docker-jmeter

Image on Docker Hub

Docker image for Apache JMeter. This Docker image can be run as the jmeter command. Find Images of this repo on Docker Hub.

Building

With the script build.sh the Docker image can be build from the Dockerfile but this is not really necessary as you may use your own docker build commandline. Or better: use one of the pre-built Images from Docker Hub.

See end of this doc for more detailed build/run/test instructions (thanks to @wilsonmar!)

Build Options

Build arguments (see build.sh) with default values if not passed to build:

JMETER_VERSION - JMeter version, default 5.4. Use as env variable to build with another version: export JMETER_VERSION=5.4
IMAGE_TIMEZONE - timezone of Docker image, default "Europe/Amsterdam". Use as env variable to build with another timezone: export IMAGE_TIMEZONE="Europe/Berlin"

Running

The Docker image will accept the same parameters as jmeter itself, assuming you run JMeter non-GUI with -n.

There is a shorthand run.sh command. See test.sh for an example of how to call run.sh.

User Defined Variables

This is a standard facility of JMeter: settings in a JMX test script may be defined symbolically and substituted at runtime via the commandline. These are called JMeter User Defined Variables or UDVs.

See test.sh and the trivial test plan for an example of UDVs passed to the Docker image via run.sh.

Installing JMeter plugins

To run the container with custom JMeter plugins installed you need to mount a volume /plugins with the .jar files. For example:

sudo docker run --name ${NAME} -i -v ${LOCAL_PLUGINS_FOLDER}:/plugins -v ${LOCAL_JMX_WORK_DIR}:${CONTAINER_JMX_WORK_DIR} -w ${PWD} ${IMAGE} $@

The ${LOCAL_PLUGINS_FOLDER} must have only .jar files. Folders and another file extensions will not be considered.

Do it for real: detailed build/run/test

Contribution by @wilsonmar

In a Terminal/Command session, install Git, navigate/make a folder, then:
```
git clone https://github.com/justb4/docker-jmeter.git
cd docker-jmeter
```
Run the Build script to download dependencies, including the docker CLI:
```
./build.sh
```
If you view this file, the docker build command within the script is for a specific version of JMeter and implements the Dockerfile in the same folder.

If you view the Dockerfile, notice the JMETER_VERSION specified is the same as the one in the build.sh script. The FROM keyword specifies the Alpine operating system, which is very small (less of an attack surface). Also, no JMeter plug-ins are used.

At the bottom of the Dockerfile is the entrypoint.sh file. If you view it, that's where JVM memory settings are specified for jmeter before it is invoked. PROTIP: Such settings need to be adjusted for tests of more complexity.

The last line in the response should be:

Successfully tagged justb4/jmeter:5.3
Run the test script:
```
./test.sh
```
If you view the script, note it invokes the run.sh script file stored at the repo's root. View that file to see that it specifies docker image commands.

File and folder names specified in the test.sh script is reflected in the last line in the response for its run:
```
==== HTML Test Report ====
See HTML test report in tests/trivial/report/index.html
```
Alternative exec by Makefile:

Like the bash script, it is possible to run the tests through a Makefile simply with the make command or by sending parameters as follows:
```
TARGET_HOST="www.map5.nl" \
TARGET_PORT="80" \
THREADS=10 \
TEST=trivial \
make
```
Switch to your machine's Folder program and navigate to the folder containing files which replaces files cloned in from GitHub:
```
cd tests/trivial
```
The files are:
- jmeter.log
- reports folder (see below)
- test-plan.jmx containing the JMeter test plan.
- test-plan.jtl containing statistics from the run displayed by the index.html file.
Navigate into the report folder and open the index.html file to pop up a browser window displaying the run report. On a Mac Terminal:
```
cd report
open index.html
```
Here is a sample report:

Specifics

The Docker image built from the Dockerfile inherits from the Alpine Linux distribution:

"Alpine Linux is built around musl libc and busybox. This makes it smaller and more resource efficient than traditional GNU/Linux distributions. A container requires no more than 8 MB and a minimal installation to disk requires around 130 MB of storage. Not only do you get a fully-fledged Linux environment but a large selection of packages from the repository."

See https://hub.docker.com/_/alpine/ for Alpine Docker images.

The Docker image will install (via Alpine apk) several required packages most specificly the OpenJDK Java JRE. JMeter is installed by simply downloading/unpacking a .tgz archive from http://mirror.serversupportforum.de/apache/jmeter/binaries within the Docker image.

A generic entrypoint.sh is copied into the Docker image and will be the script that is run when the Docker container is run. The entrypoint.sh simply calls jmeter passing all argumets provided to the Docker container, see run.sh script:

sudo docker run --name ${NAME} -i -v ${WORK_DIR}:${WORK_DIR} -w ${WORK_DIR} ${IMAGE} $@

Credits

Thanks to https://github.com/hauptmedia/docker-jmeter and https://github.com/hhcordero/docker-jmeter-server for providing the Dockerfiles that inspired me. @wilsonmar for contributing detailed instructions. Others that tested/reported after version updates.

DrNorton/docker-jmeter