Ability to have the current configuration in JSON format.
For example, per commit, it should save the configuration to some file like /run/vyos/config/current-config.json
The use case is to use custom scripts for parsing configuration (10K requests per several seconds)
Based on the requirements, it is natural to add this to the commit_revision post-commit hook of the config_mgmt module: this is low overhead as we use the existing configtree representation of the current config to save with ConfigTree().to_json().
Note that we are writing output to /run/vyatta/config/config.json, as a convenience, since the /run/vyatta dir is already created with correct permissions in:
https://github.com/vyos/vyos-1x/blob/current/src/init/vyos-router#L332-L334
One could just as easily add a /run/vyos directory with group owner 'vyattacfg' at that point, although eventually the translation 'vyatta' -> 'vyos' will take place as remaining legacy code is removed.
The PR below will handle Circinus and mergify to Sagitta; backporting to Equuleus would require a standalone post-commit hook, unless one considers backporting the config_mgmt module and vyos-save-config.py.
Added for 1.4, 1.5; as mentioned above, a backport to Equuleus will require a different implementation.