docker ee

Configure Custom CIDR Ranges in Docker EE

I recently worked with a customer to customize all of the default Classless Interdomain Routing (CIDR) ranges used for IP address allocation by Docker Enterprise Edition 3.0 (Docker EE 3.0). The customer primarily wanted to document the customization process for future use. However, there is often a real need to change some of the default CIDR ranges to avoid conflicts with existing private IP addresses already in use within a customer’s network. Typically such a conflict will make it impossible for applications running in containers or pods to access external hosts in the conflicting CIDR range.

Are you expected to own innovation? Our IT solutions team can share your challenges. We empower businesses to evolve, release projects faster, and enhance performance. Tell us how we can help.

Error: Contact form not found.

Configure Custom CIDR Ranges in Docker EE Read More »

Attack of the Kubernetes Clones

One of the customers I support is using Kubernetes under Docker EE UCP (Enterprise Edition Universal Control Plane) and has been very impressed with its stability and ease of management. Recently, however, a worker node that had been very stable for months started evicting Kubernetes pods extremely frequently, reporting inadequate CPU resources. Our DevOps team was still experimenting with determining resource requirements for many of their containerized apps, so at first, we thought the problem was caused by resource contention between pods running on the node.

Attack of the Kubernetes Clones Read More »

Building Images in a Heterogeneous Cluster

Recently I was troubleshooting a customer problem in their on-premise cluster. But I was not sure where the problem lay. So I switched over to using my colleagues Docker Enterprise demo cluster that is running in Azure. In this heterogeneous cluster are 1 Universal Control Plan (UCP) manager, 1 Docker Trusted Registry (DTR), 2 Windows workers, and 1 Linux worker.

Building Images in a Heterogeneous Cluster Read More »

Kubernetes NetworkPolicies in Docker Enterprise Edition

Kubernetes running under Docker UCP uses the Calico CNI plugin so that you can use Kubernetes NetworkPolicies to control pod to pod communication as well as communication between pods and other network endpoints.

This blog post will walk you through an example of configuring Kubernetes NetworkPolicies. We will block traffic from one namespace into another namespace, while still allowing external traffic to access the “restricted” namespace. As a high-level use case, we will consider the situation where a development team is working on multiple branches of a project, and the pods in the different branches should not be able to communicate with each other. If you are not familiar with the basic concepts of NetworkPolicies, see the Kubernetes documentation here.

Kubernetes NetworkPolicies in Docker Enterprise Edition Read More »