What is Docker Compose?
Docker
An easy-to-use Linux container technology
Docker image format
It helps in application packaging and delivery
Top Engineering College in Jaipur Rajasthan says Docker is a tool that can package an application and its dependencies in a virtual container that can run on any Linux server. This helps enable flexibility and portability on where the application can run, whether on-premises, public cloud, private cloud, bare metal, etc also It composes works in all environments: production, staging, development, testing, as well as CI workflows and with Compose, you use a YAML file to configure your application’s services.
Docker Vs Virtualization
Positive expects of Docker,
Lighter than Virtual machines.
docker images are very small in size
Deploying and scaling is relatively easy
Containers have less startup time
Less secure
Technologies Behind Docker
Control groups:
There are some keys but control Groups are another key component of Linux Containers with Cgroup we can implement resource accounting and limit and also ensure that each container gets its fair share of memory, CPand U, and disk I/O, and thanks to Group up, we can make sure that at single container cannot bring the system down by exhausting resources.
Union file systems:
It is a read-only part and a written part and merges those Docker images made up of layers.
Technologies behind docker
Namespaces also help to create isolated workspace for each process and When you run a container, Docker creates a set of namespaces for that container
SELinux:- It provides secure separation of containers by applying SELinux policy and labels.
Technologies Behind Docker
Capabilities:
One of the most important capabilities is docker drops all capabilities except those needed also "root" within a container have fewer privileges than the real "root" and the best practice for users would be to remove all capabilities except those explicitly required for their processes, so even if an intruder manages to escalate to root within a container.
Components
Docker Images
Docker containers
Docker Hub
Docker Registry
Docker daemon
Docker client
Dcokerfile
It is a text document that contains all the commands a user could call on the command line to assemble an image also it builds can build images using Dockerfile.
Let's talk about real-life applications first!
One application consists of multiple containers, and One container is dependent on another also Mutual dependence startup order, so the Process involves building containers and then deploying them, also Long docker run commands and Complexity are proportional to the number of containers involved.
Docker Compose
Private Colleges of Engineering in Jaipur Rajasthan has a tool for defining and running multi-container Docker applications, It is a YML file and composes contains information about how to build the containers and deploy containers, also Integrated with Docker Swarm so Competes with Kubernetes
Conclusion:
Best Engineering College in Jaipur Rajasthan says The big advantage of using Compose is you can define your application stack in a file, keep it at the root of your project repo (it’s now version controlled), and easily enable someone else to contribute to your project, also Someone would only need to clone your repo and start the compose app and In fact, you might see quite a few projects on GitHub/GitLab doing exactly this now, and Compose works in all environments: production, staging, development, testing, as well as CI workflows also it has commands for managing the whole life cycle of your application with security also according to client requirement they do the needful.
Start, stop and rebuild services
View the status of running services
Stream the log output of running services
Run a one-off command on a service
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