The new Swarm bundled in Docker 1.12+ is a vast improvement compared to the old orchestration and scheduling. There is no more the need to run a separate set of Swarm containers (it is bundled in Docker Engine), failover strategies are much more reliable, service discovery is baked in, the new networking works like a charm, and so on. The list of features and improvements is quite big. If you haven’t had a chance to give it a spin, please read the Docker Swarm Introduction and Integrating Proxy With Docker Swarm.
In those articles we used commands to run Docker services inside the Swarm cluster. If you are like me, you are probably used to the simplicity Docker Compose provides. Instead trying to memorize commands with all the arguments required for running services, you probably specified everything as Docker Compose files and run containers with a simple docker-compose up -d command. After all, that is much more convenient than docker service create followed by an endless number of arguments. My brain does not have the capacity to memorize all of them.
When I started “playing” with the new Swarm, my first impression was this is great, followed by I don’t want to memorize different arguments for all of my services. I want my Compose files back into the game. Continue reading →
This article continues where Docker Swarm Introduction left. I will assume that you have at least a basic knowledge how Swarm in Docker v1.12+ works. If you don’t, please read the previous article first.
The fact that we can deploy any number of services inside a Swarm cluster does not mean that they are accessible to our users. We already saw that the new Swarm networking made it easy for services to communicate with each other.
Let’s explore how we can utilize it to expose them to the public. We’ll try to integrate a proxy with the Swarm network and further explore benefits version v1.12 brought. Continue reading →
Docker just published a new Docker Engine v1.12. It is the most significant release since v1.9. Back then, we got Docker networking that, finally, made containers ready for use in clusters. With v1.12, Docker is reinventing itself with a whole new approach to cluster orchestration. Say goodbye to Swarm as a separate container that depends on an external data registry and welcome the new Docker Swarm. Everything you’ll need to manage your cluster is now incorporated into Docker Engine. Swarm is there. Service discovery is there. Improved networking is there. Continue reading →
Docker SDN (Software Defined Network) already exists for quite some time. What is new, starting from the release 1.11, is the addition of DNS round-robin load balancing. That is both a reason for celebration and an opportunity to explore Docker networking and DNS. We’ll explore internal and external networking, see how DNS fits into the picture, discuss use cases that might be a good fit, and finish with pros and cons. Continue reading →
The goal of the project is to add features and processes that are currently missing inside the Docker ecosystem. The project, at the moment, solves the problems of blue-green deployments, relative scaling, and proxy service discovery and reconfiguration. Many additional features will be added soon.
A lot changed since I published that article. The Swarm as a standalone container is deprecated in favor of Swarm Mode bundled inside Docker Engine 1.12+. On the other hand, the Docker Flow: Proxy advanced and became more feature rich and advanced. I suggest you check out the project README instead this article.
The goal of the Docker Flow: Proxy project is to provide a simple way to reconfigure proxy every time a new service is deployed or when a service is scaled. It does not try to “reinvent the wheel”, but to leverage the existing leaders and combine them through an easy to use integration. It uses HAProxy as a proxy and Consul as service registry. On top of those two, it adds custom logic that allows on-demand reconfiguration of the proxy. Continue reading →