Updated doc with connection on CLI (#175)

Co-authored-by: sc <[email protected]>

modules/ROOT/pages/airflow.adoc

@@ -14,7 +14,7 @@ This tutorial demonstrates how to use airflow with Teradata Vantage. Airflow wil
 
 == Prerequisites
 
-* Ubuntu 22.x 
+* Ubuntu 22.x
 * Access to a Teradata Vantage instance.
 +
 include::ROOT:partial$vantage_clearscape_analytics.adoc[]
@@ -62,7 +62,13 @@ airflow standalone
 ----
 2. Access the Airflow UI. Visit https://localhost:8080 in the browser and log in with the admin account details shown in the terminal.
 
-== Define a Teradata connection in Airflow UI
+
+Teradata Connections may be defined in Airflow in the following ways:
+
+1. Using Airflow Web UI
+2. Using Environment Variable
+
+== Define a Teradata connection in Airflow Web UI
 
 1. Open the Admin -> Connections section of the UI. Click the Create link to create a new connection.
 +
@@ -78,7 +84,46 @@ image::{dir}/airflow-newconnection.png[Airflow New Connection, width=75%]
 * Password (required): Specify the password to connect.
 * Click on Test and Save.
 
+== Define a Teradata connection in Environment Variable
+Airflow connections may be defined in environment variables in either of one below formats.
+
+1. JSON format
+2. URI format
+
++
+NOTE: The naming convention is AIRFLOW_CONN_{CONN_ID}, all uppercase (note the single underscores surrounding CONN).
+So if your connection id is teradata_conn_id then the variable name should be AIRFLOW_CONN_TERADATA_CONN_ID
++
+
+
+== JSON format example
+
+
+[source, bash]
+----
+export AIRFLOW_CONN_TERADATA_CONN_ID='{
+    "conn_type": "teradata",
+    "login": "teradata_user",
+    "password": "my-password",
+    "host": "my-host",
+    "schema": "my-schema",
+    "extra": {
+        "tmode": "TERA",
+        "sslmode": "verify-ca"
+    }
+}'
+
+----
+
+== URI format example
+
+
+[source, bash]
+----
+export AIRFLOW_CONN_TERADATA_CONN_ID='teradata://teradata_user:my-password@my-host/my-schema?tmode=TERA&sslmode=verify-ca'
+----
 
+Refer https://airflow.apache.org/docs/apache-airflow-providers-teradata/stable/connections/teradata.html[Teradata Hook]  for detailed information on Teradata Connection in Airflow.
 
 == Define a DAG in Airflow
 
@@ -135,7 +180,7 @@ with DAG(
 
 == Summary
 
-This tutorial demonstrated how to use Airflow and the Airflow Teradata provider with a Teradata Vantage instance. The example DAG provided creates `my_users` table in the Teradata Vantage instance defined in Connection UI. 
+This tutorial demonstrated how to use Airflow and the Airflow Teradata provider with a Teradata Vantage instance. The example DAG provided creates `my_users` table in the Teradata Vantage instance defined in Connection UI.
 
 == Further reading
 * link:https://airflow.apache.org/docs/apache-airflow/stable/start.html[airflow documentation]