This image/dockerfile is based on debian & debian's taskd. You won't need to build taskd from source if you modify this dockerfile. We also have a robust HEALTHCHECK thanks to https://github.com/jrabbit/taskd-client-go
This is still all on you.
Mount your certs to /var/lib/taskd/pki
Use taskd's 1.2 sources for pki-scripts.