fix: move writeLogsToFile doc comment to correct position

The buildRegistryAuths function was inserted between the writeLogsToFile
doc comment and the writeLogsToFile function body, causing Go to treat
the writeLogsToFile comment as part of buildRegistryAuths godoc.

Move the writeLogsToFile comment to sit directly above its function,
and keep only the buildRegistryAuths comment above buildRegistryAuths.

README.md

@@ -9,6 +9,7 @@ A simple self-hosted PaaS that auto-deploys Docker containers from Git repositor
 - Per-app UUID-based webhook URLs for Gitea integration
 - Branch filtering - only deploy on configured branch changes
 - Environment variables, labels, and volume mounts per app
+- Private Docker registry authentication for base images
 - Docker builds via socket access
 - Notifications via ntfy and Slack-compatible webhooks
 - Simple server-rendered UI with Tailwind CSS

internal/database/migrations/007_add_registry_credentials.sql

@@ -0,0 +1,11 @@
+-- Add registry credentials for private Docker registry authentication during builds
+CREATE TABLE registry_credentials (
+    id INTEGER PRIMARY KEY,
+    app_id TEXT NOT NULL REFERENCES apps(id) ON DELETE CASCADE,
+    registry TEXT NOT NULL,
+    username TEXT NOT NULL,
+    password TEXT NOT NULL,
+    UNIQUE(app_id, registry)
+);
+
+CREATE INDEX idx_registry_credentials_app_id ON registry_credentials(app_id);

internal/docker/auth_test.go

@@ -0,0 +1,96 @@
+package docker //nolint:testpackage // tests unexported buildAuthConfigs
+
+import (
+	"testing"
+)
+
+func TestBuildAuthConfigsEmpty(t *testing.T) {
+	t.Parallel()
+
+	result := buildAuthConfigs(nil)
+	if len(result) != 0 {
+		t.Errorf("expected empty map, got %d entries", len(result))
+	}
+}
+
+func TestBuildAuthConfigsSingle(t *testing.T) {
+	t.Parallel()
+
+	auths := []RegistryAuth{
+		{
+			Registry: "registry.example.com",
+			Username: "user",
+			Password: "pass",
+		},
+	}
+
+	result := buildAuthConfigs(auths)
+
+	if len(result) != 1 {
+		t.Fatalf("expected 1 entry, got %d", len(result))
+	}
+
+	cfg, ok := result["registry.example.com"]
+	if !ok {
+		t.Fatal("expected registry.example.com key")
+	}
+
+	if cfg.Username != "user" {
+		t.Errorf("expected username 'user', got %q", cfg.Username)
+	}
+
+	if cfg.Password != "pass" {
+		t.Errorf("expected password 'pass', got %q", cfg.Password)
+	}
+
+	if cfg.ServerAddress != "registry.example.com" {
+		t.Errorf("expected server address 'registry.example.com', got %q", cfg.ServerAddress)
+	}
+}
+
+func TestBuildAuthConfigsMultiple(t *testing.T) {
+	t.Parallel()
+
+	auths := []RegistryAuth{
+		{Registry: "ghcr.io", Username: "ghuser", Password: "ghtoken"},
+		{Registry: "docker.io", Username: "dkuser", Password: "dktoken"},
+	}
+
+	result := buildAuthConfigs(auths)
+
+	if len(result) != 2 {
+		t.Fatalf("expected 2 entries, got %d", len(result))
+	}
+
+	ghcr := result["ghcr.io"]
+	if ghcr.Username != "ghuser" || ghcr.Password != "ghtoken" {
+		t.Errorf("unexpected ghcr.io config: %+v", ghcr)
+	}
+
+	dkr := result["docker.io"]
+	if dkr.Username != "dkuser" || dkr.Password != "dktoken" {
+		t.Errorf("unexpected docker.io config: %+v", dkr)
+	}
+}
+
+func TestRegistryAuthStruct(t *testing.T) {
+	t.Parallel()
+
+	auth := RegistryAuth{
+		Registry: "registry.example.com",
+		Username: "testuser",
+		Password: "testpass",
+	}
+
+	if auth.Registry != "registry.example.com" {
+		t.Errorf("expected registry 'registry.example.com', got %q", auth.Registry)
+	}
+
+	if auth.Username != "testuser" {
+		t.Errorf("expected username 'testuser', got %q", auth.Username)
+	}
+
+	if auth.Password != "testpass" {
+		t.Errorf("expected password 'testpass', got %q", auth.Password)
+	}
+}

internal/docker/client.go

@@ -20,6 +20,7 @@ import (
 	"github.com/docker/docker/api/types/image"
 	"github.com/docker/docker/api/types/mount"
 	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/api/types/registry"
 	"github.com/docker/docker/client"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/go-connections/nat"
@@ -105,12 +106,20 @@ func (c *Client) IsConnected() bool {
 	return c.docker != nil
 }
 
+// RegistryAuth contains authentication credentials for a Docker registry.
+type RegistryAuth struct {
+	Registry string
+	Username string
+	Password string //nolint:gosec // credential field required for registry auth
+}
+
 // BuildImageOptions contains options for building an image.
 type BuildImageOptions struct {
 	ContextDir     string
 	DockerfilePath string
 	Tags           []string
 	LogWriter      io.Writer      // Optional writer for build output
+	RegistryAuths  []RegistryAuth // Optional registry credentials for pulling private base images
 }
 
 // BuildImage builds a Docker image from a context directory.
@@ -161,6 +170,21 @@ type PortMapping struct {
 	Protocol      string // "tcp" or "udp"
 }
 
+// buildAuthConfigs converts RegistryAuth slices into Docker's AuthConfigs map.
+func buildAuthConfigs(auths []RegistryAuth) map[string]registry.AuthConfig {
+	configs := make(map[string]registry.AuthConfig, len(auths))
+
+	for _, auth := range auths {
+		configs[auth.Registry] = registry.AuthConfig{
+			Username:      auth.Username,
+			Password:      auth.Password,
+			ServerAddress: auth.Registry,
+		}
+	}
+
+	return configs
+}
+
 // buildPortConfig converts port mappings to Docker port configuration.
 func buildPortConfig(ports []PortMapping) (nat.PortSet, nat.PortMap) {
 	exposedPorts := make(nat.PortSet)
@@ -513,12 +537,18 @@ func (c *Client) performBuild(
 	}()
 
