docker ps — To check running containers docker images — To check pulled images docker pull — To pull images from docker hub registry docker push — To push custom images to docker hub registry docker run — To start and run a container docker exec — To enter inside the container with shell docker start — To start a container docker stop — To stop a container docker restart — To restart a container docker build — To build

when we use Docker attach it will takes to PID 1 and it will wait for input and when we exit the terminal the container is no longer up. When you use docker exec and if you exit the container is still running. Both are used to check the running container if you want to do without exiting the running container use docker exec

Docker stop will stop the running container send SIGTERM and then SIGKILL with grace period. Docker kill will kill the running container with SIGKILL and is unsafe exit

Both ENTRYPOINT and CMD allow you to specify the startup command for an image. The main difference is we cannot override the ENTRYPOINT instruction by using command-line parameters to the docker run command.

docker pause will pause the processes running inside the containerDocker unpause will unpause the processes which are paused

Docker Engine:It is the main part of docker system. It follows client-server architecture.It is installed on host machine. It contains:1.Server: It is called as dockerd used to manage images containers network2.Rest API: used to instruct daemon3.CLI: where we run the docker commands Docker Client:when you run commandon CLI client sends to daemon which makes the action.Docker clientcan communicate with more than one daemon Docker Registry:It is the location where docker images are stored.it can be public or a privatewhen we

FROM : To create a base image such as an operating system RUN: A RUN instruction is used to run specified commands. We can use multiple RUN instructions to run different commands. CMD: If we need to run a default command that executed for all the containers of the image. If we want to run command during docker run command it overrides the default one. ENTRYPOINT: If we try to specify default arguments in the docker run command, it will

Docker exec command is used run a new process inside the container. Attach isn’t for running an extra thing in a container, it’s for attaching to the running process. Docker attach command is used to attaches to the process that runs in the container with PID. Docker exec is specifically for running new things in a already started container with shell.

Both docker stop and docker kill commands are stopped the container but docker stop command stops the process inside the container and safe. Docker kill command will kill the process inside the container and terminate the running container and unsafe exit for that container.

Docker pause command suspends all processes in the specified containers. Docker unpause command resumes the all suspended processes in the specified containes.

Components of docker are Docker engine Docker registry Docker image Docker container Docker engine Docker engine is a command-line and it is interact with docker daemon. When we run docker commands the instructions sends to the daemon and perform operation by other components. Docker registry Docker registry is a hosted service where the docker images are stored. We can create an repository and store our own images also. It has both private and public repositories. Docker image. Docker image is

How to submit assignment? Write Ansswer for the following questions and submit answer at BestDevOps.com as new post for each questions 1. Components of Docker and its Brief Summary 2. What is the differenet between docker pause and unpause? 3. What is the differenet between docker stop and kill? 4. What is the differenet between docker exec and attach? 5. List of dockerfile instructions and its Brief Summary? 6. What is the differenet between CMD vs Entrypoint 7. List of

Components of Docker and its Brief Summary: Docker Components : Docker Engine: Core part of the docker system. It consists following 3 components: Server: It is the docker daemon called dockerd. It can create and manage docker images. Containers, networks, etc. Rest API: It is used to instruct docker daemon what to do. Command Line Interface (CLI): It is a client which is used to enter docker commands Docker Client: Docker users can interact with Docker through a client. When any docker

Observability of a system is a property which determines how well the system’s availability, reliability and functionality can be understood using its metrics,logs,traces and events. A system’s observability helps SRE teams understand why a function is failing, or why the performance is degrading and also predict future events. Having observability of applications and systems allows SRE teams to focus and detect issues faster and respond to them sooner compared to only having monitoring and alerting systems.

systemctl start datadog-agent systemctl stop datadog-agent systemctl restart datadog-agent systemctl status datadog-agent datadog-agent configcheck datadog-agent config datadog-agent health datadog-agent hostname datadog-agent version

Start the Agent – systemctl start datadog-agentStop the Agent – systemctl stop datadog-agentRestart the Agent – systemctl restart datadog-agentStatus of the agent systemctl status datadog-agentPrint all configurations – datadog-agent configcheckRuntime configuration – datadog-agent configPrint the ggent health – datadog-agent healthPrint the hostname of Agent – datadog-agent hostnamePrint version – datadog-agent versionHelp about any command – datadog-agent help

Observability is proactively collecting, visualizing, and applying intelligence to all of our metrics, events, logs so that we can understand the behavior of our complex system. Also we can find what has caused the failures & anticipate future by predicting logs.

datadog-agent version : To know the current version of the Datadog agent running on the system. 2. datadog-agent status: To know the current status of the datadog agent installed on the system. 3. datadog-agent health: To run the health-check on the datadog agent. 4. datadog agent hostname: To know the hostname on which the datadog agent is running. 5. datadog-agent –help: To display command usage. 6. datadog-agent flare: flare gathers all of the Agent’s configuration files and logs into an

Observability means to understand what’s happening across all the components of an application and using it to detect and resolve issues keeping the systems reliable and efficient. As the application architecture is getting complex day by day, it would be difficult for the SRE/OPS team to have a proper monitoring/ failure detection setup for each and every component that’s where observability beats monitoring. Modern cloud environments are dynamic and constantly changing in scale and complexity, most problems are neither known