Merge pull request docker#380 from FrenchBen/awstream-tag

Added details about tag support for AWS log driver

engine/admin/logging/awslogs.md

@@ -63,6 +63,16 @@ specified, the container ID is used as the log stream.
 > at a time.  Using the same log stream for multiple containers concurrently
 > can cause reduced logging performance.
 
+### tag
+
+Specify `tag` as an alternative to the `awslogs-stream` option. `tag` interprets template markup (e.g., `{% raw %}{{.ID}}{% endraw %}`, `{% raw %}{{.FullID}}{% endraw %}` or `{% raw %}{{.Name}}{% endraw %}` `{% raw %}docker.{{.ID}}{% endraw %}`). 
+See the [tag option documentation](log_tags.md) for details on all supported template substitutions.
+
+When both `awslogs-stream` and `tag` are specified, the value supplied for `awslogs-stream` will override the template specified with `tag`.
+
+If not specified, the container ID is used as the log stream.
+
+
 ## Credentials
 
 You must provide AWS credentials to the Docker daemon to use the `awslogs`

engine/admin/logging/overview.md

@@ -244,11 +244,13 @@ logging driver options.
 For example, to specify both additional options:
 
 ```bash
+{% raw %}
 $ docker run -dit \
     --log-driver=fluentd \
     --log-opt fluentd-address=localhost:24224 \
     --log-opt tag="docker.{{.Name}}" \
     alpine sh
+{% endraw %}
 ```
 
 If container cannot connect to the Fluentd daemon on the specified address and
@@ -262,9 +264,12 @@ see [the fluentd logging driver](fluentd.md)
 The Amazon CloudWatch Logs logging driver supports the following options:
 
 ```bash
+{% raw %}
 --log-opt awslogs-region=<aws_region>
 --log-opt awslogs-group=<log_group_name>
 --log-opt awslogs-stream=<log_stream_name>
+--log-opt tag="docker.{{.Name}}" \
+{% endraw %}
 ```
 
 For detailed information on working with this logging driver, see [the awslogs