### rtrace
A wrapper for [recon](https://github.com/ferd/recon/) library. This application also exposes a REST api for call tracing. Although `recon` supports various trace patterns, this api allows on tracing function calls with just module and function name for a maximum of 100 calls.
### Usage
Add `rtrace` as a dependency in `rebar.config`
```erlang
{deps, [
{rtrace, "<latest release>"}
]}.
```
By default, the application listens on port 15000 for incoming api requests. This port can be customized by setting `http_port` value in `sys.config`. The application can also be restricted to listen only on a specific ip address by setting `http_host_ip` property.
```erlang
[
{rtrace, [
{http_port, 17000}, %% a different port
{http_host_ip, {127, 0, 0, 1}} %% listen only on localhost
]}
].
```
#### API
The application exposes the following api's.
<table>
<tr><td colspan="2"><strong>POST /api/v1/trace</strong></td></tr>
<tr>
<td><strong>Description</strong></td>
<td>Start trace</td>
</tr>
<tr>
<td><strong>Request</strong></td>
<td>
<pre>
{
"mod": "maps",
"fun": "get",
"calls": 10
}
</pre>
</td>
</tr>
<tr>
<td><strong>Response</strong></td>
<td>
<pre>
"cfa0b15d-0ecb-4486-8768-8bf1755a5c92"
</pre>
</td>
</tr>
</table>
<table>
<tr><td colspan="2"><strong>GET /api/v1/logs/:uuid</strong></td></tr>
<tr>
<td><strong>Description</strong></td>
<td>Get logs for specified trace request</td>
</tr>
<tr>
<td><strong>Response</strong></td>
<td>
<pre>
[
"...",
"..."
]
</pre>
The response is a list of trace logs
</td>
</tr>
</table>
**NOTE:** All requests and responses are encoded as JSON.
#### UX
Navigate to `http://localhost:15000` in your browser. You can now start tracing and view trace logs from the UI.
- Press `Start` to start trace after entering module and function names.
- The page will refresh and display a `Refresh` button along with some information.
- Press `Refresh` button to display the trace logs. The logs would not refresh if `recon` trace limit has been tripped or the function under trace is never called.
### Contributing
