I have Azure devops pipeline, building dockerfile on AKS, as AKS is deprecating docker with the latest release, kindly suggest best practice to have a dockerfile build without docker on AKS cluster.
Exploring on Kaniko, buildah to build without docker..
Nothing has changed. You can still use docker build and docker push on your developer or CI system to build and push the Docker image to a repository. The only difference is that using Docker proper as the container backend within your Kubernetes cluster isn't a supported option any more, but this is a low-level administrator-level decision that your application doesn't know or care about.
Unless you were somehow building using the host docker socket within your Kubernetes cluster, this change will not affect you. And if you were mounting the docker socket from the host in a kubernetes cluster, I'd consider that a security concern that you want to fix.
Docker Desktop runs a docker engine as a container on top of containerd, allowing developers to build and run containers in that environment. Similar can be done with DinD build patterns that run the docker engine inside a container, the difference is the underlying container management tooling is containerd instead of a full docker engine, but the containerized docker engine is indifferent to that.
As an alternative to building within the full docker engine, I'd recommend looking at buildkit which is the current default build tool in docker as of 20.10. It uses containerd and they ship a selection of manifests to run builds directly in kubernetes as a standalone builder.
I want to configure a Kubernetes cluster with only Docker containers without using vm on one machine. I think it will be, but I ask because it may not be.
Checkout Kubernetes In Docker - kind
This is probably what you want.
If I am getting your question right you want to use Kubernetes on a physical box without using any hypervisor (no vm)
You can install minikube and use Kubernetes as below
minikube start --vm-driver=none
I am new to cluster container management, and this question is the basis for all the freshers over here.
I read some documentation, but still, my understanding is not too clear, so any leads.. helping to understand?
Somewhere it is mentioned, Minikube is used to run Kubernetes locally. So if we want to maintain cluster management in my four-node Raspberry Pi, then Minikube is not the option?
Does Minikube support only a one-node system?
Docker Compose is set of instructions and a YAML file to configure and start multiple Docker containers. Can we use this to start containers of the different hosts? Then for simple orchestration where I need to call container of the second host, I don't need any cluster management, right?
What is the link between Docker Swarm and Kubernetes? Both are independent cluster management. Is it efficient to use Kubernetes on Raspberry Pi? Any issue, because I was told that Kubernetes in single node takes the complete memory and CPU usage? Is it true?
Is there other cluster management for Raspberry Pi?
I think this 4-5 set will help me better.
Presuming that your goal here is to run a set of containers over a number of different Raspberry Pi based nodes:
Minikube isn't really appropriate. This starts a single virtual machine on a Windows, MacOS or Linux and installs a Kubernetes cluster into it. It's generally used by developers to quickly start-up a cluster on their laptops or desktops for development and testing purposes.
Docker Compose is a system for managing sets of related containers. So for example if you had a web server and database that you wanted to manage together you could put them in a single Docker Compose file.
Docker Swarm is a system for managing sets of containers across multiple hosts. It's essentially an alternative to Kubernetes. It has fewer features than Kubernetes, but it is much simpler to set up.
If you want a really simple multi-node Container cluster, I'd say that Docker swarm is a reasonable choice. If you explicitly want to experiment with Kubernetes, I'd say that kubeadm is a good option here. Kubernetes in general has higher resource requirements than Docker Swarm, so it could be somewhat less suited to it, although I know people have successfully run Kubernetes clusters on Raspberry Pis.
Docker Compose
A utility to to start multiple docker containers on a single host using a single docker-compose up. This makes it easier to start multiple containers at once, rather than having do mutliple docker run commands.
Docker swarm
A native container orchestrator for Docker. Docker swarm allows you to create a cluster of docker containers running on multiple machines. It provides features such as replication, scaling, self-healing i.e. starting a new container when one dies ...
Kubernetes
Also a container orchestrator. Kubernetes and Docker swarm can be considered as alternatives to one another. They both try to handle managing containers starting in a cluster
Minikube
Creating a real kubernetes cluster requires having multiple machines either on premise or on a cloud platform. This is not always convenient if someone is just new to Kubernetes and trying to learn by playing around with Kubernetes. To solve that minikube allows you to start a very basic Kubernetes cluster that consists of a single VM on you machine, which you can use to play around with Kubernetes.
