I want to run a single python flask hello world. I deploy to App Engine, but it's showing like it's saying that the port is in use and it looks like it's running on multiple instances/threads/clones concurrently.
This is my main.py
from flask import Flask
app = Flask(__name__)
#app.route('/hello')
def helloIndex():
print("Hello world log console")
return 'Hello World from Python Flask!'
app.run(host='0.0.0.0', port=4444)
This is my app.yaml
runtime: python38
env: standard
instance_class: B2
handlers:
- url: /
script: auto
- url: .*
script: auto
manual_scaling:
instances: 1
This is my requirements.txt
gunicorn==20.1.0
flask==2.2.2
And this is the logs that I got:
* Serving Flask app 'main'
* Debug mode: off
Address already in use
Port 4444 is in use by another program. Either identify and stop that program, or start the server with a different port.
[2022-08-10 15:57:28 +0000] [1058] [INFO] Worker exiting (pid: 1058)
[2022-08-10 15:57:29 +0000] [1059] [INFO] Booting worker with pid: 1059
[2022-08-10 15:57:29 +0000] [1060] [INFO] Booting worker with pid: 1060
[2022-08-10 15:57:29 +0000] [1061] [INFO] Booting worker with pid: 1061
It says that Port 4444 is in use. Initially I tried 5000 (flask's default port) but it says it's in use. Also I tried removing the port=4444 but now it's saying Port 5000 is in use by another program, I guess flask by default assign port=5000. I'm suspecting that it's because GAE is running in multiple instances that's causing this error. If not, then please help to solve this issue.
App Engine apps should listen on port 8080 and not in any other ones.
So you may need to set this like
app.run(host='0.0.0.0', port=8080)
Close the editor and then reopen. When you stop the process next time use Ctrl+C if you're on the terminal
I figured it out. Delete your old file from your terminal and or folder that created the web app. In the terminal this is done by:
rm -file_name
Then try all over again with your a fresh file and it should be okay.
Related
My Django app was working fine on Google App Engine (Flexible) using gunicorn as entrypoint in the app.yaml file. I needed to add websockets to it so I used Django Channels (with redis). This works beautifully on my local machine (Windows 10).
For deployment, I changed my entrypoint to daphne on port 8080 since that's the default on GAE (using $PORT produces the same effect), so my yaml file now looks like this:
runtime: python
env: flex
runtime_config:
python_version: 3
entrypoint: daphne -b 127.0.0.1 -p 8080 my_project_name.asgi:application
I've checked my .asgi file and requirements.txt to ensure everything is ok and the packages are the latest versions.
But after deploying it, I get a "502 Bad Gateway Nginx" error.
The Stackdriver logs (nginx.error) on the GCP cloud console say the below:
[error] 33#33: *341 connect() failed (111: Connection refused) while connecting
to upstream, client: 172.xxx.xxx.xxx, server: , request: "GET / HTTP/1.1",
upstream: "172.17.0.1:8080", host: "my_project_name.appspot.com"
I don't recognize those IPs for upstream server or client, and I don't know what to do next. I've tried numerous things over the last 4 days, including:
using various different ports (8000, 8001 etc)
adding an nginx.conf file (based on this documentation) in my project directory, which seems to make no difference
Adding a line in the runtime_config section of the yaml file that says "nginx_conf_http_include: nginx.conf"
4.Using Unix sockets to start the daphne server in the entrypoint like "entrypoint: daphne -u /tmp/daphne.sock my_project_name.asgi:application
Deleting the entrypoint altogether after declaring the daphne server in the nginx.conf file
None of this helps. The logs stay the same, the error stays the same. I've read SO questions like this and this but I don't know how to apply them to GAE Flex since I'm not directly operating the VM instance. Please help.
I'm new to web development so I appreciate some hand-holding by the smart folks here. I'm trying to switch from gunicorn to Daphne for my Django app on GAE Flex, since I need to use Django Channels.
Previously the site worked fine with gunicorn as entrypoint (in the app.yaml file). I just replaced it with daphne (I'd like to avoid complexity by changing nginx configurations, Unix sockets etc so I guess I'm ok with Daphne serving both HTTP and ws requests). So now my app.yaml looks like:
runtime: python
env: flex
runtime_config:
python_version: 3
entrypoint: daphne -b 0.0.0.0 -p 8001 my_project_name.asgi:application
I've already made a .asgi file next to my .wsgi file and declared an application there.
In requirements.txt I've ensured the daphne(2.4.1) and asgiref(3.2.3) packages are the latest versions.
Finally when I do 'gcloud app deploy', deployment appears to happen smoothly and in the build logs I can see daphne starting:
Step #1: Step 9/9 : CMD exec daphne -b 0.0.0.0 -p 8001 my_project_name.asgi:application
Step #1: ---> Running in c6f3762a5ce2
But I'm getting a 502 Bad Gateway error on the site, with "nginx" in the next line.
Question: What am I doing wrong? Is this because Daphne is not serving http requests? Am I supposed to do anything different to make Daphne serve HTTP requests? Right now my http paths are served in Django by the urls.py module and not the routing.py module (which is taking care of only ws requests). Am I supposed to change that in some way?
