add docker info with count of containers

docs/20_Checks/check_docker_info.md

@@ -15,71 +15,38 @@ This check sends performance data.
 ```txt
 ______________________________________________________________________
 
-CHECK_DISK-IO 
-v1.1
-
-Check dis io and latency
+CHECK_DOCKER_INFO
+v1.0
 
 (c) Institute for Medical Education - University of Bern
 Licence: GNU GPL 3
-______________________________________________________________________
 
-Disk infos based on /sys/block/[NAME]/stat
-See https://www.kernel.org/doc/Documentation/block/stat.txt
-and https://www.kernel.org/doc/Documentation/iostats.txt
+https://os-docs.iml.unibe.ch/icinga-checks/Checks/check_docker_info.html
+______________________________________________________________________
 
-The system data are counters that are difficult to read.
-The output of this check for each value a delta value per second since 
-last check.
+Show docker version and count of containers total and by its status.
 
-SYNTAX:
-check_disk-io -m MODE
+USAGE:
+  check_docker_info [OPTIONS]
 
 OPTIONS:
+  -h  this help
 
-    -m MODE        set mode for type of output (required)
-    -h or --help   show this help.
-
-PARAMETERS:
-
-    MODE
-        io         read I/Os, write I/Os, discard I/0s
-        ticks      read ticks, write ticks, discard ticks
-        wait       total wait time for all requests
-
-EXAMPLE:
-check_disk-io -m io
+EXAMPLES:
+  check_docker_info
 
 ```
 
 ### Parameters
 
-`-m <MODE>` where MODE is a string to define kind of output.
+None.
 
 ## Examples
 
-`$ check_disk-io -m io` returns
+`$ ./check_docker_info` returns
 
 ```txt
-OK: Disk data ... read I/Os, write I/Os, discard I/0s, number of I/Os currently in flight 
-
---- sda
-              disk-sda-ReadIO:          0 
-             disk-sda-WriteIO:          0 
-           disk-sda-DiscardIO:          0 
-            disk-sda-FlightIO:          0 
-
---- nvme0n1
-          disk-nvme0n1-ReadIO:          3 
-         disk-nvme0n1-WriteIO:         16 
-       disk-nvme0n1-DiscardIO:          4 
-        disk-nvme0n1-FlightIO:          0 
-
---- TOTAL
-                       ReadIO:          3 
-                      WriteIO:         16 
-                    DiscardIO:          4 
-                     FlightIO:          0 
-
- |readio=3;; writeio=16;; discardio=4;; flightio=0;;
+OK: Docker 20.10.14 (Community Engine) .. containers: 2 running: 2 paused: 0 stopped: 0 .. images: 5
+All containers are running
+ |containers-running=2;;;0;2 containers-paused=0;;;0;2 containers-stopped=0;;;0;2 images=33;;
 ```