ui+server: per-job bandwidth override on Run-now

P2R-13b. POST /hosts/{id}/source-groups/{gid}/run accepts optional
bandwidth_up_kbps / bandwidth_down_kbps form fields, plumbs them onto
CommandRunPayload. Agent dispatcher already prefers per-job override
over host-wide caps (T1). UI wraps the Run-now button in a form with
a <details> 'Limit bandwidth for this run' disclosure containing two
KB/s inputs.

internal/server/http/run_group.go

@@ -9,6 +9,7 @@ package http
 import (
 	"errors"
 	stdhttp "net/http"
+	"strconv"
 
 	"github.com/go-chi/chi/v5"
 
@@ -16,6 +17,34 @@ import (
 	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
 )
 
+// parseBandwidthOverride pulls optional bandwidth_up_kbps /
+// bandwidth_down_kbps from the request (form or query). Returns nil
+// for any field absent or empty; an explicit "0" produces a non-nil
+// pointer to 0 — i.e., "no cap for this run, even if the host has
+// one set." Non-integers / negatives are rejected with an error.
+func parseBandwidthOverride(r *stdhttp.Request) (up *int, down *int, err error) {
+	parse := func(name string) (*int, error) {
+		v := r.FormValue(name)
+		if v == "" {
+			return nil, nil
+		}
+		n, perr := strconv.Atoi(v)
+		if perr != nil {
+			return nil, errors.New(name + " must be an integer")
+		}
+		if n < 0 {
+			return nil, errors.New(name + " must be >= 0")
+		}
+		return &n, nil
+	}
+	up, err = parse("bandwidth_up_kbps")
+	if err != nil {
+		return nil, nil, err
+	}
+	down, err = parse("bandwidth_down_kbps")
+	return up, down, err
+}
+
 func (s *Server) handleRunSourceGroup(w stdhttp.ResponseWriter, r *stdhttp.Request) {
 	user, ok := s.requireUser(r)
 	if !ok {
@@ -40,13 +69,25 @@ func (s *Server) handleRunSourceGroup(w stdhttp.ResponseWriter, r *stdhttp.Reque
 		return
 	}
 
+	// Optional per-run bandwidth override. Disclosed in the UI under a
+	// <details> "Limit bandwidth for this run" affordance; absent on
+	// the wire (and from JSON callers that don't supply it) means
+	// "fall back to the host's standing caps."
+	upOverride, downOverride, perr := parseBandwidthOverride(r)
+	if perr != nil {
+		s.runGroupError(w, r, stdhttp.StatusBadRequest, "invalid_value", perr.Error())
+		return
+	}
+
 	// Backup invocations don't consume RetentionPolicy — that lives on
 	// forget. Sending the resolved set here would just be dead weight.
 	res, status, code, msg := s.dispatchJobWithPayload(r.Context(), user, hostID, api.JobBackup,
 		api.CommandRunPayload{
-			Includes: g.Includes,
+			Includes:          g.Includes,
-			Excludes: g.Excludes,
+			Excludes:          g.Excludes,
-			Tag:      g.Name,
+			Tag:               g.Name,
+			BandwidthUpKBps:   upOverride,
+			BandwidthDownKBps: downOverride,
 		})
 	if code != "" {
 		s.runGroupError(w, r, status, code, msg)