 	// Build image
-	resp, err := c.docker.ImageBuild(ctx, tarArchive, dockertypes.ImageBuildOptions{
+	buildOpts := dockertypes.ImageBuildOptions{
 		Dockerfile: opts.DockerfilePath,
 		Tags:       opts.Tags,
 		Remove:     true,
 		NoCache:    false,
-	})
+	}
+
+	if len(opts.RegistryAuths) > 0 {
+		buildOpts.AuthConfigs = buildAuthConfigs(opts.RegistryAuths)
+	}
+
+	resp, err := c.docker.ImageBuild(ctx, tarArchive, buildOpts)
 	if err != nil {
 		return "", fmt.Errorf("failed to build image: %w", err)
 	}

internal/handlers/app.go

@@ -148,6 +148,7 @@ func (h *Handlers) HandleAppDetail() http.HandlerFunc {
 		labels, _ := application.GetLabels(request.Context())
 		volumes, _ := application.GetVolumes(request.Context())
 		ports, _ := application.GetPorts(request.Context())
+		registryCreds, _ := application.GetRegistryCredentials(request.Context())
 		deployments, _ := application.GetDeployments(
 			request.Context(),
 			recentDeploymentsLimit,
@@ -168,6 +169,7 @@ func (h *Handlers) HandleAppDetail() http.HandlerFunc {
 			"Labels":              labels,
 			"Volumes":             volumes,
 			"Ports":               ports,
+			"RegistryCredentials": registryCreds,
 			"Deployments":         deployments,
 			"LatestDeployment":    latestDeployment,
 			"WebhookURL":          webhookURL,
@@ -903,50 +905,92 @@ func (h *Handlers) addKeyValueToApp(
 	http.Redirect(writer, request, "/apps/"+application.ID, http.StatusSeeOther)
 }
 
-// HandleEnvVarAdd handles adding an environment variable.
+// envPairJSON represents a key-value pair in the JSON request body.
-func (h *Handlers) HandleEnvVarAdd() http.HandlerFunc {
+type envPairJSON struct {
-	return func(writer http.ResponseWriter, request *http.Request) {
+	Key   string `json:"key"`
-		h.addKeyValueToApp(
+	Value string `json:"value"`
-			writer,
-			request,
-			func(ctx context.Context, application *models.App, key, value string) error {
-				envVar := models.NewEnvVar(h.db)
-				envVar.AppID = application.ID
-				envVar.Key = key
-				envVar.Value = value
-
-				return envVar.Save(ctx)
-			},
-		)
-	}
 }
 
-// HandleEnvVarDelete handles deleting an environment variable.
+// envVarMaxBodyBytes is the maximum allowed request body size for env var saves (1 MB).
-func (h *Handlers) HandleEnvVarDelete() http.HandlerFunc {
+const envVarMaxBodyBytes = 1 << 20
+
+// validateEnvPairs validates env var pairs.
+// It rejects empty keys and duplicate keys (returns a non-empty error string).
+func validateEnvPairs(pairs []envPairJSON) ([]models.EnvVarPair, string) {
+	seen := make(map[string]bool, len(pairs))
+
+	result := make([]models.EnvVarPair, 0, len(pairs))
+
+	for _, p := range pairs {
+		trimmedKey := strings.TrimSpace(p.Key)
+		if trimmedKey == "" {
+			return nil, "empty environment variable key is not allowed"
+		}
+
+		if seen[trimmedKey] {
+			return nil, "duplicate environment variable key: " + trimmedKey
+		}
+
+		seen[trimmedKey] = true
+
+		result = append(result, models.EnvVarPair{Key: trimmedKey, Value: p.Value})
+	}
+
+	return result, ""
+}
+
+// HandleEnvVarSave handles bulk saving of all environment variables.
+// It reads a JSON array of {key, value} objects from the request body,
+// deletes all existing env vars for the app, and inserts the full
+// submitted set atomically within a database transaction.
+// Duplicate keys are rejected with a 400 Bad Request error.
+func (h *Handlers) HandleEnvVarSave() http.HandlerFunc {
 	return func(writer http.ResponseWriter, request *http.Request) {
 		appID := chi.URLParam(request, "id")
-		envVarIDStr := chi.URLParam(request, "varID")
 
-		envVarID, parseErr := strconv.ParseInt(envVarIDStr, 10, 64)
+		application, findErr := models.FindApp(request.Context(), h.db, appID)
-		if parseErr != nil {
+		if findErr != nil || application == nil {
 			http.NotFound(writer, request)
 
 			return
 		}
 
-		envVar, findErr := models.FindEnvVar(request.Context(), h.db, envVarID)
+		// Limit request body size to prevent abuse
-		if findErr != nil || envVar == nil || envVar.AppID != appID {
+		request.Body = http.MaxBytesReader(writer, request.Body, envVarMaxBodyBytes)
-			http.NotFound(writer, request)
+
+		var pairs []envPairJSON
+
+		decodeErr := json.NewDecoder(request.Body).Decode(&pairs)
+		if decodeErr != nil {
+			h.respondJSON(writer, request, map[string]string{
+				"error": "invalid request body",
+			}, http.StatusBadRequest)
 
 			return
 		}
 
-		deleteErr := envVar.Delete(request.Context())
+		modelPairs, validationErr := validateEnvPairs(pairs)
-		if deleteErr != nil {
+		if validationErr != "" {
-			h.log.Error("failed to delete env var", "error", deleteErr)
+			h.respondJSON(writer, request, map[string]string{
+				"error": validationErr,
+			}, http.StatusBadRequest)
+
+			return
 		}
 
-		http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+		replaceErr := models.ReplaceEnvVarsByAppID(
+			request.Context(), h.db, application.ID, modelPairs,
+		)
+		if replaceErr != nil {
+			h.log.Error("failed to replace env vars", "error", replaceErr)
+			h.respondJSON(writer, request, map[string]string{
+				"error": "failed to save environment variables",
+			}, http.StatusInternalServerError)
+
+			return
+		}
+
+		h.respondJSON(writer, request, map[string]bool{"ok": true}, http.StatusOK)
 	}
 }
 
@@ -1205,59 +1249,6 @@ func ValidateVolumePath(p string) error {
 	return nil
 }
 
-// HandleEnvVarEdit handles editing an existing environment variable.
-func (h *Handlers) HandleEnvVarEdit() http.HandlerFunc {
-	return func(writer http.ResponseWriter, request *http.Request) {
-		appID := chi.URLParam(request, "id")
-		envVarIDStr := chi.URLParam(request, "varID")
-
-		envVarID, parseErr := strconv.ParseInt(envVarIDStr, 10, 64)
-		if parseErr != nil {
-			http.NotFound(writer, request)
-
-			return
-		}
-
-		envVar, findErr := models.FindEnvVar(request.Context(), h.db, envVarID)
-		if findErr != nil || envVar == nil || envVar.AppID != appID {
-			http.NotFound(writer, request)
-
-			return
-		}
-
-		formErr := request.ParseForm()
-		if formErr != nil {
-			http.Error(writer, "Bad Request", http.StatusBadRequest)
-
-			return
-		}
-
-		key := request.FormValue("key")
-		value := request.FormValue("value")
-
-		if key == "" || value == "" {
-			http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
-
-			return
-		}
-
-		envVar.Key = key
-		envVar.Value = value
-
-		saveErr := envVar.Save(request.Context())
-		if saveErr != nil {
-			h.log.Error("failed to update env var", "error", saveErr)
-		}
-
-		http.Redirect(
-			writer,
-			request,
-			"/apps/"+appID+"?success=env-updated",
-			http.StatusSeeOther,
-		)
-	}
-}
-
 // HandleLabelEdit handles editing an existing label.
 func (h *Handlers) HandleLabelEdit() http.HandlerFunc {
 	return func(writer http.ResponseWriter, request *http.Request) {
@@ -1393,3 +1384,126 @@ func formatDeployKey(pubKey string, createdAt time.Time, appName string) string
 
