Chrome with selenium, python and docker

Sometimes, when I execute the Chrome inside a docker container I receive the error below:

selenium.common.exceptions.WebDriverException: Message: unknown error: Chrome failed to start: crashed

It is caused because Chrome uses the /dev/shm to share memory and the docker, by default, set 64MB for this partition.

Here, I will describe how to reproduce this error and how to resolve it.

How to reproduce

To reproduce the error, We need to create a docker image with chrome and python. Then, I create this Dockerfile. It uses a multi-stage build to install the chrome and the python.

After clone this repository, we create the image with the command:

docker build -t python_selenium_chrome .

And then, we can run one container with the command:

docker run --shm-size=1b -it python_selenium_chrome bash

Finally, we call the chrome from python with the command: python run_chrome.py

After you run it, you will receive one message error similar as we have shown before(in the first session).

How to resolve

To resolve this problem we only need to configure the correct size of the /dev/shm. We can run the container with the command:

docker run --shm-size=1g -it python_selenium_chrome bash

Now, we are running the container with 1 gigabyte of memory to /dev/shm. After this is possible to run the chrome normally inside the container.

References

P.S. English is not my first language and I create this blog to improve my write in English. If you find some errors or have some tips to improve my write and English, I will love to receive it!