Add support for .env files

.gitignore

@@ -33,3 +33,4 @@ tests.xml
 .vscode
 .DS_Store
 .history
+.env

README.md

@@ -48,6 +48,9 @@ _Please note: you will need Docker installed on your local machine._
 
 The application uses environment variables to configure all aspects.
 
+You can optionally supply these through a `.env` file that will be parsed before
+any additional environment variables.
+
 ### General Configuration
 
 * `J_ARTICLES_PER_PAGE` - Articles to display per page, default `20`

internal/app/app.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 
 	"github.com/jamiefdhurst/journal/pkg/database/rows"
+	"github.com/jamiefdhurst/journal/pkg/env"
 )
 
 // Database Define same interface as database
@@ -84,40 +85,53 @@ func DefaultConfiguration() Configuration {
 }
 
 // ApplyEnvConfiguration applies the env variables on top of existing config
+// It first loads values from a .env file (if it exists), then applies any
+// environment variables set in the system (which override .env values)
 func ApplyEnvConfiguration(config *Configuration) {
-	articles, _ := strconv.Atoi(os.Getenv("J_ARTICLES_PER_PAGE"))
+	// Parse .env file (if it exists)
+	dotenvVars, _ := env.Parse(".env")
+
+	// Helper function to get env var, preferring system env over .env file
+	getEnv := func(key string) string {
+		if val := os.Getenv(key); val != "" {
+			return val
+		}
+		return dotenvVars[key]
+	}
+
+	articles, _ := strconv.Atoi(getEnv("J_ARTICLES_PER_PAGE"))
 	if articles > 0 {
 		config.ArticlesPerPage = articles
 	}
-	database := os.Getenv("J_DB_PATH")
+	database := getEnv("J_DB_PATH")
 	if database != "" {
 		config.DatabasePath = database
 	}
-	description := os.Getenv("J_DESCRIPTION")
+	description := getEnv("J_DESCRIPTION")
 	if description != "" {
 		config.Description = description
 	}
-	enableCreate := os.Getenv("J_CREATE")
+	enableCreate := getEnv("J_CREATE")
 	if enableCreate == "0" {
 		config.EnableCreate = false
 	}
-	enableEdit := os.Getenv("J_EDIT")
+	enableEdit := getEnv("J_EDIT")
 	if enableEdit == "0" {
 		config.EnableEdit = false
 	}
-	excerptWords, _ := strconv.Atoi(os.Getenv("J_EXCERPT_WORDS"))
+	excerptWords, _ := strconv.Atoi(getEnv("J_EXCERPT_WORDS"))
 	if excerptWords > 0 {
 		config.ExcerptWords = excerptWords
 	}
-	config.GoogleAnalyticsCode = os.Getenv("J_GA_CODE")
-	port := os.Getenv("J_PORT")
+	config.GoogleAnalyticsCode = getEnv("J_GA_CODE")
+	port := getEnv("J_PORT")
 	if port != "" {
 		config.Port = port
 	}
-	config.SSLCertificate = os.Getenv("J_SSL_CERT")
-	config.SSLKey = os.Getenv("J_SSL_KEY")
+	config.SSLCertificate = getEnv("J_SSL_CERT")
+	config.SSLKey = getEnv("J_SSL_KEY")
 
-	sessionKey := os.Getenv("J_SESSION_KEY")
+	sessionKey := getEnv("J_SESSION_KEY")
 	if sessionKey != "" {
 		if len(sessionKey) != 32 {
 			log.Println("WARNING: J_SESSION_KEY must be exactly 32 bytes. Using auto-generated key instead.")
@@ -133,22 +147,22 @@ func ApplyEnvConfiguration(config *Configuration) {
 	}
 	config.SessionKey = sessionKey
 
-	sessionName := os.Getenv("J_SESSION_NAME")
+	sessionName := getEnv("J_SESSION_NAME")
 	if sessionName != "" {
 		config.SessionName = sessionName
 	}
 
-	cookieDomain := os.Getenv("J_COOKIE_DOMAIN")
+	cookieDomain := getEnv("J_COOKIE_DOMAIN")
 	if cookieDomain != "" {
 		config.CookieDomain = cookieDomain
 	}
 
-	cookieMaxAge, _ := strconv.Atoi(os.Getenv("J_COOKIE_MAX_AGE"))
+	cookieMaxAge, _ := strconv.Atoi(getEnv("J_COOKIE_MAX_AGE"))
 	if cookieMaxAge > 0 {
 		config.CookieMaxAge = cookieMaxAge
 	}
 
-	cookieHTTPOnly := os.Getenv("J_COOKIE_HTTPONLY")
+	cookieHTTPOnly := getEnv("J_COOKIE_HTTPONLY")
 	if cookieHTTPOnly == "0" || cookieHTTPOnly == "false" {
 		config.CookieHTTPOnly = false
 	}
@@ -157,19 +171,19 @@ func ApplyEnvConfiguration(config *Configuration) {
 		config.CookieSecure = true
 	}
 
-	staticPath := os.Getenv("J_STATIC_PATH")
+	staticPath := getEnv("J_STATIC_PATH")
 	if staticPath != "" {
 		config.StaticPath = staticPath
 	}
-	theme := os.Getenv("J_THEME")
+	theme := getEnv("J_THEME")
 	if theme != "" {
 		config.Theme = theme
 	}
-	themePath := os.Getenv("J_THEME_PATH")
+	themePath := getEnv("J_THEME_PATH")
 	if themePath != "" {
 		config.ThemePath = themePath
 	}
-	title := os.Getenv("J_TITLE")
+	title := getEnv("J_TITLE")
 	if title != "" {
 		config.Title = title
 	}

internal/app/app_test.go

@@ -2,6 +2,7 @@ package app
 
 import (
 	"os"
+	"path/filepath"
 	"testing"
 )
 