 	return parts[0] + " " + parts[1] + " " + comment
 }
+
+// HandleRegistryCredentialAdd handles adding a registry credential.
+func (h *Handlers) HandleRegistryCredentialAdd() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		appID := chi.URLParam(request, "id")
+
+		application, findErr := models.FindApp(request.Context(), h.db, appID)
+		if findErr != nil || application == nil {
+			http.NotFound(writer, request)
+
+			return
+		}
+
+		parseErr := request.ParseForm()
+		if parseErr != nil {
+			http.Error(writer, "Bad Request", http.StatusBadRequest)
+
+			return
+		}
+
+		registryURL := strings.TrimSpace(request.FormValue("registry"))
+		username := strings.TrimSpace(request.FormValue("username"))
+		password := request.FormValue("password")
+
+		if registryURL == "" || username == "" || password == "" {
+			http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+
+			return
+		}
+
+		cred := models.NewRegistryCredential(h.db)
+		cred.AppID = appID
+		cred.Registry = registryURL
+		cred.Username = username
+		cred.Password = password
+
+		saveErr := cred.Save(request.Context())
+		if saveErr != nil {
+			h.log.Error("failed to save registry credential", "error", saveErr)
+		}
+
+		http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+	}
+}
+
+// HandleRegistryCredentialEdit handles editing an existing registry credential.
+func (h *Handlers) HandleRegistryCredentialEdit() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		appID := chi.URLParam(request, "id")
+		credIDStr := chi.URLParam(request, "credID")
+
+		credID, parseErr := strconv.ParseInt(credIDStr, 10, 64)
+		if parseErr != nil {
+			http.NotFound(writer, request)
+
+			return
+		}
+
+		cred, findErr := models.FindRegistryCredential(request.Context(), h.db, credID)
+		if findErr != nil || cred == nil || cred.AppID != appID {
+			http.NotFound(writer, request)
+
+			return
+		}
+
+		formErr := request.ParseForm()
+		if formErr != nil {
+			http.Error(writer, "Bad Request", http.StatusBadRequest)
+
+			return
+		}
+
+		registryURL := strings.TrimSpace(request.FormValue("registry"))
+		username := strings.TrimSpace(request.FormValue("username"))
+		password := request.FormValue("password")
+
+		if registryURL == "" || username == "" || password == "" {
+			http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+
+			return
+		}
+
+		cred.Registry = registryURL
+		cred.Username = username
+		cred.Password = password
+
+		saveErr := cred.Save(request.Context())
+		if saveErr != nil {
+			h.log.Error("failed to update registry credential", "error", saveErr)
+		}
+
+		http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+	}
+}
+
+// HandleRegistryCredentialDelete handles deleting a registry credential.
+func (h *Handlers) HandleRegistryCredentialDelete() http.HandlerFunc {
+	return func(writer http.ResponseWriter, request *http.Request) {
+		appID := chi.URLParam(request, "id")
+		credIDStr := chi.URLParam(request, "credID")
+
+		credID, parseErr := strconv.ParseInt(credIDStr, 10, 64)
+		if parseErr != nil {
+			http.NotFound(writer, request)
+
+			return
+		}
+
+		cred, findErr := models.FindRegistryCredential(request.Context(), h.db, credID)
+		if findErr != nil || cred == nil || cred.AppID != appID {
+			http.NotFound(writer, request)
+
+			return
+		}
+
+		deleteErr := cred.Delete(request.Context())
+		if deleteErr != nil {
+			h.log.Error("failed to delete registry credential", "error", deleteErr)
+		}
+
+		http.Redirect(writer, request, "/apps/"+appID, http.StatusSeeOther)
+	}
+}

internal/handlers/handlers_test.go

@@ -560,45 +560,242 @@ func testOwnershipVerification(t *testing.T, cfg ownedResourceTestConfig) {
 	cfg.verifyFn(t, testCtx, resourceID)
 }
 
-// TestDeleteEnvVarOwnershipVerification tests that deleting an env var
+// TestHandleEnvVarSaveBulk tests that HandleEnvVarSave replaces all env vars
-// via another app's URL path returns 404 (IDOR prevention).
+// for an app with the submitted set (monolithic delete-all + insert-all).
-func TestDeleteEnvVarOwnershipVerification(t *testing.T) { //nolint:dupl // intentionally similar IDOR test pattern
+func TestHandleEnvVarSaveBulk(t *testing.T) {
 	t.Parallel()
 
-	testOwnershipVerification(t, ownedResourceTestConfig{
+	testCtx := setupTestHandlers(t)
-		appPrefix1: "envvar-owner-app",
+	createdApp := createTestApp(t, testCtx, "envvar-bulk-app")
-		appPrefix2: "envvar-other-app",
-		createFn: func(t *testing.T, tc *testContext, ownerApp *models.App) int64 {
-			t.Helper()
 
-			envVar := models.NewEnvVar(tc.database)
+	// Create some pre-existing env vars
-			envVar.AppID = ownerApp.ID
+	for _, kv := range [][2]string{{"OLD_KEY", "old_value"}, {"REMOVE_ME", "gone"}} {
-			envVar.Key = "SECRET"
+		ev := models.NewEnvVar(testCtx.database)
-			envVar.Value = "hunter2"
+		ev.AppID = createdApp.ID
-			require.NoError(t, envVar.Save(context.Background()))
+		ev.Key = kv[0]
+		ev.Value = kv[1]
+		require.NoError(t, ev.Save(context.Background()))
+	}
 
-			return envVar.ID
+	// Submit a new set as a JSON array of key/value objects
-		},
+	body := `[{"key":"NEW_KEY","value":"new_value"},{"key":"ANOTHER","value":"42"}]`
-		deletePath: func(appID string, resourceID int64) string {
-			return "/apps/" + appID + "/env/" + strconv.FormatInt(resourceID, 10) + "/delete"
-		},
-		chiParams: func(appID string, resourceID int64) map[string]string {
-			return map[string]string{"id": appID, "varID": strconv.FormatInt(resourceID, 10)}
-		},
-		handler: func(h *handlers.Handlers) http.HandlerFunc { return h.HandleEnvVarDelete() },
-		verifyFn: func(t *testing.T, tc *testContext, resourceID int64) {
-			t.Helper()
 
