Force memcached container log to file

We were relying on the sysconfig options to set the memcached log file,
however, this is not happening, as the redirection is being taken as an
option and ends up being ignored by the memcached command. So instead,
we set the redirection in the container template.

Change-Id: Ic94e3fd7884d518eb9558c53acdc6b294823cd0a
Closes-Bug: #1720183

docker/services/memcached.yaml

@@ -94,7 +94,15 @@ outputs:
                 -
                   - /var/lib/config-data/memcached/etc/sysconfig/memcached:/etc/sysconfig/memcached:ro
                   - /var/log/containers/memcached:/var/log/
-            command: ['/bin/bash', '-c', 'source /etc/sysconfig/memcached; /usr/bin/memcached -p ${PORT} -u ${USER} -m ${CACHESIZE} -c ${MAXCONN} $OPTIONS']
+            # NOTE: We're adding the log redirection here, even though should
+            # already be part of the options. This is because the redirection
+            # via the options is not working and ends up being passed as a
+            # parameter to the memcached command (which it silently ignores).
+            # Thus the need for the explicit redirection here. The redirection
+            # will be removed from the $OPTIONS, which is done via the puppet
+            # module, but we'll only be able to do this once the following pull
+            # request merges: https://github.com/saz/puppet-memcached/pull/88
+            command: ['/bin/bash', '-c', 'source /etc/sysconfig/memcached; /usr/bin/memcached -p ${PORT} -u ${USER} -m ${CACHESIZE} -c ${MAXCONN} $OPTIONS >> /var/log/memcached.log 2>&1']
       upgrade_tasks:
         - name: Stop and disable memcached service
           tags: step2