This Docker container provides a patched Zabbix agent to monitor a real CoreOS server and all his containers.

The Zabbix agent has been patched to read system informations from these directories:

• /coreos/proc mapped from /proc on the real host
• /coreos/dev mapped from /dev on the real host
• /coreos/sys mapped from /sys on the real host

You can access the Docker REST API through the socket file /coreos/var/run/docker.sock

# docker build -t bhuisgen/docker-zabbix-coreos .

### Configure your Zabbix server

Import the needed templates in etc/zabbix/templates

#### Create auto-registration action (optional)

To automatically create new host on the zabbix server, create a auto-registration action (Configuration/Actions/Auto-registration):

• conditions: Host metadata like 'coreos'
• actions: Add Host, Add host to groups, Link to templates (Custom Template CoreOS, Custom Template Docker, Template App SSH Service, Template ICMP Ping, Template OS Linux)

The host metadata value is the value shared by all your cluster nodes. Each node must shared the same value.

If you don't want to use the auto-registration, you must add each node in the frontend.

To create the container:

# docker run -d -p 10050:10050 -u 0 -c 1024 -m 64M --memory-swap=-1 \
    -v /proc:/coreos/proc:ro -v /sys:/coreos/sys:ro -v /dev:/coreos/dev:ro \
    -v /var/run/docker.sock:/coreos/var/run/docker.sock \
    --name zabbix-coreos bhuisgen/docker-zabbix-coreos <SERVER> <HOSTMETADATA> [<HOSTNAME>]

If you want to access directly to the network stack of the node, you can use the host network mode but it is less secure:

# docker run -d -p 10050:10050 -u 0 -c 1024 -m 64M --memory-swap=-1 --net="host" \
    -v /proc:/coreos/proc:ro -v /sys:/coreos/sys:ro -v /dev:/coreos/dev:ro \
    -v /var/run/docker.sock:/coreos/var/run/docker.sock \
    --name zabbix-coreos bhuisgen/docker-zabbix-coreos <SERVER> <HOSTMETADATA> [<HOSTNAME>]

The needed options are:

• SERVER (required): the IP address of the Zabbix server
• HOSTMETADATA (required): the metadata value shared by all servers on the same cluster. This value will match the autoregistration action
• HOSTNAME (optional): the hostname used by this agent in the zabbix frontend. If no value is given, the machine id of the host will be used

The agent will start and the auto-registration will add your agent if a auto-registration action is matched for your host metadata. If you don't want to auto-register your nodes, you need to specify the hostname value to use.

Copy this file:

# cp files/fleet/zabbix-agent /etc/default/zabbix-agent

Each node will be created with the machine id into the Zabbix frontend.

Edit the environment file to set the configuration settings:

# vim /etc/default/zabbix-agent

The configuration settings are:

• SERVER: the IP address of the Zabbix server
• HOSTMETADATA (required): the metadata value shared by all servers on the same cluster. This value will match the autoregistration action

You can start the agent on all your cluster nodes with fleet:

# fleetctl submit zabbix-agent
# fleetctl start zabbix-agent

If you don't want to use auto-registration, create your service unit file. You can use the template in files/systemd.

# cat /etc/machine-id

# docker exec -ti zabbix-coreos /bin/bash

Inside the container:

# cd /etc/zabbix/

# docker exec -ti zabbix-coreos /bin/bash

Inside the container:

# supervisorctl restart zabbix-agent

Create a custom configuration file HOSTNAME.conf in etc/zabbix/ where HOSTNAME matches the value used for your host agent. Docker will concatenate this file into the main configuration file before running the container.

Exemple 1: with manual registration, if your zabbix host is myhost:

# vim etc/zabbix/5bcc6a59c4234d1eac3d6c57e3e58eff.conf

Exemple 2: with auto-registration, if you use cluster as host metadata and 5bcc6a59c4234d1eac3d6c57e3e58eff is the machine id of your real host:

# vim etc/zabbix/cluster-5bcc6a59c4234d1eac3d6c57e3e58eff.conf