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Prepare Solstice Ledger for Fly.io and managed Postgres.

Goal

This snapshot advances Solstice Ledger by teaching you to prepare Solstice Ledger for Fly.io and managed Postgres.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use Elixir 1.15+, Mix, and Docker for Postgres stages.

Port 4001 must be free. Copy .env.example before starting database stages.

  • Elixir and Mix
  • A code editor and terminal
  • Docker from part 4 onward

Concepts

Production needs HTTPS cookies, a strong SECRET_KEY_BASE, and env-only database URLs.

Keep controllers thin: plugs prepare requests, contexts enforce rules, and HEEx escapes output by default.

Walkthrough

Review fly.toml; never commit .env.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

SECRET_KEY_BASE=...\nDATABASE_URL=postgres://...

Run and verify

Enter 12-Deploy, fetch deps, copy .env.example, and start Phoenix on port 4001.

Open http://127.0.0.1:4001. Watch the terminal for validation and database errors.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-phoenix-blog.git
cd fcc-phoenix-blog/12-Deploy
mix deps.get
cp .env.example .env
mix phx.server

Troubleshooting

If sessions vanish after deploy, check HTTPS cookie settings.

For database failures, confirm Docker and the solstice_NN name when applicable. Never commit .env or _build/deps secrets.

  • Read the first error first
  • Restart after environment changes
  • Never commit secrets

Try this

List every secret that must live only in the host environment.

Test a happy path and one invalid or unauthorized request.

  • Make one small change
  • Test it in the browser
  • Compare with the next snapshot only after it works

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