kubectl-rediscluster

kubectl-rediscluster

A kubectl plugin for inspecting your Redis Clusters deployed in Kubernetes. The plugin will collect information from the K8s API, and by querying the Redis instances within the pods.

The plugin expects a K8s Service to be able to find out which Pods that runs Redis in cluster mode.

Installation

Download the binary, or fetch it via:

GO111MODULE=on go get -u github.com/bjosv/kubectl-rediscluster@latest

A kubectl plugin binary needs to be accessible via $PATH, so make sure which kubectl-rediscluster finds the binary in $GOPATH/bin. Verify the installation by running: kubectl plugin list

Options

# Avoid long names by creating an alias like
alias kc="kubectl rediscluster"

# ..or rename the base command like:
ln -s ~/bin/kubectl-rediscluster ~/bin/kubectl-rc
kubectl rc slots

How to run

Collect cluster information by running a command like:

kubectl rediscluster <COMMAND> <SERVICE NAME>

or continuously by running:

watch -d kubectl rediscluster <COMMAND>

This will query the cluster every 2 sec and highlight the differences. The last example also excluded the <SERVICE NAME> which makes the plugin guess which K8s Service to query.

Commands

Get slots information

Get the slot distribution of a Redis Cluster, with additional information about pods and placement on the K8s hosts. Some analyzis regarding fault tolerance is shown in the remarks column.

kubectl rediscluster slots <SERVICE NAME>

Example:

> kubectl rediscluster slots cluster-redis-cluster

START  END    ROLE    IP               PODNAME                     HOST          REMARKS
0      5461   master  10.244.3.3:6379  rediscluster-cluster-lvkmz  kind-worker2
.      .      repl.   10.244.2.2:6379  rediscluster-cluster-dqrzl  kind-worker
5462   10923  master  10.244.1.3:6379  rediscluster-cluster-7tpnv  kind-worker3  *same host*
.      .      repl.   10.244.1.4:6379  rediscluster-cluster-kgtrm  kind-worker3  *same host*
10924  16383  master  10.244.3.2:6379  rediscluster-cluster-v7dcl  kind-worker2  *replica missing*

Get nodes information

Get information about the Redis Cluster instances. It shows each instance view of the Redis cluster.

kubectl rediscluster nodes <SERVICE NAME>

Example:

> kubectl rediscluster nodes cluster-redis-cluster
                                                                            SLOT    CLUSTER
HOST          PODNAME                     IP           ROLE    KEYS  SLOTS  RANGES  STATE    REMARKS
kind-worker   rediscluster-cluster-t8szs  10.244.1.13  repl.   3334  5462   10      ok
kind-worker   rediscluster-cluster-9b225  10.244.1.8   master  3328  5462   15      ok
kind-worker2  rediscluster-cluster-vxpng  10.244.2.12  master  3338  5460   9       ok
kind-worker2  rediscluster-cluster-lmlhl  10.244.2.14  repl.   3328  5462   15      ok
kind-worker3  rediscluster-cluster-mbww9  10.244.3.11  repl.   3338  5460   9       ok
kind-worker3  rediscluster-cluster-t4znw  10.244.3.3   master  3334  5462   10      ok

Options

Omit service name

Let the plugin guess which service that provides the Redis Cluster by omitting the service name. A service that provides the port 6379 will be selected.

Example:

> kubectl rediscluster slots
Using service name: cluster-redis-cluster
...

Set namespace

All the usual kubeconfig options are available, like using specific namespace. See help (-h)

Example:

> kubectl rediscluster slots -n mynamespace

Verbose logging

> kubectl rediscluster slots -v