From 501bf12837382b66d5ddb05e83f44a5c4bea6480 Mon Sep 17 00:00:00 2001
From: "Jonathan A. Sternberg" <jonathan@influxdb.com>
Date: Fri, 20 Oct 2017 10:03:21 -0500
Subject: [PATCH] Remove the pidfile after the server has exited

---
 CHANGELOG.md                       |  1 +
 cmd/kapacitord/run/command.go      | 16 +++++--
 cmd/kapacitord/run/command_test.go | 70 ++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 3 deletions(-)
 create mode 100644 cmd/kapacitord/run/command_test.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ddd68c1e23..7b6255f3e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,7 @@
 - [#1581](https://github.com/influxdata/kapacitor/pull/1581): Add SNMP sysUpTime to SNMP Trap service
 - [#1547](https://github.com/influxdata/kapacitor/issues/1547): Fix panic on recording replay with HTTPPostHandler.
 - [#1623](https://github.com/influxdata/kapacitor/issues/1623): Fix k8s incluster master api dns resolution
+- [#1630](https://github.com/influxdata/kapacitor/issues/1630): Remove the pidfile after the server has exited.
 
 ## v1.3.3 [2017-08-11]
 
diff --git a/cmd/kapacitord/run/command.go b/cmd/kapacitord/run/command.go
index 6f521e2aef..46d7fe6740 100644
--- a/cmd/kapacitord/run/command.go
+++ b/cmd/kapacitord/run/command.go
@@ -41,6 +41,7 @@ type Command struct {
 	Commit  string
 
 	closing chan struct{}
+	pidfile string
 	Closed  chan struct{}
 
 	Stdin  io.Reader
@@ -104,7 +105,7 @@ func (cmd *Command) Run(args ...string) error {
 	// Initialize Logging Services
 	cmd.diagService = diagnostic.NewService(config.Logging, cmd.Stdout, cmd.Stderr)
 	if err := cmd.diagService.Open(); err != nil {
-		return fmt.Errorf("failed to opend diagnostic service: %v", err)
+		return fmt.Errorf("failed to open diagnostic service: %v", err)
 	}
 
 	// Initialize cmd diagnostic
@@ -118,6 +119,7 @@ func (cmd *Command) Run(args ...string) error {
 	if err := cmd.writePIDFile(options.PIDFile); err != nil {
 		return fmt.Errorf("write pid file: %s", err)
 	}
+	cmd.pidfile = options.PIDFile
 
 	// Create server from config and start it.
 	buildInfo := server.BuildInfo{Version: cmd.Version, Commit: cmd.Commit, Branch: cmd.Branch}
@@ -142,6 +144,7 @@ func (cmd *Command) Run(args ...string) error {
 // Close shuts down the server.
 func (cmd *Command) Close() error {
 	defer close(cmd.Closed)
+	defer cmd.removePIDFile()
 	close(cmd.closing)
 	if cmd.Server != nil {
 		return cmd.Server.Close()
@@ -165,6 +168,14 @@ func (cmd *Command) monitorServerErrors() {
 	}
 }
 
+func (cmd *Command) removePIDFile() {
+	if cmd.pidfile != "" {
+		if err := os.Remove(cmd.pidfile); err != nil {
+			cmd.Diag.Error("unable to remove pidfile", err)
+		}
+	}
+}
+
 // ParseFlags parses the command line flags from args and returns an options set.
 func (cmd *Command) ParseFlags(args ...string) (Options, error) {
 	var options Options
@@ -191,8 +202,7 @@ func (cmd *Command) writePIDFile(path string) error {
 	}
 
 	// Ensure the required directory structure exists.
-	err := os.MkdirAll(filepath.Dir(path), 0777)
-	if err != nil {
+	if err := os.MkdirAll(filepath.Dir(path), 0777); err != nil {
 		return fmt.Errorf("mkdir: %s", err)
 	}
 
diff --git a/cmd/kapacitord/run/command_test.go b/cmd/kapacitord/run/command_test.go
new file mode 100644
index 0000000000..c70edbe13b
--- /dev/null
+++ b/cmd/kapacitord/run/command_test.go
@@ -0,0 +1,70 @@
+package run_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+	"text/template"
+	"time"
+
+	"fmt"
+
+	"github.com/influxdata/kapacitor/cmd/kapacitord/run"
+)
+
+func TestCommand_PIDFile(t *testing.T) {
+	tmpdir, err := ioutil.TempDir(os.TempDir(), "kapacitord-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	// Write out a config file that does not attempt to connect to influxdb.
+	configFile := filepath.Join(tmpdir, "kapacitor.conf")
+	configTemplate := template.Must(template.New("config_file").Parse(`data_dir = "{{.TempDir}}/data"
+[[influxdb]]
+  enabled = false
+[replay]
+  dir = "{{.TempDir}}/replay"
+[storage]
+  boltdb = "{{.TempDir}}/kapacitor.db"
+[task]
+  dir = "{{.TempDir}}/tasks"
+[load]
+  dir = "{{.TempDir}}/load"
+`))
+	var buf bytes.Buffer
+	if err := configTemplate.Execute(&buf, map[string]string{"TempDir": tmpdir}); err != nil {
+		t.Fatalf("unable to generate config file: %s", err)
+	}
+	fmt.Println(buf.String())
+	if err := ioutil.WriteFile(configFile, buf.Bytes(), 0600); err != nil {
+		t.Fatalf("unable to write %s: %s", configFile, err)
+	}
+
+	pidFile := filepath.Join(tmpdir, "kapacitor.pid")
+
+	cmd := run.NewCommand()
+	if err := cmd.Run("-config", configFile, "-pidfile", pidFile); err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	if _, err := os.Stat(pidFile); err != nil {
+		t.Fatalf("could not stat pid file: %s", err)
+	}
+	go cmd.Close()
+
+	timeout := time.NewTimer(time.Second)
+	select {
+	case <-timeout.C:
+		t.Fatal("unexpected timeout")
+	case <-cmd.Closed:
+		timeout.Stop()
+	}
+
+	if _, err := os.Stat(pidFile); err == nil {
+		t.Fatal("expected pid file to be removed")
+	}
+}