If you feel that splitting incoming requests and sending http to gunicorn is the only way, please describe those steps. What happens to the entrypoint in the app.yaml file if I do that?
My efforts so far: I see many questions on SO (such as this and this) and other tutorials online on how to use daphne on standalone linux machines but not on app engines like GAE Flex. The only GAE-related post I saw was this, but it's a different problem from mine.
I'm getting an endless stream of the following errors after deploying a Flask/Python3/Postgres app to app engine standard environment. The warning about Psycopg2 package is of concern, but not what's causing the app to fail to run. Rather, it's the invalid command line arguments to gunicorn, which are supplied by GAE, not by me. Is anyone able to deploy a Python3 Flask that uses Postgres to the Standard environment successfully?
Here's the log file output:
2018-12-11 02:51:37 +0000] [3738] [INFO] Booting worker with pid: 3738
2018-12-11 02:51:37 default[20181210t140744] /env/lib/python3.7/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
2018-12-11 02:51:37 default[20181210t140744] """)
2018-12-11 02:51:38 default[20181210t211942] usage: gunicorn [-h] [--debug] [--args]
2018-12-11 02:51:38 default[20181210t211942] gunicorn: error: unrecognized arguments: main:app --workers 1 -c /config/gunicorn.py
2018-12-11 02:51:38 default[20181210t211942] [2018-12-11 02:51:38 +0000] [882] [INFO] Worker exiting (pid: 882)
By default, if entrypoint is not defined in app.yaml, App Engine will look for an app called app in main.py. If you look at the official code sample in Github, it addresses it in the main.py file by declaring:
app = Flask(__name__)
Alternatively, this can be configured by adding an entrypoint to app.yaml pointing to another file. For example, if you declare app in a file called prod:
entrypoint: gunicorn -b :$PORT prod.app
You'll find additional details about the entrypoint configuration here.
From the comment and answer above, It looked like the problem had to be in my app. I confirmed that by running gunicorn locally on a bare-bones app without difficulty, but failing when running the real app.
One culprit turned out to be the use of argparse, which I was using so I could add a "debug" argument to the command line when working locally. Moving that code to the if __name__ == '__main__': section made the app run fine when using gunicorn locally.
But it still fails when deployed to GAE:
2018-12-12 20:09:16 default[20181212t094625] [2018-12-12 20:09:16 +0000] [8145] [INFO] Booting worker with pid: 8145
2018-12-12 20:09:16 default[20181212t094625] /env/lib/python3.7/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
2018-12-12 20:09:16 default[20181212t094625] """)
2018-12-12 20:09:16 default[20181212t094625] [2018-12-12 20:09:16 +0000] [8286] [INFO] Booting worker with pid: 8286
2018-12-12 20:09:16 default[20181212t094625] /env/lib/python3.7/site-packages/psycopg2/__init__.py:144: UserWarning: The psycopg2 wheel package will be renamed from release 2.8; in order to keep installing from binary please use "pip install psycopg2-binary" instead. For details see: <http://initd.org/psycopg/docs/install.html#binary-install-from-pypi>.
2018-12-12 20:09:16 default[20181212t094625] """)
2018-12-12 20:09:19 default[20181212t094625] usage: gunicorn [-h] [--debug] [--args]
2018-12-12 20:09:19 default[20181212t094625] gunicorn: error: unrecognized arguments: -b :8081 main:app
2018-12-12 20:09:19 default[20181212t094625] [2018-12-12 20:09:19 +0000] [8145] [INFO] Worker exiting (pid: 8145)
Here’s app.yaml (minus the environment variable for SendGrid):
runtime: python37
env: standard
#threadsafe: true
entrypoint: gunicorn --workers 2 --bind :5000 main:app
#runtime_config:
# python_version: 3
# This beta setting is necessary for the db hostname parameter to be able to handle a URI in the
# form “/cloudsql/...” where ... is the instance given here:
beta_settings:
cloud_sql_instances: provost-access-148820:us-east1:cuny-courses
Over the past week I've been seeing the number of instances on my GAE Flexible Environment fall to 0, with no new instance spinning up. My understanding of the Flexible environment is that this shouldn't be possible... (https://cloud.google.com/appengine/docs/the-appengine-environments)
I was wondering if anyone else has been seeing these issues, or if they've solved the problem on their end before. My one hypothesis is that this might be an issue with my health monitoring endpoints, but haven't seen anything that jumps out as a problem when I review the code.
This hasn't been a problem for me until last week, and now it seems like I have to redeploy my environment (with no changes) every couple of days just to "reset" the instances. It's worth noting that I have two services under this same App Engine project, both running flexible versions. But I only seem to have this issue with one of the services (what I call the worker service).
