### Purpose
Syncthing had a healthcheck API for a while, and the example Dockerfile
for it has it in the form of:
HEALTHCHECK --interval=1m --timeout=10s \
CMD curl -fkLsS -m 2 127.0.0.1:8384/rest/noauth/health | grep -o
--color=never OK || exit 1
Let's add it to the docker-compose as well
### Testing
I use this docker-compose.yml file to deploy via ansible (using
community.docker.docker_compose_v2) to my machine with success, using
`wait: true` in ansible for it to use `docker compose up --wait`.
```yml
- name: Enable syncthing docker
community.docker.docker_compose_v2:
project_src: /srv/syncthing
wait: true
wait_timeout: 90
```
Add support for setting umask value in the Docker `entrypoint.sh`
script. This is useful when
not syncing permissions and working with groups, and needing umask
values like `002` instead of `022`.
Allows for configuring the UID and GID Syncthing runs as in the container. Uses su-exec from the Alpine repos to accomplish this. Addition of su-exec results in <2MB increase in image size.
