Failing to Use Docker to Run a Project - python

So I'm trying to run this project using docker.
I followed the standard docker protocol:
docker build -t orange .
docker run -p 8080:8080 orange
I used the following command to check that the docker image was indeed created.
docker image ls
However, after running these commands, there is still no site running on localhost:8080. Any tips on troubleshooting this?
EDIT: After using the right port, I'm getting a directory listing instead of an actual site. Directory listing

By looking at the repository, it seems that the exposed port is 9999 and not 8080. Also, it looks like you can use docker-compose, that is, you can run
docker-compose up --build
to spin up the server. You should then be able to reach it at localhost:9999

Related

Dockerizing an API built with python on local machine

I have cloned a repository of an API built with python on my local machine and my goal is to be able to send requests and receive responses locally.
I'm not familiar python but the code is very readable and easy to understand, however the repository contains some dependencies and configuration files to Dockerise (and I'm not familiar with Docker and containers too) .
so what are the steps to follow in order to be able to interact with the API locally?.
Here are some files in the repository for config and requirements :
requirements.txt file :
fastapi==0.70.0
pytest==7.0.1
requests==2.27.1
uvicorn==0.15.0
Dockerfile file :
FROM tiangolo/uvicorn-gunicorn:python3.9
COPY ./requirements.txt /requirements.txt
RUN pip install -r /requirements.txt
COPY ./app /app
i already installed Python3 and docker so what's next ?
Adjust Dockerfile
Assuming all code is in the /app directory you have already copied over all your code and installed all the dependencies required for the application.
But you are missing - at least (see disclaimer) - one essential line in the Dockerfile which is actually the most important line as it is the CMD command to tell Docker which command/ process should be executed when the container starts.
I am not familiar with the particular base image you are using (which is defined using the FROM command) but after googling I found this repo which suggests the following line, which does make a lot of sense to me as it starts a web server:
# open port 80 on the container to make it accesable from the outside
EXPOSE 80
# line as described in repo to start the web server
CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]
This should start the web server on port 80 using the application stored in a variable app in your main.py when the container starts.
Build and run container
When you have added that you need to build your image using docker build command.
docker build -t asmoun/my-container .
This builds an container image asmoun/my-container using the Dockerfile in the current directory, hence the .. So make sure you execute that when in the directory with the Dockerfile. This will take some time as the base image has to download and dependencies need to be installed.
You now have an image that you can run using docker run command:
docker run --name my-fastapi-container -d -p 80:80 asmoun/my-container
This will start a container called my-fastapi-container using the image asmoun/my-container in detached mode (-d option that makes sure your TTY is not attached to the container) and define a port mapping, which maps the port 80 on the host to port 80 on the container, which we have previously exposed in the Dockerfile (EXPOSE 80).
You should now see some ID getting printed to your console. This means the container has started. You can check its state using docker ps -a and you should see it marked as running. If it is, you should be able to connect to localhost:80 now. If it is not use docker logs my-fastapi-container to view the logs of the container and you'll hopefully learn more.
Disclaimer
Please be aware that this is only a minimal guide on how you should be able to get a simple FastAPI container up and running, but some parameters could well be different depending on the application (e.g. name of main.py could be server.py or similar stuff) in which case you will need to adjust some of the parameters but the overall process (1. adjust Dockerfile, 2. build container, 3. run container) should work. It's also possible that your application expects some other stuff to be present in the container which would need to be defined in the Dockerfile but neither me, nor you (presumably) know this, as the Dockerfile provided seems to be incomplete. This is just a best effort answer.
I have tried to link all relevant resources and commands so you can have a look at what some of them do and which options/ parameters might be of interest for you.

