Using pythonunbuffered instead of flushing the sys.stdout (#3937)

* Using pythonunbuffered instead of flushing the sys.stdout

run/hello-broken/Dockerfile

@@ -18,6 +18,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/hello-broken/main.py

@@ -15,7 +15,6 @@
 # [START run_broken_service]
 import json
 import os
-import sys
 
 from flask import Flask
 
@@ -35,9 +34,6 @@ def index():
         raise Exception("Missing required service parameter.")
     # [END run_broken_service_problem]
 
-    # Flush the stdout to avoid log buffering.
-    sys.stdout.flush()
-
     return f"Hello {NAME}"
 # [END run_broken_service]
 
@@ -58,9 +54,6 @@ def improved():
         print(json.dumps(error_message))
     # [END run_broken_service_upgrade]
 
-    # Flush the stdout to avoid log buffering.
-    sys.stdout.flush()
-
     return f"Hello {NAME}"
 
 

run/image-processing/Dockerfile

@@ -16,6 +16,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/image-processing/main.py

@@ -16,7 +16,6 @@
 import base64
 import json
 import os
-import sys
 
 from flask import Flask, request
 
@@ -62,8 +61,6 @@ def index():
 
         try:
             image.blur_offensive_images(data)
-            # Flush the stdout to avoid log buffering.
-            sys.stdout.flush()
             return ('', 204)
 
         except Exception as e:

run/logging-manual/Dockerfile

@@ -16,6 +16,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/logging-manual/main.py

@@ -14,7 +14,6 @@
 
 import json
 import os
-import sys
 
 from flask import Flask, request
 
@@ -52,9 +51,6 @@ def index():
     print(json.dumps(entry))
     # [END run_manual_logging]
 
-    # Flush the stdout to avoid log buffering.
-    sys.stdout.flush()
-
     return 'Hello Logger!'
 
 

run/markdown-preview/editor/Dockerfile

@@ -16,6 +16,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8-slim
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/markdown-preview/renderer/Dockerfile

@@ -16,6 +16,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8-slim
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/pubsub/Dockerfile

@@ -18,6 +18,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # Copy application dependency manifests to the container image.
 # Copying this separately prevents re-running pip install on every code change.
 COPY requirements.txt ./

run/pubsub/main.py

@@ -15,7 +15,6 @@
 # [START run_pubsub_server_setup]
 import base64
 import os
-import sys
 
 from flask import Flask, request
 
@@ -46,9 +45,6 @@ def index():
 
     print(f'Hello {name}!')
 
-    # Flush the stdout to avoid log buffering.
-    sys.stdout.flush()
-
     return ('', 204)
 # [END run_pubsub_handler]
 

run/system-package/Dockerfile

@@ -16,6 +16,9 @@
 # https://hub.docker.com/_/python
 FROM python:3.8
 
+# Allow statements and log messages to immediately appear in the Cloud Run logs
+ENV PYTHONUNBUFFERED True
+
 # [START run_system_package_ubuntu]
 RUN apt-get update -y && apt-get install -y \
   graphviz \

run/system-package/main.py

@@ -14,7 +14,6 @@
 
 import os
 import subprocess
-import sys
 
 from flask import Flask, make_response, request
 
@@ -36,9 +35,6 @@ def index():
     except Exception as e:
         print("error: {}".format(e))
 
-        # Flush the stdout to avoid log buffering.
-        sys.stdout.flush()
-
         # If no graphviz definition or bad graphviz def, return 400
         if "syntax" in str(e):
             return "Bad Request: {}".format(e), 400