Commands can leak into image, image cannot be pulled

[zc-devs]

Component

server

Describe the bug

When the one forgot commands directive, then they join to image => image cannot be pulled, pipeline stucks.

Steps to reproduce

1. Create and run pipeline

   
   skip_clone: true

when:

• event:
  • manual

steps: hello: image: alpine

• echo Hello
• echo world

  2. See that it runs without errors and warnings
  [Screenshot 2024-06-29 1](https://github.com/woodpecker-ci/woodpecker/assets/127358482/13f2ae81-f66b-4c6c-a5cb-3d742423e52d)
  [Screenshot 2024-06-29 2](https://github.com/woodpecker-ci/woodpecker/assets/127358482/ab7bb794-9aa2-426c-b22f-59235ea91d80)
  3. Pipeline stucks until timed out or cancelled manually
  4. Check Pods and see errors

  Error: InvalidImageName

  [Screenshot 2024-06-29 3](https://github.com/woodpecker-ci/woodpecker/assets/127358482/3e9bd70c-ef6f-40f4-9e70-6a3220a8eeca)

  Failed to apply default image tag "alpine - echo Hello - echo world": couldn't parse image name "alpine - echo Hello - echo world": invalid reference format: repository name (library/alpine - echo Hello - echo world) must be lowercase

  
  [Screenshot 2024-06-29 4](https://github.com/woodpecker-ci/woodpecker/assets/127358482/1804399f-5fc7-4513-bb13-c4a3621bfa6d)

Expected behavior

Pipeline should fail and linter should warn about missed commands as well.

System Info

`2.6.0`, Kubernetes

Additional context

woodpecker-server.log woodpecker-agent.log

Validations

• [X] Read the docs.
• [X] Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• [X] Checked that the bug isn't fixed in the next version already [https://woodpecker-ci.org/faq#which-version-of-woodpecker-should-i-use]

[zc-devs]

In regard Kubernets backend, probably, wider range of statuses should be chacked (https://github.com/woodpecker-ci/woodpecker/pull/3580).