fly-deploy

# Fly.io Deployment

Deploy applications to Fly.io from source code or Docker images.

## Prerequisites

Ensure `flyctl` is installed and authenticated:

```bash
# Check installation
fly version

# Authenticate if needed
fly auth login
```

## Deployment Workflow

### 1. Detect Project Type

Examine the project root to determine the stack:

| Indicator | Type | Reference |
|-----------|------|-----------|
| `next.config.*` | Next.js | [references/nextjs.md](references/nextjs.md) |
| `Dockerfile` | Docker | [references/docker.md](references/docker.md) |
| `package.json` (no Next) | Node.js | [references/nodejs.md](references/nodejs.md) |
| `requirements.txt` / `pyproject.toml` | Python | [references/python.md](references/python.md) |
| `index.html` only | Static | [references/static.md](references/static.md) |

Read the appropriate reference file for framework-specific configuration.

### 2. Initialize or Configure

**New app:**
```bash
fly launch --no-deploy
```

This creates `fly.toml`. Review and adjust before deploying.

**Existing app (no fly.toml):**
```bash
fly launch --no-deploy
# Or create fly.toml manually using references/fly-toml.md
```

### 3. Set Secrets

Set environment variables that shouldn't be in fly.toml:

```bash
# Single secret
fly secrets set DATABASE_URL="postgres://..."

# Multiple secrets
fly secrets set KEY1=value1 KEY2=value2

# From .env file
cat .env | fly secrets import
```

Secrets trigger a redeploy. Use `--stage` to batch them:

```bash
fly secrets set --stage KEY1=value1
fly secrets set --stage KEY2=value2
fly secrets deploy
```

### 4. Deploy

```bash
fly deploy
```

**Common flags:**
- `--ha` — High availability (2+ machines, default)
- `--no-ha` — Single machine (dev/staging)
- `--strategy rolling|bluegreen|canary|immediate`
- `--wait-timeout 5m` — Extend for slow builds

### 5. Verify

```bash
# Check status
fly status

# View logs
fly logs

# Open in browser
fly open
```

## Troubleshooting

If deployment fails, consult [references/troubleshooting.md](references/troubleshooting.md) for common errors and fixes.

**Quick checks:**
1. Health check passing? Check `internal_port` matches app's listen port
2. App starting? Check `fly logs` for crash loops
3. Build failing? Check Dockerfile or buildpack compatibility

## Configuration Reference

For detailed fly.toml options, see [references/fly-toml.md](references/fly-toml.md).

**Key settings:**
- `primary_region` — Where machines deploy by default
- `[http_service]` — HTTP/HTTPS configuration
- `[env]` — Non-sensitive environment variables
- `[[vm]]` — CPU/memory sizing