-			found, findErr := models.FindEnvVar(context.Background(), tc.database, resourceID)
+	r := chi.NewRouter()
-			require.NoError(t, findErr)
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
-			assert.NotNil(t, found, "env var should still exist after IDOR attempt")
+
-		},
+	request := httptest.NewRequest(
-	})
+		http.MethodPost,
+		"/apps/"+createdApp.ID+"/env",
+		strings.NewReader(body),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusOK, recorder.Code)
+
+	// Verify old env vars are gone and new ones exist
+	envVars, err := models.FindEnvVarsByAppID(
+		context.Background(), testCtx.database, createdApp.ID,
+	)
+	require.NoError(t, err)
+	assert.Len(t, envVars, 2)
+
+	keys := make(map[string]string)
+	for _, ev := range envVars {
+		keys[ev.Key] = ev.Value
+	}
+
+	assert.Equal(t, "new_value", keys["NEW_KEY"])
+	assert.Equal(t, "42", keys["ANOTHER"])
+	assert.Empty(t, keys["OLD_KEY"], "old env vars should be deleted")
+	assert.Empty(t, keys["REMOVE_ME"], "old env vars should be deleted")
+}
+
+// TestHandleEnvVarSaveAppNotFound tests that HandleEnvVarSave returns 404
+// for a non-existent app.
+func TestHandleEnvVarSaveAppNotFound(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+
+	body := `[{"key":"KEY","value":"value"}]`
+
+	r := chi.NewRouter()
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
+
+	request := httptest.NewRequest(
+		http.MethodPost,
+		"/apps/nonexistent-id/env",
+		strings.NewReader(body),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusNotFound, recorder.Code)
+}
+
+// TestHandleEnvVarSaveEmptyKeyRejected verifies that submitting a JSON
+// array containing an entry with an empty key returns 400.
+func TestHandleEnvVarSaveEmptyKeyRejected(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+	createdApp := createTestApp(t, testCtx, "envvar-emptykey-app")
+
+	body := `[{"key":"VALID_KEY","value":"ok"},{"key":"","value":"bad"}]`
+
+	r := chi.NewRouter()
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
+
+	request := httptest.NewRequest(
+		http.MethodPost,
+		"/apps/"+createdApp.ID+"/env",
+		strings.NewReader(body),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusBadRequest, recorder.Code)
+}
+
+// TestHandleEnvVarSaveDuplicateKeyRejected verifies that when the client
+// sends duplicate keys, the server rejects them with 400 Bad Request.
+func TestHandleEnvVarSaveDuplicateKeyRejected(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+	createdApp := createTestApp(t, testCtx, "envvar-dedup-app")
+
+	// Send two entries with the same key — should be rejected
+	body := `[{"key":"FOO","value":"first"},{"key":"BAR","value":"bar"},{"key":"FOO","value":"second"}]`
+
+	r := chi.NewRouter()
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
+
+	request := httptest.NewRequest(
+		http.MethodPost,
+		"/apps/"+createdApp.ID+"/env",
+		strings.NewReader(body),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusBadRequest, recorder.Code)
+	assert.Contains(t, recorder.Body.String(), "duplicate environment variable key: FOO")
+}
+
+// TestHandleEnvVarSaveCrossAppIsolation verifies that posting env vars
+// to appA's endpoint does not affect appB's env vars (IDOR prevention).
+func TestHandleEnvVarSaveCrossAppIsolation(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+	appA := createTestApp(t, testCtx, "envvar-iso-appA")
+	appB := createTestApp(t, testCtx, "envvar-iso-appB")
+
+	// Give appB some env vars
+	for _, kv := range [][2]string{{"B_KEY1", "b_val1"}, {"B_KEY2", "b_val2"}} {
+		ev := models.NewEnvVar(testCtx.database)
+		ev.AppID = appB.ID
+		ev.Key = kv[0]
+		ev.Value = kv[1]
+		require.NoError(t, ev.Save(context.Background()))
+	}
+
+	// POST new env vars to appA's endpoint
+	body := `[{"key":"A_KEY","value":"a_val"}]`
+
+	r := chi.NewRouter()
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
+
+	request := httptest.NewRequest(
+		http.MethodPost,
+		"/apps/"+appA.ID+"/env",
+		strings.NewReader(body),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusOK, recorder.Code)
+
+	// Verify appA has exactly what we sent
+	appAVars, err := models.FindEnvVarsByAppID(
+		context.Background(), testCtx.database, appA.ID,
+	)
+	require.NoError(t, err)
+	assert.Len(t, appAVars, 1)
+	assert.Equal(t, "A_KEY", appAVars[0].Key)
+
+	// Verify appB's env vars are completely untouched
+	appBVars, err := models.FindEnvVarsByAppID(
+		context.Background(), testCtx.database, appB.ID,
+	)
+	require.NoError(t, err)
+	assert.Len(t, appBVars, 2, "appB env vars must not be affected")
+
+	bKeys := make(map[string]string)
+	for _, ev := range appBVars {
+		bKeys[ev.Key] = ev.Value
+	}
+
+	assert.Equal(t, "b_val1", bKeys["B_KEY1"])
+	assert.Equal(t, "b_val2", bKeys["B_KEY2"])
+}
+
+// TestHandleEnvVarSaveBodySizeLimit verifies that a request body
+// exceeding the 1 MB limit is rejected.
+func TestHandleEnvVarSaveBodySizeLimit(t *testing.T) {
+	t.Parallel()
+
+	testCtx := setupTestHandlers(t)
+	createdApp := createTestApp(t, testCtx, "envvar-sizelimit-app")
+
+	// Build a JSON body that exceeds 1 MB
+	// Each entry is ~30 bytes; 40000 entries ≈ 1.2 MB
+	var sb strings.Builder
+
+	sb.WriteString("[")
+
+	for i := range 40000 {
+		if i > 0 {
+			sb.WriteString(",")
+		}
+
+		sb.WriteString(`{"key":"K` + strconv.Itoa(i) + `","value":"val"}`)
+	}
+
+	sb.WriteString("]")
+
+	r := chi.NewRouter()
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
+
+	request := httptest.NewRequest(
+		http.MethodPost,
+		"/apps/"+createdApp.ID+"/env",
+		strings.NewReader(sb.String()),
+	)
+	request.Header.Set("Content-Type", "application/json")
+
+	recorder := httptest.NewRecorder()
+	r.ServeHTTP(recorder, request)
+
+	assert.Equal(t, http.StatusBadRequest, recorder.Code,
+		"oversized body should be rejected with 400")
 }
 
 // TestDeleteLabelOwnershipVerification tests that deleting a label
 // via another app's URL path returns 404 (IDOR prevention).
-func TestDeleteLabelOwnershipVerification(t *testing.T) { //nolint:dupl // intentionally similar IDOR test pattern
+func TestDeleteLabelOwnershipVerification(t *testing.T) {
 	t.Parallel()
 
 	testOwnershipVerification(t, ownedResourceTestConfig{
@@ -714,41 +911,43 @@ func TestDeletePortOwnershipVerification(t *testing.T) {
 	assert.NotNil(t, found, "port should still exist after IDOR attempt")
 }
 
