I have created the basic "Hello World" web app and deployed it. So I have the URL with my project name included in it. I wanted to create a couple of changes to the source code, but when I try refreshing it shows no changes. How do I make changes?
If you deployed the app
gcloud app update
If it's testing in Cloud Shell
I missed where you stated the app was deployed and wrote the answer below. I'll leave it for future readers or in case it might help.
To stop the local server from the command line, you press the
following:
Mac OS X or Linux: Control-C Windows: Control-Break
Then restart again with
dev_appserver.py app.yaml
This assumes you're completing the App Engine hello world tutorial.
Still not working? Maybe you have multiple processes running or something else is wrong. Let's try killing all of the web server processes and restarting.
ps aux | grep dev_appserver.py
Look at the process number.
kill PROCESS_NUM_HERE
If you see multiple processes after running ps aux... then you should kill all of them.
Then restart
dev_appserver.py app.yaml
Related
I have a web app that I deployed to a machine that has ubuntu 20 installed
to be able to run the app I should open ssh to the ubuntu machine and then run this command
cd mywebapp
python3 app.py
it works successfully, but once I close the ssh console or reboot the machine or anything happens, it stopped and I have to repeat these commands
I tried to add it as a corn job to be run after machine reboot but it does not work
I post a question in the following link : run python app after server restart does not work using crontab
nothing work with me, and I have to make sure that this web app will always be running because it should be working to send push notification to mobile devices
can anyone please advice, I have been searching and trying for so many time
I'm not expert in it, but two solutions come in my mind:
1- Using systemd:
systemd can be responsible to keep services up.
You can write a custom unit for your app, and config it as a way to be up always.
This tutorial may be useful: writing unit
2- Using Docker:
When you have containerized app, you config it as to come up, on failure or anything like that.
Read about it here
What if you have the calling piece of Python script within a bash script and run that as a daemon:
Your bash script could like below (test.sh):
#!/bin/sh
cd desired/directory
python3 app.py
and you can run the bashscript like this by using nohup:
nohup ./test.sh 0<&- &>/dev/null &
You could refer this, if you want to store the outputs of nohup.
I am looking for help deploying my flash app. I've already written the app and it works well. I'm currently using the following command in the directory of my flask code:
sudo uwsgi --socket 0.0.0.0:70 --protocol=http -w AppName:app --buffer-size=32768
This is on my Amazon Lightsail instance. I have the instance linked to a static public IP, and if I navigate to the website, it works great. However, to get the command to continuously run in the background even after logging out of the Lightsail, I first start a screen command, execute the above line of code, and then detach the screen using ctrl-a-d.
The problem is, if the app crashes (which is understandable since it is very large and under development), or if the command is left running for too long, the process is killed, and it is no longer being served.
I am looking for a better method of deploying a flask app on Amazon Lightsail so that it will redeploy the app in the event of a crash without any interaction from myself.
Generally you would write your own unit file for systemd to keep your application running, auto restart when it crashes and start when you boot your instances.
There are many tutorials out there showing how to write such a unit file. Some examples:
Systemd: Service File Examples
Creating a Linux service with systemd
How to write startup script for Systemd?
You can use pm2
Starting an application with PM2 is straightforward. It will auto
discover the interpreter to run your application depending on the
script extension. This can be configurable via the Ecosystem config
file, as I will show you later on this article.
All you need to install pm2 and then
pm2 start appy.py
Great, this application will now run forever, meaning that if the process exit or throw an exception it will get automatically restarted. If you exit the console and connect again you will still be able to check the application state.
To list application managed by PM2 run:
pm2 ls
You can also check logs
pm2 logs
Keeping Processes Alive at Server Reboot
If you want to keep your application online across unexpected (or expected) server restart, you will want to setup init script to tell your system to boot PM2 and your applications.
It’s really simple with PM2, just run this command (without sudo):
pm2 startup
Pm2 Manage-Python-Processes
I have created a Django application and uploaded in to AWS EC2. I can access the site using public IP address only when I run the python manage.py in AWS command line.
