Chances are that you are working on a containerized stack. Whether you built it yourself or joined a company and found one there, you are probably using docker-compose to replicate a local development environment as close to the production as possible. (In case that you are using a different approach, please let me know in the comments. I would love to hear it!)

I am going to guess that you have been probably typing > docker-compose up once you are on your desktop early in the morning and then taking a deep dive into an ocean of logs, scrolling up and down often for minutes until you find that single line you have been looking for. In this post I want to share how I have been working with docker-compose that helped me be more flexible and efficient and hopefully will help you too!

docker-compose up example

First, start docker-compose with the -d switch. From the docs:

Running docker-compose up -d starts the containers in the background and leaves them running.

You will notice that the commands exits immediately and you don't see the logs of the standard output anymore.

Let's see the state of the containers now:

> docker-compose ps

The output of the command is similar to the docker ps command. You will see a table with the names, the commands that have been used to start the containers, their state and their exposes ports. If the state of a container is Up, it means that it successfully booted up.

But where are the logs you will be wondering.

> docker-compose logs

and you will see the same output as from when we were not using the -d switch. As your docker-compose stack grows though, those logs will start to become harder and harder to watch. And also, why would you want to watch Redis logs while you are working on refactoring your favorite class?

So, since you are working on one container only and you want to watch its logs, append the container's name at then end of the command as it's written in your docker-compose.yml file. For a container called api:

> docker-compose logs api

logs will dump all logs that docker has been collecting for the whole lifetime of that container are running. These can be long and every time you call the logs command will be taking more and more time to reach the end of the output. As a solution, we can only dump the tail of our logs by using the --tail switch. Let's dump only the last 1000 lines:

> docker-compose logs --tail=1000 api

Great. But now you will have to switch on your terminal and rerun the command every time. We can leave it open with the -f switch:

> docker-compose logs --tail=1000 -f api

Yeah! That's definitely better. Add that as an alias to your shell so you won't have to remember and type it every time.

Thank you for reading this little piece. Let me know of your tips and tricks while working on your local development environment in the comments. 😎