Kerbeos and Azure Flashcards
What is the Stackable Unification File System (Unionfs)?
UnionFS (Union File System) is a file system that allows multiple file systems (branches) to be mounted together in a way that they appear as a single unified file system. This allows you to overlay different directories, files, or layers, and work with them as if they were part of a single file system.
What is a Dockerfile?
A Dockerfile is a text file that contains the instructions we use to build and run a Docker image. It defines the following aspects of the image:
The base or parent image we use to create the new image
Commands to update the base OS and install additional software
Build artifacts to include, such as a developed application
Services to expose, such as storage and network configuration
Command to run when the container is launched
How to list images?
docker images
How to remove an image?
docker rmi
You can’t remove an image if a container is still using the image.
Specify the name or ID of the image to remove.
docker rmi temp-ubuntu:version-1.0
What is a container image?
A container image is a lightweight, standalone, and executable package that includes everything needed to run a piece of software. This includes the application code, runtime, libraries, environment variables, configuration files, and dependencies.
What is the host OS?
The host OS is the OS on which the Docker engine runs. Docker containers running on Linux share the host OS kernel, and don’t require a container OS as long as the binary can access the OS kernel directly.
What is the container OS?
The container OS is the OS that’s part of the packaged image. We have the flexibility to include different versions of Linux or Windows operating systems in a container. This flexibility allows us to access specific OS features or install additional software our applications might use.
What is a base image?
A base image in Docker is the foundational image upon which you build your custom Docker images. It contains the minimal set of operating system files and dependencies that provide the environment for your application to run.
In a Dockerfile, the base image is specified using the FROM directive. This is the first line in the Dockerfile and tells Docker which image to use as the starting point.
Specify the base image
FROM ubuntu:20.04
How to view available containers
docker ps -a
How to run a container
docker run -d tmp-ubuntu
How to restart a container
docker restart happy_wilbur
How to remove a container
docker rm happy_wilbur
What is the bridge network?
The bridge network is the default configuration applied to containers when launched without specifying any other network configuration. This network is an internal, private network used by the container, and it isolates the container network from the Docker host network.
The bridge network doesn’t allow communication between containers using hostnames.
By default, Docker doesn’t publish any container ports. To enable port mapping between the container ports and the Docker host ports, use the Docker port –publish flag.
In this example, your tracking portal is accessible to clients browsing to port 80. You’ll have to map port 80 from the container to an available port on the host. You have port 8080 open on the host, which allows you to set the flag like this:
-publish 8080:80
What is the host network?
The host network enables you to run the container on the host network directly. This configuration effectively removes the isolation between the host and the container at a network level.
In this example, let’s assume you decide to change the networking configuration to the host network option. Your tracking portal is still accessible using the host IP. You can now use the well-known port 80 instead of a mapped port.
There are three key mechanisms through which Azure resource can communicate
VNets, VNet service endpoints, and VNet peering