Calling Docker command within Dockerized app

It's been asked before but I haven't been able to find the answer so far. I have a script which is called via a Flask app. It's Dockerized and I used docker-compose.yml. The docker command, which worked outside of Docker, creates a html file using openscad. As you can see below, it takes a variable path:
cmd_args = f"docker run -v '{path}':/documents/ --rm --name manual-asciidoc-to-html " \
f"asciidoctor/docker-asciidoctor asciidoctor -D /documents *.adoc"
Popen(cmd_args, shell=True)
time.sleep(1)
When the script executes, the print out in Terminal shows:
myapp | /bin/sh: 1: docker: not found
How can I get this docker command to run in my already running docker container?
I don’t really get what you are trying to say here but I‘m assuming you want to run the docker command from within your container. You don’t really do it that way. The way to communicate with the docker daemon from within a container is to add the Docker Unix socket from the host system to the container using the -v when starting the container or adding it to the volumes section of your docker-compose:
volumes:
- /var/run/docker.sock:/var/run/docker.sock
After doing that you should be able to use a docker API (https://github.com/docker/docker-py) to connect to the Daemon from within the container and do the actions you want to. You should be able to convert the command you initially wanted to execute to simple docker API calls.
Regards
Dominik

Is there a way to modify files inside docker via PyCharm?

I want to modify files inside docker container with PyCharm. Is there possibility of doing such thing?
What you want to obtain is called Bind Mounting and it can be obtained adding -v parameter to your run command, here's an example with an nginx image:
docker run --name=nginx -d -v ~/nginxlogs:/var/log/nginx -p 5000:80 nginx
The specific parameter obtaining this result is -v.
-v ~/nginxlogs:/var/log/nginx sets up a bindmount volume that links the /var/log/nginx directory from inside the Nginx container to the ~/nginxlogs directory on the host machine.
Docker uses a : to split the host’s path from the container path, and the host path always comes first.
In other words the files that you edit on your local filesystem will be synced to the Docker folder immediately.
Source
Yes. There are multiple ways to do this, and you will need to have PyCharm installed inside the container.
Following set of instructions should work -
docker ps - This will show you details of running containers
docker exec -it *<name of container>* /bin/bash
At this point you will oh shell inside the container. If PyCharm is not installed, you will need to install. Following should work -
sudo apt-get install pycharm-community
Good to go!
Note: The installation is not persistence across Docker image builds. You should add the installation step of PyCharm on DockerFile if you need to access it regularly.

Why does django inside a container needs the "it" flag?

I try to run django on a docker container using sqllite as the db and the django dev server. So far I was able to launch locally the django server:
python .\manage.py runserver
I can build the docker image using Dockerfile:
docker build . -t pythocker
But when I run the image with docker run -p 8000:8000 pythocker no output is shown and the machine is not reachable, I have to kill the running container.
If I add the -it flag on the docker run command then the server is running and I can go to http://192.168.99.100:8000 and display the django welcome page. Why is this flag mandatory here?
Docker logs on the container gives nothing. I also tried to add custom logging inside the manage.py but it's not diplayed in the console or in the docker logs.
I am using the Docker Windows toolbox as I have only a windows home computer.

Docker development workflow

What's the proper development workflow for code that runs in a Docker container?
Solomon Hykes said that the "official" workflow involves building and running a new Docker image for each Git commit. That makes sense, but what if I want to test a change before committing it to the Git repo?
I can think of two ways to do it:
Run the code on a local development server (e.g., the Django development server). Edit a file; test on the dev server; make a Git commit; rebuild the Docker image with the new code; test again on the local Docker container.
Don't run a local dev server. Instead, build and run a new Docker image each time I edit a file, and then test the change on local Docker container.
Both approaches are pretty inefficient. Is there a better way?
A more efficient way is to run a new container from the latest image that was built (which then has the latest code).
You could start that container starting a bash shell so that you will be able to edit files from inside the container:
docker run -it <some image> bash -l
You would then run the application in that container to test the new code.
Another way to alter files in that container is to start it with a volume. The idea is to alter files in a directory on the docker host instead of messing with files from the command line from the container itself:
docker run -it -v /home/joe/tmp:/data <some image>
Any file that you will put in /home/joe/tmp on your docker host will be available under /data/ in the container. Change /data to whatever path is suitable for your case and hack away.

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