fix(execd): expand env before file read/stat

[Pangjiping]

Summary

• expand env before file read/stat
• resolved issue which execd cannot process file like $HOME/abc, ~/abc or $MY_WORKSPACE/abc
• closes BUG: cannot read $HOME/file #711

Testing

• Not run (explain why)
• Unit tests
• Integration tests
• e2e / manual verification

Breaking Changes

• None
• Yes (describe impact and migration path)

Checklist

• Linked Issue or clearly described motivation
• Added/updated docs (if needed)
• Added/updated tests (if needed)
• Security impact considered
• Backward compatibility considered

[chatgpt-codex-connector]

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[ninan-nn]

Question: should cwd expansion also consider request.Envs?

Right now cwd is expanded before cmd.Env is built, and pathutil.ExpandPath only reads the execd process env. So a request like this will fail if WORKDIR is not set on execd, even though the command itself would receive it via envs:

{
  "command": "pwd",
  "cwd": "$WORKDIR",
  "envs": {
    "WORKDIR": "/tmp/ws"
  }
}

Is this intended, or should cwd be expanded using the same effective env as the command?

[Pangjiping]

Question: should cwd expansion also consider request.Envs?

Right now cwd is expanded before cmd.Env is built, and pathutil.ExpandPath only reads the execd process env. So a request like this will fail if WORKDIR is not set on execd, even though the command itself would receive it via envs:

{
  "command": "pwd",
  "cwd": "$WORKDIR",
  "envs": {
    "WORKDIR": "/tmp/ws"
  }
}

Is this intended, or should cwd be expanded using the same effective env as the command?

Good idea. It is an excellent addition.

Considering the scope of the command request, we should support expanding paths from request.env, and I’ve already implemented this in the latest commit. bb7cd3e

[ninan-nn]

LGTM