Download actions job logs from API (#33858)

Related to #33709, #31416

It's similar with
https://docs.github.com/en/rest/actions/workflow-jobs?apiVersion=2022-11-28#download-job-logs-for-a-workflow-run--code-samples.

This use `job_id` as path parameter which is consistent with Github's
APIs.

---------

Co-authored-by: ChristopherHX <christopher.homberger@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/api/v1/api.go

@@ -1168,6 +1168,10 @@ func Routes() *web.Router {
 					m.Post("/{workflow_id}/dispatches", reqRepoWriter(unit.TypeActions), bind(api.CreateActionWorkflowDispatch{}), repo.ActionsDispatchWorkflow)
 				}, context.ReferencesGitRepo(), reqToken(), reqRepoReader(unit.TypeActions))
 
+				m.Group("/actions/jobs", func() {
+					m.Get("/{job_id}/logs", repo.DownloadActionsRunJobLogs)
+				}, reqToken(), reqRepoReader(unit.TypeActions))
+
 				m.Group("/hooks/git", func() {
 					m.Combo("").Get(repo.ListGitHooks)
 					m.Group("/{id}", func() {

routers/api/v1/repo/actions_run.go

@@ -0,0 +1,64 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"errors"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/routers/common"
+	"code.gitea.io/gitea/services/context"
+)
+
+func DownloadActionsRunJobLogs(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/actions/jobs/{job_id}/logs repository downloadActionsRunJobLogs
+	// ---
+	// summary: Downloads the job logs for a workflow run
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: name of the owner
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repository
+	//   type: string
+	//   required: true
+	// - name: job_id
+	//   in: path
+	//   description: id of the job
+	//   type: integer
+	//   required: true
+	// responses:
+	//   "200":
+	//     description: output blob content
+	//   "400":
+	//     "$ref": "#/responses/error"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	jobID := ctx.PathParamInt64("job_id")
+	curJob, err := actions_model.GetRunJobByID(ctx, jobID)
+	if err != nil {
+		ctx.APIErrorInternal(err)
+		return
+	}
+	if err = curJob.LoadRepo(ctx); err != nil {
+		ctx.APIErrorInternal(err)
+		return
+	}
+
+	err = common.DownloadActionsRunJobLogs(ctx.Base, ctx.Repo.Repository, curJob)
+	if err != nil {
+		if errors.Is(err, util.ErrNotExist) {
+			ctx.APIErrorNotFound(err)
+		} else {
+			ctx.APIErrorInternal(err)
+		}
+	}
+}