Update README.md

README.md

@@ -7,7 +7,7 @@
 [![Maintainability](https://api.codeclimate.com/v1/badges/52f9e1f0388e8aa38bfe/maintainability)](https://codeclimate.com/github/hipages/php-fpm_exporter/maintainability)
 [![Test Coverage](https://api.codeclimate.com/v1/badges/52f9e1f0388e8aa38bfe/test_coverage)](https://codeclimate.com/github/hipages/php-fpm_exporter/test_coverage)
 
-A prometheus exporter for PHP-FPM.
+A [prometheus](https://prometheus.io/) exporter for PHP-FPM.
 The exporter connects directly to PHP-FPM and exports the metrics via HTTP.
 
 A webserver such as NGINX or Apache is **NOT** needed!
@@ -17,22 +17,70 @@ A webserver such as NGINX or Apache is **NOT** needed!
 * Export single or multiple pools
 * Export to CLI as text or JSON
 * Connects directly to PHP-FPM via TCP or Socket
+* Maps environment variables to CLI options
 
 ## Usage
 
-* ```php-fpm_exporter get --phpfpm.scrape-uri 127.0.0.1:9000,127.0.0.1:9001,[...]```
+`php-fpm_exporter` is released as [binary](https://github.com/hipages/php-fpm_exporter/releases) and [docker](https://hub.docker.com/r/hipages/php-fpm_exporter/) image.
-* ```php-fpm_exporter server --phpfpm.scrape-uri 127.0.0.1:9000,127.0.0.1:9001,[...]```
+It uses sensible defaults which usually avoids the need to use command parameters or environment variables.
+
+`php-fpm_exporter` supports 2 commands, `get` and `server`.
+The `get` command allows to retrieve information from PHP-FPM without running as a server and exposing an endpoint.
+The `server` command runs the server required for prometheus to retrieve the statistics.
+
+### Options and defaults
+
+| Option                 | Description                                           | Environment variable         | Default value   |
+|------------------------|-------------------------------------------------------|------------------------------|-----------------|
+| `--web.listen-address` | Address on which to expose metrics and web interface. | `PHP_FPM_WEB_LISTEN_ADDRESS` | [`:9253`](https://github.com/prometheus/prometheus/wiki/Default-port-allocations)         |
+| `--web.telemetry-path` | Path under which to expose metrics.                   | `PHP_FPM_WEB_TELEMETRY_PATH` | `/metrics`      |
+| `--phpfpm.scrape-uri`  | FastCGI address, e.g. unix:///tmp/php.sock;/status or tcp://127.0.0.1:9000/status | `PHP_FPM_SCRAPE_URI` | `tcp://127.0.0.1:9000/status` |
+
+### CLI Examples
+
+* Retrieve information from PHP-FPM running on `127.0.0.1:9000` with status endpoint being `/status`
+
+  ```php-fpm_exporter get```
+
+* Retrieve information from PHP-FPM running on `127.0.0.1:9000` and `127.0.0.1:9001`
+
+  ```php-fpm_exporter get --phpfpm.scrape-uri tcp://127.0.0.1:9000/status,tcp://127.0.0.1:9001/status```
+
+* Run as server with 2 pools:
+
+  ```php-fpm_exporter server --phpfpm.scrape-uri tcp://127.0.0.1:9000/status,tcp://127.0.0.1:9001/status```
+
+### Docker Examples
+
+* docker pull hipages/php-fpm_exporter
+* docker run -it --rm -e PHP_FPM_SCRAPE_URI="tcp://127.0.0.1:9000/status,tcp://127.0.0.1:9001/status" hipages/php-fpm_exporter
 
 ## Metrics collected
 
-| Metric | Type |
+```
-|--------|------|
+# HELP phpfpm_accepted_connections The number of requests accepted by the pool.
-
+# TYPE phpfpm_accepted_connections counter
-
+# HELP phpfpm_active_processes The number of active processes.
-
+# TYPE phpfpm_active_processes gauge
-## TODO
+# HELP phpfpm_idle_processes The number of idle processes.
-
+# TYPE phpfpm_idle_processes gauge
-- [ ] Test with unix socket
+# HELP phpfpm_listen_queue The number of requests in the queue of pending connections.
+# TYPE phpfpm_listen_queue gauge
+# HELP phpfpm_listen_queue_length The size of the socket queue of pending connections.
+# TYPE phpfpm_listen_queue_length gauge
+# HELP phpfpm_max_active_processes The maximum number of active processes since FPM has started.
+# TYPE phpfpm_max_active_processes counter
+# HELP phpfpm_max_children_reached The number of times, the process limit has been reached, when pm tries to start more children (works only for pm 'dynamic' and 'ondemand').
+# TYPE phpfpm_max_children_reached counter
+# HELP phpfpm_max_listen_queue The maximum number of requests in the queue of pending connections since FPM has started.
+# TYPE phpfpm_max_listen_queue counter
+# HELP phpfpm_slow_requests The number of requests that exceeded your 'request_slowlog_timeout' value.
+# TYPE phpfpm_slow_requests counter
+# HELP phpfpm_start_since The number of seconds since FPM has started.
+# TYPE phpfpm_start_since counter
+# HELP phpfpm_total_processes The number of idle + active processes.
+# TYPE phpfpm_total_processes gauge
+```
 
 ## Contributing
 
@@ -41,3 +89,9 @@ The maintainers actively manage the issues list, and try to highlight issues sui
 The project follows the typical GitHub pull request model.
 See " [How to Contribute to Open Source](https://opensource.guide/how-to-contribute/) " for more details.
 Before starting any work, please either comment on an existing issue, or file a new one.
+
+## Alternatives
+
+* [bakins/php-fpm-exporter](https://github.com/bakins/php-fpm-exporter)
+* [peakgames/php-fpm-prometheus](https://github.com/peakgames/php-fpm-prometheus)
+* [craigmj/phpfpm_exporter](https://github.com/craigmj/phpfpm_exporter)