---
title: Following Log Files on Disk
---

# Following Log Files on Disk

Some containers do not write logs to `sysout` or `syserr`. Many folks have asked if Dozzle can also show logs that are written to files. Unfortunately, files in containers are not accessible to other containers and so Dozzle wouldn't have a way to access these files. Dozzle can only access logs written to `sysout` or `syserr` which is the same functionality as `docker logs` command.

If you are creating a service using Docker then make sure to write logs to streams. An application should not attempt to write to logfiles. Instead delegate the logging to Docker. The [twelve factor app](https://12factor.net/logs) has a great principle around logging that explains the importance of this principle.

However, there are workarounds to be able to still access files using mounts.

## Mounting Local Log Files with Alpine

Dozzle reads any output stream. This can be used in combination with alpine to `tail` a mounted file. An example of this is:

```sh
docker run -v /var/log/system.log:/var/log/test.log alpine tail -f /var/log/test.log
```

In the above example `/var/log/system.log` is mounted from the host and used with `tail -f` to follow the file. `tail` is smart to follow log rotations. During my testing, using alpine only uses about `300KB` of memory.