Features for configuring plugins in a bootstrap phase

[sanderob]

Proposed functionality

One or more fields that allow for appending configuration to the configuration.py file: either a free text field for appended config or a specific boolean for the exact use case that is described below. This feature is needed due to the need to run python-code

This functionality is not covered today:

• The features extraDeploy, extraVolumes and extraVolumeMounts, where configuration is mounted to /etc/netbox/config/, the configuration is not run before the plugins are imported into the project.
• The feature extraConfig mounts the configuration to a different path, but the configuration is still not run before the plugin modules are imported.
• The feature related to netbox.yaml is not sufficient because it does not allow for running python code -- only defining KEY:VALUE fields.

This is related to #833, but this PR was closed due to other suggested solutions, but these have proven insufficient. I can propose a new pull request if the feature is approved, but I am hesitant, as the mentioned PR was closed.

Use case

This feature request is the outcome of a need to configure the plugin netbox branching (developed by Netbox Labs): the plugin needs the configuration.py file to contain custom python code that is executed before the Pip module of the plugin is imported; the __init__.py sequence of the module requires the configuration to be present.

For this exact use case, the configuration looks like this:

from netbox_branching.utilities import DynamicSchemaDict
DATABASES = DynamicSchemaDict(DATABASES)
DATABASE_ROUTERS = ['netbox_branching.database.BranchAwareRouter']

This use case can be covered by a free text field for appending configuration (as #833 suggested, and shown above) or with a boolean flag that contains a related if-case:

if "netbox_branching" in PLUGINS:
    from netbox_branching.utilities import DynamicSchemaDict
    DATABASES = DynamicSchemaDict(DATABASES)
    DATABASE_ROUTERS = ['netbox_branching.database.BranchAwareRouter']

As this is a necessary feature for configuring plugins from Netbox Labs, I believe this chart should include this functionality. However, there is to be noted a disclaimer that my interpretation of the issue may be imprecise: there may be other configuration alternatives that have gone over my head.

[ifoughal]

Any updates on this? it would be nice if Netbox' Chart supported this, othwise the workaround I've found is to add a local_settings context to my container image:

...
COPY ./local_settings.py /opt/netbox/netbox/netbox/local_settings.py
...

local_settings.py

from netbox_branching.utilities import DynamicSchemaDict
from .configuration import DATABASES

# Wrap the already-loaded DATABASES
DATABASES = DynamicSchemaDict(DATABASES)

# Preserve any existing routers, then add the branching router
DATABASE_ROUTERS = list(globals().get("DATABASE_ROUTERS", []))
if "netbox_branching.database.BranchAwareRouter" not in DATABASE_ROUTERS:
    DATABASE_ROUTERS.append("netbox_branching.database.BranchAwareRouter")

# Ensure branching is enabled exactly once and always loaded last
PLUGINS = list(globals().get("PLUGINS", []))
PLUGINS = [p for p in PLUGINS if p != "netbox_branching"]
PLUGINS.append("netbox_branching")

setting the local settings this would would then NOT require to append DATABASE_ROUTERS to extraConfig, as it would become redundent.

The biggest downsides to this approach is that we are setting static configurations on the base image, but it works as a temporary workaround if someone needs it...