Improved Health Checks and Networking

We have been working hard on building tooling to alleviate the limitations of Kubernetes health-checks, Kubernetes endpoint slices and Istio. This increases the reliability during blue green deployments, free service continuous deployment and correctness of health-check routing for start-up, readiness and liveness probes.

Northflank has developed a Kubernetes admission controller to enable graceful termination of user workloads by forcing DNS propagation before service termination - allowing in-progress requests to complete and preventing new requests to soon-to-be terminated containers, solely routing to healthy containers.

Northflank’s service mesh will auto-retry three times before failing a request to maintain service uptime during redeployments. We have identified a number of factors that could interfere with request routing:

• Avoid transient failures - a client should not perceive a failed request if a service was momentarily unavailable.
• Expect race conditions occurring in Kubernetes state vs DNS configuration - this often could be just a few milliseconds.
• Workload stability - load-balance retries across available workload instances.

Further UX improvements have been made:

• Improved real-time health check propagation via Prometheus metrics into the Northflank UI
• When configuring an HTTP liveness probe a readiness probe will automatically be generated
• New health checks descriptions:
  • Readiness Probe - ensures a new container is ready to serve traffic before terminating an old container and handling new requests
  • Liveness Probe - will restart containers that are failing checks
  • Startup Probe - will delay readiness and liveness probes until checks are passed

Other features & fixes

• Introduced a new instance selector that is now applied across the whole UI
• Added a new secret group type Build & Environment which is fetched both during build and deployment phases
• Fixed an issue where very large repositories would take a long time to build
• Fixed an issue where an empty project dashboard would render strangely on Safari
• Fixed an issue where API endpoint assign service to subdomain would error
• Fixed an issue where full DNS entry on Networking would not display service name as slug
• Fixed an issue where heroku/buildpacks:20 with PHP and Laravel would not run due to an error with permissions
• Improved changing ports and custom domains RBAC
• Fixed rendering of the team member role selector
• Fixed rendering custom CMD override if quotes were used in the command