[Feature request] Tail logs of all deployed containers

[DennisVis]

For Skaffold to be truly useful as a CI tool it will need to be able to tail the logs of all containers in the deployed cluster.

Say I've written a database integration test for my application. My application is built by Skaffold, the database image is ready made and fetched from docker hub, both are included in a deployment. When running skaffold run in this situation I'll only see my application logs. If the database container crashed I won't be able to see why that happened.

[tejal29]

Revive #1911

[tstromberg]

This personally feels a bit like scope-creep to me, but at the same time it sounds like we should provide the necessary duct-tape to piece this together yourself. Leaving open for now.

[briandealwis]

I support this request. I use jobs to run checks, and I'm fortunate that the gcr.io/cloud-builders/kubectl image includes a number of useful tools such that I can just script them directly within the job's yaml definition:

apiVersion: batch/v1
kind: Job
metadata:
  name: connect-to-nodejs12
spec:
  ttlSecondsAfterFinished: 10
  backoffLimit: 1
  template:
    spec:
      restartPolicy: Never
      containers:
      - name: verify-nodejs12
        image: gcr.io/cloud-builders/kubectl
        command: [sh, -c, 'sleep 5;
          kubectl port-forward pod/nodejs12pod 9229:9229 &
          sleep 2;
          set -x;
          curl -i localhost:9229/json']

But because I didn't create this as an image, Skaffold doesn't show logs.

Skaffold annotates the actual k8s object — it has a run-id, it has skaffold.dev/tail = true — and it's an image I created, so I'd like Skaffold to log it for me too.

I'd be happy for Skaffold to mark objects with non-built containers as skaffold.dev/tail = false, or even have skaffold.dev/tail be a list of container names to log.

[briandealwis]

I encounter this somewhat regularly #2303 (review)

[briandealwis]

A user in #3946 has an initContainer invoking shell scripts using the busybox image whose output is not logged.

[gsquared94]

@briandealwis if you haven't started working on this already, then I can take it up.