running tectonic as aws lambda function

[karun211]

Hi,

Did anyone try to run tectonic in aws lambda function? We have a use case that requires us to run it as a lambda function. We built a docker image with necessary libraries and able to build pdf's when we run docker image locally. But when we try to run as lambda function we are getting "Read-Only filesystem error", as lambda locks filesystem except /tmp. We identified, tectonic binary writes to the following directories,
/root/.cache
/root/.config
we created symlinks for these two directories to /tmp/root/.cache and /tmp/root/.config and set TECTONIC_CACHE_DIR=/tmp/tech_cache in docker image before uploading it to lambda. But we are still encountering Read-only FS error. Unfortunately, lambda doesn't support strace for security reasons.

Also tried creating a new user generator with /tmp/home/generator as home directory in docker image and executing tectonic with this account, its still failing in lambda.

Any guidance or suggestions would be very helpful.

Thanks!
Karun

[karun211]

Found the answer after digging in source code. Export the following env variables accordingly before executing binary.

export XDG_CONFIG_HOME=
export XDG_CACHE_HOME=

I was able to run tectonic as AWS lambda function successfully.

Thanks to all the contributors for the wonderful work.