So I've been meaning to create a cron job on my prototype Flask app running on Heroku. Searching the web I found that the best way is by using Flask-Script but I fail to see the point of using it. Do I get easier access to my app logic and storage info? And if I do use Flask-Script, how do I organize it around my app? I'm using it right now to start my server without really knowing the benefits. My folder structure is like this:
/app
/manage.py
/flask_prototype
all my Flask code
Should I put the 'script.py' to be run by the Heroku Scheduler on app folder, the same level as manage.py? If so, do I get access to the models defined within flask_prototype?
Thank you for any info
Flask-Script just provides a framework under which you can create your script(s). It does not give you any better access to the application than what you can obtain when you write a standalone script. But it handles a few mundane tasks for you, like command line arguments and help output. It also folds all of your scripts into a single, consistent command line master script (this is manage.py, in case it isn't clear).
As far as where to put the script, it does not really matter. As long as manage.py can import it and register it with Flask-Script, and that your script can import what it needs from the application you should be fine.
Related
So im building app based on Express and using Prisma ORM. What i need is to SSH to a server, open up express.js console and create new db entry using prisma. Something similar to python manage.py shell for Django or rails console for Rails. Is there a solution for this of any kind?
Like I pointed in the comment there is a way ( kind of ) to get access to a running express instance. If that's all you need follow:
How can I open a console to interact with Express app?
Express doesn't exactly have a feature like rails console which is a framework feature in that case.
That said, I question the long term implication of this approach. If you really just need to seed some data, write an "init" script, and call it after you ssh into a server or using some CI/CD approach. This is more re-usable, since you can even pass a json file to the script to load dynamic data.
Also, Prismajs has an official way to seed the data ( if that's what you need) that you can leverage:
https://www.prisma.io/docs/guides/database/seed-database
UPDATE:
If you are able to run to code on your machine and point the remote database, then you can use node --inspect to debug in a chrome console. Which should give you about the same effect as a rails REPL
https://medium.com/#tbernardes/debugging-nodejs-with-chrome-inspector-devtools-1cd2ef323b5e
I have two apps running on the same server.
Now it seems like when adding withoutOverlapping() to the scheduler job and managing the base cronjob via cron itself, these 2 apps are blocking each other in execution.
Could that be?
Yes, withoutOverlapping only works per application.
Laravel creates a file in the storage folder with a hash of the job. This way, if the file exists, Laravel knows the job is still running. The one application cannot possibly know if the other one is currently running a job because it does not have access to the storage folder of the other application.
If your code looks like the following
$schedule->command('process:queue 0')->everyMinute()->withoutOverlapping();
$schedule->command('process:queue 1')->everyMinute()->withoutOverlapping();
It is because same commands with different parameters might bc considered overlapping.
I.e. the hash of the job will consider only the command signature.
Using Codeigniter 2.2.0 for my project. Is $this->input->is_cli_request() validation is necessary for a cron job?
It is recommended to protect your cronjob not to execute when someone type the URL in their browser. However if you don't have any problem running your cronjob invoked by anyone then can avoid this check.
Refer https://ellislab.com/codeigniter/user-guide/general/cli.html for more details.
It recommented to run cron jobs with command line.
There are many reasons for running CodeIgniter from the command-line, but they are not always obvious.
Run your cron-jobs without needing to use wget or curl
Make your cron-jobs inaccessible from being loaded in the URL by checking for $this->input->is_cli_request()
Make interactive "tasks" that can do things like set permissions, prune cache folders, run backups, etc.
Integrate with other applications in other languages. For example, a random C++ script could call one command and run code in your models!
More info read here
But you also can prevent calling from URL in your server.
I'm creating an init.d script that will run a couple of tasks when the instance starts up.
it will create a new volume with our code repository and mount it if it doesn't exist already.
it will tag the instance
The tasks above being complete will be crucial for our site (i.e. without the code repository mounted the site won't work). How can I make sure that the server doesn't end up being publicly visible? Should I start my init.d script with de-registering the instance from the ELB (I'm not even sure if it will be registered at that point), and then register it again when all the tasks finished successfully?
What is the best practice?
Thanks!
You should have a health check on your ELB. So your server shouldn't get in unless it reports as happy. And it shouldn't report happy if the boot script errors out.
(Also, you should look into using cloud-init. That way you can change the boot script without making a new AMI.)
I suggest you use CloudFormation instead. You can bring up a full stack of your system by representing it in a JSON format template.
For example, you can create an autoscale group that has an instances with unique tags and the instances have another volume attached (which presumably has your code)
Here's a sample JSON template attaching an EBS volume to an instance:
https://s3.amazonaws.com/cloudformation-templates-us-east-1/EC2WithEBSSample.template
And here many other JSON templates that you can use for your guidance and deploy your specific Stack and Application.
http://aws.amazon.com/cloudformation/aws-cloudformation-templates/
Of course you can accomplish the same using init.d script or using the rc.local file in your instance but I believe CloudFormation is a cleaner solution from the outside (not inside your instance)
You can also write your own script that brings up your stack from the outside by why reinvent the wheel.
Hope this helps.
Is there way to invoke a CakePHP console shell on server without shell access? I have written a shell for performing some once off (and hence not a cron task) post DB upgrade tasks.
I could always just copy the logic into a temporary controller, call its actions via http and then delete it, but was wondering if there was a better way to go about it.
It seems that this is a one off script you might want to typically be running after DB updates right?
If that's the case, you can make it part of your "DB update script"
If you use anything like capistrano, you can include there too.
In all cases, if you don't want to touch the shell, I agree that having a controller to call the console code (or any php file running exec() as mentioned previously) would do the trick.
Also, if you want to run it just once and have it scheduled - don't forget that you have the "at" command (instead of cron) which will run it at that scheduled date (see http://linux.about.com/library/cmd/blcmdl1_at.htm)
Hope it helps,
Cheers,
p.s: if its a console shell and you don't want to run it from the console, then just don't make it a console shell.
I have to agree with elvy. Since this is something that you need to do once in a while after other events have happened, why not just create an 'admin' area for your application and stick code for that update in there?
you may be able to use php's exec function to call it from any old php script.
http://www.php.net/exec