Running FreshRSS on Fly.io
FreshRSS is a free, self-hostable RSS feeds aggregator. Fly.io is a super amazing platform that runs application servers close to end users.
Fly.io can take Docker images (or Dockerfiles, or buildpacks) and boot them into Firecracker powered microVMs. When you deploy with Fly.io, you get an Anycast IP, along with TLS offloading by them. The Firecracker microVMs can scale up & down per traffic, and it comes with a pretty generous free tier that includes
- Up to 3 shared-cpu-1x 256MB VMs
- 3GB of total persistent volume storage
- 160GB outbound data transfer
Since FreshRSS comes with a Docker image, adapting it to fly.io was as straightforward as pointing to FreshRSS' Docker image. These are the steps if you wish to run FreshRSS on your fly.io account
- Sign up for Fly.io or sign-in
- Install flyctl
- Sign into your Fly.io account by typing
flyctl auth login
- Create a
fly.tomlfile similar to the one in my repo. Make sure to update the appname to a unique name.
- Review the environment variables listed in the
[env]section and update if required. You can check FreshRSS' docs on the environment variables that can be updated
- Create a volume for persisting data using the command
fly volumes create freshrss_data --size 1
- In this command, we create a volume of size 1GB. This can be increased later, so I selected the lowest possible number, as flyctl expects size in GB and doesn’t accept fractional numbers.
- Save the
fly.tomlfile. From the same directory where
fly.tomlis present, deploy FreshRSS the application using
fly launch. Fly.io will pull the Docker image and launch the VM. The output should be as shown below:
That’s it! FreshRSS should be accessible from the URL
<appname>.fly.dev. You can front a custom domain as well. Head over to the Certificates tab from Fly.io’s dashboard, or use the
flyctl tool to provision a certificate by typing
flyctl certs add <domain>. Add the CNAME that Fly tells you about, and then add an A record for the (sub)domain, pointing to the Anycast IP you get from deploying FreshRSS. See Fly.io’s docs on how to do this.
- FreshRSS extensions need to be available on
/var/www/FreshRSS/extensions, however - Fly.io doesn’t support having same mount for mulitple directories, or having multiple mounts.
- Trying to mount just
/var/www/FreshRSScaused the microVM to throw kernel panics, mainly because the underlying Docker container expects something there - probably the webserver config and mounting an empty VM causes errors
- You could try to play with Fly’s internal networking, including setting up a wireguard tunnel, but I didn’t try.
- Another icky way is to build a custom Dockerfile copying the required extensions into the image during the build step..
- Trying to mount just
- I haven’t run this for long, will update if I run into issues
Automated updates and deploys
Fly.io’s CLI-oriented approach makes updates via GitHub actions easy. While I haven’t set up for FreshRSS, you can look at this PR where I add a GitHub action to deploy my blog, sathyabh.at, a static site powered by Hugo to Fly.io.
Fly.io’s community Discourse is quite active if you run into any problems. Hope this gives you a good taste of what Fly.io can offer.
See also: Github repo of the fly.io config file.