Add helm chart

Description

Issue: Helm Charts for AI Gateway deployment (gitlab-org/gitlab#452490 - closed)

Add helm chart for AI Gateway.

Testing

1. Clone the repository.

2. Create a test.values.yaml file with the following context

   image:
     tag: latest
   
   logging:
     level: "debug"
     json: false
   
   gitlab:
     url: "http://gdk.test:3000/"
     apiUrl: "http://gdk.test:3000/api/v4/"
   
   customerPortalUrl: "http://gdk.test:5000/"
   
   authBypassExternal: true
   
   anthropicApiKey:
     value: "REPLACE_ME"
   
   vertexTextModel:
     project: "REPLACE_ME"
     jsonKey:
       value: |-
         {
           "type": "service_account",
           "project_id": "REPLACE_ME",
           "private_key_id": "REPLACE_ME",
           "private_key": "REPLACE_ME",
           "client_email": "REPLACE_ME",
           "client_id": "REPLACE_ME",
           "auth_uri": "https://accounts.google.com/o/oauth2/auth",
           "token_uri": "https://oauth2.googleapis.com/token",
           "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
           "client_x509_cert_url": "REPLACE_ME",
           "universe_domain": "googleapis.com"
         }
   
   extraEnvironmentVariables:
     - name: TEST
       value: test

3. Replace all instances of REPLACE_ME in the above file with appropriate values.

4. Tip - Follow https://developers.google.com/workspace/guides/create-credentials if you need to create the GOOGLE_APPLICATION_CREDENTIALS.

5. Verify the helm chart is rendering correctly

   helm template ai-gateway-test . \
     -f values.yaml \
     -f test.values.yaml

6. Install the helm chart

   helm upgrade --install ai-gateway-test . \
     --namespace ai-gateway-test \
     --create-namespace \
     -f values.yaml \
     -f test.values.yaml

7. Verify if everything is working correctly

   export POD_NAME=$(kubectl get pods --namespace ai-gateway-test -l "app.kubernetes.io/name=ai-gateway,app.kubernetes.io/instance=ai-gateway-test" -o jsonpath="{.items[0].metadata.name}")
   kubectl --namespace ai-gateway-test logs -f $POD_NAME

   export POD_NAME=$(kubectl get pods --namespace ai-gateway-test -l "app.kubernetes.io/name=ai-gateway,app.kubernetes.io/instance=ai-gateway-test" -o jsonpath="{.items[0].metadata.name}")
   export CONTAINER_PORT=$(kubectl get pod --namespace ai-gateway-test $POD_NAME -o jsonpath="{.spec.containers[0].ports[0].containerPort}")
   kubectl --namespace ai-gateway-test port-forward $POD_NAME 8080:$CONTAINER_PORT

   curl localhost:8080/docs

8. Delete the helm chart

   helm -n ai-gateway-test delete ai-gateway-test

Notes/Questions

• Some options like server reload are not added to the helm chart because it is not needed in a non-development environment. Are there other such options which are present in the helm chart but need to be removed? e.g. auth external bypass
• Need feedback from the team if the name for values options in values.yaml look right or if they want to rename/restructure them?
• registry.gitlab.com/gitlab-org/modelops/applied-ml/code-suggestions/ai-assist/model-gateway:v1.0.0 has been failing for me. Is that image stable?
• Need clarity on gitlab-org/gitlab#452490 (comment 1879031638) before merging this MR.

Next steps

• Create a followup issue to publish on charts.gitlab.io