v0.66.1: inject USERDATA_PATH on first deploy too (shared withUserdataPath)

DeployStack's initial compose-up builds env from deploy values (not stackEnv), so
v0.66.0 missed USERDATA_PATH on first deploy → ${USERDATA_PATH} resolved to '' and
Docker bound a root-owned dir at the container root (found live: radarr /media/movies
was 0:0 755). Shared withUserdataPath injector now used by stackEnv AND
composeExecWithEnv. Regression test included.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

controller/internal/stacks/deploy.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"gitea.dooplex.hu/admin/felhom-controller/internal/appbackup"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/crypto"
 	"gitea.dooplex.hu/admin/felhom-controller/internal/system"
 	"gopkg.in/yaml.v3"
@@ -513,16 +514,31 @@ func (m *Manager) RedeployFromEnv(name string, env map[string]string) error {
 	return m.RefreshStatus()
 }
 
-// composeExecWithEnv runs a compose command with custom env vars injected.
+// composeExecWithEnv runs a compose command with custom env vars injected. Used by the initial deploy
+// path (DeployStack), which builds env from the deploy values rather than from app.yaml via stackEnv —
+// so USERDATA_PATH must be injected here too (mirrors stackEnv), else the FIRST deploy resolves
+// ${USERDATA_PATH} to "" and binds a bogus root-owned dir at the container root.
 func (m *Manager) composeExecWithEnv(dir string, env map[string]string, args ...string) (string, error) {
 	cmdEnv := os.Environ()
 	for k, v := range env {
 		cmdEnv = append(cmdEnv, fmt.Sprintf("%s=%s", k, v))
 	}
 	cmdEnv = append(cmdEnv, fmt.Sprintf("DOMAIN=%s", m.cfg.Customer.Domain))
+	cmdEnv = withUserdataPath(cmdEnv, env["HDD_PATH"])
 	return m.composeExecCustomEnv(dir, cmdEnv, args...)
 }
 
+// withUserdataPath appends USERDATA_PATH=<hdd>/userdata to a "K=V" env slice when hdd is non-empty.
+// Shared by BOTH compose-env builders (stackEnv for start/redeploy, composeExecWithEnv for the initial
+// deploy) so ${USERDATA_PATH} always resolves — the initial-deploy path missing it bound a bogus
+// root-owned dir at the container root.
+func withUserdataPath(cmdEnv []string, hdd string) []string {
+	if hdd != "" {
+		cmdEnv = append(cmdEnv, "USERDATA_PATH="+appbackup.UserdataDir(hdd))
+	}
+	return cmdEnv
+}
+
 // GetDeployFields returns the deployment fields for a stack (for the deploy form).
 func (m *Manager) GetDeployFields(name string) (*Metadata, *AppConfig, error) {
 	stack, ok := m.GetStack(name)

controller/internal/stacks/manager.go

@@ -860,9 +860,7 @@ func (m *Manager) stackEnv(stackDir string) []string {
 		// Inject USERDATA_PATH = <namespace root>/userdata alongside HDD_PATH (v0.66.0). HDD_PATH IS
 		// the namespace root (the chosen StoragePath: a Model-A user drive's mount, or the SSD's
 		// felhom-data dir), so the catalog's ${USERDATA_PATH}/... mounts resolve under userdata/.
-		if hdd := appCfg.Env["HDD_PATH"]; hdd != "" {
-			env = append(env, fmt.Sprintf("USERDATA_PATH=%s", appbackup.UserdataDir(hdd)))
-		}
+		env = withUserdataPath(env, appCfg.Env["HDD_PATH"])
 	}
 
 	return env

controller/internal/stacks/userdata_belt_test.go

@@ -71,3 +71,26 @@ func TestEnsureUserdataMounts_CreatesBeltDirs(t *testing.T) {
 	}
 	_ = appbackup.SharedContentGID // keep import referenced cross-platform
 }
+
+// TestWithUserdataPath: the shared injector adds USERDATA_PATH=<hdd>/userdata when HDD_PATH is set, and
+// adds nothing when it's empty. Regression for the initial-deploy bug where ${USERDATA_PATH} resolved
+// to "" and bound a bogus root-owned dir at the container root.
+func TestWithUserdataPath(t *testing.T) {
+	got := withUserdataPath([]string{"DOMAIN=x"}, "/mnt/felhom-usb")
+	want := "USERDATA_PATH=" + appbackup.UserdataDir("/mnt/felhom-usb")
+	found := false
+	for _, e := range got {
+		if e == want {
+			found = true
+		}
+	}
+	if !found {
+		t.Errorf("USERDATA_PATH not injected: got %v, want %q", got, want)
+	}
+	// companion: empty HDD_PATH → no USERDATA_PATH at all
+	for _, e := range withUserdataPath([]string{"DOMAIN=x"}, "") {
+		if len(e) >= 13 && e[:13] == "USERDATA_PATH" {
+			t.Errorf("USERDATA_PATH must NOT be set when HDD_PATH is empty: %q", e)
+		}
+	}
+}