blog/content/posts/podman-setup.md

+++
title = 'Podman Setup - p1'
date = 2024-10-25T23:11:17+03:00
draft = false
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# Podman

In this 'article' I will be walking you through my process of how I
host everything on this server.

When first creating this website, I had a small issue with how I wrote
my code and deployed it: whenever I made a small change to the page, I had
to manually rebuild it, then upload the updated version to server and put it
in the web directory.

This is a cumbersome process. For comparison, in my new setup, all I have to
do is to run `git commit` and `git push` after any change and my website will be
automatically built and deployed. 

The previous "manual" approach also depends on me having already installed all
necessary software. If you have a dedicated server that you're running yourself,
that's probably okay, you just have to setup once, but I'm running this on a VPS
that I'm not sure I'll keep forever. The ability to reproduce this exact setup 
within minutes actually matters.

After reading a bit on this topic, I decided I would use podman for this. Docker would
work just as nicely (any containerisation software would work, really), but I decided 
on podman because it can run without a daemon and without root privilages. Also,
it has pretty neat support for kubernetes pods (which are honestly a lot more useful
than I would've given them credit for before I started this whole project).

That's really why I'm writing this. So that you, the reader (or possibly my future self) can
understand the methodology of podman, how to create pods, run containers and configure all
of this automatically, and so that I may demonstrate and share what I've learnt during
this process.

## Motivation

Basically, I'm already running a web server. Why shouldn't I also host several other services
for friends and family while I'm at it? Why shouldn't I make the entire setup reproducable?

Here are some of the services I wanted to self-host:
    - Web server: obviously, who doesn't want a website?
    - Some git server: having my own place to show off all the things I've done is certainly really cool.
    - Wireguard: Free VPN along with the website? sign me up.
    - CI/CD: automatic testing and releases of my software is cool, and also incredibly useful because that's
how I plan to handle the website as well.

Of course, there are always more things I could be self-hosting. So it makes sense to automate
the setup, and that's where podman comes in.

## Basics of podman

Before we can get to the exciting stuff, we need to go over what podman is, and how to
use it. Essentially, podman is a container engine: it lets you build and run applications in
a containerized environment. Containers are useful because they provide security,
easy setup and most importantly, reproducability.

I'm not going to spend any more time explaining what containers are and why they're
good, that's been done to death already. Right now, what matters is the actual setup,
so let's get on with it.

If you've used docker before, you'll feel right at home. Many commands are unchanged
from docker, making podman a suitable drop-in replacement. Some things like network
setups tend to be a little different, but that won't matter too much right now.

In case you're unfamiliar with docker, here are some basic commands:

```sh
# Search for container images (on docker.io unless you configure otherwise)
$ podman search <image name>

# Download (pull) an image from remote repo
$ podman pull <image name>

# list the images you have pulled.
$ podman images

# run a container.
$ podman run <image name>

# run a container, but with a LOT of flags. I just listed the most useful ones.
$ podman run
    -i # interactive, so you can e.g. run a shell in the container
    -t # allocates a tty. useful with -i so that shell completion etc. can work
    -d # opposite of -i, detach and run in the background
    --port <HOST PORT>:<CONTAINER PORT> # port forwarding, for when you need a server.
    -v <HOST DIR>:<CONT DIR>:<FLAGS> # give the container access to some directory
    <image name>
    <command> # ... want a shell?

# list running containers. add -a to list ALL containers, running or stopped.
# podman ps <-a>

# stop a running container.
$ podman stop <id>

# stopped containers don't automatically get removed. This command removes it.
$ podman rm <id>
```

## Pods are nice.

Pods are basically just a collection of containers - multiple programs working with each other.

Usually, on a server, each application *isn't* totally separate from each other - for my own usecase,
I want my git server (e.g. gogs) to automatically build and update my website whenever I push to its git
repository. That means my git server and web server can't be *totally* separate, there's some amount of
relation. Pods can help with this.

Pods allow you to create a "pod" containing several containers, sharing resources with each other, etc.
For example, I could run a pod with nginx and gogs running in seperate containers - then, the nginx
server could act as a reverse proxy based on host name, showing the web page on emin.software,
and the git server on git.emin.software. Nginx redirects to gogs which only binds to *the pod's localhost
address*, so only nginx can reach it. Likewise, a database server can be added to the pod only for the
git server to use, so that it can't be reached from the outside the pod - and it is logically grouped
along with the rest of the pod.

On top of this, pods can be built purely from a kubernetes-compatible configuration file, so setting them
up is relatively easy.