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Docker Volume type "tmpfs"

shashikiran — Wed, 16 Nov 2022 05:22:07 +0000

How can we store container data in memory using docker volume
We use docker tmpfs volume to store container data in host's memory. As we are storing this in memory it will be volatile. Also we can not attach this volume with some other container because we don't know the Physical location in this case.

Example:
docker run -itd --name tmpfstest --tmpfs /var/tmpfs ubuntu

Now if we inspect this container, we will get following in output:
"Tmpfs": {
"/var/tmpfs": ""
}

Day 2 Assignment 1

shashikiran — Tue, 15 Nov 2022 04:36:00 +0000

What is the use of "docker update"?

Docker Update is used to configuration of one or more containers, several options to configure CPU, memory.
this can be done on runtime to modify the resources like number of CPU, memory limit, PID limit dynamically to avoid limit the usage of resources on the host machine.

What is the use of "docker wait"?

Docker wait blocks until one or more containers stop, then print their exit codes

DevOps Training - Docker Assessment 2

shashikiran — Mon, 14 Nov 2022 10:08:40 +0000

What is the difference between docker pause and docker unpause? (Hint - docker stats)
The docker pause command suspends all processes
docker unpause command resumes all processes in the specified container.
What is the difference between docker stop and docker kill (Hints - Return value of linux + SIGNALs)
Below are the differences -
a) docker stop 1. shutdown the container
2. returns None as return value
docker kill 1. stops/terminates the container immediately.
2. docker kill sends a SIGKILL signal.

DevOps Training - Docker Assessment 1

shashikiran — Mon, 14 Nov 2022 10:05:01 +0000

What is Docker? it is Container Management Tool which helps to build, deploy, run, update and manage containers.
Why Docker? it is used in order to mainly save time and resources. To avoid the havoc of multiple resource creation and management.
What is Container it is a runnable instance of a docker image which can be used to run applications.
Docker workflow Docker Daemon -> Docker CLI -> Docker Engine API Docker Host -> Docker Client -> Docker Registry (Hub)
How container created? Source Docker Image -> Run the image -> make it active Daemon requests the kernel for creating a Linux namespace with a mount, an isolated network and the runtime environment.