Xvfb fails with "XKB: Failed to compile keymap" in Lambda container images Environment

[khanzzirfan]

• Lambda container image based on public.ecr.aws/lambda/nodejs:20
• Amazon Linux 2023
• Xvfb from xorg-x11-server-Xvfb

Issue: Running Xvfb directly in Lambda fails with:

XKB: Failed to compile keymap
Keyboard initialization failed. This could be a missing or incorrect setup of xkeyboard-config.
Fatal server error: Failed to activate virtual core keyboard: 2

Root Cause: Lambda's read-only filesystem prevents xkbcomp from writing compiled keymaps to /var/lib/xkb. Even with xkeyboard-config and xkbcomp installed, Xvfb cannot initialize because XKB compilation fails. Workaround: Using xvfb-run wrapper instead of direct Xvfb invocation works, as it handles XKB setup internally. Request: Please provide either:

1. A Lambda layer with pre-configured Xvfb/XKB support
2. Documentation for headless GL rendering in Lambda containers
3. Allow /var/lib/xkb to be writable or support XKB_OUTPUT_DIR environment variable

[jtuliani]

Thank you @khanzzirfan for raising this. Does setting XKB_OUTPUT_DIR to the /tmp folder work? The /tmp folder is the only writable folder in Lambda execution environments today.