Screenshot from App Engine UI:
Screenshot from Logs UI that shows the SIGTERM being sent:
PS - Could this have anything to do with the recent Google Compute issues that have been coming up... https://news.ycombinator.com/item?id=18436187
Edit: Adding the yaml file for "worker" service. Note that I'm using Honcho to add an endpoint to monitor health of the worker service via Flask. I added those code examples as well.
yaml File
service: worker
runtime: python
threadsafe: yes
env: flex
entrypoint: honcho start -f /app/procfile worker monitor
runtime_config:
python_version: 3
resources:
cpu: 1
memory_gb: 4
disk_size_gb: 10
automatic_scaling:
min_num_instances: 1
max_num_instances: 20
cool_down_period_sec: 120
cpu_utilization:
target_utilization: 0.7
Procfile for Honcho
default: gunicorn -b :$PORT main:app
worker: python tasks.py
monitor: python monitor.py /tmp/psq.pid
monitor.py
import os
import sys
from flask import Flask
# The app checks this file for the PID of the process to monitor.
PID_FILE = None
# Create app to handle health checks and monitor the queue worker. This will
# run alongside the worker, see procfile.
monitor_app = Flask(__name__)
#monitor_app.route('/_ah/health')
def health():
"""
The health check reads the PID file created by tasks.py main and checks the proc
filesystem to see if the worker is running.
"""
if not os.path.exists(PID_FILE):
return 'Worker pid not found', 503
with open(PID_FILE, 'r') as pidfile:
pid = pidfile.read()
if not os.path.exists('/proc/{}'.format(pid)):
return 'Worker not running', 503
return 'healthy', 200
#monitor_app.route('/')
def index():
return health()
if __name__ == '__main__':
PID_FILE = sys.argv[1]
monitor_app.run('0.0.0.0', 8080)
I'm trying to deploy Managed VM (Python) on Google App / Compute Engine with command:
gcloud --verbosity debug preview app deploy ./app.yaml --set-default
during deployment VM instance is created but it exits on error (here is paste of last few lines of listing):
DEBUG: Display disabled.
Copying certificates for secure access. You may be prompted to create an SSH keypair.
DEBUG: Loaded Command Group: ['gcloud', 'compute', 'copy_files']
DEBUG: Detected docker environment variables: DOCKER_HOST=tcp://104.197.50.238:2376, DOCKER_CERT_PATH=../../../../../tmp/tmpPbKmOs, DOCKER_TLS_VERIFY=True
INFO: Starting new HTTPS connection (1): 104.197.50.238
DEBUG: Failed to connect to Docker daemon due to an SSL problem: [Errno 1] _ssl.c:523: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
DEBUG: (gcloud.preview.app.deploy) Couldn't connect to the Docker daemon due to an SSL problem.
Traceback (most recent call last):
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/calliope/cli.py", line 591, in Execute
result = args.cmd_func(cli=self, args=args)
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/calliope/backend.py", line 1191, in Run
resources = command_instance.Run(args)
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/appengine/app_commands/deploy.py", line 208, in Run
implicit_remote_build)
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/appengine/lib/deploy_command_util.py", line 137, in BuildAndPushDockerImages
with docker_util.DockerHost(cli, version_id, remote) as docker_client:
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/appengine/lib/images/docker_util.py", line 215, in __enter__
return containers.NewDockerClient(local=(not self._remote), **kwargs)
File "/home/zdenulo/bin/google-cloud-sdk/./lib/googlecloudsdk/appengine/lib/docker/containers.py", line 313, in NewDockerClient
'Couldn\'t connect to the Docker daemon due to an SSL problem.' + msg)
DockerDaemonConnectionError: Couldn't connect to the Docker daemon due to an SSL problem.
ERROR: (gcloud.preview.app.deploy) Couldn't connect to the Docker daemon due to an SSL problem.
apparently there is problem with SSL but I have no idea how to solve it, and I'm quite desperate at the moment :)
I have:
Docker version 1.8.2, build 0a8c2e3
Boot2Docker-cli version: v1.8.0 Git commit: 9a26066
Google Cloud SDK 0.9.79
app 2015.09.23
app-engine-java 1.9.26
app-engine-python 1.9.26
bq 2.0.18
bq-nix 2.0.18
core 2015.09.23
core-nix 2015.09.03
gcloud 2015.09.21
gsutil 4.15
gsutil-nix 4.14
preview 2015.09.21
OpenSuse 13.2
OpenSSL 1.0.1k-fips 8 Jan 2015
I would very much appreciate help of any kind.
EDIT:
app.yaml
module: default
runtime: python27
api_version: 1
threadsafe: yes
vm: true
resources:
cpu: .5
memory_gb: 1.3
manual_scaling:
instances: 1
handlers:
- url: .*
script: main.app
Are you using homebrew Python on OS X? If so, there's an existing bug for OpenSSL and Docker here.
The easiest way around this is to temporary use a virtualenv with system python.
pip install virtualenv
virtualenv ~/system-python-env
source ~/system-python-env
gcloud preview app deploy ...
You can get at a short-lived SSL with "gcloud docker --authorize-only". Then immediately do your "gcloud preview app deploy..".
gcloud docker --authorize-only
gcloud preview app deploy app.yaml --promote