infra-rebuild/README.md

# infra-rebuild

infra-rebuild mirrors nixos-rebuild closely in its command-line interface, but focuses on making infrastructure deployment more convenient. It is built for infrastructure defined in a flake, where each hosts configuration is represented by a different `nixosConfiguration` in the flakes output.

For building the configuration of e.g. two hosts called `web-01` and `git` one can simply run:

```
infra-rebuild build web-01 git
```

For deploying the hosts - using the switch operation - it's as simple as:

```
infra-rebuild switch web-01 git
```

Here infra-rebuild will simply run `nixos-rebuild switch` with the `target-host` option set for each host.
Because infra-rebuild tries to be usable without any configuration, by default it queries the hosts FQDN from its `nixosConfiguration` and uses that for the target host.
However to override aspects of the target host for specific or all hosts, infra-rebuild also accepts a `deployment_configuration.json` as configuration.

## Configuration

infra-rebuild accepts optional configuration in a `deployment_configuration.json`. \
The following keys are available to be set for configuring various aspects of deployment for specific or all hosts:

- `default.targetPort`: A default port to use for connecting to all host.
- `default.targetUser`: A default user to use for connecting to all host.
- `hosts.<host>.targetPort`: The port to use for connecting to `<host>`.
- `hosts.<host>.targetUser`: The user to use for connecting to `<host>`.
- `hosts.<host>.targetHostname`: The hostname to use for connecting to `<host>`.

### Example

An example `deployment_configuration.json` might look like this then:

```json
{
  "default": {
    "targetPort": 2222,
    "targetUser": "deploy"
  },
  "hosts": {
    "web-01": {
      "targetUser": "web-deploy",
      "targetHostname": "web-01-intern.infra.example",
      "targetPort": 22
    }
  },
  "git": {
    "targetUser": "git-deploy"
  }
}
```

### Order of Precedence

The order of precedence from least to greatest for `targetPort` and `targetUser` is the following:

1. system default
2. `default.targetPort/User`
3. `hosts.<host>.targetPort/User`

The order of precedence from least to greatest for `targetHostname` is the following:

1. FQDN from hosts nixosConfiguration
2. `hosts.<host>.targetHostname`

## License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.