Improve README; check-postgresql
# check-postgresql
## Description
+Checks for PostgreSQL.
-Checks for PostgreSQL
-## Sub Commands
+## Synopsis
+```
+check-postgresql connection --host=127.0.0.1 --port=5432 --user=USER --password=PASSWORD --database=DBNAME --warning=70 --critical=90
+```
-- connection
+## Installation
-## check-postgresql connection
+First, build this program.
-Checks the number of PostgreSQL connections.
+```
+go get github.com/mackerelio/go-check-plugins
+cd $(go env GOPATH)/src/github.com/mackerelio/go-check-plugins/check-postgresql
+go install
+```
+
+Or you can use this program by installing the official Mackerel package. See [Using the official check plugin pack for check monitoring - Mackerel Docs](https://mackerel.io/docs/entry/howto/mackerel-check-plugins).
+
+
+Next, you can execute this program :-)
+
+```
+check-postgresql connection --host=127.0.0.1 --port=5432 --user=USER --password=PASSWORD --database=DBNAME --warning=70 --critical=90
+```
+
+
+## Setting for mackerel-agent
-### Setting
+If there are no problems in the execution result, add s setting in mackerel-agent.conf .
```
-[plugin.checks.postgresql_connection]
-command = "/path/to/check-postgresql connection --host=127.0.0.1 --port=5432 --user=USER --password=PASSWORD --database=DBNAME --warning=70 --critical=90
+[plugin.checks.check-postgresql-sample]
+command = ["check-postgresql", "connection", "--host", "127.0.0.1", "--port", "5432", "--user", "USER", "--password", "PASSWORD", "--database", "DBNAME", "--warning", "70", "--critical", "90"]
```
+
+## Usage
+### Subcommands
+
+```
+ connection
+```
+
+### Options
+#### `connection` subcommand
+
+Checks the number of PostgreSQL connections.
+
+```
+ -H, --host= Hostname (default: localhost)
+ -p, --port= Port (default: 5432)
+ -u, --user= Username (default: postgres)
+ -P, --password= Password [$PGPASSWORD]
+ -d, --database= DBname
+ -s, --sslmode= SSLmode (default: disable)
+ -t, --timeout= Maximum wait for connection, in seconds. (default: 5)
+ -w, --warning= warning if the number of connection is over (default: 70)
+ -c, --critical= critical if the number of connection is over (default: 90)
+```
+
+## For more information
+
+Please execute `check-postgresql -h` and you can get command line options.
