Alpine Linux is a very small distro, built on musl libc and busybox. It uses ash as the default shell, OpenRC as the init system, and apk as the package manager. According to their website, an Alpine container "requires no more than 8 MB and a minimal installation to disk requires around 130 MB of storage." An actual bare metal machine is recommended to have 100 MB of RAM and 0-700 MB of storage space.
Historically, I've used Ubuntu's minimal installation image as my server OS for the last five years. Ubuntu worked well and helped as my original server contained an nVidia GPU and no onboard graphics, so quite a few distros won't boot or install without a lot of tinkering.
Alpine has given me a huge increase in performance across my Docker apps and Nginx websites. CPU load for the new server I'm using to test Alpine hovers around 0-5% on average with an Intel(R) Core(TM) i3-6100 CPU @ 3.70GHz.
The only services I haven't moved over to Alpine are Plex Media Server and Syncthing, which may increase CPU load quite a bit depending on how many streams are running.
In terms of installation, Alpine has an incredibly useful wiki that will guide a user throughout the installation and post-installation processes, as well as various other articles and guides.
To install Alpine, find an appropriate image to download and flash it to a USB using software such as Rufus or Etcher. I opted to use the Standard image for my x86~64~ architecture.
Once the USB is ready, plug it into the machine and reboot. Note that
you may have to use a key such as
to access the boot menu. The Alpine Linux terminal will load quickly and
for a login.
To log in to the installation image, use the
there is no password. Once logged-in, execute the setup command:
The setup script will ask a series of questions to configure the system. Be sure to answer carefully or else you may have to re-configure the system after boot.
- Keyboard Layout (Local keyboard language and usage mode, e.g., us and variant of us-nodeadkeys.)
- Hostname (The name for the computer.)
- Network (For example, automatic IP address discovery with the "DHCP" protocol.)
- DNS Servers (Domain Name Servers to query. For privacy reasons, it is NOT recommended to route every local request to servers like Google's 18.104.22.168 .)
- Proxy (Proxy server to use for accessing the web. Use "none" for direct connections to the internet.)
- Mirror (From where to download packages. Choose the organization you trust giving your usage patterns to.)
- SSH (Secure SHell remote access server. "Openssh" is part of the default install image. Use "none" to disable remote login, e.g. on laptops.)
- NTP (Network Time Protocol client used for keeping the system clock in sync with a time-server. Package "chrony" is part of the default install image.)
- Disk Mode (Select between diskless (disk="none"), "data" or "sys", as described above.)
Once the setup script is finished, be sure to reboot the machine and remove the USB device.
There are many things you can do once your Alpine Linux system is up and running, and it largely depends on what you'll use the machine for. I'm going to walk through my personal post-installation setup for my web server.
Upgrade the System
First, login as
rootin order to update and upgrade the system:
Adding a User
I needed to add a user so that I don't need to log in as root. Note that if you're used to using the
sudocommand, you will now need to use the
doascommand on Alpine Linux.
You can now log out and log back in using the newly-created user:
Enable Community Packages
In order to install more common packages that aren't found in the
mainrepository, you will need to enable the
Uncomment the community line for whichever version of Alpine you're running:
#http://dl-cdn.alpinelinux.org/alpine/edge/main #http://dl-cdn.alpinelinux.org/alpine/edge/community #http://dl-cdn.alpinelinux.org/alpine/edge/testing
Install Required Packages
Now that the community packages are available, you can install any packages you need. In my case, I installed the web server packages I need for my services:
If you didn't install OpenSSH as part of the installation, you can do so now:
Next, either create a new key or copy your SSH key to the server from your current machines:
# Create a new key
If you need to copy an existing SSH key from a current machine:
# Copy key from existing machines
Lastly, I installed
ufwabove as my firewall. To set up, default to deny incoming and allow outgoing connections. Then selectively allow other ports or apps as needed.
If you don't like the hostname set during installation, you just need to edit two files. First, edit the simple hostname file:
Next, edit the
Nginx Web Server
To set up my web server, I simply created the
www user and
created the necessary files.
If you're running a simple webroot, you can alter the main
nginx.conf file. Otherwise, you can drop configuration
files in the following directory. You don't need to enable or symlink
the configuration file like you do in other systems.
Once the configuration is set and pointed at the
directory to serve files, enable the Nginx service:
# Note that 'default' must be included or Nginx will not start on boot
Docker works exactly the same as other systems. Either execute a
docker run command or create a
docker-compose.yml file and do
docker-compose up -d.
I went in-depth on how to self-host a git server in another post: Self-Hosting a Personal Git Server.
However, there are a few differences with Alpine. First note that in
order to change the
git user's shell, you must do a few
things a little different:
Thoughts on Alpine
So far, I love Alpine Linux. I have no complaints about anything at this point, but I'm not completely finished with the migration yet. Once I'm able to upgrade my hardware to a rack-mounted server, I will migrate Plex and Syncthing over to Alpine as well - possibly putting Plex into a container or VM.
The performance is stellar, the
apk package manager is
seamless, and system administration tasks are effortless. My only regret
is that I didn't install Alpine sooner.