Setting Up the LXC Container

Tue, 30 Jul 2024 17:11:22 +0100

I’m using LXC containers on Proxmox. If you have a different method of working with containers I’m pretty sure you’ll be able to use the info here and repurpose it to your preferences.

Create an Alpine container

I won’t go into the details of how to do this as it’s specific to Proxmox and no different to setting up any other LXC container in Proxmox.

I’m using Alpine Linux as the container distro as it’s very lightweight and the F-Droid tools don’t need anything fancy.

~~In terms of resources, it doesn’t need much, the following has been more than enough for me so far:~~

~~512MB RAM~~
~~512MB swap~~
~~8GB disk~~

How naive of me, Gradle is much more greedy than I originally thought and I was getting build errors due to low resources. So I set the container up with:

6GB RAM
1GB swap
16GB disk

Set up the container for F-Droid builds

While logged into my Alpine container, first I set up some basics:

# Ensure everything is up to date
apk update
apk upgrade

# Install and configure git
apk add git vim
git config --global user.name "<YOUR_NAME>"
git config --global user.email "<YOUR_EMAIL>"
ssh-keygen
cat .ssh/id_rsa.pub 
# ... then copy key to gitlab SSH keys

F-Droid build instructions depend on docker, so:

apk add docker

# Start docker on boot
rc-update add docker boot

# Start docker now (or reboot so the above command can take effect)
service docker start

Now get the F-Droid stuff installed:

git clone --depth=1 git@gitlab.com:<YOUR_ACCOUNT>/fdroiddata.git ~/fdroiddata
cd ~/fdroiddata
git checkout -b com.example
cp templates/build-gradle.yml metadata/com.example.yml



# If (like me) you already created a fork before it's a little different 
# and you have to do this instead of the above

# git clone --depth=1 git@gitlab.com:<YOUR_ACCOUNT>/fdroiddata.git ~/fdroiddata
# cd fdroiddata/

# Shallow cloning makes other branches inaccessible, fix that
# git remote set-branches origin '*'
# git fetch -v --depth=1

# And now the branch can be checked out
# git checkout com.example

The container is set up now, later on on we’ll get around to how to actually use it…

Intro

Tue, 30 Jul 2024 17:11:20 +0100

Building apps for F-Droid is a fairly complex process, involving:

A couple of git repos (besides any your own project may have)
Using docker
Forking and merge requests on GitLab
F-Droid’s specialised build commands

F-Droid gives instructions on their process here.

I managed to get my first Android app (BendyStraw) published on F-Droid but felt a little out of my depth at times and didn’t have a clear mental model of all the moving parts.

So in this series of articles I’m going to write up the process in my own words. I’ll add a couple of scripts which help reduce some repetitive steps, and as the fdroid build command can take a while I’ve set things up so that I can automatically be sent a message on Telegram when the process is finished.

Proxmox

My main development machine runs Proxmox, a special OS which just hosts virtual machines and containers. Roughly speaking, a virtual machine virtualises the hardware, whereas a container virtualises the operating system.

With Proxmox the main OS is only used for managing these virtual systems. Everyday computer usage such as development work is always done inside a virtual environment, for example if I’m writing Flutter code I’ll be working inside a Debian virtual machine.

I decided to make a small separate container dedicated only to building apps for F-Droid. I’ll be releasing more apps on F-Droid in future so it will be nice to have a clean environment siloed off for the job. Proxmox uses LXC containers and I chose to use an Alpine Linux template to get me started because Alpine is very lean.

Lxc on mm-dev

Setting Up the LXC Container

Create an Alpine container

Set up the container for F-Droid builds

Intro

Proxmox