Is there a roadmap for swarm with regards to new features and future direction of the project? Some of us out here using swarm are starting to get concerned about Docker's future plans for swarm given all the focus from Docker seems to be around Kubernetes
Just as an example, looking at the recent 2018 Dockercon agenda there 67 Kubernetes references and only 11 for swarm.
What is the current and future roadmap for swarm?
Is swarm being put into a maintenance mode only in favor of Kubernetes?
Swarm is alive and well. It’s open source and no road map that I know of. Lots of Swarm fans at dockercon. http://www.bretfisher.com/is-swarm-dead-answered-by-a-docker-captain/
According to the latest news, Docker Swarm is Dead.
News from Mirantis
What About Docker Swarm?
The primary orchestrator going forward is Kubernetes. Mirantis is
committed to providing an excellent experience to all Docker
Enterprise platform customers and currently expects to support Swarm
for at least two years, depending on customer input into the roadmap.
Mirantis is also evaluating options for making the transition to
Kubernetes easier for Swarm users.
Reference : https://www.mirantis.com/blog/mirantis-acquires-docker-enterprise-platform-business/
It's important to know that, Docker swarm ≠ Docker swarm mode. Please read here
What is Legacy Docker Swarm. Read this please
https://docs.docker.com/swarm/overview/
Swarm Mode is built-in
https://docs.docker.com/engine/swarm/
The good news is, Swarm Mode will live on.
Related
I have a project to containerize several applications (Gitlab, Jenkins, Wordpress, Python Flask app...). Currently each application runs on a Compute Engine VM each at GCP. My goal would be to move everything to a cluster (Swarm or Kubernetes).
However I have different questions about Docker Swarm on Google Cloud Platform:
How can I expose my Python application on the outside (HTTP load balancer) as well as the other applications only available in my private VPC ?
From what I've seen on the internet, I have the impression that docker swarm is very little used. Should I go for a kubernetes cluster instead ? (I have good knowledge of Docker/Kubernetes)
It is difficult to find information about Docker Swarm in cloud providers. What would be an architecture with Docker Swarm on GCP?
Thanks for your help.
I'd create a template and from that an instance group for all VM, which shall host the Docker swarm. And a separate instance or instance group for said internal purposes - so that there is a strict separation, which can then be used to route the internal & external traffic accordingly (this would apply in any case). Google Kubernetes Engine is about the same as such an instance group, but Google managed infrastructure. See the tutorial, there's not much difference - except that it better integrates with gcloud & kubectl. While there is no requirement to want or need to maintain the underlying infrastructure, GKE is probably less effort.
What you are basically asking is:
Kubernetes vs. Docker Swarm: What’s the Difference?
Docker Swarm vs Kubernetes: A Helpful Guide for Picking One
Kubernetes vs. Docker: What Does it Really Mean?
Docker Swarm vs. Kubernetes: A Comparison
Kubernetes vs Docker Swarm
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'm a bit lost with some of the basic concepts. It seems like the documentation / getting started requirements are basic knowledge about docker world that I don't have yet.
A swarm is a cluster of Docker engines, or nodes, where you deploy
services. The Docker Engine CLI and API include commands to manage
swarm nodes (e.g., add or remove nodes), and deploy and orchestrate
services across the swarm.
I understand that a cluster is a group of physical/virtual computers behaving as one. What is a cluster in the context of docker?
Docker engine is what creating the docker daemon + rest api + provide CLI in the machine docker is installed. What are docker engines?
What is a node?
What is a docker node?
what is a swarm node?
what is a orchestrate service?
Finally, what is a swarm?
I'm not looking for an article for each concept, only the minimal explanation that will help understand each concept in a overall. From there, I can easily continue on my own.
Please explain any additional concept which is more advance then the mentioned ones.
Thanks.
This is a great website which I believe will answer all your questions.
A cluster in Docker context is a group of hosts on which the Docker engine is installed
The Docker engine it is the main client - server application. More on this here
A node is a physical or a virtual machine
A node is a physical or a virtual machine running the Docker engine
A swarm node it is the same as 3 and 4, however, the difference is that SWARM will be running on it alongside the Docker engine.
An orchestration service is something that will take care of container creation and their dependencies. More here
Swarm is a clustering and scheduling tool for Docker.
Also, to learn more just do a Google search for the topic that you are interested in and you will find lots of useful explanations as well as examples :)
i'm learning about docker swarm, and got confused about the swarm discovery option, i see that lots of tutorials on internet use this option to create containers with docker-machine, but when i enter the documentation on docker swarm doc it says:
You are viewing docs for legacy standalone Swarm. These topics describe standalone Docker Swarm. In Docker 1.12 and higher, Swarm mode is integrated with Docker Engine. Most users should use integrated Swarm mode.
So, what are the use cases for the discovery options? All the tutorials use the docker-machine to create a swarm, i always need it or can just install the docker on machines in my cluster, join them in swarm and use normal?
I saw some names like Docker Swarm and Docker Swarm Mode, are there any difference or just different ways to call the same feature?
Q. Docker Swarm discovery is still relevant?
A: No, if you use docker Swarm Mode and an overlay network (see below)
Q. Are there any difference between Docker Swarm and Docker Swarm Mode?
A: Yes, TL;DR Docker Swarm is deprecated and should not be used anymore, Docker Swarm Mode (we should just say Swarm Mode) is the recommended way of clustering containers and have reliability, load-balancing, scaling, and rolling service upgrades.
Docker Swarm (official doc) :
is the old fashioned way (<1.12) of clustering containers
uses a dedicated container for building a Docker Swarm cluster
needs a discovery service like Consul to reference containers in cluster
Swarm Mode (official doc):
is the new and recommended way (>=1.12) of clustering containers on host nodes (called managers / workers)
is built-in in Docker engine, you don't need an additional container
has a built-in discovery service if you use an overlay network (DNS resolution is done within this network), you don't need an additional container
You can have a look to this SO thread on same topic.
Q. Do i always need docker-machine to create a swarm?
A: No, docker-machine is a helper to create virtual hosts in the cloud like amazon ec2, azure, digitalocean, google, openstack..., or your own network with virtual box.
To create a Swarm Mode, you need :
a multiple hosts cluster with docker engine installed on each host (called node) (that is what docker-machine facilitates)
run docker swarm init to switch to Swarm Mode on your first manager node
run docker swarm join on worker nodes to add them in the cluster
There are some subtle adjustments to Swarm mode to increase high availability (recommended number of managers in the swarm, node placement in multiple availability zones in the cloud)
Hope this helps!
looking for docker support for bare metal so that it can join the swarm cluster.
Could possibly be a docker machine, so that integration with docker swarm is easily possible.
Tried a lot but couldn't find a possible solution.
You could have a look at docker 12. It contains a native swarm mode which only requires docker engine to run. This hardly requires configuration, so should be very easy to setup.
Shameless plug: I wrote a blog article describing how to create a docker swarm using swarm mode on Accidental Simplicity.