This guide will demonstrate how to secure an instance of Grafana behind Pomerium proxy to provide users with a seamless login to Grafana using your identity provider.

What is Grafana?

Grafana is an open-source analytics visualization and monitoring tool. It provides many user-contributed Dashboards that make it popular for enthusiasts as well as professionals.

Getting Started

Note: This guide uses GitHub as the pre-configured Identity Provider (IdP), but you can use any supported IdP.

To complete this guide, you need:

Docker and Docker Compose
A pre-configured identity provider (IdP)

See the Pomerium Quick-start guide to run Pomerium in a containerized Docker environment.

Build a Grafana Route

In your config.yaml file, add the following Grafana route:

- from: https://grafana.localhost.pomerium.io
  to: http://grafana:3000
  host_rewrite_header: true
  pass_identity_headers: true
  policy:
    - allow:
        or:
          - email:
              is: user@example.com

In the code above:

host_rewrite_header rewrites the Host: header to match an incoming header value. Without this option enabled, Grafana will throw a 403: Origin not allowed error after login when you attempt to add users.

This behavior is due to a CSRF check added in Grafana v8.3.5 (this guide uses v9.2.4) that requires the Origin request header to match the server origin.

See this GitHub issue for more information.

Configure Grafana to use JWT Verification

Configuring Grafana to use JWT authentication makes it possible for Grafana to accept identity claims sent upstream by Pomerium.

Since you're not using a grafana.ini file to configure your Grafana instance, you can override Grafana's configuration using environment variables. See the Grafana docs for more information.

In your docker-compose.yaml file, add the Grafana Docker image as a service:

grafana:
  image: grafana/grafana:latest
  ports:
    - 3000:3000
  environment:
    - GF_AUTH_SIGNOUT_REDIRECT_URL=https://grafana.localhost.pomerium.io/.pomerium/sign_out
    - GF_AUTH_JWT_ENABLED=true
    - GF_AUTH_JWT_HEADER_NAME=X-Pomerium-Jwt-Assertion
    - GF_AUTH_JWT_EMAIL_CLAIM=email
    - GF_AUTH_JWT_JWK_SET_URL=https://grafana.localhost.pomerium.io/.well-known/pomerium/jwks.json
    - GF_AUTH_JWT_CACHE_TTL=60m
  volumes:
    - ./grafana-storage:/var/lib/grafana

Here's what the environment variables do:

GF_AUTH_SIGNOUT_REDIRECT_URL: signs users out of Pomerium when they sign out of Grafana
GF_AUTH_JWT_ENABLED: enables JWT authentication (Grafana disables it by default)
GF_AUTH_JWT_HEADER_NAME: tells Grafana which HTTP header to look at for the JWT (see Identity Verification for more information)
GF_AUTH_JWT_EMAIL_CLAIM: associates the email_claim in the JWT with the email of the Grafana user
GF_AUTH_JWT_JWK_SET_URL: defines the URL with the signing key to validate the JWT
GF_AUTH_JWT_CACHE_TTL: sets a 60-minute cache time for the token

Congratulations, your Grafana now has a secured route. Let's add users.

Add users to Grafana

At this stage, Grafana is configured to use the email claim in the JWT to associate an incoming connection with a user (you will configure Pomerium to include identity information via the JWT in the next section).

But, the user first must exist in Grafana to be associated. Otherwise, you will see the following error in the browser after authenticating:

{"message": "User not found"}

To avoid this error, create a user with administrator privileges. (If you plan on administering Grafana through a direct connection to the service, skip this section.)

To add users without requiring them to accept an invitation:

Log in to Grafana directly as an admin user at https://grafana.localhost.pomerium.io (if this is your first time signing up for Grafana, admin is the default username and password)
Select Server Admin, Users

Caution: This is distinct from the Users option under the Configuration cog wheel, which will only finalize a new user when they accept an invite via email or link.
Select New user to create a new user. Make sure that the email address matches the one provided by Pomerium via your IdP. If you want to check the data provided by Pomerium in the JWT, you can access the special endpoint /.pomerium from any Pomerium route to view it.

After creating a new user in Grafana, that user should be logged in automatically when they access Grafana from the Pomerium route (after first authenticating with your IdP, of course).

Manage access at scale

First, ensure Grafana is up to date to take advantage of auto_sign_up, as it is only available for JWT as of version 8.4.0.

The steps outlined above work to confirm the configuration for small teams, but adding users individually and manually does not scale for larger organizations. To add users to Grafana at scale, you can use the Grafana's auto_sign_up configuration to auto sign up users as they log in:

[auth]
signout_redirect_url = https://grafana.localhost.pomerium.io/.pomerium/sign_out
[auth.jwt]
enabled = true
header_name = X-Pomerium-Jwt-Assertion
email_claim = email
jwk_set_url = https://grafana.localhost.pomerium.io/.well-known/pomerium/jwks.json
cache_ttl = 60m
username_claim = sub ;sets the username to the value of the "sub" claim
auto_sign_up = true ;sets the login to automatically create a new user if one doesn't exist
[users]
auto_assign_org = true ;auto assigns the user to the existing default organization
auto_assign_org_role = Editor ;auto assigns the user the "Editor" role

Note that the value of auto_assign_org_role could also be "Admin" or "Viewer".

This will automatically create a user with their email and username populated.

Pomerium autopopulates the JWT name claim by default with the value provided by the identity provider to save you time. This configuration will allow seamless authentication and authorization without any additional toil for your team.

For teams using Google as an IdP, the user field is populated by a numeric value that you cannot configure. Note that Grafana can accept the name field as a username, including spaces:

username_claim = name

Troubleshooting

Local Signing Key

In instances where Grafana cannot get the signing key for the JWTs from the Pomerium authenticate service, you can place a copy of the key locally.

For example, wildcard certificates signed by LetsEncrypt may still be cross-signed by the [expired DST R3 root]. While many browsers still trust these certificates (as long as they are also signed by a valid root), some applications reject them, including Grafana:

logger=context error=Get "https://grafana.localhost.pomerium.io/.well-known/pomerium/jwks.json": x509: certificate signed by unknown authority

To circumvent this issue, you can use curl or wget to download the signing key locally:

curl

From the Grafana host:

curl https://grafana.localhost.pomerium.io/.well-known/pomerium/jwks.json > /etc/grafana/jwks.json

wget

From the Grafana host:

wget -O /etc/grafana/jwks.json https://grafana.localhost.pomerium.io/.well-known/pomerium/jwks.json

Edit grafana.ini and add the jwk_set_file key to provide it to Grafana:

[auth.jwt]
enabled = true
header_name = X-Pomerium-Jwt-Assertion
email_claim = email
jwk_set_file = /etc/grafana/jwks.json
cache_ttl = 60m

If you have other issues with this guide, please reach out to Pomerium on our forums!

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