Add proper file handling

cmd/event_handler/main.go

@@ -34,7 +34,7 @@ func processEvent(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("failed to open event log: %s", err)
 	}
-	defer logFile.Close()
+	defer func() { _ = logFile.Close() }()
 
 	log.SetOutput(logFile)
 	log.Printf("event: %s, node: %d, success: %s, details: %s\n", *event, *nodeID, *success, *details)
@@ -68,7 +68,7 @@ func processEvent(ctx context.Context) error {
 		}
 	}
 
-	return nil
+	return logFile.Sync()
 }
 
 func evaluateClusterState(ctx context.Context, conn *pgx.Conn, node *flypg.Node) error {

internal/flycheck/vm.go

@@ -20,9 +20,7 @@ func CheckVM(checks *check.CheckSuite) *check.CheckSuite {
 		return checkDisk("/data/")
 	})
 
-	checks.AddCheck("checkLoad", func() (string, error) {
-		return checkLoad()
-	})
+	checks.AddCheck("checkLoad", checkLoad)
 
 	pressureNames := []string{"memory", "cpu", "io"}
 	for _, n := range pressureNames {

internal/flypg/config.go

@@ -119,7 +119,7 @@ func ReadFromFile(path string) (ConfigMap, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	conf := ConfigMap{}
 	scanner := bufio.NewScanner(file)
@@ -138,7 +138,7 @@ func writeInternalConfigFile(c Config) error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	internal := c.InternalConfig()
 
@@ -147,19 +147,25 @@ func writeInternalConfigFile(c Config) error {
 		file.Write([]byte(entry))
 	}
 
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file: %s", err)
+	} else if err := file.Close(); err != nil {
+		return fmt.Errorf("failed to close file: %s", err)
+	}
+
 	if err := utils.SetFileOwnership(c.InternalConfigFile(), "postgres"); err != nil {
 		return fmt.Errorf("failed to set file ownership on %s: %s", c.InternalConfigFile(), err)
 	}
 
-	return file.Sync()
+	return nil
 }
 
 func writeUserConfigFile(c Config) error {
 	file, err := os.Create(c.UserConfigFile())
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	internal := c.InternalConfig()
 
@@ -169,9 +175,15 @@ func writeUserConfigFile(c Config) error {
 		file.Write([]byte(entry))
 	}
 
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file: %s", err)
+	} else if err := file.Close(); err != nil {
+		return fmt.Errorf("failed to close file: %s", err)
+	}
+
 	if err := utils.SetFileOwnership(c.UserConfigFile(), "postgres"); err != nil {
 		return fmt.Errorf("failed to set file ownership on %s: %s", c.UserConfigFile(), err)
 	}
 
-	return file.Sync()
+	return nil
 }

internal/flypg/flypg.go

@@ -80,25 +80,29 @@ func (c *FlyPGConfig) CurrentConfig() (ConfigMap, error) {
 func (c *FlyPGConfig) initialize() error {
 	c.SetDefaults()
 
-	internal, err := os.Create(c.internalConfigFilePath)
+	file, err := os.Create(c.internalConfigFilePath)
 	if err != nil {
 		return err
 	}
-	defer func() {
-		if err := internal.Close(); err != nil {
-			fmt.Printf("failed to close file: %s\n", err)
-		}
-	}()
+	defer func() { _ = file.Close() }()
 
-	user, err := os.Create(c.userConfigFilePath)
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file: %s", err)
+	} else if err := file.Close(); err != nil {
+		return fmt.Errorf("failed to close file: %s", err)
+	}
+
+	file, err = os.Create(c.userConfigFilePath)
 	if err != nil {
 		return err
 	}
-	defer func() {
-		if err := user.Close(); err != nil {
-			fmt.Printf("failed to close file: %s\n", err)
-		}
-	}()
+	defer func() { _ = file.Close() }()
+
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file: %s", err)
+	} else if err := file.Close(); err != nil {
+		return fmt.Errorf("failed to close file: %s", err)
+	}
 
 	return nil
 }

internal/flypg/node.go

@@ -522,7 +522,7 @@ func (n *Node) setDefaultHBA() error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	for _, entry := range entries {
 		str := fmt.Sprintf("%s %s %s %s %s\n", entry.Type, entry.Database, entry.User, entry.Address, entry.Method)

