- #Starting iwth docker and kubernetes install
- #Starting iwth docker and kubernetes full
- #Starting iwth docker and kubernetes password
If the main process stops, the container stops. When a container is started, it will run that command/program (although you can override it and make it run a different command/program).Ī container is running as long as the main process (command or program) is running.Ī container normally has a single process, but it's also possible to start subprocesses from the main process, and that way you will have multiple processes in the same container.īut it's not possible to have a running container without at least one running process. Very similar to what would be if it was in the command line. Containers and Processes ¶Ī container image normally includes in its metadata the default program or command that should be run when the container is started and the parameters to be passed to that program. So, you would run multiple containers with different things, like a database, a Python application, a web server with a React frontend application, and connect them together via their internal network.Īll the container management systems (like Docker or Kubernetes) have these networking features integrated into them. That way, in many cases you can learn about containers and Docker and re-use that knowledge with many different tools and components. In most cases, you can use the official images, and just configure them with environment variables. Container Images ¶ĭocker has been one of the main tools to create and manage container images and containers.Īnd there's a public Docker Hub with pre-made official container images for many tools, environments, databases, and applications.įor example, there's an official Python Image.Īnd there are many other images for different things like databases, for example for:īy using a pre-made container image it's very easy to combine and use different tools. The container stops when there's no process running in it. In fact, a container is running only when it has a process running (and normally it's only a single process). python and some file main.py.Īnd the container itself (in contrast to the container image) is the actual running instance of the image, comparable to a process. Those changes will exist only in that container, but would not persist in the underlying container image (would not be saved to disk).Ī container image is comparable to the program file and contents, e.g. When the container is started and running (started from a container image) it could create or change files, environment variables, etc. In contrast to a " container image" that is the stored static contents, a " container" normally refers to the running instance, the thing that is being executed. Static here means that the container image is not running, it's not being executed, it's only the packaged files and metadata. What is a Container Image ¶Ī container is run from a container image.Ī container image is a static version of all the files, environment variables, and the default command/program that should be present in a container. This way, containers consume little resources, an amount comparable to running the processes directly (a virtual machine would consume much more).Ĭontainers also have their own isolated running processes (commonly just one process), file system, and network, simplifying deployment, security, development, etc.
#Starting iwth docker and kubernetes full
This just means that they are very lightweight (compared to full virtual machines emulating an entire operating system). Linux containers run using the same Linux kernel of the host (machine, virtual machine, cloud server, etc).
#Starting iwth docker and kubernetes install
RUN pip install -no-cache-dir -upgrade -r /code/requirements.txtĬMD # If running behind a proxy like Nginx or Traefik add -proxy-headers # CMD What is a Container ¶Ĭontainers (mainly Linux containers) are a very lightweight way to package applications including all their dependencies and necessary files while keeping them isolated from other containers (other applications or components) in the same system. Number of Processes on the Official Docker ImageĪlternatives, Inspiration and ComparisonsįROM python:3.9 WORKDIR /code COPY. Official Docker Image with Gunicorn - Uvicorn
![starting iwth docker and kubernetes starting iwth docker and kubernetes](https://cdn.hashnode.com/res/hashnode/image/upload/v1604217974210/jDsBj8FA-.jpeg)
Previous Steps Before Starting and Containers
![starting iwth docker and kubernetes starting iwth docker and kubernetes](https://www.instana.com/media/Docker_vs_Kubernetes_logos.png)
One Load Balancer - Multiple Worker ContainersĬontainers with Multiple Processes and Special Cases
![starting iwth docker and kubernetes starting iwth docker and kubernetes](https://portworx.com/wp-content/uploads/2018/03/Twitter-Social-Graphic-142.png)
#Starting iwth docker and kubernetes password
OAuth2 with Password (and hashing), Bearer with JWT tokensĬustom Response - HTML, Stream, File, othersīuild a Docker Image with a Single-File FastAPI Dependencies in path operation decorators