feat: implement logging configuration with access log setup

backend/internal/caddy/config.go

@@ -10,7 +10,32 @@ import (
 // GenerateConfig creates a Caddy JSON configuration from proxy hosts.
 // This is the core transformation layer from our database model to Caddy config.
 func GenerateConfig(hosts []models.ProxyHost, storageDir string, acmeEmail string) (*Config, error) {
+	// Define log file paths
+	// We assume storageDir is like ".../data/caddy/data", so we go up to ".../data/logs"
+	// Or we can just use a relative path if Caddy's working directory is set correctly.
+	// In Docker, WORKDIR is /app, and storageDir passed here is usually /app/data/caddy.
+	// Let's put logs in /app/data/logs/access.log
+	logFile := "/app/data/logs/access.log"
+
 	config := &Config{
+		Logging: &LoggingConfig{
+			Logs: map[string]*LogConfig{
+				"access": {
+					Writer: &WriterConfig{
+						Output:       "file",
+						Filename:     logFile,
+						Roll:         true,
+						RollSize:     10, // 10 MB
+						RollKeep:     5,  // Keep 5 files
+						RollKeepDays: 7,  // Keep for 7 days
+					},
+					Encoder: &EncoderConfig{
+						Format: "json",
+					},
+					Include: []string{"http.log.access.access_log"},
+				},
+			},
+		},
 		Apps: Apps{
 			HTTP: &HTTPApp{
 				Servers: map[string]*Server{},
@@ -47,6 +72,7 @@ func GenerateConfig(hosts []models.ProxyHost, storageDir string, acmeEmail strin
 		return config, nil
 	}
 
+	// We already initialized srv0 above, so we just append routes to it
 	routes := make([]*Route, 0)
 
 	for _, host := range hosts {
@@ -123,6 +149,9 @@ func GenerateConfig(hosts []models.ProxyHost, storageDir string, acmeEmail strin
 			Disable:      false,
 			DisableRedir: false,
 		},
+		Logs: &ServerLogs{
+			DefaultLoggerName: "access_log",
+		},
 	}
 
 	return config, nil

backend/internal/caddy/types.go

@@ -3,8 +3,44 @@ package caddy
 // Config represents Caddy's top-level JSON configuration structure.
 // Reference: https://caddyserver.com/docs/json/
 type Config struct {
-	Apps    Apps    `json:"apps"`
-	Storage Storage `json:"storage,omitempty"`
+	Apps    Apps           `json:"apps"`
+	Logging *LoggingConfig `json:"logging,omitempty"`
+	Storage Storage        `json:"storage,omitempty"`
+}
+
+// LoggingConfig configures Caddy's logging facility.
+type LoggingConfig struct {
+	Logs  map[string]*LogConfig `json:"logs,omitempty"`
+	Sinks *SinkConfig           `json:"sinks,omitempty"`
+}
+
+// LogConfig configures a specific logger.
+type LogConfig struct {
+	Writer  *WriterConfig  `json:"writer,omitempty"`
+	Encoder *EncoderConfig `json:"encoder,omitempty"`
+	Level   string         `json:"level,omitempty"`
+	Include []string       `json:"include,omitempty"`
+	Exclude []string       `json:"exclude,omitempty"`
+}
+
+// WriterConfig configures the log writer (output).
+type WriterConfig struct {
+	Output       string `json:"output"`
+	Filename     string `json:"filename,omitempty"`
+	Roll         bool   `json:"roll,omitempty"`
+	RollSize     int    `json:"roll_size_mb,omitempty"`
+	RollKeep     int    `json:"roll_keep,omitempty"`
+	RollKeepDays int    `json:"roll_keep_days,omitempty"`
+}
+
+// EncoderConfig configures the log format.
+type EncoderConfig struct {
+	Format string `json:"format"` // "json", "console", etc.
+}
+
+// SinkConfig configures log sinks (e.g. stderr).
+type SinkConfig struct {
+	Writer *WriterConfig `json:"writer,omitempty"`
 }
 
 // Storage configures the storage module.