added config-validation mode

lib/cnf/cnf_file/main.go

@@ -31,14 +31,14 @@ func readConfig() (config []byte) {
 			return config
 		}
 	}
-	config, err = readConfigFile(cnf.CONFIG_FILE_ABS)
+	config, err = readConfigFile(cnf.ConfigFileAbs)
 	if err == nil && config != nil {
 		return config
 	}
 	log.ErrorS("config", fmt.Sprintf(
-		"Neither config file could be read: (%s, %s)", cwdConfig, cnf.CONFIG_FILE_ABS,
+		"Neither config file could be read: (%s, %s)", cwdConfig, cnf.ConfigFileAbs,
 	))
-	panic(fmt.Errorf("no valid config file found! (%s, %s)", cwdConfig, cnf.CONFIG_FILE_ABS))
+	panic(fmt.Errorf("no valid config file found! (%s, %s)", cwdConfig, cnf.ConfigFileAbs))
 }
 
 func Load() {

lib/cnf/hardcoded.go

@@ -9,5 +9,6 @@ const (
 	LOG_TIME_FORMAT string = "2006-01-02 15:04:05"
 	UDP_TTL                = 30 * time.Second
 	UDP_BUFFER_SIZE int    = 4096
-	CONFIG_FILE_ABS string = "/etc/calamary/config.yml"
 )
+
+var ConfigFileAbs string = "/etc/calamary/config.yml"

lib/main/main.go

@@ -1,10 +1,13 @@
 package main
 
 import (
+	"flag"
 	"fmt"
+	"os"
 
 	"github.com/superstes/calamary/cnf"
 	"github.com/superstes/calamary/cnf/cnf_file"
+	"github.com/superstes/calamary/log"
 )
 
 func welcome() {
@@ -18,7 +21,20 @@ func welcome() {
 }
 
 func main() {
+	var modeValidate bool
+	flag.BoolVar(&modeValidate, "v", false, "Only validate config")
+	flag.StringVar(&cnf.ConfigFileAbs, "f", cnf.ConfigFileAbs, "Path to the config file")
+	flag.Parse()
+
 	cnf.C = &cnf.Config{}
+
+	if modeValidate {
+		cnf.C.Service.Debug = true
+		cnf_file.Load()
+		log.Info("config", "Config validated successfully")
+		os.Exit(0)
+	}
+
 	welcome()
 	cnf_file.Load()
 	service := &service{}

scripts/buildrun.sh

@@ -3,5 +3,5 @@
 set -e
 
 cd "$(dirname "$0")/../lib/main"
-go build
-./main
+go build -o calamary
+./calamary

systemd.service

@@ -0,0 +1,30 @@
+[Unit]
+Description=Calamary Forward Proxy
+Documentation=https://docs.calamary.net
+Documentation=https://github.com/superstes/calamary
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+Environment=CONFIG=/etc/calamary/config.yml
+
+# validate before start/restart
+ExecStartPre=/usr/bin/calamary -f $CONFIG -v
+ExecStart=/usr/bin/calamary -f $CONFIG
+
+# validate before reload
+ExecReload=/usr/bin/calamary -f $CONFIG -v
+ExecReload=/bin/kill -HUP $MAINPID
+
+User=proxy
+Group=proxy
+Restart=on-failure
+RestartSec=5s
+
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=calamary
+
+[Install]
+WantedBy=multi-user.target