Open up RPC ports to allow for monitoring

[gilescope]

From discord node / validators chat:

Chunky Monkey [MNKY] — Yesterday at 12:30
In the next docker release would it be possible to open up the RPC server to allow connections from anywhere, and we can control access from the host firewall? This would be very useful so that we can remotely monitor our validators via RPC:

midnight-node-docker_midnight-node-testnet_1 | Running JSON-RPC server: addr=127.0.0.1:9944, allowed origins=["http://localhost:*", "http://127.0.0.1:*", "https://localhost:*", "https://127.0.0.1:*", "https://polkadot.js.org/"

(originally raised at https://github.com/midnight-ntwrk/midnight-node-docker/issues/3 )

[gilescope]

@TrevorBenson said:

For security in environments where using root bypasses existing firewall rules when publishing ports (as seen with exposure of the postgres 5432 leading to exploited containers) it's probably best to configure his to localhost by default if ARGS are changed to allow rpc calls from outside the container:

    ports:
      - "127.0.0.1:9944:9944"
      - "30333:30333"

The user can then remove the binding to loopback if they want to access it from another host, but will be responsible for ensuring they have properly configured the firewall and limited access to their own infrastructure.