OPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 6: CONTROLLING EGRESS TRAFFIC

OpenShift 3.3 and later contain the functionality to route pod traffic to the external world via a well-defined IP address. This is useful for example if your external services are protected using a firewall and you do not want to open the firewall to all cluster nodes. The way it works is that a egress … Read moreOPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 6: CONTROLLING EGRESS TRAFFIC

OPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 5: OPENSHIFT ROUTER

In the OpenShift world, Services take place on the OSI Layer 3 / IP, while Routing is an OSI Layer 7 / HTTP/TLS concept. Once you’ve wrapped your head around this backwards choice of naming, things are fairly easy: An OpenShift Router is a component which listens on a physical host’s HTTP/S ports for incoming … Read moreOPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 5: OPENSHIFT ROUTER

OPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 4: CONTAINER NETWORKING USING OPENSHIFT/KUBERNETES SERVICES

To allow stable endpoints in an environment of ever changing starting and stopping Pods (and therefore constantly changing IP addresses), Kubernetes introduces (and OpenShift uses) the concept of services. Services are stable IP addresses (taken per default from the 172.30.0.0/16 subnet) that remain the same as long as the service exists. Connection requests to a … Read moreOPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 4: CONTAINER NETWORKING USING OPENSHIFT/KUBERNETES SERVICES

OPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 3: CONTAINER NETWORKING ACROSS OPENSHIFT NODES

So far, this sounds like a lot of effort to achieve a little more than a plain docker host – containers that can talk to each other and to the host network, potentially segregated based on kubernetes namespace. However OpenShift SDN also allows pods on different nodes to communicate with each other. To this end, … Read moreOPENSHIFT NETWORKING FROM A CONTAINER/WORKLOAD POINT OF VIEW – PART 3: CONTAINER NETWORKING ACROSS OPENSHIFT NODES