Improve README; check-ntpoffset
# check-ntpoffset
## Description
-
Check ntp offset.
-## Setting
+
+## Synopsis
+```
+check-ntpoffset -w=50 -c=100
+```
+
+## Installation
+
+First, build this program.
```
-[plugin.checks.ntpoffset]
-command = "/path/to/check-ntpoffset -w=50 -c=100"
+go get github.com/mackerelio/go-check-plugins
+cd $(go env GOPATH)/src/github.com/mackerelio/go-check-plugins/check-ntpoffset
+go install
```
-## Options
+Or you can use this program by installing the official Mackerel package. See [Using the official check plugin pack for check monitoring - Mackerel Docs](https://mackerel.io/docs/entry/howto/mackerel-check-plugins).
+
+
+Next, you can execute this program :-)
```
--w --warning Warning threshold of ntp offset(ms) (default: 50)
--c --critical Critical threshold of ntp offset(ms) (default: 100)
+check-ntpoffset -w=50 -c=100
```
+## Setting for mackerel-agent
+
+If there are no problems in the execution result, add s setting in mackerel-agent.conf .
+
+```
+[plugin.checks.cert-file]
+command = ["check-ntpoffset", "-w", "50", "-c", "100"]
+```
+
+## Usage
+### Options
+
+```
+ -c, --critical= Critical threshold of ntp offset(ms) (default: 100)
+ -w, --warning= Warning threshold of ntp offset(ms) (default: 50)
+ -s, --ntp-servers= Use specified NTP Servers(plural servers can be set separated by ,). When set plural servers, use first
+ response. If not set, use local command just like ntpd/chronyd.
+ -t, --ntp-timeout= Timeout of NTP Server Querying(in seconds). (default: 15)
+```
+
+
+## For more information
+
+Please execute `check-ntpoffset -h` and you can get command line options.
