feat: add --postgres-database-url-file flag for file-based DB credentials

go/internal/database/manager.go

@@ -2,6 +2,8 @@ package database
 
 import (
 	"fmt"
+	"os"
+	"strings"
 	"sync"
 
 	"github.com/glebarez/sqlite"
@@ -30,7 +32,8 @@ type SqliteConfig struct {
 }
 
 type PostgresConfig struct {
-	URL string
+	URL     string
+	URLFile string
 }
 
 type Config struct {
@@ -63,7 +66,15 @@ func NewManager(config *Config) (*Manager, error) {
 			TranslateError: true,
 		})
 	case DatabaseTypePostgres:
-		db, err = gorm.Open(postgres.Open(config.PostgresConfig.URL), &gorm.Config{
+		url := config.PostgresConfig.URL
+		if config.PostgresConfig.URLFile != "" {
+			resolved, resolveErr := resolveURLFile(config.PostgresConfig.URLFile)
+			if resolveErr != nil {
+				return nil, fmt.Errorf("failed to resolve postgres URL from file: %w", resolveErr)
+			}
+			url = resolved
+		}
+		db, err = gorm.Open(postgres.Open(url), &gorm.Config{
 			Logger:         logger.Default.LogMode(logLevel),
 			TranslateError: true,
 		})
@@ -142,6 +153,20 @@ func (m *Manager) Reset(recreateTables bool) error {
 	return nil
 }
 
+// resolveURLFile reads a database connection URL from a file and returns the
+// trimmed contents. Returns an error if the file cannot be read or is empty.
+func resolveURLFile(path string) (string, error) {
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("reading URL file: %w", err)
+	}
+	url := strings.TrimSpace(string(content))
+	if url == "" {
+		return "", fmt.Errorf("URL file %s is empty or contains only whitespace", path)
+	}
+	return url, nil
+}
+
 // Close closes the database connection
 func (m *Manager) Close() error {
 	if m.db == nil {

go/internal/database/manager_test.go

@@ -0,0 +1,60 @@
+package database
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestResolveURLFile(t *testing.T) {
+	tests := []struct {
+		name        string
+		fileContent string
+		wantUrl     string
+		wantErr     bool
+	}{
+		{
+			name:        "reads URL from file",
+			fileContent: "postgres://testuser:testpass@host:5432/testdb",
+			wantUrl:     "postgres://testuser:testpass@host:5432/testdb",
+		},
+		{
+			name:        "trims whitespace and newlines",
+			fileContent: "  postgres://user:pass@host:5432/db\n",
+			wantUrl:     "postgres://user:pass@host:5432/db",
+		},
+		{
+			name:        "empty file returns error",
+			fileContent: "",
+			wantErr:     true,
+		},
+		{
+			name:        "whitespace-only file returns error",
+			fileContent: "  \n\t\n  ",
+			wantErr:     true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpFile := filepath.Join(t.TempDir(), "db-url")
+			err := os.WriteFile(tmpFile, []byte(tt.fileContent), 0600)
+			assert.NoError(t, err)
+
+			url, err := resolveURLFile(tmpFile)
+			if tt.wantErr {
+				assert.Error(t, err)
+				return
+			}
+			assert.NoError(t, err)
+			assert.Equal(t, tt.wantUrl, url)
+		})
+	}
+
+	t.Run("missing file returns error", func(t *testing.T) {
+		_, err := resolveURLFile("/nonexistent/path/db-url")
+		assert.Error(t, err)
+	})
+}

go/pkg/app/app.go

@@ -123,9 +123,10 @@ type Config struct {
 	WatchNamespaces    string
 	A2ABaseUrl         string
 	Database           struct {
-		Type string
-		Path string
-		Url  string
+		Type    string
+		Path    string
+		Url     string
+		UrlFile string
 	}
 }
 
