Allow using Hostname in PeerAddress

[pydio-bot]

There are several cases where Docker doesn't allow a static IP; for example when running swarm mode, or when using Kubernetes.

Each container instance that is started gets a dynamic IP, and this conflicts with the need to specify a PeerAddress IP in /root/.config/pydio/cells/pydio.json, for example:

"pydio.grpc.data.index.cellsdata": {
  "PeerAddress": "10.0.1.229",

Docker does a great job of resolving the container's hostname, so this would work nicely if we could instead specify the hostname:

"pydio.grpc.data.index.cellsdata": {
  "PeerAddress": "cells",

Note that I'm currently using a workaround of overriding the start command in the docker compose file, but this feels very ugly, and a bit fragile:

  cells:
    image: pydio/cells:latest
    command: [ '/bin/sh', '-c', 'echo `tail -1 /etc/hosts | cut -f 1` > /home/ip.txt; sed -i "/PeerAddress/ s/: .*/: \"`cat /home/ip.txt`\",/g" /root/.config/pydio/cells/pydio.json; exec /bin/docker-entrypoint.sh cells start' ]

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#57
{gid:cells:406106025}

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#67
{gid:cells:410854373}