CODEWITHSUNDEEP
dockerlogfile
zhangyi
zhangyi

Reputation: 71

docker tomcat Log issue

Docker container can only to daemon mode: I run catalina.sh to start the tomcat.
But the problem is my log will not appear in catalina.out.

I can look at `docker logs , but this certainly cannot run in a production environment.
I would like to ask how, in production environment, can I have the Tomcat log stored in the document and without the container stopping?

Upvotes: 7

Views: 15599

Answers (4)

Torprendido
Torprendido

Reputation: 55

You can override CMD like this:

CMD bash -c "catalina.sh run | tee -a logs/catalina.out"

This way you can show and store the log output at the same time.

But if you even want to store all errors:

CMD bash -c "catalina.sh run |& tee -a logs/catalina.out"

And store into volume like this:

docker run --rm -it -v /some/place:/usr/local/tomcat/logs yourImage

Upvotes: 0

Nauraushaun
Nauraushaun

Reputation: 1673

There are options in this (off topic) question to make the tomcat logs run in the foreground.

But to answer your actual question, the docker logs command is the usual way to get logs from a container. You can also find them on the host as they live in a file.

But the best way is to use an external logging service to collect and aggregate the logs, so you don't have to log in to the production server. Logentries is one example (though it's far from perfect). Splunk is another. The Docker logging drivers docs may help.

Upvotes: 3

Vaibhav Ranglani
Vaibhav Ranglani

Reputation: 213

You need to have one process running in foreground in docker container to have the container running.

I use a hack with all my docker images. Create a script run.sh with the following code

#!/bin/sh

service tomcat start
tail -f /dev/null

Make sure before you run the run.sh file in docker, change the permissions.

Addition to Dockerfile will be

COPY run.sh ./run.sh
RUN chmod 755 ./run.sh
CMD ["./run.sh"]

Upvotes: -1

VonC
VonC

Reputation: 1324377

If you look at the official tomcat docker image, it runs 

CMD ["catalina.sh", "run"]

That is enough to starts tomcat in the foreground, displaying the logs on the console.
But, as you said, that might not populate catalina.out.

An alternative would be:

CMD service tomcat start && tail -f /var/lib/tomcat/logs/catalina.out

Upvotes: 4

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