internal/server/http/run_group_bandwidth_test.go

@@ -0,0 +1,133 @@
+// run_group_bandwidth_test.go — covers the per-job bandwidth override
+// that operators can set via the Run-now form's "Limit bandwidth for
+// this run" disclosure (P2R-13b).
+package http
+
+import (
+	"context"
+	"encoding/json"
+	stdhttp "net/http"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/coder/websocket"
+	"github.com/oklog/ulid/v2"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
+)
+
+// TestRunSourceGroupBandwidthOverride: connect a fake agent, POST the
+// per-group Run-now endpoint with bandwidth_up_kbps=512, assert the
+// dispatched command.run carries it.
+func TestRunSourceGroupBandwidthOverride(t *testing.T) {
+	t.Parallel()
+	srv, ts, st := rawTestServer(t)
+	hostID, token := enrolHostForWS(t, srv, st, "bw-host")
+
+	// Pre-seed an init job so auto-init doesn't fire on hello and
+	// pollute our envelope sequence.
+	if err := st.CreateJob(context.Background(), store.Job{
+		ID: ulid.Make().String(), HostID: hostID, Kind: "init",
+		ActorKind: "system", CreatedAt: time.Now().UTC(),
+	}); err != nil {
+		t.Fatalf("seed init: %v", err)
+	}
+
+	gid := ulid.Make().String()
+	if err := st.CreateSourceGroup(context.Background(), &store.SourceGroup{
+		ID: gid, HostID: hostID, Name: "etc", Includes: []string{"/etc"},
+	}); err != nil {
+		t.Fatalf("group: %v", err)
+	}
+
+	c := agentDial(t, srv, ts, hostID, token)
+	sendHello(t, c, "bw-host")
+	// Drain on-hello burst before issuing the run-now.
+	_ = drainUntil(t, c, api.MsgScheduleSet)
+
+	cookie := loginAsAdmin(t, st)
+	form := url.Values{
+		"bandwidth_up_kbps":   {"512"},
+		"bandwidth_down_kbps": {"256"},
+	}
+	req, _ := stdhttp.NewRequest("POST",
+		ts.URL+"/hosts/"+hostID+"/source-groups/"+gid+"/run",
+		strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+	req.AddCookie(cookie)
+	res, err := stdhttp.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("do: %v", err)
+	}
+	res.Body.Close()
+	if res.StatusCode != stdhttp.StatusAccepted {
+		t.Fatalf("status: got %d, want 202", res.StatusCode)
+	}
+
+	// Read the dispatched command.run; assert overrides are present.
+	deadline := time.Now().Add(3 * time.Second)
+	for time.Now().Before(deadline) {
+		ctx, cancel := context.WithTimeout(context.Background(), 800*time.Millisecond)
+		mt, raw, rerr := c.Read(ctx)
+		cancel()
+		if rerr != nil {
+			break
+		}
+		if mt != websocket.MessageText {
+			continue
+		}
+		var env api.Envelope
+		_ = json.Unmarshal(raw, &env)
+		if env.Type != api.MsgCommandRun {
+			continue
+		}
+		var p api.CommandRunPayload
+		if err := env.UnmarshalPayload(&p); err != nil {
+			t.Fatalf("unmarshal: %v", err)
+		}
+		if p.Kind != api.JobBackup {
+			continue
+		}
+		if p.BandwidthUpKBps == nil || *p.BandwidthUpKBps != 512 {
+			t.Fatalf("BandwidthUpKBps: got %v, want 512", p.BandwidthUpKBps)
+		}
+		if p.BandwidthDownKBps == nil || *p.BandwidthDownKBps != 256 {
+			t.Fatalf("BandwidthDownKBps: got %v, want 256", p.BandwidthDownKBps)
+		}
+		return
+	}
+	t.Fatal("timed out waiting for command.run with bandwidth override")
+}
+
+// TestRunSourceGroupBandwidthRejectsNegative: invalid value → 400.
+func TestRunSourceGroupBandwidthRejectsNegative(t *testing.T) {
+	t.Parallel()
+	_, url2, st := newTestServerWithHub(t)
+	cookie := loginAsAdmin(t, st)
+	hostID := makeHost(t, st, "bw-rej-host")
+	gid := ulid.Make().String()
+	if err := st.CreateSourceGroup(context.Background(), &store.SourceGroup{
+		ID: gid, HostID: hostID, Name: "etc", Includes: []string{"/etc"},
+	}); err != nil {
+		t.Fatalf("group: %v", err)
+	}
+	form := url.Values{"bandwidth_up_kbps": {"-1"}}
+	req, _ := stdhttp.NewRequest("POST",
+		url2+"/hosts/"+hostID+"/source-groups/"+gid+"/run",
+		strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+	req.AddCookie(cookie)
+	res, err := stdhttp.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("do: %v", err)
+	}
+	defer res.Body.Close()
+	if res.StatusCode != stdhttp.StatusBadRequest {
+		t.Fatalf("status: got %d, want 400", res.StatusCode)
+	}
+}

web/templates/pages/host_sources.html

@@ -53,12 +53,27 @@
               {{if gt $row.SnapshotCount 0}} · <span class="mono">{{$row.SnapshotCount}}</span> snapshot{{if ne $row.SnapshotCount 1}}s{{end}}{{end}}
             </div>
           </div>
-          <div class="flex justify-end row-action" style="gap: 6px;">
+          <div class="flex flex-col items-end row-action" style="gap: 6px;">
             {{if and (gt (len $g.Includes) 0) (eq $host.Status "online")}}
-              <button class="btn btn-primary"
+              <form id="run-{{$g.ID}}" class="flex flex-col items-end" style="gap: 4px;">
-                      hx-post="/hosts/{{$host.ID}}/source-groups/{{$g.ID}}/run"
+                <button class="btn btn-primary"
-                      hx-swap="none"
+                        hx-post="/hosts/{{$host.ID}}/source-groups/{{$g.ID}}/run"
-                      hx-disabled-elt="this">Run now</button>
+                        hx-include="#run-{{$g.ID}}"
+                        hx-swap="none"
+                        hx-disabled-elt="this">Run now</button>
+                <details class="text-[11px] text-ink-fade" style="text-align: right;">
+                  <summary class="cursor-pointer hover:text-ink-mid select-none">Limit bandwidth for this run</summary>
+                  <div class="flex items-center mt-2" style="gap: 6px; font-family: var(--font-mono);">
+                    <label class="text-[10.5px] text-ink-mute">↑</label>
+                    <input type="number" min="0" name="bandwidth_up_kbps" placeholder="—" class="input mono"
+                           style="width: 70px; height: 22px; padding: 0 6px; font-size: 11px;">
+                    <label class="text-[10.5px] text-ink-mute">↓</label>
+                    <input type="number" min="0" name="bandwidth_down_kbps" placeholder="—" class="input mono"
+                           style="width: 70px; height: 22px; padding: 0 6px; font-size: 11px;">
+                    <span class="text-[10.5px] text-ink-fade">KB/s</span>
+                  </div>
+                </details>
+              </form>
             {{else}}
               <button class="btn" disabled
                       title="{{if eq (len $g.Includes) 0}}add at least one include path before running{{else}}host is offline{{end}}">Run now</button>