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network-mapper
Map Kubernetes traffic: in-cluster, to the Internet, and to AWS IAM and export as text, intents, or an image
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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
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After multiple iterations, research sessions and some trial & error, we could produce an exportable list of network connections in any Kubernetes cluster. You might recall that our larger goal was to get to a logical (functional) map of pod-to-pod traffic, and that will be covered in a future posting. After adding that capability, here’s an example output from our project, now called network-mapper, when pointed at one of the clusters in our “lab” environment:
But another approach that could work in Kubernetes, because the DNS servers are within the cluster itself, would be to work directly with the DNS server pods. In most Kubernetes clusters, whether standalone or managed (GKE, AKS, EKS), the cluster DNS is either coredns or kube-dns. That was great to minimize how much configuration options we’d need to support. We realized we could edit the coredns or kube-dns configmap resources to enable their log option, which would make them log all the queries they handle. We’ll cover exactly how it’s done in more detail below.
In generic Kubernetes network policies, there is no action field. The Calico CNI plugin (Kubernetes network plugin that implements the Container Network Interface) provides this functionality, and in particular provides logging even for allowed traffic. And this worked when we tried it in our test clusters and in our own back end.