internal/flypg/pg.go

@@ -249,19 +249,19 @@ func (c *PGConfig) initialize() error {
 }
 
 func (c *PGConfig) writePGConfigEntries(entries []string) error {
-	f, err := os.OpenFile(c.configFilePath, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
+	file, err := os.Create(c.configFilePath)
 	if err != nil {
 		return err
 	}
-	defer f.Close()
+	defer func() { _ = file.Close() }()
 
 	for _, entry := range entries {
-		if _, err := f.WriteString(entry); err != nil {
+		if _, err := file.WriteString(entry); err != nil {
 			return fmt.Errorf("failed append configuration entry: %s", err)
 		}
 	}
 
-	return f.Sync()
+	return file.Sync()
 }
 
 func memTotalInBytes() (int64, error) {

internal/flypg/repmgr.go

@@ -101,16 +101,21 @@ func (r *RepMgr) initialize() error {
 	if err != nil {
 		return nil
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	entries := []string{"include 'repmgr.internal.conf'\n", "include 'repmgr.user.conf'\n"}
-
 	for _, entry := range entries {
 		if _, err := file.WriteString(entry); err != nil {
 			return fmt.Errorf("failed append configuration entry: %s", err)
 		}
 	}
 
+	if err := file.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file: %s", err)
+	} else if err := file.Close(); err != nil {
+		return fmt.Errorf("failed to close file: %s", err)
+	}
+
 	if err := r.writePasswdConf(); err != nil {
 		return fmt.Errorf("failed creating pgpass file: %s", err)
 	}
@@ -231,11 +236,11 @@ func (r *RepMgr) clonePrimary(ipStr string) error {
 
 func (r *RepMgr) writePasswdConf() error {
 	path := "/data/.pgpass"
-	file, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0600)
+	file, err := os.Create(path)
 	if err != nil {
 		return fmt.Errorf("failed to open repmgr password file: %s", err)
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	if err := utils.SetFileOwnership(path, "postgres"); err != nil {
 		return fmt.Errorf("failed to set file ownership: %s", err)

internal/flypg/restore.go

@@ -120,7 +120,7 @@ func grantLocalAccess() error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	perm := []byte("host all postgres ::0/0 trust")
 	_, err = file.Write(perm)
@@ -143,7 +143,7 @@ func restoreHBAFile() error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	// revert back to our original config
 	_, err = file.Write(data)
@@ -160,11 +160,11 @@ func restoreHBAFile() error {
 }
 
 func setRestoreLock() error {
-	file, err := os.OpenFile(restoreLockFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	file, err := os.Create(restoreLockFile)
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() { _ = file.Close() }()
 
 	_, err = file.WriteString(os.Getenv("FLY_APP_NAME"))
 	if err != nil {

internal/flypg/ssh.go

@@ -37,32 +37,33 @@ func writeSSHKey() error {
 func writePrivateKey() error {
 	key := os.Getenv("SSH_KEY")
 
-	keyFile, err := os.Create(privateKeyFile)
+	file, err := os.Create(privateKeyFile)
 	if err != nil {
 		return err
 	}
-	defer keyFile.Close()
-	_, err = keyFile.Write([]byte(key))
+	defer func() { _ = file.Close() }()
+
+	_, err = file.Write([]byte(key))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to write contents to pvt key: %s", err)
 	}
 
-	return keyFile.Sync()
+	return file.Sync()
 }
 
 func writePublicKey() error {
 	cert := os.Getenv("SSH_CERT")
 
-	certFile, err := os.Create(publicKeyFile)
+	file, err := os.Create(publicKeyFile)
 	if err != nil {
 		return err
 	}
-	defer certFile.Close()
+	defer func() { _ = file.Close() }()
 
-	_, err = certFile.Write([]byte(cert))
+	_, err = file.Write([]byte(cert))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to write contents to pub key: %s", err)
 	}
 
-	return certFile.Sync()
+	return file.Sync()
 }

internal/supervisor/utils.go

@@ -14,5 +14,5 @@ func fatalOnErr(err error) {
 func fatal(i ...interface{}) {
 	fmt.Fprint(os.Stderr, "hivemind: ")
 	fmt.Fprintln(os.Stderr, i...)
-	os.Exit(1)
+	panic(i)
 }