docs(samples): Adding code samples for log reading (#56)

* docs(samples): Adding code samples for log reading

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: m-strzelczyk

compute/batch/requirements-test.txt

@@ -1,4 +1,4 @@
 pytest==7.2.0
 google-cloud-compute==1.6.1
 google-cloud-resource-manager==1.6.3
-google-cloud-storage==2.5.0
+google-cloud-storage==2.5.0

compute/batch/requirements.txt

@@ -1,3 +1,4 @@
 isort==5.10.1
 black==22.10.0
 google-cloud-batch==0.4.0
+google-cloud-logging==3.2.5

compute/batch/snippets/logs/read_job_logs.py

@@ -0,0 +1,39 @@
+#  Copyright 2022 Google LLC
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+
+# [START batch_job_logs]
+from typing import NoReturn
+
+from google.cloud import batch_v1
+from google.cloud import logging
+
+
+def print_job_logs(project_id: str, job: batch_v1.Job) -> NoReturn:
+    """
+    Prints the log messages created by given job.
+
+    Args:
+        project_id: name of the project hosting the job.
+        job: the job which logs you want to print.
+    """
+    # Initialize client that will be used to send requests across threads. This
+    # client only needs to be created once, and can be reused for multiple requests.
+    log_client = logging.Client(project=project_id)
+    logger = log_client.logger("batch_task_logs")
+
+    for log_entry in logger.list_entries(filter_=f"labels.job_uid={job.uid}"):
+        print(log_entry.payload)
+
+# [END batch_job_logs]

compute/batch/snippets/tests/test_basics.py

@@ -27,6 +27,7 @@
 from ..get.get_task import get_task
 from ..list.list_jobs import list_jobs
 from ..list.list_tasks import list_tasks
+from ..logs.read_job_logs import print_job_logs
 
 PROJECT = google.auth.default()[1]
 REGION = 'europe-north1'
@@ -82,11 +83,18 @@ def _check_tasks(job_name):
     print('Tasks tested')
 
 
-def test_script_job(job_name):
+def _check_logs(job, capsys):
+    print_job_logs(PROJECT, job)
+    output = [line for line in capsys.readouterr().out.splitlines(keepends=False) if line != ""]
+    assert len(output) == 4
+    assert all(log_msg.startswith("STDOUT") for log_msg in output)
+
+
+def test_script_job(job_name, capsys):
     job = create_script_job(PROJECT, REGION, job_name)
-    _test_body(job, additional_test=lambda: _check_tasks(job_name))
+    _test_body(job, additional_test=lambda: _check_logs(job, capsys))
 
 
 def test_container_job(job_name):
     job = create_container_job(PROJECT, REGION, job_name)
-    _test_body(job)
+    _test_body(job, additional_test=lambda: _check_tasks(job_name))