# Antelope API Healthcheck for HAProxy

[![Test](https://github.com/eosswedenorg/antelope-api-healthcheck/actions/workflows/test.yml/badge.svg)](https://github.com/eosswedenorg/antelope-api-healthcheck/actions/workflows/test.yml)
[![Report](https://goreportcard.com/badge/github.com/eosswedenorg/antelope-api-healthcheck)](https://goreportcard.com/report/github.com/eosswedenorg/antelope-api-healthcheck)

This program implements Antelope healthcheck for HAProxy over TCP.

## Compiling

You will need golang version `1.16` or later to compile the source.

compile with `compile.sh` script

```sh
./compile.sh
```

Execute `./compile.sh --help` to see all available flags to crosscompile for different systems/architectures.

### Package

run `./package.sh` to generate package. Debian (.deb) and FreeBSD are supported.

## TCP Protocol

The protocol is simple and has 4 rules.

1. Data is transmitted in `packets` encoded in ascii and ends with newline `\n`.
2. There are two types of packages: `Request` and `Response`. Each `Request` has exactly one `Response`.
3. Each parameter inside a `Request` is separated by `|`
4. Each response contains exactly one `status code` (see below)

### Request

The following parameters are supported in a request and are ordered from
first to last below:

| # | Name       | Required                  | Description                                                                                  |
| - | ---------- | ------------------------- | -------------------------------------------------------------------------------------------- |
| 1 | api        | Yes                       | Type of API to check against,`v1` = standard, `v2` = Hyperion, `atomic` = atomicassets |
| 2 | url        | Yes (port default `80`) | http url to the api.`http(s)://<ip-or-domain>(:<port>)`                                    |
| 3 | num_blocks | No (default `10`)       | Number of blocks the api can drift before reported `down`                                  |
| 4 | host       | No (default from `url`) | Value to send in the `HTTP Host Header` to the API                                         |

### Response

The api can respond with exactly one `status code`.
See [HAproxy documentation](https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#5.2-agent-check) for more information

| code        | Description                                                  |
| ----------- | ------------------------------------------------------------ |
| `up`      | Api is healthy                                               |
| `down`    | Api is not healthy                                           |
| `fail`    | The program failed to read the status from the api.          |
| `maint`   | Api is set in maintenance mode (not used)                    |
| `ready`   | Api is ready again after being in `maint` state (not used) |
| `stopped` | Api has been stopped manually (not used)                     |

## Author

Henrik Hautakoski - [henrik@eossweden.org](mailto:henrik@eossweden.org)