How I setup Fossil on https://fly.io. I don't know that this is the best way, but it's working for me so far, so I thought I'd share the recipe. Feedback welcome.

Here's the live result today: https://flyio-fossil.fly.dev/ (no guarantees it will remain up or functioning; I'm still experimenting).

Before adding any repos the functioning machine image is only 5.7 MB(!) I see no reason it will cost any money at all to keep running as long as Fly keeps their "any usage under $5 a month is free" tier active.

The most significant missing bit I'm aware of at the moment is securing the site.

The nut of it is a Dockerfile like this:

# Dockerfile for initializing Fossil machine on Fly.io
FROM alpine:latest
RUN apk add --no-cache fossil
WORKDIR /app

# Declare volume and expose port
VOLUME ["/persistent"]
EXPOSE 8080

# Create a separate startup script file
COPY <<EOF /app/startup.sh
#!/bin/sh
mkdir -p /persistent/repos

if [ ! -f /persistent/repos/*.fossil ]; then
  echo "No repositories found, initializing new Fossil repo..." > /persistent/fossil-init.log
  fossil version >> /persistent/fossil-init.log
  
  fossil new --project-name flyio-fossil \\
    --project-desc "Hosting Fossil SCM on Fly.io" \\
    /persistent/repos/flyio.fossil \\
    --admin-user CHANGE_ME \\
    >> /persistent/fossil-init.log
    
  echo "Repository initialization complete" >> /persistent/fossil-init.log
else
  echo "Fossil repository already exists" > /persistent/fossil-init.log
fi

echo "Starting Fossil server..."
exec fossil server /persistent/repos --repolist \\
  --port 8080 \\
  --jsmode bundled \\
  --baseurl https://\$FLY_APP_NAME.fly.dev
EOF

RUN chmod +x /app/startup.sh

# Use the startup script as the entry point
ENTRYPOINT ["/app/startup.sh"]

And fly app config file like this:

# fly.toml app configuration file generated for flyio-fossil on 2025-04-02T20:54:55-07:00
#
# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
#

app = 'flyio-fossil'
primary_region = 'yyz'

[build]
  dockerfile = 'Dockerfile'

[[mounts]]
  source = 'persistent'
  destination = '/persistent'

[http_service]
  internal_port = 8080
  force_https = true
  auto_stop_machines = 'stop'
  auto_start_machines = true
  min_machines_running = 0
  processes = ['app']

[[vm]]
  size = 'shared-cpu-1x'

Initialized and published with:

fly launch --no-deploy --dockerfile Dockerfile --vm-memory 256 --generate-name --org personal --region yyz

fly vol create persistent --region yyz --size 1 --count 2

fly deploy

Expanded details of the recipe at https://flyio-fossil.fly.dev/flyio/file?name=Readme.md&ci=tip)