fixing auth error on invoking ML pipeline

Author: Eugene Fedorenko

docs/getting_started.md

@@ -127,7 +127,7 @@ Add a command line step **Run Training Pipeline** with the following script:
 ```bash
 docker run  -v $(System.DefaultWorkingDirectory)/_ci-build/mlops-pipelines/ml_service/pipelines:/pipelines \
 -w=/pipelines -e MODEL_NAME=$MODEL_NAME -e EXPERIMENT_NAME=$EXPERIMENT_NAME \
--e TENANT_ID=$TENANT_ID -e SP_APP_ID=$SP_APP_ID -e SP_APP_SECRET=$SP_APP_SECRET \
+-e TENANT_ID=$TENANT_ID -e SP_APP_ID=$SP_APP_ID -e SP_APP_SECRET=$(SP_APP_SECRET) \
 mcr.microsoft.com/mlops/python:latest python run_train_pipeline.py
 ```
 

environment_setup/Dockerfile

@@ -10,8 +10,4 @@ COPY environment_setup/requirements.txt  /setup/
 
 RUN apt-get update && apt-get install gcc -y && pip install --upgrade -r /setup/requirements.txt   
 
-COPY environment_setup/python.sh /usr/local/sbin/python.sh
-RUN rm /usr/local/bin/python && ln -s /usr/local/sbin/python.sh /usr/local/bin/python
-
-
 CMD ["python"]

ml_service/pipelines/run_train_pipeline.py

@@ -2,9 +2,13 @@
 import os
 import json
 import requests
-from azureml.core.authentication import AzureCliAuthentication
+from azure.common.credentials import ServicePrincipalCredentials
 
 
+tenant_id = os.environ.get("TENANT_ID")
+app_id = os.environ.get("SP_APP_ID")
+app_secret = os.environ.get("SP_APP_SECRET")
+
 try:
     with open("train_pipeline.json") as f:
         train_pipeline_json = json.load(f)
@@ -15,16 +19,24 @@
 experiment_name = os.environ.get("EXPERIMENT_NAME")
 model_name = os.environ.get("MODEL_NAME")
 
-cli_auth = AzureCliAuthentication()
-token = cli_auth.get_authentication_header()
+credentials = ServicePrincipalCredentials(
+    client_id=app_id,
+    secret=app_secret,
+    tenant=tenant_id
+)
+
+token = credentials.token['access_token']
+print("token", token)
+auth_header = {"Authorization": "Bearer " + token}
 
 rest_endpoint = train_pipeline_json["rest_endpoint"]
 
 response = requests.post(
-    rest_endpoint, headers=token,
+    rest_endpoint, headers=auth_header,
     json={"ExperimentName": experiment_name,
           "ParameterAssignments": {"model_name": model_name}}
 )
 
 run_id = response.json()["Id"]
 print("Pipeline run initiated ", run_id)
+