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In April 2024, I join a large, enterprise Electronics/Information Technology company in Indonesia with hundreds of engineers. After eight years working in two small startups, I found that working at large company is something new, a refreshing environment.

In this journal, I want to collect some of the weird and amusing cases of software engineering and IT in general. Please takes this notes as your future reflection, not as critics, so we can learn together.

Weird IP address

When I got my laptop, I get assigned with IP address. My forehead immediately wrinkled. If not mistaken this IP address is not in private network. After checking with WHOIS database, it is a public IP address belong to ATT-MOBILITY-LLC.

Also, there is some websites that we cannot be opened and some are broken. Some are actually blocked, and some websites maybe broken due to IP address conflict with our "internal" networks.


Case 1: Over dockerism

Over dockerism is when you try to dockerize everything which makes things that should be simple become complicated without any additional advantages.

In my case, we try to run Jenkins using docker. Not only that, the agent (the one that responsible to run the Jenkins’ jobs) also run inside the docker.

Notes that, we are a small team, a three person with only three-to-five active repository.

Things that should be simple like these,

Simple jenkins flow

Become complex like these,

Jenkins on docker

Running Jenkins server in container will be make sense if your distro cannot provides Java version that is supported by Jenkins. Jenkins application is distributed in war file that can be run in single command. It only needs a dedicated user (to isolate with the rest of system) and a directory, as a workspace.

Running Jenkins agent that triggered by Jenkins server does not make sense on small team. It make senses if you are creating an application like GitHub Actions or Circle-CI where a resource needs to be limited (but in my theory, the agent should be running 24/7, not start-and-stopped frequently).

There is another problem that I found when we run a Jenkins agent as container. Assume that your project require three tools to build, lint, and test. The frontend require nodejs and npm, and the backend require python with pyenv.

If we trigger the job inside the Jenkins agent, we need to either, (1) install all of those tools inside the same image as Jenkins agent, or (2) install it as separate images, like agent-with-nodejs and agent-with-pyenv.

The list of things that you need to do (building image, testing image, deploying images) become cumbersome.

The simplest solution is by installing and managing the nodejs using nvm and python version using pyenv, inside the host OS and run the agent directly from the host too.

Using container is make sense if your projects depends on archaic or specific version of glibc or third party libraries that are NOT supported on the host operating system (which you should upgrade).

Using docker inside Jenkins

The containers contains the tools and what the agent do is to mount the repository into the container and run build, lint, test inside the container.

When you want to upgrade the tools to new version, you create new image and publish it and update the Jenkins job to use new image.

Case 2: Multiple services on one container

Even thought it is possible to run multiple services inside one container, it is advisable to separate it.

In our case, we have one containers that run five services in the background, three backends, one HTTP server, and one message broker.

We use s6 to do that.