fail closed on quarantine misconfig and first-seen errors

- backfill quarantine_days<=0 to 3 with migration 0006
- reject quarantine_enabled with quarantine_days<1 on create and update
- cap upstream Last-Modified at now
- answer 503 with Retry-After when the first-seen lookup fails

internal/api/v2/remotes.go

@@ -71,11 +71,8 @@ func (h *RemotesHandler) get(w http.ResponseWriter, r *http.Request) {
 // that omits mutable_ttl gets it, an explicit 0 still means never expire.
 const defaultMutableTTL = 3600
 
-// defaultQuarantineDays matches the remotes.quarantine_days column default.
-const defaultQuarantineDays = 3
-
 func (h *RemotesHandler) create(w http.ResponseWriter, r *http.Request) {
-	remote := models.Remote{MutableTTL: defaultMutableTTL, QuarantineDays: defaultQuarantineDays}
+	remote := models.Remote{MutableTTL: defaultMutableTTL, QuarantineDays: models.DefaultQuarantineDays}
 	if err := json.NewDecoder(r.Body).Decode(&remote); err != nil {
 		http.Error(w, "invalid json", http.StatusBadRequest)
 		return
@@ -107,6 +104,10 @@ func (h *RemotesHandler) create(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}
+	if err := remote.ValidateQuarantine(); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
 	if err := h.db.CreateRemote(r.Context(), &remote); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -148,6 +149,10 @@ func (h *RemotesHandler) update(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}
+	if err := remote.ValidateQuarantine(); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
 	if err := h.db.UpdateRemote(r.Context(), &remote); err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return

internal/api/v2/remotes_ttl_test.go

@@ -91,3 +91,31 @@ func TestQuarantineDaysDefault(t *testing.T) {
 		}
 	}
 }
+
+func TestQuarantineDaysValidation(t *testing.T) {
+	if testDSN == "" {
+		t.Skip("Docker unavailable")
+	}
+	db, err := database.New(testDSN)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+	h := NewRemotesHandler(db, nil, nil).Routes()
+	const body = `"package_type":"npm","base_url":"https://example.com"`
+	for i, s := range []struct {
+		method, path, json string
+		want               int
+	}{
+		{"POST", "/", `{"name":"q-val",` + body + `,"quarantine_enabled":true,"quarantine_days":0}`, 400},
+		{"POST", "/", `{"name":"q-val",` + body + `,"quarantine_enabled":true,"quarantine_days":-1}`, 400},
+		{"POST", "/", `{"name":"q-val",` + body + `,"quarantine_days":0}`, 201},
+		{"PUT", "/q-val", `{` + body + `,"quarantine_enabled":true}`, 400},
+		{"PUT", "/q-val", `{` + body + `,"quarantine_enabled":true,"quarantine_days":1}`, 200},
+		{"PUT", "/q-val", `{` + body + `,"quarantine_enabled":true,"quarantine_days":0}`, 400},
+	} {
+		if c := do(t, h, s.method, s.path, s.json); c != s.want {
+			t.Errorf("step %d %s %s = %d, want %d", i, s.method, s.path, c, s.want)
+		}
+	}
+}