# <a id="logs"></a>Log Handling

Although Docker logging is tied into this same Linux terminal I/O design, we cannot assign the several differences in container logging under RouterOS to the same design differences as above.

The actual causes stem first from the fact that RouterOS boxes try to keep logging to a minimum by default, whereas Docker logs everything the container says, without restriction. RouterOS takes the surprising default of logging to volatile RAM in order to avoid burning out the flash. Additionally, it ignores all messages issued under “topics” other than the four preconfigured by default, which does not include the “container” topic you get access to by installing `container.npk`.

To prevent your containers’ log messages from being sent straight to the bit bucket, you must say:
Here’s one way to prevent your containers’ log messages from being sent straight to the bit bucket:

    /container/{add,set} … logging=yes
    /system/logging add topics=container action=…

Having done so, we have a new limitation to contend with: messages logged via this path get mixed together in real time, requiring you to dig through the history manually to tease them apart. Compare Docker and Podman logging, which let you get the logs for a single container, independent of the others.(^Podman does this in a particularly elegant way by implementing its `logs` command in terms of systemd’s unified “journal” subsystem.)

RouterOS 7.20 solves this in part by adding the `/container/log` command, which stores up to 100 messages in-memory per container.
RouterOS 7.20 partially solves this by adding the `/container/log` command, which stores up to 100 messages in-memory per container.


# <a id="cache"></a>There Is No Local Image Cache

I stated this [in the list above](#global), but what does that mean in practice? What do we lose as a result?

A surprising number of knock-on effects result from this lack: