Icingacli checks

[t3easy]

BTW.: do you have a good idea for icingacli checks? As web and icinga are splitted, the checks can't run as there is no icingacli.

Maybe a Phar of the icingacli plus configuration deployed to the Icinga container. But I don't know if creating the Phar works that easily.

Originally posted by @lippserd in https://github.com/lippserd/docker-compose-icinga/issues/17#issuecomment-1172136693

I just had an idea how to run such tests. As there is a by_ssh command, that runs commands on a remote server by ssh, we could implement a by_docker command that can run check commands inside an existing container by docker exec icingaweb icingacli ... or by creating a new container with a custom check command docker run --rm check_xy_image.

Therefore the docker cli in the icinga2 image and the docker socket of the host of the icinga2 service or a ssh/tls DOCKERHOST is required.

Its not perfect for all hosting environments but the best solution for common.

[t3easy]

Here what I did so far as a first quick but working solution:

ARG ICINGA2_VERSION==2.13.5
ARG DOCKER_VERSION=20.10

FROM docker:${DOCKER_VERSION} as docker-cli

# Icinga 2
FROM icinga/icinga2:${ICINGA2_VERSION} as icinga2
USER root
COPY --from=docker-cli /usr/local/bin/docker /usr/local/bin/docker
RUN set -eux; \
        groupadd -g 999 docker; \
        usermod -aG docker icinga;
USER icinga

services:
  icinga2:
    volumes:
    - /var/run/docker.sock:/var/run/docker.sock

object CheckCommand "by_docker" {
    import "plugin-check-command"
    command = [ "/usr/local/bin/docker" ]
    arguments += {
        docker_command = {
            order = 10
            required = true
            skip_key = true
            value = {{
                if (macro("$by_docker_run$")) {
                return "run"
            } else {
                return "exec"
            }
            }}
        }
        docker_container = {
            description = "The container in that the command will be executed"
            order = 20
            required = true
            skip_key = true
            value = "$by_docker_container$"
        }
        docker_container_command = {
            description = "The command that will be executed in the container"
            order = 30
            required = true
            skip_key = true
            value = "$by_docker_container_command$"
        }
        docker_container_command_arguments = {
            description = "The arguments for the command that will be executed in the container"
            order = 40
            skip_key = true
            value = "$by_docker_container_command_arguments$"
        }
    }
}

template Service "Icingacli by Docker" {
    check_command = "by_docker"
    check_interval = 1m
    retry_interval = 30s
    vars.by_docker_container = "monitoring-icingaweb2-1"
    vars.by_docker_container_command = "/usr/local/bin/icingacli"
}