cmd: Add pidfile support (closes #3235)

2 files changed, 19 insertions, 2 deletions

diff --git a/cmd/commandfuncs.go b/cmd/commandfuncs.go
index efdcfdc..f9e1033 100644
--- a/cmd/commandfuncs.go
+++ b/cmd/commandfuncs.go
@@ -41,6 +41,7 @@ import (
 func cmdStart(fl Flags) (int, error) {
 	startCmdConfigFlag := fl.String("config")
 	startCmdConfigAdapterFlag := fl.String("adapter")
+	startCmdPidfileFlag := fl.String("pidfile")
 	startCmdWatchFlag := fl.Bool("watch")
 
 	// open a listener to which the child process will connect when
@@ -71,6 +72,9 @@ func cmdStart(fl Flags) (int, error) {
 	if startCmdWatchFlag {
 		cmd.Args = append(cmd.Args, "--watch")
 	}
+	if startCmdPidfileFlag != "" {
+		cmd.Args = append(cmd.Args, "--pidfile", startCmdPidfileFlag)
+	}
 	stdinpipe, err := cmd.StdinPipe()
 	if err != nil {
 		return caddy.ExitCodeFailedStartup,
@@ -149,6 +153,7 @@ func cmdRun(fl Flags) (int, error) {
 	runCmdResumeFlag := fl.Bool("resume")
 	runCmdPrintEnvFlag := fl.Bool("environ")
 	runCmdWatchFlag := fl.Bool("watch")
+	runCmdPidfileFlag := fl.String("pidfile")
 	runCmdPingbackFlag := fl.String("pingback")
 
 	// if we are supposed to print the environment, do that first
@@ -225,6 +230,16 @@ func cmdRun(fl Flags) (int, error) {
 		go watchConfigFile(configFile, runCmdConfigAdapterFlag)
 	}
 
+	// create pidfile
+	if runCmdPidfileFlag != "" {
+		err := caddy.PIDFile(runCmdPidfileFlag)
+		if err != nil {
+			caddy.Log().Error("unable to write PID file",
+				zap.String("pidfile", runCmdPidfileFlag),
+				zap.Error(err))
+		}
+	}
+
 	// warn if the environment does not provide enough information about the disk
 	hasXDG := os.Getenv("XDG_DATA_HOME") != "" &&
 		os.Getenv("XDG_CONFIG_HOME") != "" &&
diff --git a/cmd/commands.go b/cmd/commands.go
index e02f6a0..5a40b1d 100644
--- a/cmd/commands.go
+++ b/cmd/commands.go
@@ -74,7 +74,7 @@ func init() {
 	RegisterCommand(Command{
 		Name:  "start",
 		Func:  cmdStart,
-		Usage: "[--config <path> [--adapter <name>]] [--watch]",
+		Usage: "[--config <path> [--adapter <name>]] [--watch] [--pidfile <file>]",
 		Short: "Starts the Caddy process in the background and then returns",
 		Long: `
 Starts the Caddy process, optionally bootstrapped with an initial config file.
@@ -87,6 +87,7 @@ using 'caddy run' instead to keep it in the foreground.`,
 			fs := flag.NewFlagSet("start", flag.ExitOnError)
 			fs.String("config", "", "Configuration file")
 			fs.String("adapter", "", "Name of config adapter to apply")
+			fs.String("pidfile", "", "Path of file to which to write process ID")
 			fs.Bool("watch", false, "Reload changed config file automatically")
 			return fs
 		}(),
@@ -95,7 +96,7 @@ using 'caddy run' instead to keep it in the foreground.`,
 	RegisterCommand(Command{
 		Name:  "run",
 		Func:  cmdRun,
-		Usage: "[--config <path> [--adapter <name>]] [--environ] [--watch]",
+		Usage: "[--config <path> [--adapter <name>]] [--environ] [--resume] [--watch] [--pidfile <fil>]",
 		Short: `Starts the Caddy process and blocks indefinitely`,
 		Long: `
 Starts the Caddy process, optionally bootstrapped with an initial config file,
@@ -132,6 +133,7 @@ development environment.`,
 			fs.Bool("environ", false, "Print environment")
 			fs.Bool("resume", false, "Use saved config, if any (and prefer over --config file)")
 			fs.Bool("watch", false, "Watch config file for changes and reload it automatically")
+			fs.String("pidfile", "", "Path of file to which to write process ID")
 			fs.String("pingback", "", "Echo confirmation bytes to this address on success")
 			return fs
 		}(),