This adds support to display names or id of container instead of what
was provided in the request.
This keeps the default behavior (`docker stats byname` will display
`byname` in the `CONTAINER` colmun and `docker stats byid` will display
the id in the `CONTAINER` column) but adds two new format directive.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
The formatter.ContainerStats struct exposes its Mutex.
This is a bad design and should be fixed.
To fix that, I separated the statistics
attributes from ContainerStats to StatsEntry and
hid the mutex. Notice that the mutex protects both
the `err` field and the statistics attributes.
Then, implemented SetStatistics, SetError, GetStatistics
and GetError to avoid races.
Moreover, to make this less granular, I decided to
replace the read-write mutex with the regular mutex and
to pass a StatsEntry slice to formatter.ContainerStatsWrite
Signed-off-by: Boaz Shuster <ripcurld.github@gmail.com>
