/couchbase-dotnet-on-k8s

Primary LanguageC#

Generic .NET Core 5 App for Couchbase on Kubernetes

The motivation for this was a need to test a DNS SRV lookup scenario under Kubernetes, but this should be reusable in general

Steps

  1. Get KIND, Kubernetes in Docker
  2. Set up a K8S cluster. I used 1.20. From the k8s directory in this repo, kind create cluster --config kind-config.yaml --name appdemo
  3. Deploy Couchbase Operator/DAC. From the k8s/kube-deployment directory… kubectl apply -f couchbase-crd.yaml then the same for the secrets, then the same for the cb-operator-dac-deployment.yaml
  4. Deploy Couchbase Server. kubectl apply -f cbcluster-buckets-users.yaml
  5. Build the .NET app from the dockerfile and push it to KIND. From the root… docker build -t dotnetappdemo:0.4 . and kind load --name appdemo docker-image dotnetappdemo:0.4
  6. Deploy the app and look at the log output: kubectl apply -f dotnetexample.yaml and kubectl logs -f service/dotnetexample

Do note that the above steps require a little bit of time between each one. Probably just enough to copy and paste, but as an example the DAC needs to be deployed before creating a cluster.

ToDo

  1. Properly use secrets from the app
  2. Set up a way to attach a debugger
  3. Have a better app that doens't exit and maybe sticks around with HTTP endpoints for making it do things.
  4. Prometheus.

Misc. Notes

To check the DNS SRV records, the DNS utils pod may be deployed. Then you can check like so:

kube-deployment % kubectl exec -ti dnsutils -- nslookup -q=SRV _couchbase._tcp.cb-appdemo.default.svc               
Server:         10.96.0.10
Address:        10.96.0.10#53

_couchbase._tcp.cb-appdemo.default.svc.cluster.local    service = 0 33 11210 cb-appdemo-0000.cb-appdemo.default.svc.cluster.local.
_couchbase._tcp.cb-appdemo.default.svc.cluster.local    service = 0 33 11210 cb-appdemo-0001.cb-appdemo.default.svc.cluster.local.
_couchbase._tcp.cb-appdemo.default.svc.cluster.local    service = 0 33 11210 cb-appdemo-0002.cb-appdemo.default.svc.cluster.local.

Issue related MichaCo/DnsClient.NET#4 (comment)