Merge pull request #1806 from hashicorp/f-docker4mac-fixes

A couple fixes to make Docker For Mac work

client/client.go

@@ -287,6 +287,12 @@ func (c *Client) init() error {
 		if err != nil {
 			return fmt.Errorf("failed creating temporary directory for the StateDir: %v", err)
 		}
+
+		p, err = filepath.EvalSymlinks(p)
+		if err != nil {
+			return fmt.Errorf("failed to find temporary directory for the StateDir: %v", err)
+		}
+
 		c.config.StateDir = p
 	}
 	c.logger.Printf("[INFO] client: using state directory %v", c.config.StateDir)
@@ -302,6 +308,12 @@ func (c *Client) init() error {
 		if err != nil {
 			return fmt.Errorf("failed creating temporary directory for the AllocDir: %v", err)
 		}
+
+		p, err = filepath.EvalSymlinks(p)
+		if err != nil {
+			return fmt.Errorf("failed to find temporary directory for the AllocDir: %v", err)
+		}
+
 		c.config.AllocDir = p
 	}
 

client/driver/docker.go

@@ -476,13 +476,15 @@ func (d *DockerDriver) createContainer(ctx *ExecContext, task *structs.Task,
 	memLimit := int64(task.Resources.MemoryMB) * 1024 * 1024
 
 	if len(driverConfig.Logging) == 0 {
-		d.logger.Printf("[DEBUG] driver.docker: Setting default logging options to syslog and %s", syslogAddr)
-		driverConfig.Logging = []DockerLoggingOpts{
-			{Type: "syslog", Config: map[string]string{"syslog-address": syslogAddr}},
+		if runtime.GOOS != "darwin" {
+			d.logger.Printf("[DEBUG] driver.docker: Setting default logging options to syslog and %s", syslogAddr)
+			driverConfig.Logging = []DockerLoggingOpts{
+				{Type: "syslog", Config: map[string]string{"syslog-address": syslogAddr}},
+			}
 		}
-	}
 
-	d.logger.Printf("[DEBUG] driver.docker: Using config for logging: %+v", driverConfig.Logging[0])
+		d.logger.Printf("[DEBUG] driver.docker: deferring logging to docker on Docker for Mac")
+	}
 
 	hostConfig := &docker.HostConfig{
 		// Convert MB to bytes. This is an absolute value.
@@ -495,10 +497,14 @@ func (d *DockerDriver) createContainer(ctx *ExecContext, task *structs.Task,
 		// local directory for storage and a shared alloc directory that can be
 		// used to share data between different tasks in the same task group.
 		Binds: binds,
-		LogConfig: docker.LogConfig{
+	}
+
+	if len(driverConfig.Logging) != 0 {
+		d.logger.Printf("[DEBUG] driver.docker: Using config for logging: %+v", driverConfig.Logging[0])
+		hostConfig.LogConfig = docker.LogConfig{
 			Type:   driverConfig.Logging[0].Type,
 			Config: driverConfig.Logging[0].Config,
-		},
+		}
 	}
 
 	d.logger.Printf("[DEBUG] driver.docker: using %d bytes memory for %s", hostConfig.Memory, task.Name)
@@ -817,7 +823,9 @@ func (d *DockerDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle
 
 	// Only launch syslog server if we're going to use it!
 	syslogAddr := ""
-	if len(driverConfig.Logging) == 0 || driverConfig.Logging[0].Type == "syslog" {
+	if runtime.GOOS == "darwin" && len(driverConfig.Logging) == 0 {
+		d.logger.Printf("[DEBUG] driver.docker: disabling syslog driver as Docker for Mac workaround")
+	} else if len(driverConfig.Logging) == 0 || driverConfig.Logging[0].Type == "syslog" {
 		ss, err := exec.LaunchSyslogServer()
 		if err != nil {
 			pluginClient.Kill()

client/driver/executor/executor.go

@@ -457,8 +457,14 @@ func (e *UniversalExecutor) Exit() error {
 	if e.syslogServer != nil {
 		e.syslogServer.Shutdown()
 	}
-	e.lre.Close()
-	e.lro.Close()
+
+	if e.lre != nil {
+		e.lre.Close()
+	}
+
+	if e.lro != nil {
+		e.lro.Close()
+	}
 
 	if e.consulSyncer != nil {
 		e.consulSyncer.Shutdown()

website/source/docs/drivers/docker.html.md

@@ -461,3 +461,18 @@ Containers essentially have a virtual file system all to themselves. If you
 need a higher degree of isolation between processes for security or other
 reasons, it is recommended to use full virtualization like
 [QEMU](/docs/drivers/qemu.html).
+
+## Docker For Mac Caveats
+
+Docker For Mac runs docker inside a small VM and then allows access to parts of
+the host filesystem into that VM. At present, nomad uses a syslog server bound to
+a unix socket within a path that both the host and the VM can access to forward
+log messages back to nomad. But at present, Docker For Mac does not work for
+unix domain sockets (https://github.com/docker/for-mac/issues/483) in one of
+these shared paths.
+
+As a result, using nomad with the docker driver on OS X/macOS will work, but no
+logs will be available to nomad. Users must use the native docker facilities to
+examine the logs of any jobs running under docker.
+
+In the future, we will resolve this issue, one way or another.