Update variables usage in bigquery_github_trends DAG

Author: tuanavu

examples/gcloud-example/dags/bigquery_github/bigquery_github_trends.py

@@ -2,9 +2,17 @@
 from datetime import timedelta, datetime
 
 from airflow import DAG
+from airflow.models import Variable
 from airflow.contrib.operators.bigquery_operator import BigQueryOperator
 from airflow.contrib.operators.bigquery_check_operator import BigQueryCheckOperator
 
+
+# Config variables
+dag_config = Variable.get("bigquery_github_trends_variables", deserialize_json=True)
+BQ_CONN_ID = dag_config["bq_conn_id"]
+BQ_PROJECT = dag_config["bq_project"]
+BQ_DATASET = dag_config["bq_dataset"]
+
 default_args = {
     'owner': 'airflow',
     'depends_on_past': True,    
@@ -28,11 +36,6 @@
     schedule_interval=schedule_interval
     )
 
-# Config variables
-BQ_CONN_ID = "my_gcp_conn"
-BQ_PROJECT = "my-bq-project"
-BQ_DATASET = "my-bq-dataset"
-
 ## Task 1: check that the github archive data has a dated table created for that date
 # To test this task, run this command:
 # docker-compose -f docker-compose-gcloud.yml run --rm webserver airflow test bigquery_github_trends bq_check_githubarchive_day 2018-12-01

examples/gcloud-example/dags/bigquery_github/config/variables.json

@@ -0,0 +1,7 @@
+{
+	"bigquery_github_trends_variables": {
+		"bq_conn_id": "my_gcp_conn",
+		"bq_project": "my_bq_project",
+		"bq_dataset": "my_bq_dataset"
+	}
+}