If I close the Putty window, I am not able to access the site. How can I make sure that the site is available always even if I close the command line / putty?
I tried WSGI option but its not working at all. Appreciate your help to give us a solution to run the Python application in AWS.
It happens because you are running the app from within the SSH session, which means that ending the session (SIGHUP) will kill your application.
There are several ways to keep the app running after you disconnect the SSH, the simplest would be to run it inside a screen session and keeping this instance running while disconnecting from SSH, the advantage of this method is that you can still control the app when you are reconnecting to this machine and control the state of the app and also potentially see the logs.
Although it might be pretty cool it's considered a patch, the more stable and solid way would be to create a service that will run the app and will allow you to start, stop and look at logs using the nifty wrappers of systemd.
Keep the process running with screen:
First you'll have to make sure screen is installed (apt-get or yum) whatever suits your desired distro.
Run screen.
Run the app just like you did outside screen.
Detach from the screen session by pressing Ctrl+A and then d.
Disconnect from the SSH and see how the service is still running.
Creating a systemd service is a bit more complicated so try and read through the following manual.
I am trying to create a web application using flask. I have already gotten somewhat comfortable with using python, and have done so using spyder, inside of Anacanda Navigator. Now I am playing around with flask doing basic functions and have successful so far by testing it out in local server 127.0.0.1:5000. The problem I am having is that I cannot stop the server once I run the script in spyder. I have stopped the script and run other scripts through the console, but the local server remains the same.
The reason this is a problem for me is because when I try to change files and run a different flask script, the server does not update with the new information. For example, if I run a flask script that returns "Hello World" on the main page, and then I stop that file, open a new file that has a different flask script that returns "The sky is blue" the server does not change when I check it on chrome or any other browser. It will onyl return "Hello World"
I have been able to fix this problem by completely restarting my computer, but I am wondering if there is another way, just to restart the local server, 127.0.0.1:5000. Thank You!
Also I am using windows
I do : "Run > Configuration per file > Execute in an external system terminal",
then when you run your .py containing the app.run, it will be launched in an external console. If you close the console the server will be closed too.
To Kill the local server, you may use Ctrl+C command and not any other command. This command is also mentioned when the server is up and running.
I've been having this precise issue and have been smashing my head against the wall for a couple of hours. I posted the referenced StackOverflow question (my first actually) and it seems that running a script from inside Spyder is the wrong way to go as it leaves runaway background processes running, even after restarting Spyder.
I got the recommendation to only launch my *.py code from the command prompt. Furthermore I was told to do this:
set FLASK_APP=main1.py then set FLASK_DEBUG=1 then flask run
though I'm not sure what that does, so I will investigate. I was about to restart my computer as a last ditch effort until I looked in my Windows Task Manager and found some Python tasks running. After [end task] them both I was able to launch the updated webpage on my local host.
So, probably a dumb question, but I am beginning to learn all this so your feedback will be valuable for me.
The question is: In flask documentation it says start the flask server by entering the command 'python hello.py' and I do it successfully to see the output on localhost:5000. Now, I have a shared hosting plan and if I upload this file over there will i need to initiate the server over there as well like this? If so, when I close the terminal over there, will the flask server shut down (because when I close the terminal on my computer it shuts down the flask server and the results are no more available on localhost:5000)?.. It basically suggests me that I have to keep running the terminal all the time..please tell me what is the basic idea here? Thanks.
What you're asking is how you deploy your app. There are many options, that will depend on your needs, your hosting service, etc.
You should check the flask docs for the options. http://flask.pocoo.org/docs/deploying/
In essence, you'll have your flask app running as a local service on the server, so it's not shut down when you close the terminal, and an HTTP server that somehow proxies requests to that service. I guess the most popular is uWSGI with nginx.
When you upload your code to a remote host, you will need to provide a way to start the server and get things running. How this works is host- and software-dependent. As an example, here is some documentation for how you would fire Flask up on Heroku.