[CLOUD] Docker

<aside> 💡 Virtualization is the process of creating a simulated environment that abstracts away essential underlying components of a computer, such as the hardware.

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<aside> 💡 Virtualization allows us to interact with a computer environment without the computer physically being in front of us, this is called a Virtual Machine (VM)

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<aside> 💡 Every VM requires its own OS as well as virtual copies of the hardware needed for the OS to function. This means that VMs are resource intensive.

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<aside> 💡 Instead of virtualizing the entire computer like a VM, Docker only virtualizes the OS.

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<aside> 💡 Docker containers sit on top of the OS of the host machine and share the OS kernel, binaries, and libraries, which leads to containers must share the OS of their host machine. (Windows container on a Windows machine, linux container on a linux machine).

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<aside> 💡 These containers are lightweight, requires less storage, memory, and time to complete basic functions like starting up. In a cloud-native computing environment, containers are a first-choice solution for deploying infrastructure.

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<aside> 💡 Amazon has a service called ECR, which is a online registry for public and private container images.

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<aside> 💡 Docker containers are stored in repos and these repos can be pulled using :

<aside> 💡 A Container image is composed of multiple layers, there could be sensitive information in an underlying container layer.

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<aside> 💡 Container images are built from a source file known as DockerFile.

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<aside> 💡 Should save the image file as a tar file then unpack it and investigate further. There should be multiple container image layers and a file that compose the final container image.

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<aside> 💡 Should save the underlying container images in a tar file and investigate each of them to get some kind of info.

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Questions -

1 - List local docker images

2 - Grab the challenge image and list it

3 - Run the challenge image

4 - Create a temporary folder, download and investigate the challenge image