test(e2e): cover host mode, reusable workflows, scheduling, reconnect and CLI flags (#1347)

Extends the e2e suite with scenarios for host labels, local `workflow_call`, label routing, `runner.capacity`, a dropped and restored connection to Gitea, and the daemon's `--once`, `--labels` and `shutdown_timeout` behaviour.

Stacked on https://gitea.com/gitea/runner/pulls/1346, so its commit shows here until that merges. The new scenarios pass locally against gitea/gitea:latest and main-nightly.

Assisted-by: Codet:codet
Co-authored-by: Zettat123 <[email protected]>
Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1347
Reviewed-by: Zettat123 <[email protected]>

e2e/scheduling_test.go

@@ -0,0 +1,113 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build e2e
+
+package e2e
+
+import (
+	"context"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+)
+
+// testLabelRouting checks that each job reaches the runner owning its label and that a
+// job with no matching runner stays queued.
+func testLabelRouting(t *testing.T) {
+	t.Parallel()
+	ctx := t.Context()
+
+	api, repo := newScenario(t)
+	startRunner(t, repo, "e2e-route-a", runnerOptions{host: true, name: "-a"})
+	startRunner(t, repo, "e2e-route-b", runnerOptions{host: true, name: "-b"})
+	pushWorkflow(t, api, repo, "route.yml")
+
+	wfRun := waitForRun(t, api, repo)
+	ctx, cancel := context.WithTimeout(ctx, runTimeout)
+	defer cancel()
+	var jobs map[string]ActionJob
+	for {
+		list, err := api.Jobs(ctx, repo, wfRun.ID)
+		if err != nil {
+			t.Fatalf("list jobs: %v", err)
+		}
+		jobs = map[string]ActionJob{}
+		for _, job := range list {
+			jobs[job.Name] = job
+		}
+		if jobs["a"].Status == "completed" && jobs["b"].Status == "completed" {
+			break
+		}
+		select {
+		case <-ctx.Done():
+			t.Fatalf("jobs a and b did not complete: %+v", list)
+		case <-time.After(pollInterval):
+		}
+	}
+
+	for name, suffix := range map[string]string{"a": "-a", "b": "-b"} {
+		if got := jobs[name].RunnerName; !strings.HasSuffix(got, suffix) {
+			t.Errorf("job %s ran on runner %q, want the one named *%s", name, got, suffix)
+		}
+		if jobs[name].Conclusion != "success" {
+			t.Errorf("job %s concluded %q", name, jobs[name].Conclusion)
+		}
+	}
+	// a and b were picked up after unmatched was queued, so a runner that could take it would have by now
+	if status := jobs["unmatched"].Status; status == "in_progress" || status == "completed" {
+		t.Errorf("job with no matching runner is %q, want it queued", status)
+	}
+}
+
+// testCapacity checks that runner.capacity bounds how many jobs run at once.
+func testCapacity(t *testing.T) {
+	t.Parallel()
+	for _, tc := range []struct {
+		name       string
+		capacity   int
+		concurrent bool
+	}{
+		{"serial", 1, false},
+		{"parallel", 2, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			api, repo := newScenario(t)
+			startRunner(t, repo, "e2e-capacity", runnerOptions{capacity: tc.capacity})
+			pushWorkflow(t, api, repo, "capacity.yml")
+
+			wfRun := waitForRun(t, api, repo)
+			requireSuccess(t, api, repo, wfRun.ID)
+
+			jobs, err := api.Jobs(t.Context(), repo, wfRun.ID)
+			if err != nil || len(jobs) != 2 {
+				t.Fatalf("list jobs: %v (%d jobs)", err, len(jobs))
+			}
+			var start, end [2]int64
+			for i, job := range jobs {
+				logs, err := api.JobLogs(t.Context(), repo, job.ID)
+				if err != nil {
+					t.Fatalf("job logs: %v", err)
+				}
+				start[i] = spanValue(t, logs, "span-start=")
+				end[i] = spanValue(t, logs, "span-end=")
+			}
+			overlap := max(start[0], start[1]) < min(end[0], end[1])
+			if overlap != tc.concurrent {
+				t.Errorf("capacity %d: jobs overlapped=%v, want %v (starts %v ends %v)", tc.capacity, overlap, tc.concurrent, start, end)
+			}
+		})
+	}
+}
+
+func spanValue(t *testing.T, logs, prefix string) int64 {
+	t.Helper()
+	row := commandRow(logs, prefix)
+	n, err := strconv.ParseInt(strings.TrimPrefix(row, prefix), 10, 64)
+	if err != nil {
+		t.Fatalf("no %q value in logs:\n%s", prefix, logs)
+	}
+	return n
+}