I have a django docker container for the backend on my website. There is a volume for the database so i can save the database even if i change the backend configuration.
I have tried to put the createsuperuser in my Dockerfile and in a script launched with "command" in docker-compose. In the Dockerfile, the problem is the prompt is not connected to the database...
In the script, the command is re-run each time the container is started
I would like this command to be run only once, but i dont know how to proceed.
The problem is the container is rebuilt in my ci/cd pipeline if i change the configuration files, and so the command is re-run.
I have seen this post Run command in Docker Container only on the first start but that also works only if the container is not rebuilt.
A workaround with a createsuperuser command that would fail would work and that seemed to be the case with django previous versions (before version 4) but i now have "django.db.utils.IntegrityError: UNIQUE constraint failed: auth_user.username" error which tells me the command seems to be run multiple times and gives me errors in the database...
You can use environment variables to run createsuperuser based on those variables.
If you ignore the return value of the command, it doesn't matter whether the superuser already exists or not. Additionally, you would benefit from being sure that the defined superuser always exists.
And if you change the environment variables, the superuser will be recreated with the changed values.
See similar question here: run initial commands in a docker-compose service
Related
Why do I have to restart my docker container every time I make a change in my Django python files? I'm running a Django app via Docker and it seems any changes I make in my Views(and possibly elsewhere) are not reflected until I restart my container.
For example, if I log an output to the terminal or make changes, then refresh, there's no change. If I restart my container and then refresh, I get the result I would expect.
As I know you can consider Docker environment like immutable type doesn’t allow any change in the object once it has been created.
And that will give us more security.
If you want a solution there is some vs code extensions can run script contain some command after you edit your files, you can insert docker command in this script to reload environment after you edit any file.
Inside the cpanel -> python app i have tried several time to create super user. when I tried to execute this commad inside Execute python script
manage.py createsuperuser
then it will return this error
Superuser creation skipped due to not running in a TTY. You can run `manage.py createsuperuser` in your project to create one manually.
How to solve this problem, or any manuall solution, i found several solution but all the solution for local server.
There is no difference between creating superuser on local server and production server. You have to do next:
Enter your server via ssh.
Go to your project root folder (with manage.py file)
Type python manage.py createsuperuser (use your virtual environment or system interpreter, depends on).
I am developing Django Wagtail application on my local machine connected to a local postgres server.
I have a test server and a production server.
However when I develop locally and try upload it there is always some issue with makemigration and migrate e.g. KeyError etc.
What are the best practices of ensuring I do not get run into these issues? What files do I need to port across?
so ill tell you what i do and what most of the companies that i worked as a django developer did and i can tell you by experience that worked pretty well.
First containerize your application, this will make your life much more easy and you will remove external influence in your code, also will get you an easy way to reproduce your environment.
Your Dockerfile should be from some python image and should do 3 basically things:
Install your requirements dependencies
Run the python manage.py migrate --noinput command
Run a http server such as gunicorn with gunicorn -c /gunicorn.py wsgi:application
You ill do the makemigration in your local machine and make sure that everything is working before commit then to the repo.
In your gunicorn.py you ill put your settings to run the app such as the number of CPU, the binding port, the folder that your app is, something like:
import os
import multiprocessing
# Chdir to specified directory before apps loading.
# https://docs.gunicorn.org/en/stable/settings.html#chdir
chdir = '/app/'
# Bind the application on localhost both on ipv6 and ipv4 interfaces.
# https://docs.gunicorn.org/en/stable/settings.html#bind
bind = '0.0.0.0:8000'
Second containerize your other stuff, for example the postgres database, the redis (for cache), a connection pooler for the database depending on the size of your application.
Its highly recommend that you have a step in the pipeline to do tests, they need to run before everything, maybe just after lint
Ok what now? now you need a way to deploy that stuff, the best for that scenario is: pull your image to github registry, and you can add a tag to that for example:
IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
# Change all uppercase to lowercase
IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
docker tag $IMAGE_NAME $IMAGE_ID:staging
docker push $IMAGE_ID:staging
This can be add in a github action in the build step for example.
After having your new code in a new image inside github you just need to update the current one, this can be done by creaaing a script to do it in the server and running that script from github action, is something like:
docker pull ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
echo 'Restarting Application...'
docker stop {YOUR_CONTAINER} && docker up -d
sudo systemctl restart nginx
echo 'Cleaning old images'
sudo docker system prune -af
You can see that i create the image with a staging tag, you can create a rule in github actions for example to trigger that action when you create a new release for example, and create another action to be trigger in every new commit and build/deploy for a dev tag.