@@ -355,3 +356,102 @@ func TestApplyEnvConfiguration_Combined(t *testing.T) {
 		t.Errorf("Expected Port '8080', got %q", config.Port)
 	}
 }
+
+func TestApplyEnvConfiguration_DotEnvFile(t *testing.T) {
+	// Save current working directory
+	originalWd, _ := os.Getwd()
+	defer os.Chdir(originalWd)
+
+	// Create a temporary directory for testing
+	tmpDir := t.TempDir()
+	os.Chdir(tmpDir)
+
+	// Create a .env file
+	envContent := `J_PORT=9000
+J_TITLE=Test Journal
+J_DESCRIPTION=A test journal
+J_ARTICLES_PER_PAGE=15
+J_COOKIE_MAX_AGE=3600
+`
+	if err := os.WriteFile(filepath.Join(tmpDir, ".env"), []byte(envContent), 0644); err != nil {
+		t.Fatalf("Failed to create .env file: %v", err)
+	}
+
+	config := DefaultConfiguration()
+	ApplyEnvConfiguration(&config)
+
+	if config.Port != "9000" {
+		t.Errorf("Expected Port '9000' from .env, got %q", config.Port)
+	}
+	if config.Title != "Test Journal" {
+		t.Errorf("Expected Title 'Test Journal' from .env, got %q", config.Title)
+	}
+	if config.Description != "A test journal" {
+		t.Errorf("Expected Description 'A test journal' from .env, got %q", config.Description)
+	}
+	if config.ArticlesPerPage != 15 {
+		t.Errorf("Expected ArticlesPerPage 15 from .env, got %d", config.ArticlesPerPage)
+	}
+	if config.CookieMaxAge != 3600 {
+		t.Errorf("Expected CookieMaxAge 3600 from .env, got %d", config.CookieMaxAge)
+	}
+}
+
+func TestApplyEnvConfiguration_EnvOverridesDotEnv(t *testing.T) {
+	// Save current working directory and environment
+	originalWd, _ := os.Getwd()
+	defer os.Chdir(originalWd)
+	defer os.Unsetenv("J_PORT")
+	defer os.Unsetenv("J_TITLE")
+
+	// Create a temporary directory for testing
+	tmpDir := t.TempDir()
+	os.Chdir(tmpDir)
+
+	// Create a .env file
+	envContent := `J_PORT=9000
+J_TITLE=DotEnv Title
+J_DESCRIPTION=DotEnv Description
+`
+	if err := os.WriteFile(filepath.Join(tmpDir, ".env"), []byte(envContent), 0644); err != nil {
+		t.Fatalf("Failed to create .env file: %v", err)
+	}
+
+	// Set environment variables that should override .env
+	os.Setenv("J_PORT", "7777")
+	os.Setenv("J_TITLE", "Override Title")
+
+	config := DefaultConfiguration()
+	ApplyEnvConfiguration(&config)
+
+	// Environment variables should override .env values
+	if config.Port != "7777" {
+		t.Errorf("Expected Port '7777' from env var (not .env), got %q", config.Port)
+	}
+	if config.Title != "Override Title" {
+		t.Errorf("Expected Title 'Override Title' from env var (not .env), got %q", config.Title)
+	}
+	// Values not overridden should come from .env
+	if config.Description != "DotEnv Description" {
+		t.Errorf("Expected Description 'DotEnv Description' from .env, got %q", config.Description)
+	}
+}
+
+func TestApplyEnvConfiguration_NoDotEnvFile(t *testing.T) {
+	// Save current working directory
+	originalWd, _ := os.Getwd()
+	defer os.Chdir(originalWd)
+
+	// Create a temporary directory without .env file
+	tmpDir := t.TempDir()
+	os.Chdir(tmpDir)
+
+	// Should work fine even without .env file
+	config := DefaultConfiguration()
+	ApplyEnvConfiguration(&config)
+
+	// Should have default values
+	if config.Port != "3000" {
+		t.Errorf("Expected default Port '3000', got %q", config.Port)
+	}
+}

pkg/env/parser.go

@@ -0,0 +1,63 @@
+package env
+
+import (
+	"bufio"
+	"os"
+	"strings"
+)
+
+// Parse reads a .env file and returns a map of key-value pairs
+// It does not modify the actual environment variables
+func Parse(filepath string) (map[string]string, error) {
+	result := make(map[string]string)
+
+	file, err := os.Open(filepath)
+	if err != nil {
+		// If file doesn't exist, return empty map (not an error)
+		if os.IsNotExist(err) {
+			return result, nil
+		}
+		return nil, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+
+		// Skip empty lines and comments
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		// Split on first = sign
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) != 2 {
+			continue
+		}
+
+		key := strings.TrimSpace(parts[0])
+		value := strings.TrimSpace(parts[1])
+
+		// Remove quotes if present
+		value = unquote(value)
+
+		result[key] = value
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+// unquote removes surrounding quotes from a string
+func unquote(s string) string {
+	if len(s) >= 2 {
+		if (s[0] == '"' && s[len(s)-1] == '"') || (s[0] == '\'' && s[len(s)-1] == '\'') {
+			return s[1 : len(s)-1]
+		}
+	}
+	return s
+}