Plugins

Plugins allow you to alter a document right before indexing. This is useful for applying custom transformations and offers greater flexibility, though it requires some development effort.

Plugins are currently supported only in the Python Language.

For example, imagine you had a user profile database with firstname and lastname fields and generating the Elasticsearch/OpenSearch doc below.

{
    "firstname": "feng",
    "lastname": "shui"
}

we can create a plugin to add a fullname field to the document right before indexing.

Create a "plugins" directory and add it to your PYTHONPATH.

The PYTHONPATH should point to the parent directory containing your "plugins" folder.

e.g:

export PYTHONPATH=$PYTHONPATH:/path/to/myplugindir

Make sure you have created an empty init module inside the "plugins" directory i.e plugins/__init__.py

Create a plugin module - fullnameplugin.py inside the "plugins" directory and add the code below:

from pgsync import plugin


class FullnamePlugin(plugin.Plugin):
    name = 'Fullname'

    def transform(self, doc, **kwargs):
        firstname = doc['firstname']
        lastname = doc['lastname']
        doc['fullname'] = f'{firstname} {lastname}'
        return doc

Your plugins directory layout should look like this:

• plugins/fullnameplugin.py
• plugins/__init__.py

Then simply activate the plugin by adding it to the list of plugins in the schema.json

[
    {
        "database": "users",
        "index": "users",
        "plugins": ["Fullname"],
        "nodes": {
            "table": "profile"
        }
    }
]

To get this document in Elasticsearch/OpenSearch

{
    "firstname": "feng",
    "lastname": "shui",
    "fullname": "feng shui"
}

Info

Plugin names are case sensitive