Minikube is not for a production or multi-node cluster. There are many tools that can be used to create a multi-node Kubernetes cluster such as kubeadm
Containers are the future of application deployment. Containers are smallest unit of deployment in docker. There are three components in docker as docker engine to run a single container, docker-compose to run a multi-container application on a single host and docker-swarm to run multi-container application across hosts which also an orchestration tool.
In kubernetes, the smallest unit of deployment is Pod(which is composed of multiple container). Minikube is a single node cluster where you can install it locally and try, test and feel the kubernetes features locally. But, you can't scale this to more than a single machine. Kubernetes is an orchestration tool like Docker Swarm but more prominent than Docker Swarm with respect to features, scaling, resiliency, and security.
You can do the analysis and think about which tool will be fit for your requirements. Each one having their own pros or cons like docker swarm is good and easy to manage small clusters whereas kubernetes is much better for larger once. There is another orchestration tool Mesos which is also popular and used in largest size clusters.
Check this out, Choose your own Adventure but, it's just a general analogy and only to understand because all the three technologies are evolving rapidly.
I get the impression you're mostly looking for confirmation and am happy to help with that if I can.
Yes, minikube is local-only
Yes, minikube is intended to be single-node
Docker-compose isn't really an orchestration system like swarm and Kubernetes are. It helps with running related containers on a single host, but it is not used for multi-host.
Kubernetes and Docker Swarm are both container orchestration systems. These systems are good at managing scaling up, but they have an overhead associated with them so they're better suited to multi-node.
I don't know the range of orchestration options for Raspberry Pi, but there are Kubernetes examples out there such as Build Your Own Cloud with Kubernetes and Some Raspberry Pi.
For Pi, you can use Docker Swarm Mode on one or more Pi's. You can even run ARM emulation for testing on Docker for Windows/Mac before trying to get it all working directly on a Pi. Same goes for Kubernetes, as it's built-in to Docker for Windows/Mac now (no minikube needed).
Alex Ellis has a good blog on Pi and Docker and this post may help too.
I've been playing around with orchestrating Docker containers on a subnet of Raspberry Pis (3Bs).
I found Docker-swarm easiest to set up and work with, and adequate for my purposes. Guide: https://docs.docker.com/engine/swarm/swarm-tutorial/
For Kubernetes there are two main options; k3s and microk8s. Some guides:
k3s
https://bryanbende.com/development/2021/05/07/k3s-raspberry-pi-initial-setup
microk8s
https://ubuntu.com/tutorials/how-to-kubernetes-cluster-on-raspberry-pi#1-overview
I have a silly question regarding docker swarm.
I am thinking I can start a web application image in two containers, either in same server or two vm servers, then I start a load balance container, pointing to two web app containers through IP and port.
In this case, why do I need docker swarm for clustering management? What benefits can docker swarm bring?
I have read from docker documentation, they only introduce what is swarm and how to use swarm. But I can not find out answer for why I have to use swarm.
Thanks
What is swarming managing? turns a pool of Docker hosts into a single, virtual Docker host.
Can swarm auto-start the container if the container died? Yes it can, so can the Docker daemon on each host.
Can swarm auto-create more nodes if the resource is not enough? No it cannot. It does not aims on providing this service. Nevertheless you can program a node that start and run containers when needed.
Which mean, if traffic grows fast, do we still manually create more node and deploy more containers? Yes, unfortunately.
update
If needed, here is an answer that details how to deploy a Swarm cluster.
I've used Docker Swarm - I can put the management and the agents in docker containers. Can I do the same with Kubernetes?
I don't want to pollute my machine.
All of the master components in Kubernetes run inside of containers.
Due to limitations of Docker, the kubelet agent has been difficult to get running in a container. The Kubernetes folks have been working on this for the last year (see kubernetes#4869), and with Docker 1.10 it looks like it is getting close to working.