Docker Swarm

  A Docker Swarm is a group of either physical or virtual machines that are running the Docker application and that has been configured to join together in a cluster. ... Docker swarm is a container orchestration tool, meaning that it allows the user to manage multiple containers deployed across multiple host machines

How nodes work

Docker Engine 1.12 introduces swarm mode that enables you to create a cluster of one or more Docker Engines called a swarm. A swarm consists of one or more nodes: physical or virtual machines running Docker Engine 1.12 or later in swarm mode.

There are two types of nodes: managers and workers.

 



Docker Swarm- Setup Worker and Manager Nodes


1.  Create a 3 Nodes Cluster ( 1 for master node and other 2 are for worker nodes)

2.  Name these as master, worker01, worker02 nodes

3.  On master node run the command docker swarm init

4.  Copy the join command and run it on worker01 and worker02

5.  Run docker node ls command on master node. It should show all the nodes in active state

6.  Command  docker swarm join-token worker will give token value for worker node

7.  Command  docker swarm join-token manager will give token value for manager node

8.  Command docker info will give you swarm information as well like it is active or not

9.  Command docker swarm leave will leave the node(worker node) from the cluster and docker info will return Swarm as inactive.

11. Command docker node rm -f worker02 will forcefully remove the worker from the list .

12. Command docker node inspect worker01 will inspect worker01 node.

13. Command docker node promote worker01 worker02 will promote worker01 and worker02 as manager node.

14. Command docker node demote worker01 worker02 will promote worker01 and worker02 as worker node.

Docker Swarm- Backup and Restore

Backup

systemctl stop docker

tar -zcvf swarm.tar.gz swarm/

systemctl start docker

docker node ls

systemctl stop docker

Restore 

rm -fr swarm

tar -xvzf swarm.tar.gz

systemctl start docker


Run Below command to run docker visualizer

docker service create  --name=viz --publish=8080:8080/tcp  --constraint=node.role==manager --mount=type=bind,src=/var/run/docker.sock,dst=/var/run/docker.sock dockersamples/visualizer


Learn more about the Docker Swarm here :




Comments

Post a Comment

Popular posts from this blog

Terraform

Image
  Terraform is an infrastructure as code tool that lets you build, change, and version cloud and on-prem resources safely and efficiently. HashiCorp Terraform is an infrastructure as code tool that lets you define both cloud and on-prem resources in human-readable configuration files that you can version, reuse, and share. You can then use a consistent workflow to provision and manage all of your infrastructure throughout its lifecycle. Terraform can manage low-level components like compute, storage, and networking resources, as well as high-level components like DNS entries and SaaS features. How does Terraform work? Terraform creates and manages resources on cloud platforms and other services through their application programming interfaces (APIs). Providers enable Terraform to work with virtually any platform or service with an accessible API. HashiCorp and the Terraform community have already written  thousands of providers  to manage many different types of resources...
Read more

Different Types of Reports in Scrum - Agile

Image
  Introduction to Agile Reporting I’m not going to elaborate on the Agile Framework itself here.  1. Sprint Burndown At a Sprint-level, the burndown presents the  easiest way to track and report status  (the proverbial  Red / Amber / Green ), i.e., whether your Sprint is on or off-track, and what are the chances of meeting the Sprint goals. The burndown chart – when used right – can provide  near-real time updates  on Sprint progress. “If your team do it right, then they would take in just the right amount of work into a sprint.” At the beginning of a Sprint, the Scrum team perform Sprint Planning and agree to take on development work worth a certain number of Story points. This forms the basis for the Sprint Burndown chart. The total story points agreed at the beginning of the sprint make up the y-axis, and the individual dates in the Sprint make up x-axis. If your team do it right, then they would take in just the right amount of work into ...
Read more

Scrum Master Interview help - Bootcamp

Understanding the MoSCoW prioritization | How to implement it into your project Projects, irrespective of their size or complexity, often juggle numerous tasks and requirements. In such a scenario,  MoSCoW prioritization  becomes essential to ensure the successful completion of the project.  Besides, it is also a very effective way to manage project priorities. With a straightforward and adaptable approach, the MoSCoW method helps manage stakeholder expectations and improve project outcomes. What is the MoSCoW prioritization technique?  The MoSCoW method is a prioritization matrix widely used in project management and software development. The term MoSCoW is an acronym that stands for  Must have ,  Should have ,  Could have , and  Won’t have , each denoting a level of priority. Here is the breakdown of the MoSCoW method:  Must have:  These are critical requirements that the project cannot be completed withou...
Read more