-// TestHandleEnvVarDeleteUsesCorrectRouteParam verifies that HandleEnvVarDelete
+// TestHandleEnvVarSaveEmptyClears verifies that submitting an empty JSON
-// reads the "varID" chi URL parameter (matching the route definition {varID}),
+// array deletes all existing env vars for the app.
-// not a mismatched name like "envID".
+func TestHandleEnvVarSaveEmptyClears(t *testing.T) {
-func TestHandleEnvVarDeleteUsesCorrectRouteParam(t *testing.T) {
 	t.Parallel()
 
 	testCtx := setupTestHandlers(t)
+	createdApp := createTestApp(t, testCtx, "envvar-clear-app")
 
-	createdApp := createTestApp(t, testCtx, "envdelete-param-app")
+	// Create a pre-existing env var
+	ev := models.NewEnvVar(testCtx.database)
+	ev.AppID = createdApp.ID
+	ev.Key = "DELETE_ME"
+	ev.Value = "gone"
+	require.NoError(t, ev.Save(context.Background()))
 
-	envVar := models.NewEnvVar(testCtx.database)
+	// Submit empty JSON array
-	envVar.AppID = createdApp.ID
-	envVar.Key = "DELETE_ME"
-	envVar.Value = "gone"
-	require.NoError(t, envVar.Save(context.Background()))
-
-	// Use chi router with the real route pattern to test param name
 	r := chi.NewRouter()
-	r.Post("/apps/{id}/env-vars/{varID}/delete", testCtx.handlers.HandleEnvVarDelete())
+	r.Post("/apps/{id}/env", testCtx.handlers.HandleEnvVarSave())
 
 	request := httptest.NewRequest(
 		http.MethodPost,
-		"/apps/"+createdApp.ID+"/env-vars/"+strconv.FormatInt(envVar.ID, 10)+"/delete",
+		"/apps/"+createdApp.ID+"/env",
-		nil,
+		strings.NewReader("[]"),
 	)
-	recorder := httptest.NewRecorder()
+	request.Header.Set("Content-Type", "application/json")
 
+	recorder := httptest.NewRecorder()
 	r.ServeHTTP(recorder, request)
 
-	assert.Equal(t, http.StatusSeeOther, recorder.Code)
+	assert.Equal(t, http.StatusOK, recorder.Code)
 
-	// Verify the env var was actually deleted
+	// Verify all env vars are gone
-	found, findErr := models.FindEnvVar(context.Background(), testCtx.database, envVar.ID)
+	envVars, err := models.FindEnvVarsByAppID(
-	require.NoError(t, findErr)
+		context.Background(), testCtx.database, createdApp.ID,
-	assert.Nil(t, found, "env var should be deleted when using correct route param")
+	)
+	require.NoError(t, err)
+	assert.Empty(t, envVars, "all env vars should be deleted")
 }
 
 // TestHandleVolumeAddValidatesPaths verifies that HandleVolumeAdd validates

internal/models/app.go

@@ -119,6 +119,11 @@ func (a *App) GetWebhookEvents(
 	return FindWebhookEventsByAppID(ctx, a.db, a.ID, limit)
 }
 
+// GetRegistryCredentials returns all registry credentials for the app.
+func (a *App) GetRegistryCredentials(ctx context.Context) ([]*RegistryCredential, error) {
+	return FindRegistryCredentialsByAppID(ctx, a.db, a.ID)
+}
+
 func (a *App) exists(ctx context.Context) bool {
 	if a.ID == "" {
 		return false

internal/models/env_var.go

@@ -1,4 +1,3 @@
-//nolint:dupl // Active Record pattern - similar structure to label.go is intentional
 package models
 
 import (
@@ -129,13 +128,48 @@ func FindEnvVarsByAppID(
 	return envVars, rows.Err()
 }
 
-// DeleteEnvVarsByAppID deletes all env vars for an app.
+// EnvVarPair is a key-value pair for bulk env var operations.
-func DeleteEnvVarsByAppID(
+type EnvVarPair struct {
+	Key   string
+	Value string
+}
+
+// ReplaceEnvVarsByAppID atomically replaces all env vars for an app
+// within a single database transaction. It deletes all existing env
+// vars and inserts the provided pairs. If any operation fails, the
+// entire transaction is rolled back.
+func ReplaceEnvVarsByAppID(
 	ctx context.Context,
 	db *database.Database,
 	appID string,
+	pairs []EnvVarPair,
 ) error {
-	_, err := db.Exec(ctx, "DELETE FROM app_env_vars WHERE app_id = ?", appID)
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("beginning transaction: %w", err)
+	}
 
-	return err
+	defer func() { _ = tx.Rollback() }()
+
+	_, err = tx.ExecContext(ctx, "DELETE FROM app_env_vars WHERE app_id = ?", appID)
+	if err != nil {
+		return fmt.Errorf("deleting env vars: %w", err)
+	}
+
+	for _, p := range pairs {
+		_, err = tx.ExecContext(ctx,
+			"INSERT INTO app_env_vars (app_id, key, value) VALUES (?, ?, ?)",
+			appID, p.Key, p.Value,
+		)
+		if err != nil {
+			return fmt.Errorf("inserting env var %q: %w", p.Key, err)
+		}
+	}
+
+	err = tx.Commit()
+	if err != nil {
+		return fmt.Errorf("committing transaction: %w", err)
+	}
+
+	return nil
 }

internal/models/label.go

@@ -1,4 +1,3 @@
-//nolint:dupl // Active Record pattern - similar structure to env_var.go is intentional
 package models
 
 import (

internal/models/models_test.go

@@ -23,6 +23,7 @@ const (
 	testBranch    = "main"
 	testValue     = "value"
 	testEventType = "push"
+	testUser      = "user"
 )
 
 func setupTestDB(t *testing.T) (*database.Database, func()) {
@@ -704,6 +705,127 @@ func TestAppGetWebhookEvents(t *testing.T) {
 	assert.Len(t, events, 1)
 }
 
