Allow users to set CERTDIR as an environment variable

[m0wer]

Reporting bugs/issues

• When reporting a bug/issue:

  • Ensure that you are using the latest release. true
  • Revert any custom modifications or environment varibles to insure they're not the cause. true

• Please provide the following information:

  • OS/distribution version (command for your OS may differ):

  user@host:~$ lsb_release -a
  No LSB modules are available.
  Distributor ID: Debian
  Description:    Debian GNU/Linux 9.8 (stretch)
  Release:        9.8
  Codename:       stretch
  
  

  • Docker version:

  user@host:~$ docker --version
  Docker version 18.09.5, build e8ff056dbc
  

  • Labels from container:

  user@host:~$ docker inspect goofball222/murmur:<tagname>
  ...
              "Labels": {
              "org.label-schema.build-date": "2019-04-01T02:00:28Z",
              "org.label-schema.license": "Apache-2.0",
              "org.label-schema.name": "Murmur Server",
              "org.label-schema.schema-version": "1.0",
              "org.label-schema.url": "https://github.com/goofball222/murmur",
              "org.label-schema.vcs-ref": "107157b",
              "org.label-schema.vcs-url": "https://github.com/goofball222/murmur.git",
              "org.label-schema.vendor": "The Goofball - [email protected]",
              "org.label-schema.version": "1.2.19"
          }
  ...
  

  • Details on how to reproduce the trouble, if available:

I want to use some Let's Encrypt certs for this service. I mount them in readonly mode and I only mount the ones needed for the murmur server domain. When mounted on /opt/murmur/cert, the chown fails because it's a readonly filesystem. The certificates shouldn't be modified, not even the permissions, because murmur just needs to be able to read them.

A possible solution would be allowing the user to set the CERTDIR environment variable to somwhere outside of /opt/murmur and mount the certificates there. Then, you could run the image like this:

/usr/bin/docker run --rm --name "murmur" \
-e 'PUID=1000' -e 'PGID=1000' \
-e "CERTDIR=/etc/letsencrypt/live/[domain]" \
-v "/data/murmur/conf":/opt/murmur/config \
-v "/data/murmur/data":/opt/murmur/data \
-v "/data/murmur/log":/opt/murmur/log \
-v '/etc/localtime:/etc/localtime:ro' \
-v /etc/letsencrypt/live/[domain]:/etc/letsencrypt/live/[domain]/:ro \
-v /etc/letsencrypt/archive/[domain]:/etc/letsencrypt/archive/[domain]/:ro \
-p "64738:64738/tcp" \
-p "64738:64738/udp" \
"goofball222/murmur:latest"

Note mounting live and archive is needed for the symlinks to work, a simpler approach would be to just mount the whole /etc/letsencrypt directory.