I'd like to configure a Heroku app to run a scheduled task once per day. My source tree looks like this:
bin/myScript
Procfile
package.json
When I deploy the app, I see the following error:
2017-01-11T04:31:36.660973+00:00 app[web.1]: npm ERR! missing script: start
I believe this is because Heroku tries to spin up a web dyno. I don't have a web dyno, nor do I want one. So I created a Procfile with this line:
heroku ps:scale web=0
To prevent heroku from spinning up a web dyno. That didn't work. What else can I do to prevent my app from crashing upon deployment? Does it matter if the scheduled task is going to be run in a separate one-off Dyno anyway?
You should not have the line "heroku ps:scale web=0" in your Procfile.
Doing so tells heroku to create a process type called "heroku" that attempts to run the following command on any dyno instances instantiated for it: "ps:scale web=0". That would probably generate errors, and at any rate, is not what you intended.
Instead You should run "heroku ps:scale web=0" as a Heroku toolbelt CLI command (or do the equivalent from the Resources tab of the GUI, as you already did).
I think I found a fix: in the "Resources" tab of the GUI for the web, there is a list of dynos with on/off sliders next to them. I switched the web dyno slider to off, and now when I deploy there is no crash. Still, it's unclear to me why the Procfile line was insufficient.
Related
Im trying to host my object detection api on heroku but i can't due to it not recognizing my
Procfile, which is a file and not a text file. the way its spelled is Procfile, its contents are
web:gunicorn app:app
the way i know that its the Procfile thats the problem is because when i run bash and look at the root directory of the heroku git i see Procfile but when i look at the logs i see that no web process is running and on the dashboard the dynos is completely empty.
i've tried doing
web: gunicorn app: app instead of web:gunicorn app:app
to no avail, i've made sure that gunicorn is in the requirements.txt and know that its pip installing the requirements.txt as the cmd tells me that it is when i do git push heroku master. i've tried doing echo>Procfile and then modifying the contents of the file. i've tried both echo "web:gunicorn app:app"> Procfile and echo web:gunicorn app:app>Procfile i tried doing heroku ps:scale web=1 and get Scaling web dynos... failed ! No such process type web defined in Procfile. and when i do heroku ps i get nothing
I am trying to host a discord bot on Heroku (Discord JDA, Maven). I do this by connecting to Github and then deploying. The bot 'deploys' (view attachment) but doesn't actually work (view attachment).
What could I be doing wrong, or has anyone else come across a similar issue?
Quick and dirty way to deploy it:
You'll need to setup a Procfile, extensive info on that right here: https://devcenter.heroku.com/articles/procfile
The procfile is basically a file with no extension that tells the dyno how to execute your program.
A simple
worker: java $JAVA_OPTS -jar <PATH_TO_JAR>
will work fine if you don't need more config, refer to that link for more.
You can then deploy it like this (Good to have procfile and jar on the same directory):
$ heroku deploy:jar -a <YOUR_HEROKU_APP_NAME> --jdk <JDK_VERSION> --jar <PATH_TO_JAR> -i Procfile
Then to start it just do (Assuming you want a worker dyno, which is what discord should need)
$ heroku ps:scale -a <YOUR_HEROKU_APP_NAME> worker=1
Then stop it with:
$ heroku ps:scale -a <YOUR_HEROKU_APP_NAME> worker=0
I've found this is much simpler than using git, especially if you're doing tests or simple/quick stuff.
Possible solutions:
Set up a Procfile. A Procfile basically tells Heroku what command to run when your app is deployed. Inside the Procfile, write worker: node index.js. Also, make sure Procfile has a capital "P".
Set up package.json.
npm init
Then just skip through the set up and your file should be automatically created. IMPORTANT. In your package.json file, add your node and npm versions.
node -v
npm -v
Then go an type this in your package.json.
"engines": {
node: "your-version-here"
npm: "your-version-here"
}
Then try deploying your app to Heroku again. Also, make sure you have the "nodejs" buildpack set up for your app. Run it and test the discord bot.
I'm trying to have my dynos restarted every 2 hours or so. I don't have a CLI connection installed or anything like that, I'd like to do this directly in the web interface with Heroku Scheduler.
The web interface has a "Run console" option in the "More" menu.
If I try to run the heroku ps:restart command there, it says:
bash: heroku: command not found
It's the same result if I try to run just ps:restart.
And the same result if I put either of those in the Heroku Scheduler.
Is there a way for me to achieve this with Heroku Scheduler?
Without setting up extra scripts and authorizations etc. as described here: Schedule Heroku to restart dynos every 10 or so minutes
The default dyno image doesn't have the Heroku CLI installed. But there is a buildpack you can add on top of your current language buildpack, and you'll have the heroku command in your app.
I pushed my flask app to Heroku and I'm trying to connect through my frontend for the first time. I was getting a 503 Error and did a heroku log which revealed
desc="No web processes running".
I double checked my Procfile, deleted it, saw that git was noticing the changes to the file, made sure there was no extension to the file, then recreated it and pushed it back to heroku and ran heroku ps:scale web=1 but I'm still getting
Couldn't find that formation.
Is there anything else I should try?
This is what I have inside the Procfile web: gunicorn manage:app. I'm creating the Procfile on TextEdit, could that be causing the issue?
This might be obvious to others, but it took me a while to figure it out. I was using TextEdit on my Mac to create the Procfile. I made sure to delete the extension after creating the file. Apparently, thats not good enough. I went into google drive and created a Procfile.txt then downloaded it to my apps root directory and removed the extension. Pushed the changes and ran heroku ps:scale web=1 and it worked.
Use case is to bust the cache.
What is a good way to run given code (or rake task) whenever a Ruby Heroku app is restarted (or deployed)?
There's no way to do this via the Heroku API far as I know. The Heroku Platform API doesn't support this.
What you can do (if you're fast, however!) is listen for a SIGTERM message in your code (that's what Heroku sends to your application process when it attempts to restart it) -- you can then fire off your script quickly.
Here's more information on SIGTERM on Heroku: https://devcenter.heroku.com/articles/dynos#graceful-shutdown-with-sigterm
If you're using some sort of CI, you can probably configure it there. Heres how to do it with CircleCI:
deployment:
production:
branch: production
commands:
- git push git#heroku.com:foo-bar-123.git $CIRCLE_SHA1:master
- heroku run rake <your task> --app <your app name>
If you're not using a CI you can still whip together a script that first does the git push to Heroku and then executes your cache busting task through heroku run (the app's bin/ folder would be an obvious place to put it).
Note: you can also use heroku run:detached, which will send output to your logs instead of stdout.
You can use "release" feature that allows you to run any command before a new release is deployed. https://devcenter.heroku.com/articles/release-phase
Define the command that should be run in your Procfile.
release: rake db:migrate
From documentation:
The release command is run immediately after a release is created, but before the release is deployed to the app’s dyno formation. That means it will be run after an event that creates a new release.