+// RegistryCredential Tests.
+
+func TestRegistryCredentialCreateAndFind(t *testing.T) {
+	t.Parallel()
+
+	testDB, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	app := createTestApp(t, testDB)
+
+	cred := models.NewRegistryCredential(testDB)
+	cred.AppID = app.ID
+	cred.Registry = "registry.example.com"
+	cred.Username = "myuser"
+	cred.Password = "mypassword"
+
+	err := cred.Save(context.Background())
+	require.NoError(t, err)
+	assert.NotZero(t, cred.ID)
+
+	creds, err := models.FindRegistryCredentialsByAppID(
+		context.Background(), testDB, app.ID,
+	)
+	require.NoError(t, err)
+	require.Len(t, creds, 1)
+	assert.Equal(t, "registry.example.com", creds[0].Registry)
+	assert.Equal(t, "myuser", creds[0].Username)
+	assert.Equal(t, "mypassword", creds[0].Password)
+}
+
+func TestRegistryCredentialUpdate(t *testing.T) {
+	t.Parallel()
+
+	testDB, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	app := createTestApp(t, testDB)
+
+	cred := models.NewRegistryCredential(testDB)
+	cred.AppID = app.ID
+	cred.Registry = "old.registry.com"
+	cred.Username = "olduser"
+	cred.Password = "oldpass"
+
+	err := cred.Save(context.Background())
+	require.NoError(t, err)
+
+	cred.Registry = "new.registry.com"
+	cred.Username = "newuser"
+	cred.Password = "newpass"
+
+	err = cred.Save(context.Background())
+	require.NoError(t, err)
+
+	found, err := models.FindRegistryCredential(context.Background(), testDB, cred.ID)
+	require.NoError(t, err)
+	require.NotNil(t, found)
+	assert.Equal(t, "new.registry.com", found.Registry)
+	assert.Equal(t, "newuser", found.Username)
+	assert.Equal(t, "newpass", found.Password)
+}
+
+func TestRegistryCredentialDelete(t *testing.T) {
+	t.Parallel()
+
+	testDB, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	app := createTestApp(t, testDB)
+
+	cred := models.NewRegistryCredential(testDB)
+	cred.AppID = app.ID
+	cred.Registry = "delete.registry.com"
+	cred.Username = testUser
+	cred.Password = "pass"
+
+	err := cred.Save(context.Background())
+	require.NoError(t, err)
+
+	err = cred.Delete(context.Background())
+	require.NoError(t, err)
+
+	creds, err := models.FindRegistryCredentialsByAppID(
+		context.Background(), testDB, app.ID,
+	)
+	require.NoError(t, err)
+	assert.Empty(t, creds)
+}
+
+func TestRegistryCredentialFindByIDNotFound(t *testing.T) {
+	t.Parallel()
+
+	testDB, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	found, err := models.FindRegistryCredential(context.Background(), testDB, 99999)
+	require.NoError(t, err)
+	assert.Nil(t, found)
+}
+
+func TestAppGetRegistryCredentials(t *testing.T) {
+	t.Parallel()
+
+	testDB, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	app := createTestApp(t, testDB)
+
+	cred := models.NewRegistryCredential(testDB)
+	cred.AppID = app.ID
+	cred.Registry = "ghcr.io"
+	cred.Username = testUser
+	cred.Password = "token"
+	_ = cred.Save(context.Background())
+
+	creds, err := app.GetRegistryCredentials(context.Background())
+	require.NoError(t, err)
+	assert.Len(t, creds, 1)
+	assert.Equal(t, "ghcr.io", creds[0].Registry)
+}
+
 // Cascade Delete Tests.
 
 //nolint:funlen // Test function with many assertions - acceptable for integration tests
@@ -749,6 +871,13 @@ func TestCascadeDelete(t *testing.T) {
 		deploy.Status = models.DeploymentStatusSuccess
 		_ = deploy.Save(context.Background())
 
+		regCred := models.NewRegistryCredential(testDB)
+		regCred.AppID = app.ID
+		regCred.Registry = "registry.example.com"
+		regCred.Username = testUser
+		regCred.Password = "pass"
+		_ = regCred.Save(context.Background())
+
 		// Delete app.
 		err := app.Delete(context.Background())
 		require.NoError(t, err)
@@ -778,6 +907,11 @@ func TestCascadeDelete(t *testing.T) {
 			context.Background(), testDB, app.ID, 10,
 		)
 		assert.Empty(t, deployments)
+
+		regCreds, _ := models.FindRegistryCredentialsByAppID(
+			context.Background(), testDB, app.ID,
+		)
+		assert.Empty(t, regCreds)
 	})
 }
 

internal/models/registry_credential.go

@@ -0,0 +1,130 @@
+package models
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"sneak.berlin/go/upaas/internal/database"
+)
+
+// RegistryCredential represents authentication credentials for a private Docker registry.
+type RegistryCredential struct {
+	db *database.Database
+
+	ID       int64
+	AppID    string
+	Registry string
+	Username string
+	Password string //nolint:gosec // credential field required for registry auth
+}
+
+// NewRegistryCredential creates a new RegistryCredential with a database reference.
+func NewRegistryCredential(db *database.Database) *RegistryCredential {
+	return &RegistryCredential{db: db}
+}
+
+// Save inserts or updates the registry credential in the database.
+func (r *RegistryCredential) Save(ctx context.Context) error {
+	if r.ID == 0 {
+		return r.insert(ctx)
+	}
+
+	return r.update(ctx)
+}
+
+// Delete removes the registry credential from the database.
+func (r *RegistryCredential) Delete(ctx context.Context) error {
+	_, err := r.db.Exec(ctx, "DELETE FROM registry_credentials WHERE id = ?", r.ID)
+
+	return err
+}
+
+func (r *RegistryCredential) insert(ctx context.Context) error {
+	query := "INSERT INTO registry_credentials (app_id, registry, username, password) VALUES (?, ?, ?, ?)"
+
+	result, err := r.db.Exec(ctx, query, r.AppID, r.Registry, r.Username, r.Password)
+	if err != nil {
+		return err
+	}
+
+	id, err := result.LastInsertId()
+	if err != nil {
+		return err
+	}
+
+	r.ID = id
+
+	return nil
+}
+
+func (r *RegistryCredential) update(ctx context.Context) error {
+	query := "UPDATE registry_credentials SET registry = ?, username = ?, password = ? WHERE id = ?"
+
+	_, err := r.db.Exec(ctx, query, r.Registry, r.Username, r.Password, r.ID)
+
+	return err
+}
+
+// FindRegistryCredential finds a registry credential by ID.
+//
+//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
+func FindRegistryCredential(
+	ctx context.Context,
+	db *database.Database,
+	id int64,
+) (*RegistryCredential, error) {
+	cred := NewRegistryCredential(db)
+
+	row := db.QueryRow(ctx,
+		"SELECT id, app_id, registry, username, password FROM registry_credentials WHERE id = ?",
+		id,
+	)
+
+	err := row.Scan(&cred.ID, &cred.AppID, &cred.Registry, &cred.Username, &cred.Password)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, nil
+		}
+
+		return nil, fmt.Errorf("scanning registry credential: %w", err)
+	}
+
+	return cred, nil
+}
+
+// FindRegistryCredentialsByAppID finds all registry credentials for an app.
+func FindRegistryCredentialsByAppID(
+	ctx context.Context,
+	db *database.Database,
+	appID string,
+) ([]*RegistryCredential, error) {
+	query := `
+		SELECT id, app_id, registry, username, password FROM registry_credentials
+		WHERE app_id = ? ORDER BY registry`
+
+	rows, err := db.Query(ctx, query, appID)
+	if err != nil {
+		return nil, fmt.Errorf("querying registry credentials by app: %w", err)
+	}
+
+	defer func() { _ = rows.Close() }()
+
+	var creds []*RegistryCredential
+
+	for rows.Next() {
+		cred := NewRegistryCredential(db)
+
+		scanErr := rows.Scan(
+			&cred.ID, &cred.AppID, &cred.Registry, &cred.Username, &cred.Password,
+		)
+		if scanErr != nil {
+			return nil, scanErr
+		}
+
+		creds = append(creds, cred)
+	}
+
+	return creds, rows.Err()
+}

internal/server/routes.go

@@ -82,10 +82,8 @@ func (s *Server) SetupRoutes() {
 			r.Post("/apps/{id}/stop", s.handlers.HandleAppStop())
 			r.Post("/apps/{id}/start", s.handlers.HandleAppStart())
 
