Merge pull request #961 from hashicorp/executor-tests

Making the calls to exit idempotent

client/driver/logging/rotator.go

@@ -10,6 +10,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 )
 
@@ -35,6 +36,9 @@ type FileRotator struct {
 	logger      *log.Logger
 	purgeCh     chan struct{}
 	doneCh      chan struct{}
+
+	closed     bool
+	closedLock sync.Mutex
 }
 
 // NewFileRotator returns a new file rotator
@@ -194,6 +198,9 @@ func (f *FileRotator) flushPeriodically() {
 }
 
 func (f *FileRotator) Close() {
+	f.closedLock.Lock()
+	defer f.closedLock.Unlock()
+
 	// Stop the ticker and flush for one last time
 	f.flushTicker.Stop()
 	if f.bufw != nil {
@@ -201,8 +208,11 @@ func (f *FileRotator) Close() {
 	}
 
 	// Stop the purge go routine
-	f.doneCh <- struct{}{}
+	if !f.closed {
-	close(f.purgeCh)
+		f.doneCh <- struct{}{}
+		close(f.purgeCh)
+		f.closed = true
+	}
 }
 
 // purgeOldFiles removes older files and keeps only the last N files rotated for

client/driver/logging/syslog_server.go

@@ -6,6 +6,7 @@ import (
 	"bufio"
 	"log"
 	"net"
+	"sync"
 )
 
 // SyslogServer is a server which listens to syslog messages and parses them
@@ -14,7 +15,10 @@ type SyslogServer struct {
 	messages chan *SyslogMessage
 	parser   *DockerLogParser
 
-	doneCh chan interface{}
+	doneCh   chan interface{}
+	done     bool
+	doneLock sync.Mutex
+
 	logger *log.Logger
 }
 
@@ -71,6 +75,12 @@ func (s *SyslogServer) read(connection net.Conn) {
 
 // Shutdown shutsdown the syslog server
 func (s *SyslogServer) Shutdown() {
-	close(s.doneCh)
+	s.doneLock.Lock()
-	close(s.messages)
+	s.doneLock.Unlock()
+
+	if !s.done {
+		close(s.doneCh)
+		close(s.messages)
+		s.done = true
+	}
 }