hubauth

Hubauth is a service that provides Single Sign-On for Flynn clusters. It operates as an OAuth 2.0 server that the Flynn CLI and Dashboard interact with, and issues signed tokens that the Flynn controller consumes.

Users are authenticated using G Suite via OpenID Connect, and their group membership is checked to determine which clusters (audiences) they have access to.

The service is deployed on Google Cloud Run, and uses Firestore in Datastore mode as the database.

Cloud Key Management Service is used to store signing keys.

Testing

The test environment can be built in Docker by running:

docker build -t hubauth-test -f test.Dockerfile .

The tests can be run with:

docker run --rm -v `pwd`:/app hubauth-test

Deployment in testing

Create docker tag for gcr.io and push the image:

docker build -t us.gcr.io/<PROJECT_ID>/hubauth-dev:latest -f build.Dockerfile .
docker push us.gcr.io/<PROJECT_ID/hubauth-dev:latest

# if not authorized, you may need to run `gcloud auth configure-docker`

In Security > Cryptographic Keys

Create a KMS keyring:

• name: hubauth-keyring
• location: global Create a KMS key:
• name: refresh_key
• type: software Asymmetric sign key

And save its version 1 resource name

In Security > Secret manager: Create secrets

• HUBAUTH_COOKIE_KEY_SECRET: secure random value
• HUBAUTH_CODE_KEY_SECRET: secure random value

And save their resource IDs

In IAM

Grant default compute account the roles:

• Cloud KMS CryptoKey Signer/Verifier
• Cloud Trace Agent
• Cloud Datastore User
• Errors Writer
• Service Account Token Creator
• Monitoring Metric Writer
• Cloud Run Invoker
• Secret Manager Secret Accessor

In Cloud Run

Create service:

• Name: hubauth-ext
• Allows unauthenticated invocations
• Select the previously pushed docker image

Then edit & deploy new revision:

• Container command: /app/hubauth-ext
• Variables:
  • PROJECT_ID: current GCP project id
  • REFRESH_KEY: set it to the KMS refresh_key resource name saved previously
  • COOKIE_KEY_SECRET: set to the resource ID from HUBAUTH_COOKIE_KEY_SECRET
  • CODE_KEY_SECRET: set to the resource ID from HUBAUTH_CODE_KEY_SECRET
  • KMS_LOCATION: global
  • KMS_KEYRING: hubauth-keyring

And save the deployment URL

Create service:

• Name: hubauth-int
• Allows unauthenticated invocations
• Select the previously pushed docker image

Then edit & deploy new revision:

• Container command: /app/hubauth-int
• Variables:
  • PROJECT_ID: current GCP project id

And save the deployment URL

In APIs & Services

Enable the APIs:

• Cloud Run Admin API
• Cloud Trace API
• Secret Manager API
• Cloud Key Management Service (KMS) API
• IAM Service Account Credentials API
• Cloud Scheduler API
• Admin SDK
• Cloud Functions API

Create OAUTH Consent screen:

• Application type: internal
• Application name: hubauth
• Authorized domains: add the cloud run url for hubauth-ext

Create OAUTH Credential:

• Type: web application
• Name: hubauth
• Authorized url: add the cloud run url for hubauth-ext: <URL>/rp/google

Save Client ID and Client secret

In Cloud RUN

Create a new deployment for hubauth-ext, and set the following variables:

• BASE_URL: add the cloud run url for hubauth-ext
• RP_GOOGLE_CLIENT_ID: the previously saved Client ID
• RP_GOOGLE_CLIENT_SECRET: the previously saved Client secret

In Cloud Scheduler

Create a new job:

• Name: hubauth-cron
• Frequency: 0 */1 * * *
• URL: use the hubauth-int URL: <URL>/cron

Hubauth CLI

Configure gcloud auth application-default with the following command, and follow the browser instructions:

gcloud auth application-default login

You'll need to create a client, and audience and ask an admin for setting up the policy (it requires allowing your app and user on org level, and allow the compute service account oauth ClientID on GSuite domain).

Example commands

# create client
go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" clients create \
    --redirect-uris http://localhost \
    --refresh-token-expiry 3600

# list clients
go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" clients list

# create audience
go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" audiences create \
    --audience-url https://localhost \
    --client-ids EhEKBkNsaWVudBCAgIDo14eBCg \
    --kms-location global \
    --kms-keyring hubauth

# list audiences
go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" audiences list

# set audience policy
go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" audiences set-policy \
    --audience-url https://localhost \
    --domain domain.io \
    --api-user [email protected] \
    --groups group1,group2

go run cmd/hubauth/main.go --project-id="<PROJECT_ID>" audiences key \
    --audience-url https://localhost \
    --kms-location global \
    --kms-keyring hubauth