feat(actions): add job summaries (GITHUB_STEP_SUMMARY) (#37500)

- Add GitHub-style Actions **job summaries** support
(`GITHUB_STEP_SUMMARY` / `workflow/SUMMARY.md`) and render them on the
run Summary view.
- Store uploaded summaries internally in the DB (not as downloadable
artifacts).
- Add runtime-token endpoint for runners to upload summaries:
- `PUT
/api/actions_pipeline/_apis/pipelines/workflows/{run_id}/jobs/{job_id}/summary`
- Advertise support to runners via `RunnerService.Declare` response
header:
  - `X-Gitea-Actions-Capabilities: job-summary`
- Devtest: extend `/devtest/repo-action-view/...` to include mock
`jobSummaries` for previewing UI rendering.

## Compatibility
- New Gitea + old runner: no summary upload → UI shows nothing (no
behavior change)
- New runner + old Gitea: capability not advertised → runner skips
upload (no behavior change)

## Screenshot:

<img width="2017" height="729"
src="https://github.com/user-attachments/assets/31f8b945-50c4-40e1-9f40-382901a53013"
/>


Fixes #23721
PR on gitea-runner https://gitea.com/gitea/runner/pulls/917

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

routers/api/actions/artifacts.go

@@ -121,6 +121,9 @@ func ArtifactsRoutes(prefix string) *web.Router {
 		m.Get("/{artifact_id}/download", r.downloadArtifact)
 	})
 
+	// Job summary upload endpoint (GITHUB_STEP_SUMMARY).
+	m.Put(jobSummaryRouteBase, uploadJobSummary)
+
 	return m
 }
 

routers/api/actions/job_summary.go

@@ -0,0 +1,104 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package actions
+
+import (
+	"errors"
+	"io"
+	"mime"
+	"net/http"
+	"slices"
+	"strconv"
+
+	actions_model "gitea.dev/models/actions"
+	"gitea.dev/modules/log"
+	"gitea.dev/modules/util"
+)
+
+const jobSummaryRouteBase = "/_apis/pipelines/workflows/{run_id}/jobs/{job_id}/steps/{step_index}/summary"
+
+func uploadJobSummary(ctx *ArtifactContext) {
+	task, _, ok := validateRunID(ctx)
+	if !ok {
+		return
+	}
+
+	jobID := ctx.PathParamInt64("job_id")
+	if jobID <= 0 || task.Job.ID != jobID {
+		ctx.HTTPError(http.StatusBadRequest, "job_id mismatch")
+		return
+	}
+
+	stepIndex, err := strconv.ParseInt(ctx.PathParam("step_index"), 10, 64)
+	if err != nil || stepIndex < 0 {
+		ctx.HTTPError(http.StatusBadRequest, "invalid step_index")
+		return
+	}
+	steps, err := actions_model.GetTaskStepsByTaskID(ctx, task.ID)
+	if err != nil {
+		log.Error("Error getting task steps: %v", err)
+		ctx.HTTPError(http.StatusInternalServerError, "Error getting task steps")
+		return
+	}
+	if !slices.ContainsFunc(steps, func(s *actions_model.ActionTaskStep) bool { return s.Index == stepIndex }) {
+		ctx.HTTPError(http.StatusBadRequest, "step_index mismatch")
+		return
+	}
+
+	contentType, ok := normalizeJobSummaryContentType(ctx.Req.Header.Get("Content-Type"))
+	if !ok {
+		ctx.HTTPError(http.StatusBadRequest, "invalid summary content type")
+		return
+	}
+
+	body, err := io.ReadAll(io.LimitReader(ctx.Req.Body, actions_model.MaxJobSummarySize+1))
+	if err != nil {
+		log.Error("Error reading job summary request body: %v", err)
+		ctx.HTTPError(http.StatusInternalServerError, "read request body")
+		return
+	}
+	message := "success"
+	if len(body) == 0 {
+		// PUT with an empty body clears any previously-stored summary for this step.
+		if err := actions_model.DeleteActionRunJobSummary(ctx, task.Job.RepoID, task.Job.RunID, task.Job.RunAttemptID, task.Job.ID, stepIndex); err != nil {
+			log.Error("Error deleting job summary: %v", err)
+			ctx.HTTPError(http.StatusInternalServerError, "Error deleting job summary")
+			return
+		}
+		message = "cleared"
+	} else if err := actions_model.UpsertActionRunJobSummary(ctx, task.Job.RepoID, task.Job.RunID, task.Job.RunAttemptID, task.Job.ID, stepIndex, contentType, body); err != nil {
+		if errors.Is(err, actions_model.ErrJobSummaryAggregateExceeded) {
+			ctx.HTTPError(http.StatusBadRequest, "job summary aggregate size exceeded")
+			return
+		}
+		if errors.Is(err, util.ErrInvalidArgument) {
+			ctx.HTTPError(http.StatusBadRequest, "invalid summary")
+			return
+		}
+		log.Error("Error upsert job summary: %v", err)
+		ctx.HTTPError(http.StatusInternalServerError, "Error upsert job summary")
+		return
+	}
+
+	ctx.JSON(http.StatusOK, map[string]any{
+		"message":    message,
+		"sizeBytes":  len(body),
+		"runAttempt": task.Job.RunAttemptID,
+	})
+}
+
+func normalizeJobSummaryContentType(contentType string) (string, bool) {
+	if contentType == "" || contentType == "application/octet-stream" {
+		return actions_model.JobSummaryContentTypeMarkdown, true
+	}
+
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return "", false
+	}
+	if mediaType != actions_model.JobSummaryContentTypeMarkdown {
+		return "", false
+	}
+	return actions_model.JobSummaryContentTypeMarkdown, true
+}

routers/api/actions/runner/runner.go

@@ -161,7 +161,7 @@ func (s *Service) Declare(
 		return nil, status.Errorf(codes.Internal, "update runner: %v", err)
 	}
 
-	return connect.NewResponse(&runnerv1.DeclareResponse{
+	resp := connect.NewResponse(&runnerv1.DeclareResponse{
 		Runner: &runnerv1.Runner{
 			Id:      runner.ID,
 			Uuid:    runner.UUID,
@@ -170,7 +170,11 @@ func (s *Service) Declare(
 			Version: runner.Version,
 			Labels:  runner.AgentLabels,
 		},
-	}), nil
+	})
+	// Capabilities are communicated via headers to avoid a hard dependency on a proto bump.
+	// Older runners ignore unknown headers; newer runners can use this for feature negotiation.
+	resp.Header().Set("X-Gitea-Actions-Capabilities", actions_model.RunnerCapabilities())
+	return resp, nil
 }
 
 // FetchTask assigns a task to the runner