dbms.backup.address config value cannot be overridden by an env variable about docker-neo4j

[jangaraj]

@benbc Will you accept PR, which will allow to overwrite any current/further neo4j setting from the env variable, which will start with prefix NEO4J_?

Concept:

# read env variables, which start with NEO4J_ prefix
# and update conf settings based on their values
for i in $( printenv | grep ^NEO4J_ | awk -F'=' '{print $1}' | sort -rn ); do
    setting=$(echo ${i} | sed 's|^NEO4J_||' | sed 's|_|.|g')
    value=$(echo ${!i})
    sed --in-place "s|.*${setting}=.*|${setting}=${value}|" conf/neo4j.conf
done

[benbc]

You are quite right, this is a bit of a pain currently. In fact I don't think that the setting even needs to be configurable because the backup server should be listening on 0.0.0.0 inside a container. There is a PR on this at #35.

We also have an ambition to make all settings overridable by environment variables, but that requires a product change and we haven't been able to prioritize it yet.

[spacecowboy]

@jangaraj this is a feature we've been considering so if you are willing to do the work I'd be happy to review and help.

Some things to keep in mind:

• Some settings are commented by default and some are not
• Not all settings are actually present (commented or not) in the config file. So a sed by itself is not guaranteed to replace something
• A user might define a custom config volume AND some environment variables.

The reference of all configuration options might be of interest: https://neo4j.com/docs/operations-manual/current/reference/configuration-settings/