Add ENGINE column driven by coordinator context by nicksieger · Pull Request #13959 · docker/compose

nicksieger · 2026-07-21T21:09:58Z

What I did

Show an ENGINE column in compose ps default table output when the
current Docker context is coordinator-enabled, using the
com.docker.compose.engine label value per row. Column is omitted
otherwise. Expose {{.Engine}} for custom --format templates.

Supports future multi-engine coordinators and workloads.

NOTE: based on #13958, wait to rebase after merging.

Related issue

(not mandatory) A picture of a cute animal, if possible in relation to what you did

Detect the `com.docker.compose.project.config` context metadata key (bool true or string "true"); when set, POST the full project config to the coordinator at `/v{version}/compose/project` over the engine socket dialer at the start of `compose up`, before any other Docker API call. - version-gated behind new apiVersionComposeProjectConfig constant - skipped in dry-run - non-fatal: warn and continue on request or engine error Signed-off-by: Nick Sieger <nick@nicksieger.com>

docker-agent

Assessment: 🟢 APPROVE

The ENGINE column feature is clean and correct. The implementation:

Correctly guards against nil Labels maps in the new Engine() method — no panic risk for containers without labels
Only shows the ENGINE column when at least one container carries the com.docker.compose.engine label
The hasEngine detection loop correctly reflects the filtered container set
Format string construction order (ENGINE before SIZE) is internally consistent
New test covers the happy-path scenario

No bugs were found in the added code.

codecov · 2026-07-21T21:24:27Z

Codecov Report

❌ Patch coverage is 89.70588% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/coordinator/coordinator.go	92.00%	2 Missing and 2 partials ⚠️
pkg/compose/up.go	62.50%	2 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

glours

hasEngine scans the filtered container set (cmd/compose/ps.go), so column presence depends on which services you name. Say svc1 carries the com.docker.compose.engine label and svc2 doesn't:

compose ps → ENGINE column shown (svc2 gets an empty cell)
compose ps svc2 → no ENGINE column, even though svc2's row is identical to the one just shown
compose ps svc1 → shown again

Same rows, different schema. That breaks table-parsing and diverges from docker ps, where columns are never data-gated.

As this is a very specific display, could we gate it on the coordinator context (the same context-metadata detection as the project-config work, living under internal/) instead of the data? Presence then stays stable across ps / ps <subset>.

Nit: api.EngineLabel (com.docker.compose.engine) collides by name with desktop.EngineLabel (com.docker.desktop.address), can we consider a more specific name?

Relocate the coordinator-specific project-config push out of pkg/compose, which is Compose's reusable surface, into a dedicated internal/coordinator package mirroring internal/desktop. Detection, the engine-dialer HTTP client, the versioned URL and outcome handling now live there; up.go keeps a thin call-site. Bound the push with an http.Client timeout so a coordinator that accepts the connection but never responds cannot hang "compose up", preserving the non-fatal warn-and-continue guarantee. Signed-off-by: Nick Sieger <nick@nicksieger.com>

docker-agent

Assessment: 🟢 APPROVE

The ENGINE column feature is well-structured. The new internal/coordinator package correctly gates the feature on Docker context metadata, the label constant matches the documented name (com.docker.compose.engine), and error paths (HTTP timeouts, non-200 responses, missing coordinator) are handled. Test coverage is present for the new coordinator logic, the formatter, and compose ps.

