Output Controls

drydock keeps stdout machine-parseable for structured output. Diagnostics and failure summaries go to stderr unless status text is the primary output.

Formats

Use -o or --output to select the format supported by each command:

-o name is intended for list-style output. It is not supported for manifest diffs, and removed-only image changes print no names while still counting as a diff for exit-code behavior.

Diagnostics remain on stderr for unified, JSON, YAML, and name output so stdout stays parseable. Markdown manifest diff output embeds successful diagnostics in the generated report because the markdown document is the review surface.

test apps text output prints PASS, FAIL, or SKIPPED status lines. When stdout and stderr are terminals, status lines stream as Applications complete and stderr shows an in-place progress counter. Redirected text output stays plain and buffered.

Diff Controls

Unified manifest and image diffs support terminal color with --color=auto|always|never. The default auto colors only when stdout is a terminal. JSON and YAML outputs never include ANSI color.

Use markdown output when the result will be read in a pull request comment:

drydock diff apps --repo . --ref HEAD --ref-orig origin/main -o markdown
drydock diff images --repo . --ref HEAD --ref-orig origin/main -o markdown

For local browser review, manifest diff commands can also write the standalone Full Rendered Diff View used by the PR action artifact:

drydock diff apps \
  --repo . \
  --ref HEAD \
  --ref-orig origin/main \
  -o markdown \
  --html-output-file rendered-diff.html

Markdown remains the PR-comment stdout format. --html-output-file writes an additional HTML file with the same standalone review view.

Manifest markdown includes a summary plus expandable per-Application rendered manifest patches. Image markdown is a companion view for scanning rendered image reference changes and omits unchanged images by default.

Exit Codes

Diff commands use fixed exit codes:

Use --exit-code=false for local inspection when a diff should not fail the command.

For related operator guides, see the reference hub . For action outputs and PR comment controls, see the GitHub Actions guide .