This guide helps to setup and configure `DataHubValidationAction` in Great Expectations to send assertions(expectations) and their results to DataHub using DataHub's Python Rest emitter.
1. Install the required dependency in your Great Expectations environment.
```shell
pip install 'acryl-datahub-gx-plugin'
```
2. To add `DataHubValidationAction` in Great Expectations Checkpoint, add following configuration in action_list for your Great Expectations `Checkpoint`. For more details on setting action_list, see [Checkpoints and Actions](https://docs.greatexpectations.io/docs/reference/checkpoints_and_actions/)
```yml
action_list:
- name: datahub_action
action:
module_name: datahub_gx_plugin.action
class_name: DataHubValidationAction
server_url: http://localhost:8080 #datahub server url
```
**Configuration options:**
-`server_url` (required): URL of DataHub GMS endpoint
-`env` (optional, defaults to "PROD"): Environment to use in namespace when constructing dataset URNs.
-`exclude_dbname` (optional): Exclude dbname / catalog when constructing dataset URNs. (Highly applicable to Trino / Presto where we want to omit catalog e.g. `hive`)
-`platform_alias` (optional): Platform alias when constructing dataset URNs. e.g. main data platform is `presto-on-hive` but using `trino` to run the test
-`platform_instance_map` (optional): Platform instance mapping to use when constructing dataset URNs. Maps the GX 'data source' name to a platform instance on DataHub. e.g. `platform_instance_map: { "datasource_name": "warehouse" }`
-`graceful_exceptions` (defaults to true): If set to true, most runtime errors in the lineage backend will be suppressed and will not cause the overall checkpoint to fail. Note that configuration issues will still throw exceptions.
-`token` (optional): Bearer token used for authentication.
-`retry_status_codes` (optional): Retry HTTP request also on these status codes.
-`retry_max_times` (optional): Maximum times to retry if HTTP request fails. The delay between retries is increased exponentially.
-`extra_headers` (optional): Extra headers which will be added to the datahub request.
-`parse_table_names_from_sql` (defaults to false): The integration can use an SQL parser to try to parse the datasets being asserted. This parsing is disabled by default, but can be enabled by setting `parse_table_names_from_sql: True`. The parser is based on the [`sqllineage`](https://pypi.org/project/sqllineage/) package.
-`convert_urns_to_lowercase` (optional): Whether to convert dataset urns to lowercase.
To see the Great Expectations in action, check out [this demo](https://www.loom.com/share/d781c9f0b270477fb5d6b0c26ef7f22d) from the Feb 2022 townhall.