No high- or medium-severity bugs were found in the changed code.

http.Transport is allocated per call and discarded; without CloseIdleConnections its persistConn goroutines linger until IdleConnTimeout. Tear them down eagerly in the deferred cleanup. Signed-off-by: Nick Sieger <nick@nicksieger.com>

glours

Sounds good, maybe will need some refactoring depending of pending comments on #13958

glours · 2026-07-23T08:32:32Z

+		assert.Assert(t, strings.Contains(out.String(), "moby"), out.String())
+	})
+
+	t.Run("engine column hidden when no label present", func(t *testing.T) {


Suggested change

t.Run("engine column hidden when no label present", func(t *testing.T) {

t.Run("engine column hidden when coordinateur disabled", func(t *testing.T) {

Co-authored-by: Guillaume Lours <705411+glours@users.noreply.github.com> Signed-off-by: Nick Sieger <nick@nicksieger.com>

"compose up" with no service arguments and no profiles applied resolves the whole project; naming services narrows it to a subset (+ dependency closure), and an applied profile disables the services outside it. Advertise which one the coordinator received via a new X-Compose-Project-Complete header so it can merge partial pushes with stored config instead of treating every push as authoritative. - mark complete only when the service selection is empty and no profile is active; blank profile entries (compose-go's no-profile sentinel) are ignored via hasActiveProfiles - set the header explicitly (true/false); absent means older client and must be read as "false" so no prune is ever triggered on its behalf Signed-off-by: Nick Sieger <nick@nicksieger.com>

Use the metadata to indicate coordinator presense, not just capable of accepting the push project config api. Signed-off-by: Nick Sieger <nick@nicksieger.com>

Signed-off-by: Nick Sieger <nick@nicksieger.com>

Show an ENGINE column in `compose ps` default table output when the current Docker context is coordinator-enabled (detected via the project-config context metadata, internal/coordinator.PushEnabled), rather than gating on which listed containers carry the engine label. Column presence is now stable across `ps` and `ps <subset>`; per-row value comes from the com.docker.compose.engine label. Expose {{.Engine}} for custom --format templates. Rename api.EngineLabel to api.ContainerEngineLabel to avoid the name collision with desktop.EngineLabel (com.docker.desktop.address). Signed-off-by: Nick Sieger <nick@nicksieger.com>

nicksieger requested review from a team as code owners July 21, 2026 21:09

nicksieger requested review from glours and ndeloof July 21, 2026 21:10

docker-agent reviewed Jul 21, 2026

View reviewed changes

glours requested changes Jul 22, 2026

View reviewed changes

nicksieger force-pushed the ps-engine-column branch from cadb256 to 47e560e Compare July 22, 2026 15:23

glours requested a review from docker-agent July 22, 2026 15:36

docker-agent reviewed Jul 22, 2026

View reviewed changes

glours reviewed Jul 23, 2026

View reviewed changes

nicksieger and others added 4 commits July 23, 2026 10:38

fix: apply suggestions from code review

44141c2

Co-authored-by: Guillaume Lours <705411+glours@users.noreply.github.com> Signed-off-by: Nick Sieger <nick@nicksieger.com>

refactor: Rename PushEnabled to just Enabled

95d5383

Use the metadata to indicate coordinator presense, not just capable of accepting the push project config api. Signed-off-by: Nick Sieger <nick@nicksieger.com>

fix: response to code review suggestions; use DisabledServices

30a105a

Signed-off-by: Nick Sieger <nick@nicksieger.com>

nicksieger force-pushed the ps-engine-column branch from 47e560e to f5f73b6 Compare July 28, 2026 15:59

nicksieger changed the title ~~Add ENGINE column driven by com.docker.compose.engine label~~ Add ENGINE column driven by coordinator context Jul 28, 2026

nicksieger force-pushed the ps-engine-column branch from f5f73b6 to 01bb74d Compare July 28, 2026 16:08

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Add ENGINE column driven by coordinator context - #13959

Add ENGINE column driven by coordinator context#13959
nicksieger wants to merge 8 commits into
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nicksieger:ps-engine-column

nicksieger commented Jul 21, 2026 •

edited by glours

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	t.Run("engine column hidden when no label present", func(t *testing.T) {
	t.Run("engine column hidden when coordinateur disabled", func(t *testing.T) {

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Assessment: 🟢 APPROVE

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nicksieger commented Jul 21, 2026 •

edited by glours

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