Running Metricbeat on Docker
editRunning Metricbeat on Docker
editDocker images for Metricbeat are available from the Elastic Docker registry. The base image is centos:7.
A list of all published Docker images and tags is available at www.docker.elastic.co. The source code is in GitHub.
These images are free to use under the Elastic license. They contain open source and free commercial features and access to paid commercial features. Start a 30-day trial to try out all of the paid commercial features. See the Subscriptions page for information about Elastic license levels.
Pulling the image
editObtaining Beats for Docker is as simple as issuing a docker pull
command
against the Elastic Docker registry.
docker pull docker.elastic.co/beats/metricbeat:6.3.2
Alternatively, you can download other Docker images that contain only features available under the Apache 2.0 license. To download the images, go to www.docker.elastic.co.
Configure Metricbeat on Docker
editThe Docker image provides several methods for configuring Metricbeat. The conventional approach is to provide a configuration file via a bind mount, but it’s also possible to create a custom image with your configuration included.
Bind-mounted configuration
editOne way to configure Metricbeat on Docker is to provide metricbeat.yml
via a bind mount.
With docker run
, the bind mount can be specified like this:
docker run \ --mount type=bind,source="$(pwd)"/metricbeat.yml,target=/usr/share/metricbeat/metricbeat.yml \ docker.elastic.co/beats/metricbeat:6.3.2
Custom image configuration
editIt’s possible to embed your Metricbeat configuration in a custom image. Here is an example Dockerfile to achieve this:
FROM docker.elastic.co/beats/metricbeat:6.3.2 COPY metricbeat.yml /usr/share/metricbeat/metricbeat.yml USER root RUN chown root:metricbeat /usr/share/metricbeat/metricbeat.yml USER metricbeat
Monitor the host machine
editWhen executing Metricbeat in a container, there are some important things to be aware of if you want to monitor the host machine or other containers. Let’s walk-through some examples using Docker as our container orchestration tool.
This example highlights the changes required to make the system module work properly inside of a container. This enables Metricbeat to monitor the host machine from within the container.
docker run \ --mount type=bind,source=/proc,target=/hostfs/proc,readonly \ --mount type=bind,source=/sys/fs/cgroup,target=/hostfs/sys/fs/cgroup,readonly \ --mount type=bind,source=/,target=/hostfs,readonly \ --net=host docker.elastic.co/beats/metricbeat:6.3.2 -system.hostfs=/hostfs
Metricbeat’s system module collects much of its data through the Linux proc
filesystem, which is normally located at |
|
By default, cgroup reporting is enabled for the
system process metricset, so you need
to mount the host’s cgroup mountpoints within the container. They need to be
mounted inside the directory specified by the |
|
If you want to be able to monitor filesystems from the host by using the system filesystem metricset, then those filesystems need to be mounted inside of the container. They can be mounted at any location. |
|
The system network metricset uses data from |
The special filesystems /proc
and /sys
are only available if the
host system is running Linux. Attempts to bind-mount these filesystems will
fail on Windows and MacOS.
Monitor a service in another container
editNext, let’s look at an example of monitoring a containerized service from a Metricbeat container.
docker run \ --network=mysqlnet \ -e MYSQL_PASSWORD=secret \ docker.elastic.co/beats/metricbeat:6.3.2
Placing the Metricbeat and MySQL containers on the same Docker network
allows Metricbeat access to the exposed ports of the MySQL container, and
makes the hostname |
|
If you do not want to hardcode certain values into your Metricbeat
configuration, then you can pass them into the container either as environment
variables or as command line flags to Metricbeat (see the |
The mysql module configuration would look like this: