Unable to Take Screenshots Using Firefox Nodes - selenium

Question

My Selenium tests are designed to take screenshots on failure and add them to the report. The screenshots are displaying perfectly for chrome browsers, but Firefox screenshots are just white rectangles.The changelog says something about a "pass through" mode https://github.com/SeleniumHQ/selenium/blob/master/java/CHANGELOG which I've tried to disable, but nothing seems to be working.
Here's my docker compose file:
seleniumhub:
image: selenium/hub
ports:
- 4444:4444
firefoxnode:
image: selenium/node-firefox-debug
ports:
- 4577
links:
- seleniumhub:hub
environment:
- enablePassThrough=false
- NODE_MAX_INSTANCES=5
- NODE_MAX_SESSION=5
chromenode:
image: selenium/node-chrome-debug
ports:
- 4578
links:
- seleniumhub:hub
environment:
- NODE_MAX_INSTANCES=5
- NODE_MAX_SESSION=5

Answer 1

I don't think enablePassThrough is a valid environment variable. The configuration is generated from https://github.com/SeleniumHQ/docker-selenium/blob/master/NodeFirefox/generate_config which only contains your NODE_MAX_INSTANCES and NODE_MAX_SESSION.
However, there is a SE_OPTS variable from the parent base image in the entrypoint at https://github.com/SeleniumHQ/docker-selenium/blob/master/NodeBase/entry_point.sh#L28-L30. You can use this to set -enablePassThrough false. Your service definition in Docker Compose would be something like this instead:
firefoxnode:
image: selenium/node-firefox-debug
ports:
- 4577
links:
- seleniumhub:hub
environment:
- SE_OPTS="-enablePassThrough false"
- NODE_MAX_INSTANCES=5
- NODE_MAX_SESSION=5