Documentation update and linting fix.

.golangci.yml

@@ -18,6 +18,7 @@ linters-settings:
     min-complexity: 40
   funlen:
     lines: 200
+    statements: 100
 
 issues:
   exclude-rules:

docs/CLIENT.md

@@ -0,0 +1,53 @@
+# Metricator Client
+
+Metricator client was created to help with Metricator daemon communication. It is able to produce different output based on selected format.
+
+## Parameters
+
+| Parameter | Type | Description |
+| --------- | ---- | ----------- |
+| `-application` | string | Name of application to query. |
+| `-apps-list` | bool | Request type: applications list. |
+| `-config` | string | Path to configuration file. **MANDATORY** |
+| `-metric` | string | Request type: single metric. Name of metric to request. |
+| `-metricator-host` | URL | URL to Metricator daemon. (e.g. `http://127.0.0.1:34421`). **MANDATORY** |
+| `-metricator-timeout` | integer | Timeout in seconds for Metricator Client's HTTP requests. By default - 5 seconds. |
+| `-metrics-list` | bool | Request type: list of metrics. **Requires `-application` parameter to be filled.** |
+| `-output` | string | Type of output to produce (see below). |
+
+## Request types
+
+One of following parameters should be defined:
+
+* `-apps-list` to get listing of applications that is registered at Metricator daemon.
+* `-metrics-list` with `-application` parameters to get list of metrics for application which Metricator know.
+* `-metric` with name of metric and `-application` (with a name of application) parameters to get specific metric for application which Metricator know.
+
+See Examples section below.
+
+## Outputs
+
+Currently Metricator client is able to produce JSON and "Plain By Line" outputs. Their meanings:
+
+* When `-output=json` is specified (or `-output` wasn't specified at all) Metricator Client will just dump response from Metricator Daemon.
+* When `-output=plain-by-line` is specified Metricator Client will transform received data into line-by-line output, e.g. every application name on separate line, every metric name on separate line, etc.
+
+## Examples
+
+* Get list of applications registered at Metricator daemon line-by-line (for later use with metrics autodiscovery helper):
+
+```shell
+metricator-client -config=./metricator.yaml -metricator-host http://127.0.0.1:34421 -output plain-by-line -apps-list
+```
+
+* Get list of metrics for application `test` in JSON format:
+
+```shell
+metricator-client -config ./metricator.yaml -metricator-host http://127.0.0.1:34421 -application test -metrics-list
+```
+
+* Get specific metric for application `test`:
+
+```shell
+metricator-client -config ./metricator.yaml -metricator-host http://127.0.0.1:34421 -application test -metric mymegametric
+```

docs/INDEX.md

@@ -31,3 +31,4 @@ dnsdist_frontend_responses/frontend:127.0.0.1:53/proto:UDP/thread:0
 * [Installation](INSTALL.md)
 * [Configuration](CONFIGURE.md)
 * [API](API.md)
+* [Client](CLIENT.md)