## CHECK_DOCKER_INFO

Script: `check_docker_info`

**check_docker_info_** shows the docker version and count of containers.
You get the count of containers by state running, paused or stopped.
This check sends performance data.

## Requirements

* `docker` Docker must be installed
* `jq` Docker must be installed
* sudo permissions on docker command

```txt
icingaclient ALL=(ALL) NOPASSWD:SETENV: /usr/bin/docker
```

## Standalone installation

From this repository ypu need next to this script:

* `inc_pluginfunctions` shared function for all IML checks written in bash
* `inc_dockerfunctions.sh`

## Rootless docker

It works with docker setups as root and can handle rootless docker instances.

To bring it up and running with an unpriviledged icinga user it must be able to access docker. Copy the docker binary eg. from /home/dockeruser/bin/docker to /usr/bin/. Then use the parameter `-p /usr/bin`.

If DOCKER_HOST is not set then the docker socket is detected from a running docker instance and will be fetched from the process list.

## Syntax

```txt
______________________________________________________________________

CHECK_DOCKER_INFO
v1.5

(c) Institute for Medical Education - University of Bern
Licence: GNU GPL 3

https://os-docs.iml.unibe.ch/icinga-checks/Checks/check_docker_info.html
______________________________________________________________________

Show docker version and count of containers total and by its status.

It returns 
  CRITICAL if a created container is not running.
  OK if no container was created yet or all conmtainers are running.
  UNKNOWM if
    - docker or jq were not found
    - docker data were not fetched
    - docker cannot be connected

This check provides performance data.

USAGE:
  check_docker_info [OPTIONS]

OPTIONS:

  General:
  -h, --help        this help
  -d, --debug       Debug; Flag: show all docker system infos

  Connect to docker:
  -p, --path        Custom directory for docker binary
  -t, --target      Custom docker target; value for DOCKER_HOST
                    Needed only if Docker does not run on a unix socket or
                    multiple users run a rootless docker daemon.

  Flags:
  -c, --containers  Flag: Show containers (slow)
  -e, --errors      Flag: Show containers on error only (slow)

EXAMPLES:
  check_docker_info
    Show Status of all containers

  check_docker_info -c
    Show Status of all containers and a list of container names with its
    status. Warning: this feature uses docker ps --all and can be slow.

  check_docker_info -e
    Show Status of all containers. If not all containers are running you
    get a list of container names with its status.

  check_docker_info -p /usr/bin
    Show Status of all containers. The docker binary will be searched in
    given path first - then in all other dirs of $PATH

  check_docker_info -d
    Show Status of all containers and json with all docker system infos.

```

### Parameters

None.

## Examples

`$ ./check_docker_info` returns

```txt
OK: Docker 20.10.14 (Community Engine, rootless) .. 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;;
```

## Troubleshooting

### Missing environment

```txt
sudo: sorry, you are not allowed to preserve the environment
UNKNOWN: No data. Unable to fetch Docker information.
```

Solution: you did not set SETENV in the sudoers config file

icingaclient ALL=(ALL) NOPASSWD:**SETENV:** /usr/bin/docker

### Docker not found

If you get an error message that docker was not found then it is not reachable in ofe of the directories of $PATH.
This can happen especialy in rootless docker instances.

Solution: Use the parameter `-p /usr/bin` to define a target. Copy the docker binary there.