-			// Environment variables
+			// Environment variables (monolithic bulk save)
-			r.Post("/apps/{id}/env-vars", s.handlers.HandleEnvVarAdd())
+			r.Post("/apps/{id}/env", s.handlers.HandleEnvVarSave())
-			r.Post("/apps/{id}/env-vars/{varID}/edit", s.handlers.HandleEnvVarEdit())
-			r.Post("/apps/{id}/env-vars/{varID}/delete", s.handlers.HandleEnvVarDelete())
 
 			// Labels
 			r.Post("/apps/{id}/labels", s.handlers.HandleLabelAdd())
@@ -100,6 +98,11 @@ func (s *Server) SetupRoutes() {
 			// Ports
 			r.Post("/apps/{id}/ports", s.handlers.HandlePortAdd())
 			r.Post("/apps/{id}/ports/{portID}/delete", s.handlers.HandlePortDelete())
+
+			// Registry Credentials
+			r.Post("/apps/{id}/registry-credentials", s.handlers.HandleRegistryCredentialAdd())
+			r.Post("/apps/{id}/registry-credentials/{credID}/edit", s.handlers.HandleRegistryCredentialEdit())
+			r.Post("/apps/{id}/registry-credentials/{credID}/delete", s.handlers.HandleRegistryCredentialDelete())
 		})
 	})
 

internal/service/deploy/deploy.go

@@ -830,6 +830,13 @@ func (svc *Service) buildImage(
 	logWriter := newDeploymentLogWriter(ctx, deployment)
 	defer logWriter.Close()
 
+	// Fetch registry credentials for private base images
+	registryAuths, err := svc.buildRegistryAuths(ctx, app)
+	if err != nil {
+		svc.log.Warn("failed to fetch registry credentials", "error", err, "app", app.Name)
+		// Continue without auth — public images will still work
+	}
+
 	// BuildImage creates a tar archive from the local filesystem,
 	// so it needs the container path where files exist, not the host path.
 	imageID, err := svc.docker.BuildImage(ctx, docker.BuildImageOptions{
@@ -837,6 +844,7 @@ func (svc *Service) buildImage(
 		DockerfilePath: app.DockerfilePath,
 		Tags:           []string{imageTag},
 		LogWriter:      logWriter,
+		RegistryAuths:  registryAuths,
 	})
 	if err != nil {
 		svc.notify.NotifyBuildFailed(ctx, app, deployment, err)
@@ -1227,6 +1235,34 @@ func (svc *Service) failDeployment(
 	_ = app.Save(ctx)
 }
 
+// buildRegistryAuths fetches registry credentials for an app and converts them
+// to Docker RegistryAuth objects for use during image builds.
+func (svc *Service) buildRegistryAuths(
+	ctx context.Context,
+	app *models.App,
+) ([]docker.RegistryAuth, error) {
+	creds, err := app.GetRegistryCredentials(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get registry credentials: %w", err)
+	}
+
+	if len(creds) == 0 {
+		return nil, nil
+	}
+
+	auths := make([]docker.RegistryAuth, 0, len(creds))
+
+	for _, cred := range creds {
+		auths = append(auths, docker.RegistryAuth{
+			Registry: cred.Registry,
+			Username: cred.Username,
+			Password: cred.Password,
+		})
+	}
+
+	return auths, nil
+}
+
 // writeLogsToFile writes the deployment logs to a file on disk.
 // Structure: DataDir/logs/<hostname>/<appname>/<appname>_<sha>_<timestamp>.log.txt
 func (svc *Service) writeLogsToFile(app *models.App, deployment *models.Deployment) {

static/js/app-detail.js

@@ -6,6 +6,103 @@
  */
 
 document.addEventListener("alpine:init", () => {
+    // ============================================
+    // Environment Variable Editor Component
+    // ============================================
+    Alpine.data("envVarEditor", (appId) => ({
+        vars: [],
+        editIdx: -1,
+        editKey: "",
+        editVal: "",
+        appId: appId,
+
+        init() {
+            this.vars = Array.from(this.$el.querySelectorAll(".env-init")).map(
+                (span) => ({
+                    key: span.dataset.key,
+                    value: span.dataset.value,
+                }),
+            );
+        },
+
+        startEdit(i) {
+            this.editIdx = i;
+            this.editKey = this.vars[i].key;
+            this.editVal = this.vars[i].value;
+        },
+
+        saveEdit(i) {
+            this.vars[i] = { key: this.editKey, value: this.editVal };
+            this.editIdx = -1;
+            this.submitAll();
+        },
+
+        removeVar(i) {
+            if (!window.confirm("Delete this environment variable?")) {
+                return;
+            }
+
+            this.vars.splice(i, 1);
+            this.submitAll();
+        },
+
+        addVar(keyEl, valEl) {
+            const k = keyEl.value.trim();
+            const v = valEl.value.trim();
+
+            if (!k) {
+                return;
+            }
+
+            this.vars.push({ key: k, value: v });
+            this.submitAll();
+        },
+
+        submitAll() {
+            const csrfInput = this.$el.querySelector(
+                'input[name="gorilla.csrf.Token"]',
+            );
+            const csrfToken = csrfInput ? csrfInput.value : "";
+
+            fetch("/apps/" + this.appId + "/env", {
+                method: "POST",
+                headers: {
+                    "Content-Type": "application/json",
+                    "X-CSRF-Token": csrfToken,
+                },
+                body: JSON.stringify(
+                    this.vars.map((e) => ({ key: e.key, value: e.value })),
+                ),
+            })
+                .then((res) => {
+                    if (res.ok) {
+                        window.location.reload();
+                        return;
+                    }
+                    res.json()
+                        .then((data) => {
+                            window.alert(
+                                data.error ||
+                                    "Failed to save environment variables.",
+                            );
+                        })
+                        .catch(() => {
+                            window.alert(
+                                "Failed to save environment variables.",
+                            );
+                        });
+                })
+                .catch(() => {
+                    window.alert(
+                        "Network error: could not save environment variables.",
+                    );
+                });
+        },
+    }));
+
+    // ============================================
+    // App Detail Page Component
+    // ============================================
     Alpine.data("appDetail", (config) => ({
         appId: config.appId,
         currentDeploymentId: config.initialDeploymentId,

