Merge pull request #4 from layer8co/readme

add readme

Author: demurky

README.md

@@ -1,3 +1,77 @@
 # netexp
 
 netexp is a Prometheus exporter that provides advanced network usage metrics.
+
+It provides the amount of `transmitted` and `recieved` bytes in each second,
+from the active network interface. besides that, it also provides the maximum `bursts`
+of these two qualities, in different time durations.
+
+By default, the information is based on the pseudo-file `/proc/net/dev` which is
+populated by the Linux kernel.
+
+## Installation
+
+### Using go toolchain 
+```go
+go install github.com/layer8co/netexp/cmd/netexp@latest
+```
+
+## Usage
+```bash
+$ netexp --help 
+
+netexp is a Prometheus exporter that provides advanced network usage metrics.
+
+Usage:
+  -burst-windows string
+    	comma-separated burst window durations (default "1s,5s")
+  -iface-regexp string
+    	regexp to match network interface names (default "^(eth\\d+|en[osp]\\d+\\S+|enx\\S+|w[lw]\\S+)$")
+  -interval duration
+    	polling interval (e.g. 500ms, 1s) (default 1s)
+  -listen string
+    	address to listen on (default ":9298")
+  -output-windows string
+    	comma-separated output window durations (default "15s,30s,60s")
+
+$ netexp -listen :9290
+listening on :9298
+matched interfaces: enp0s31f6, wlp4s0
+```
+
+## Exported metrics
+
+Here is the example output:
+```
+netexp_recv_bytes 1443950207
+netexp_trns_bytes 192449225
+
+netexp_max_1s_recv_burst_bps_over_15s 11169295
+netexp_max_1s_trns_burst_bps_over_15s 148677
+
+netexp_max_1s_recv_burst_bps_over_30s 11169295
+netexp_max_1s_trns_burst_bps_over_30s 148677
+
+netexp_max_1s_recv_burst_bps_over_1m0s 11169295
+netexp_max_1s_trns_burst_bps_over_1m0s 148677
+
+netexp_max_5s_recv_burst_bps_over_15s 8127323
+netexp_max_5s_trns_burst_bps_over_15s 114077
+
+netexp_max_5s_recv_burst_bps_over_30s 8127323
+netexp_max_5s_trns_burst_bps_over_30s 114077
+
+netexp_max_5s_recv_burst_bps_over_1m0s 8127323
+netexp_max_5s_trns_burst_bps_over_1m0s 114077
+```
+
+- `netexp_recv_bytes` The total number of bytes of data, that has been recieved
+  by the interface. which is in our case: 1443950207
+
+- `netexp_trns_bytes` The total number of bytes of data, that has been recieved
+  by the interface. which is in our case: 192449225
+  
+- `netexp_max_{burst-duration}_{direction}_burst_bps_over_{observation-duration}`
+Shows how much the maximum traffic rate observed within specific time windows.
+It basically shows __The Peak Rates__ of the network interface at small time
+windows.