@@ -156,6 +157,7 @@ func (cfg *Config) SetFlags(commandLine *flag.FlagSet) {
 	commandLine.StringVar(&cfg.Database.Type, "database-type", "sqlite", "The type of the database to use. Supported values: sqlite, postgres.")
 	commandLine.StringVar(&cfg.Database.Path, "sqlite-database-path", "./kagent.db", "The path to the SQLite database file.")
 	commandLine.StringVar(&cfg.Database.Url, "postgres-database-url", "postgres://postgres:kagent@db.kagent.svc.cluster.local:5432/crud", "The URL of the PostgreSQL database.")
+	commandLine.StringVar(&cfg.Database.UrlFile, "postgres-database-url-file", "", "Path to a file containing the PostgreSQL database URL. Takes precedence over --postgres-database-url.")
 
 	commandLine.StringVar(&cfg.WatchNamespaces, "watch-namespaces", "", "The namespaces to watch for .")
 
@@ -350,7 +352,8 @@ func Start(getExtensionConfig GetExtensionConfig) {
 			DatabasePath: cfg.Database.Path,
 		},
 		PostgresConfig: &database.PostgresConfig{
-			URL: cfg.Database.Url,
+			URL:     cfg.Database.Url,
+			URLFile: cfg.Database.UrlFile,
 		},
 	})
 	if err != nil {

go/pkg/app/app_test.go

@@ -248,6 +248,23 @@ func TestLoadFromEnvDurationFlags(t *testing.T) {
 	}
 }
 
+func TestDatabaseUrlFileFlag(t *testing.T) {
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg := Config{}
+	cfg.SetFlags(fs)
+
+	// Verify the flag exists and has the right default
+	f := fs.Lookup("postgres-database-url-file")
+	assert.NotNil(t, f, "postgres-database-url-file flag should be registered")
+	assert.Equal(t, "", f.DefValue, "default should be empty string")
+
+	// Verify env var loading works for the new flag
+	t.Setenv("POSTGRES_DATABASE_URL_FILE", "/etc/credentials/db-url")
+	err := LoadFromEnv(fs)
+	assert.NoError(t, err)
+	assert.Equal(t, "/etc/credentials/db-url", cfg.Database.UrlFile)
+}
+
 func TestLoadFromEnvIntegration(t *testing.T) {
 	envVars := map[string]string{
 		"METRICS_BIND_ADDRESS":           ":9090",

helm/kagent/templates/controller-configmap.yaml

@@ -48,9 +48,13 @@ data:
   {{- end }}
   {{- if eq .Values.database.type "sqlite" }}
   SQLITE_DATABASE_PATH: /sqlite-volume/{{ .Values.database.sqlite.databaseName }}
-  {{- else if and (eq .Values.database.type "postgres") (not (eq .Values.database.postgres.url "")) }}
+  {{- else if eq .Values.database.type "postgres" }}
+  {{- if not (eq .Values.database.postgres.urlFile "") }}
+  POSTGRES_DATABASE_URL_FILE: {{ .Values.database.postgres.urlFile | quote }}
+  {{- else if not (eq .Values.database.postgres.url "") }}
   POSTGRES_DATABASE_URL: {{ .Values.database.postgres.url | quote }}
   {{- end }}
+  {{- end }}
   STREAMING_INITIAL_BUF_SIZE: {{ .Values.controller.streaming.initialBufSize | quote }}
   STREAMING_MAX_BUF_SIZE: {{ .Values.controller.streaming.maxBufSize | quote }}
   STREAMING_TIMEOUT: {{ .Values.controller.streaming.timeout | quote }}

helm/kagent/values.yaml

@@ -56,6 +56,9 @@ database:
     databaseName: kagent.db
   postgres:
     url: postgres://postgres:kagent@pgsql-postgresql.kagent.svc.cluster.local:5432/postgres
+    # Path to a file containing the database URL.
+    # Takes precedence over url when set.
+    urlFile: ""
 
 # ==============================================================================
 # CONTROLLER CONFIGURATION