templates/app_detail.html

@@ -101,9 +101,10 @@
     </div>
 
     <!-- Environment Variables -->
-    <div class="card p-6 mb-6">
+    <div class="card p-6 mb-6" x-data="envVarEditor('{{.App.ID}}')">
         <h2 class="section-title mb-4">Environment Variables</h2>
-        {{if .EnvVars}}
+        {{range .EnvVars}}<span class="env-init hidden" data-key="{{.Key}}" data-value="{{.Value}}"></span>{{end}}
+        <template x-if="vars.length > 0">
         <div class="overflow-x-auto mb-4">
             <table class="table">
                 <thead class="table-header">
@@ -114,33 +115,91 @@
                     </tr>
                 </thead>
                 <tbody class="table-body">
-                    {{range .EnvVars}}
+                    <template x-for="(env, idx) in vars" :key="idx">
+                    <tr>
+                        <template x-if="editIdx !== idx">
+                            <td class="font-mono font-medium" x-text="env.key"></td>
+                        </template>
+                        <template x-if="editIdx !== idx">
+                            <td class="font-mono text-gray-500" x-text="env.value"></td>
+                        </template>
+                        <template x-if="editIdx !== idx">
+                            <td class="text-right">
+                                <button @click="startEdit(idx)" class="text-primary-600 hover:text-primary-800 text-sm mr-2">Edit</button>
+                                <button @click="removeVar(idx)" class="text-error-500 hover:text-error-700 text-sm">Delete</button>
+                            </td>
+                        </template>
+                        <template x-if="editIdx === idx">
+                            <td colspan="3">
+                                <form @submit.prevent="saveEdit(idx)" class="flex gap-2 items-center">
+                                    <input type="text" x-model="editKey" required class="input flex-1 font-mono text-sm">
+                                    <input type="text" x-model="editVal" required class="input flex-1 font-mono text-sm">
+                                    <button type="submit" class="btn-primary text-sm">Save</button>
+                                    <button type="button" @click="editIdx = -1" class="text-gray-500 hover:text-gray-700 text-sm">Cancel</button>
+                                </form>
+                                <p class="text-xs text-amber-600 mt-1">⚠ Container restart needed after env var changes.</p>
+                            </td>
+                        </template>
+                    </tr>
+                    </template>
+                </tbody>
+            </table>
+        </div>
+        </template>
+        <form @submit.prevent="addVar($refs.newKey, $refs.newVal)" class="flex flex-col sm:flex-row gap-2">
+            <input x-ref="newKey" type="text" placeholder="KEY" required class="input flex-1 font-mono text-sm">
+            <input x-ref="newVal" type="text" placeholder="value" required class="input flex-1 font-mono text-sm">
+            <button type="submit" class="btn-primary">Add</button>
+        </form>
+        <div class="hidden">{{ .CSRFField }}</div>
+    </div>
+
+    <!-- Registry Credentials -->
+    <div class="card p-6 mb-6">
+        <h2 class="section-title mb-4">Registry Credentials</h2>
+        <p class="text-sm text-gray-500 mb-3">Authenticate to private Docker registries when pulling base images during builds.</p>
+        {{if .RegistryCredentials}}
+        <div class="overflow-x-auto mb-4">
+            <table class="table">
+                <thead class="table-header">
+                    <tr>
+                        <th>Registry</th>
+                        <th>Username</th>
+                        <th>Password</th>
+                        <th class="text-right">Actions</th>
+                    </tr>
+                </thead>
+                <tbody class="table-body">
+                    {{range .RegistryCredentials}}
                     <tr x-data="{ editing: false }">
                         <template x-if="!editing">
-                            <td class="font-mono font-medium">{{.Key}}</td>
+                            <td class="font-mono">{{.Registry}}</td>
                         </template>
                         <template x-if="!editing">
-                            <td class="font-mono text-gray-500">{{.Value}}</td>
+                            <td class="font-mono">{{.Username}}</td>
+                        </template>
+                        <template x-if="!editing">
+                            <td class="font-mono text-gray-400">••••••••</td>
                         </template>
                         <template x-if="!editing">
                             <td class="text-right">
                                 <button @click="editing = true" class="text-primary-600 hover:text-primary-800 text-sm mr-2">Edit</button>
-                                <form method="POST" action="/apps/{{$.App.ID}}/env-vars/{{.ID}}/delete" class="inline" x-data="confirmAction('Delete this environment variable?')" @submit="confirm($event)">
+                                <form method="POST" action="/apps/{{$.App.ID}}/registry-credentials/{{.ID}}/delete" class="inline" x-data="confirmAction('Delete this registry credential?')" @submit="confirm($event)">
                                     {{ $.CSRFField }}
                                     <button type="submit" class="text-error-500 hover:text-error-700 text-sm">Delete</button>
                                 </form>
                             </td>
                         </template>
                         <template x-if="editing">
-                            <td colspan="3">
+                            <td colspan="4">
-                                <form method="POST" action="/apps/{{$.App.ID}}/env-vars/{{.ID}}/edit" class="flex gap-2 items-center">
+                                <form method="POST" action="/apps/{{$.App.ID}}/registry-credentials/{{.ID}}/edit" class="flex gap-2 items-center">
                                     {{ $.CSRFField }}
-                                    <input type="text" name="key" value="{{.Key}}" required class="input flex-1 font-mono text-sm">
+                                    <input type="text" name="registry" value="{{.Registry}}" required class="input flex-1 font-mono text-sm" placeholder="registry.example.com">
-                                    <input type="text" name="value" value="{{.Value}}" required class="input flex-1 font-mono text-sm">
+                                    <input type="text" name="username" value="{{.Username}}" required class="input flex-1 font-mono text-sm" placeholder="username">
+                                    <input type="password" name="password" required class="input flex-1 font-mono text-sm" placeholder="password">
                                     <button type="submit" class="btn-primary text-sm">Save</button>
                                     <button type="button" @click="editing = false" class="text-gray-500 hover:text-gray-700 text-sm">Cancel</button>
                                 </form>
-                                <p class="text-xs text-amber-600 mt-1">⚠ Container restart needed after env var changes.</p>
                             </td>
                         </template>
                     </tr>
@@ -149,10 +208,11 @@
             </table>
         </div>
         {{end}}
-        <form method="POST" action="/apps/{{.App.ID}}/env" class="flex flex-col sm:flex-row gap-2">
+        <form method="POST" action="/apps/{{.App.ID}}/registry-credentials" class="flex flex-col sm:flex-row gap-2">
             {{ .CSRFField }}
-            <input type="text" name="key" placeholder="KEY" required class="input flex-1 font-mono text-sm">
+            <input type="text" name="registry" placeholder="registry.example.com" required class="input flex-1 font-mono text-sm">
-            <input type="text" name="value" placeholder="value" required class="input flex-1 font-mono text-sm">
+            <input type="text" name="username" placeholder="username" required class="input flex-1 font-mono text-sm">
+            <input type="password" name="password" placeholder="password" required class="input flex-1 font-mono text-sm">
             <button type="submit" class="btn-primary">Add</button>
         </form>
     </div>