Deploy to Fly.io

Fly.io runs the Docker image directly. You deploy the container from a scaffolded project (npm create flaghoist@latest team-flags -- --platform container) or a copy of examples/docker, and back it with Postgres. About ten minutes.

Install flyctl, then:

fly auth login

2. Launch the app

From the container project (it has the Dockerfile), scaffolded with the CLI or copied from examples/docker:

fly launch --no-deploy

Answer the prompts for a name and region. fly launch detects the Dockerfile and writes a fly.toml. Make sure its [http_service] block has internal_port = 8080, the port the container listens on.

3. Attach Postgres

fly postgres create               # creates a Postgres app
fly postgres attach <pg-app-name> # sets DATABASE_URL on your app

Fly’s internal Postgres is reached over the private network without TLS, so append ?sslmode=disable to the connection string it set, otherwise the container tries to negotiate SSL and the connection fails:

fly secrets set DATABASE_URL="postgres://…internal:5432/<db>?sslmode=disable"

Any managed Postgres works too (Supabase, Neon), using its own URL. Those require TLS, which the container enables by default, so no sslmode is needed.

4. Set the rest of the config

fly secrets set FLAGS_STORAGE=postgres \
  ADMIN_TOKEN="$(openssl rand -hex 32)" \
  READ_API_KEY="$(openssl rand -hex 32)"

5. Deploy

fly deploy

Fly gives you https://<app>.fly.dev.

6. Verify

curl https://<app>.fly.dev/health

Create a flag from the dashboard at https://<app>.fly.dev/admin (paste your ADMIN_TOKEN), then read it back:

curl -X POST https://<app>.fly.dev/ofrep/v1/evaluate/flags/new-checkout \
  -H "x-api-key: $READ_API_KEY" -H "content-type: application/json" \
  -d '{"context":{"targetingKey":"tester-1"}}'

Everything Docker-specific is in Deploy with Docker; Fly just runs that image.