update readme with docker deets

etl/run_sql/README.md

@@ -8,14 +8,26 @@ This tool enables us to run arbitrary SQL using the Hasura [schema API](https://
 
 2. Save a copy of the `env_template` file as `.env`, and fill in the graphql endpoint and admin secret. Note that the endpoint should end with `/v2/query` (see the [Hasura docs](https://hasura.io/docs/2.0/api-reference/schema-api/run-sql/) for more info).
 
-3. Configure a python environment with `requests` installed. 
+3. Buld the Docker image, which provides the Python dependencies
 
+```shell
+docker build -t atddocker/vz-run-sql:latest
 ```
-# see available commands
-python run_sql.py -h
-```
 
+4. With the image built, you can mount yor local copy of the script into the container and run it, like so:
+
+```shell
+docker run -it --rm -v $PWD:/app --env-file .env atddocker/vz-run-sql:latest  python run_sql.py -c refresh_location_crashes
 ```
-# refresh location crashes
-python run_sql.py -c refresh_location_crashes
+
+5. To see all available sql commands that can be executed, use the `--help` flag
+
+```shell
+docker run -it --rm -v $PWD:/app --env-file .env atddocker/vz-run-sql:latest  python run_sql.py --help
 ```
+
+## Deployment + CI
+
+A github action is configured to build and push this ETL's image to the Docker hub whenever files in this directory are changed.
+
+The ETL itself is deployed via [atd-airflow](https://github.com/cityofaustin/atd-airflow).