Docker

A docker contain is a great way to set up an environment. Once the docker container is built and running, one can attach to it from VSCode and use it as a remote machine. To do this, install “Remote Development” extension pack, then one can attach the container in VSCode by going to a command pallette (Cmd+Shift+P) and typing “Attach to running container”. If typing sudo all the time is annoying add user to the docker group:

sudo usermod -aG docker $USER

and (maybe, not always) restart the machine.

Build a Docker image

One needs Dockerfile and requirements.txt. See Dockerfile for details on steps.

We’ll use docker build -t <some_image_name> . to build docker image from files in the current folder (indicated by the . at the end)

sudo docker build -t my_project:1.0 .  

Very common command:

sudo docker images  # to see existing images

Running a container

After building an Image we now run a container (one can run many containers from the same image).

Important flags: | flag | action | |———-|———-| | -it/-d | runs container in interactivemode |
| -rm | removes docker after it’s done the task |
| -p X:Y | maps port X on docker container to port Y on local machine |

Very common commands:

sudo docker run <image name>  # to run a container 
sudo docker ps      # to see running containers
sudo docker container stop <container name>  # to stop specific container
sudo docker container stop $(sudo docker container ls -aq)  # to stop all containers

Detached mode

To run container in detached mode requires defining entry point in the Dockerfile (typically last command there see CMD or ENTRYPOINT):

sudo docker run -d -p 8501:8501 my_project:1.0

Now simply go to localhost:8501 in your browser and you should see the app.

To connect to the terminal of a running container (find container name using sudo docker ps):

sudo docker exec -it <container_name> bash

Interactive mode

Run container and then run the some commnad (here for example Streamlit app)

sudo docker run -p 8501:8501 -it my_project:1.0 bash    # bash here is what will run 
streamlit run entry_file.py --server.port 8501

To exit from a container’s bash use:

exit

If you had flag -rm this exit would kill the container. Without the flag the container would still be running (see with sudo docker ps).

Docker-compose

When deploying Docker to a remote machine, to set up ports, env variables, memory to reserve etc, one uses docker-compose.yaml.