VALS_FILES=[secretref]:/pomerium/config.yaml` and set any other Pomerium Environment Variables directly or with secret refs such as `ref+gcpsecrets://PROJECT/SECRET(#/key])`.

### Config

Set up a config.yaml to contain your IdP credentials and secrets (config.yaml):

<<< @/examples/cloudrun/config.yaml

Substitute `cloudrun.pomerium.io` for your own subdomain and your e-mail domain if appropriate (policy.template.yaml):

<<< @/examples/cloudrun/policy.template.yaml

### DNS

Substitute `cloudrun.pomerium.io` for your own subdomain (zonefile.txt):

<<< @/examples/cloudrun/zonefile.txt

Or set an equivalent CNAME in your DNS provider.

## Deploy

Ensure you have set a default project:

```shell
glcoud config set default-project MYTESTPROJECT
```

<<< @/examples/cloudrun/deploy.sh

## Results

### Overview

We should see two applications deployed. The `hello` app is our protected app, and pomerium is...Pomerium!

![Cloud Run Overview](./img/cloud-run/cloudrun-overview.png)

Notice that Pomerium allows unauthenticated access, but `hello` does not.

Here are the domain mappings set up:

![Cloud Run Domains](./img/cloud-run/cloudrun-domains.png)

### Direct Access

Let's verify we cannot access the main application directly by visiting <https://hello-direct.cloudrun.pomerium.io>

![Hello Direct Access](./img/cloud-run/hello-direct.png)

You should see a 403 error because you do not have the proper credentials.

### Authenticated Access

Now let's access via <https://hello.cloudrun.pomerium.io>

We should get an auth flow through your IdP:

![Hello Sign In](./img/cloud-run/hello-signin.png)

And a hello page:

![Hello](./img/cloud-run/hello-success.png)

### Non-GCP Applications

If your target application is not running on GCP, you can also perform your own header validation.

Browse to [https://verify.cloudrun.pomerium.io](https://verify.cloudrun.pomerium.io/headers)

You should see your identity header set:

![Hello](./img/cloud-run/headers.png)

See [getting user's identity](../docs/topics/getting-users-identity.md) for more details on using this header.