For the migration problem, the first thing is, when your application go live squash every migration to the first one (you can drop the database and all the migration then create the database and run the makemigration command again to reach this), so you can have a clean migration in the server. Never creates unnecessary relation between the tables, prefer always doing cached properties instead of add new columns, use UUID for unique ids, and try to not do breaking changes in the database, its hard but if you plan the database before is not so difficult to do.
Hit me if you have any questions. A lot of the stuff that i said can be done in a lot of other platforms such as gitlab, travis, circle ci, but i use the github action in the example because i think is more simple to picture.
EDIT:
I forgot to tell you to have a cron in your server doing backups of your databases, the migrate command ill apply the changes only after the verification but if something else break the database this can save your life.
I have a rather complex K8s environment that one of the Deployments is a Django application. Currently we are having a very hard time whenever I need to update a model that has already been migrated to a PostgreSQL database.
Let's say for instance that I create an application named Sample, that has a simple table on the models.py. My development process (skaffold) builds the docker and apply it locally on the minikube, after this is done I connect to the pod via kubectl exec and execute the python manage.py makemigrations and python manage.py migrate, so far so good.
After some time, let's say I need to create a new table on the models.py file of the Sample application, the skaffold builds the docker, kills the old pod, and create the new pod. So I connect as usual via kubectl exec and try to execute the makemigrations and migrate command, lo and behold, there's no migration to apply. And of course no change is made on the PostgreSQL.
Upon further searching this, I believe that the reason for this is that since the docker is built without the Sample/migrations folder, and there's already a table (the original one) on the PostgreSQL, when I run the makemigrations it creates only the 0001_initial.py file, that has all the tables but, since the table already exists, when executing the migratethe django believes that the migration is already applied, therefore it won't apply.
If what I found out is true, how can I keep this files on a PVC, so that they are always kept between each pod recreation?
Thank you.
I know there are a lot of questions floating around there relating to similar issues, but I think I have a specific flavor which hasn't been addressed yet. I'm attempting to create my local postgresql database so that I can do local development in addition to pushing to Heroku.
I have found basic answers on how to do this, for example (which I think is a wee bit outdated):
'#DATABASES = {'default': dj_database_url.config(default='postgres://fooname:barpass#localhost/dbname')}'
This solves the "ENGINE" is not configured error. However, when I run 'python manage.py syncdb' I get the following error:
'OperationalError: FATAL: password authentication failed for user "foo"
FATAL: password authentication failed for user "foo"'
This happens for all conceivable combinations of username/pass. So my ubuntu username/pass, my heroku username/pass, etc. Also this happens if I just try to take out the Heroku component and build it locally as if I was using postgresql while following the tutorial. Since I don't have a database yet, what the heck do those username/pass values refer to? Is the problem exactly that, that I need to create a database first? If so how?
As a side note I know I could get the db from heroku using the process outlined here: Should I have my Postgres directory right next to my project folder? If so, how?
But assuming I were to do so, where would the new db live, how would django know how to access it, and would I have the same user/pass problems?
Thanks a bunch.
Assuming you have postgres installed, connect via pgadmin or psql and create a new user. Then create a new database and with your new user as the owner. Make sure you can connect via psql with the new user into to the database. you will then need to set up an env variable in your postactivate file in your virtualenv's bin folder and save it. Here is what I have for the database:
export DATABASE_URL='postgres://{{username}}:{{password}}#localhost:5432/{{database}}'
Just a note: adding this value to your postactivate doesn't do anything. The file is not run upon saving. You will either need to run this at the $ prompt, or simply deactivate and active your virtualenv.
Your settings.py should read from this env var:
DATABASES = {'default': dj_database_url.config()}
You will then configure Heroku with their CLI tool to use your production database when deployed. Something like:
heroku config:set DATABASE_URL={{production value here}}
(if you don't have Heroku's CLI tool installed, you need to do it)
If you need to figure how exactly what that value you need for your production database, you can get it by logging into heroku's postgresql subdomain (at the time this is being written, it's https://postgres.heroku.com/) and selecting the db from the list and looking at the "Connection Settings : URL" value.
This way your same settings.py value will work for both local and production and you keep your usernames/passwords out of version control. They are just env config values.