Sheng Liang is the CEO and Co-founder of Rancher Labs. Today we announced Series A funding and officially launched our company Rancher Labs. We started Rancher Labs because we saw the benefits of running Docker containers in production and wanted to build tools to help make it happen. We are building two open source software products: Rancher and RancherOS. Rancher is a container infrastructure platform designed to make it simple to operate Docker in production. RancherOS is a minimal Linux distribution designed specifically for running Docker. While we believe combining Rancher and RancherOS can result in a uniquely capable production platform, Rancher and RancherOS are not tightly coupled. Rancher can manage Ubuntu, RHEL/CentOS, or CoreOS just as well as it manages RancherOS.
Why we decided to build Rancher and RancherOS
The motivations for both products, Rancher and RancherOS, are rooted in our belief that Docker is much more than a packaging format, and that it will become the predominant application runtime platform in the future. We form this belief based on our learnings from many Docker, Rancher, and RancherOS users. Three trends have started to appear: First, users are gravitating towards the native Docker experience. Despite the numerous orchestration platforms that wrap Docker runtime and provide high-level abstractions for Docker management, most users choose to stick with the Docker CLI (e.g, docker run) and the standard Docker API. This is not a surprise since Docker’s native CLI and API are exceptionally well built and well designed. We have spoken with many organizations who are foregoing complex container orchestration solutions and instead use configuration management tools such as Chef, Puppet, Ansible, and SaltStack to orchestrate Docker native CLI in production. As Docker continues to develop, the scope of native Docker experience will broaden to include Docker native orchestration and scheduling, enabled by Docker Machine, Docker Compose, and Docker Swarm. Second, Docker containers are transforming application management. By introducing a common application packaging, distribution, and runtime format, Docker transforms application management. Reusable application blueprints become a reality and can be deployed independent of the programming language and target cloud platform. Application provisioning, scaling, and upgrades can be separated from the application logic itself. Application management can finally be practiced by the devops team independent of the application developers. Docker-built tools such as Docker Compose and third-party tools such as Kubernetes are both promising developments in Docker application management. Third, containerized applications have created requirements for a new set of infrastructure services for containers. Docker as a new way of consuming infrastructure has defined a new set of requirements on infrastructure. Whether you are running a traditional multi-tier app or cutting-edge microservices app using containers, you will likely require the following infrastructure services:
- A number of Linux hosts capable of running Docker containers. These hosts may be virtual machines or physical machines in your data center, or they may be cloud-hosted instances. A networked Linux host is the standard unit of computing resources for Docker. Regardless where it comes from, each Linux host provides largely consistent CPU, memory, storage, and network connectivity.
- A network that enables containers on different hosts to communicate with each other. This can be achieved using coordinated port mappings or software defined network (SDN) technologies running on the Linux hosts.
- Load balancer, DNS, and health check support. Load balancers are required to expose services to the Internet. DNS is commonly used to implement service discovery. Integrated health check ensures only healthy containers are used to serve requests.
- A way to perform actions triggered by certain events, such as restarting new containers on host failure, ensuring a fixed number of healthy containers are available, or ensuring new hosts and containers are created in response to increased load.
- A way to clone services by creating new containers from existing containers. This is required, for example, when we upgrade a service by creating containers running a new version of the Docker image. After we make sure the newly cloned service works, we can complete the upgrade by redirecting the load balancer and DNS from the existing containers to the cloned containers.
- Storage snapshot and backup. This is required, for example, when we want to backup a stateful container for disaster recovery purposes.
We have talked to many organizations who have had to make a sizable development effort and to integrate a number of open source technologies in container SDN, service discovery, load balancing, DNS, and distributed storage management. A product that delivers a powerful set of infrastructure services out of the box will make it easier for organizations to run Docker in production.
How we built Rancher and RancherOS
We designed Rancher to address all of the above three use cases. Rancher is not another orchestration or management layer that shields users from the native Docker experience. As Docker platform grows over time, a wrapper layer will likely be superseded by native Docker features. Rancher instead works in the background so that users can continue to use native Docker CLI and Docker Compose templates. Rancher uses Docker labels--a Docker 1.6 feature contributed by Rancher Labs--to pass additional information through the native Docker CLI. Because Rancher supports native Docker CLI and API, third-party tools like Kubernetes work on Rancher automatically. Rancher implements a set of infrastructure services including multi-host networking, load balancer, DNS, health checks, event triggers, service cloning, and storage management. Rancher implements all the infrastructure services as software, and does not depend on any underlying cloud or virtualization platform API. Rancher requires just Linux hosts running Docker with CPU, memory, local disks, and network connectivity. Rancher includes user, project, and environment management so multiple users can collaborate over multiple projects and across dev, QA, staging, and production environments. Recognizing the fundamental unit of computing for Docker is a Linux host, we designed RancherOS to be the best Linux platform for running Docker containers. By using Docker daemon itself as PID 1 and running all system services as containers, RancherOS offers the smallest (at around 20MB), easiest-to-manage, and the most robust Linux distribution for running Docker in production. Many organizations have already started to work with Rancher and RancherOS. A major SaaS provider is orchestrating their Docker containers using Puppet scripts and Rancher, leveraging Rancher’s abilities to work with the native Docker CLI. A web company has gone a step further and is deploying a full-stack Docker production platform using Rancher and RancherOS. In a more traditional IT setting, a major bank is evaluating using Rancher to manage container workload running on their existing vSphere cluster, leveraging Rancher’s abilities to manage multiple users, projects, and environments. If you have not done so, check out our product pages for Rancherand RancherOS or our open source GitHubrepositories. It is easy to get Rancher and RancherOS up and running. All you need is the ability to create a couple of Linux instances on your laptop or in the cloud. We are putting the finishing touches on Rancher and RancherOS products and are getting ready to launch official Beta programs on both products. Stay tuned for further announcements, and to learn more please join us for our June 16th online meetup to see a demo of Rancher and meet some of our team. You can register by following the link below: