@@ -21,6 +21,9 @@ const (

 	logLabelsKey  = "labels"

 	logEnvKey     = "env"

 	logCmdKey     = "gcp-log-cmd"

+	logZoneKey    = "gcp-meta-zone"

+	logNameKey    = "gcp-meta-name"

+	logIDKey      = "gcp-meta-id"

 )

 var (

@@ -142,6 +145,12 @@ func New(ctx logger.Context) (logger.Logger, error) {

 			Name: instanceName,

 			ID:   instanceID,

 		}

+	} else if ctx.Config[logZoneKey] != "" || ctx.Config[logNameKey] != "" || ctx.Config[logIDKey] != "" {

+		l.instance = &instanceInfo{

+			Zone: ctx.Config[logZoneKey],

+			Name: ctx.Config[logNameKey],

+			ID:   ctx.Config[logIDKey],

+		}

 	}

 	// The logger "overflows" at a rate of 10,000 logs per second and this

@@ -163,7 +172,7 @@ func New(ctx logger.Context) (logger.Logger, error) {

 func ValidateLogOpts(cfg map[string]string) error {

 	for k := range cfg {

 		switch k {

-		case projectOptKey, logLabelsKey, logEnvKey, logCmdKey:

+		case projectOptKey, logLabelsKey, logEnvKey, logCmdKey, logZoneKey, logNameKey, logIDKey:

 		default:

 			return fmt.Errorf("%q is not a valid option for the gcplogs driver", k)

 		}

@@ -37,6 +37,10 @@ The `--gcp-project` takes precedence over information discovered from the metada

 so a Docker daemon running in a Google Cloud Project can be overridden to log to a different

 Google Cloud Project using `--gcp-project`.

+Docker fetches the values for zone, instance name and instance id from Google

+Cloud metadata server. Those values can be provided via options if metadata

+server is not available. They will not override the values from metadata server.

+

 ## gcplogs options

 You can use the `--log-opt NAME=VALUE` flag to specify these additional Google

@@ -48,6 +52,9 @@ Cloud Logging driver options:

 | `gcp-log-cmd`               | optional | Whether to log the command that the container was started with. Defaults to false.                                                          |

 | `labels`                    | optional | Comma-separated list of keys of labels, which should be included in message, if these labels are specified for container.                   |

 | `env`                       | optional | Comma-separated list of keys of environment variables, which should be included in message, if these variables are specified for container. |

+| `gcp-meta-zone`             | optional | Zone name for the instance. |

+| `gcp-meta-name`             | optional | Instance name. |

+| `gcp-meta-id`               | optional | Instance ID. |

 If there is collision between `label` and `env` keys, the value of the `env`

 takes precedence. Both options add additional fields to the attributes of a

@@ -57,13 +64,22 @@ Below is an example of the logging options required to log to the default

 logging destination which is discovered by querying the GCE metadata server.

     docker run --log-driver=gcplogs \

-        --log-opt labels=location

-        --log-opt env=TEST

-        --log-opt gcp-log-cmd=true

-        --env "TEST=false"

-        --label location=west

+        --log-opt labels=location \

+        --log-opt env=TEST \

+        --log-opt gcp-log-cmd=true \

+        --env "TEST=false" \

+        --label location=west \

         your/application

 This configuration also directs the driver to include in the payload the label

 `location`, the environment variable `ENV`, and the command used to start the

 container.

+

+An example of the logging options for running outside of GCE (the daemon must be

+configured with GOOGLE_APPLICATION_CREDENTIALS):

+

+    docker run --log-driver=gcplogs \

+        --log-opt gcp-project=test-project

+        --log-opt gcp-meta-zone=west1 \

+        --log-opt gcp-meta-name=`hostname` \

+        your/application