Container Deployment
Category:
Definition
Container deployment is the process of taking an OCI container image from a registry, scheduling it on compute infrastructure, configuring networking and secrets, and making the application accessible to end users.
Detailed Explanation
A complete container deployment pipeline involves several distinct phases:
**1. Build** Source code is compiled and packaged into an OCI image using a Dockerfile or buildpack. The image is tagged (e.g., myapp:v1.2.3) and pushed to a container registry.
**2. Image pull** The container runtime on the target compute node pulls the image from the registry. Unchanged layers are served from the node's local cache; only new layers are downloaded.
**3. Scheduling** An orchestrator (Kubernetes, Nomad, ECS) decides which compute node will run the new container based on resource availability, affinity rules, and constraints.
**4. Runtime configuration** The container starts with injected environment variables, mounted secrets, and networking configuration. Port bindings are established.
**5. Health checks** The orchestrator probes the container (HTTP liveness/readiness probes or TCP checks) to confirm it is healthy before routing traffic to it.
**6. Traffic cutover** Once healthy, the load balancer shifts traffic from the old container revision to the new one. This is typically done as a rolling update to avoid downtime.
**7. Cleanup** Old container revisions are terminated (after a grace period for in-flight requests to drain) and their resources are freed.
On Kubeletto, all seven steps are automated. You trigger a deployment — via GitHub push or CLI — and Kubeletto handles the rest.
How Kubeletto provides Container Deployment
Kubeletto automates the full container deployment lifecycle. GitHub webhooks trigger BuildKit builds; images are pushed to an internal registry; Knative Serving schedules the new revision on worker nodes; health probes confirm readiness; Kourier routes traffic to the new revision; old revisions are retained for instant rollback. All in under 2 minutes.
Frequently Asked Questions
What is zero-downtime deployment?
Zero-downtime deployment ensures no requests are dropped when a new version is deployed. Kubeletto achieves this by routing traffic to new revisions only after they pass health checks, while the old revision continues serving traffic during the transition.
How is a container deployment different from a VM deployment?
Container deployments are faster (seconds vs. minutes), more portable, and more resource-efficient than VM deployments. Containers share the host OS kernel, so there's no OS boot time. Multiple containers run on a single VM without overhead.
What happens if a container deployment fails?
On Kubeletto, a failed build or failing health check prevents the new revision from receiving traffic. The previous revision continues serving requests until you fix and redeploy.
See Container Deployment in action
Deploy your first app on Kubeletto — free during our active beta.