OCI Container Engine for Kubernetes (OKE) Pod CrashLoopBackOff with gRPC Service Integration
I'm not sure how to approach I'm a bit lost with I'm writing unit tests and I'm sure I'm missing something obvious here, but I'm having a frustrating scenario with my OCI Container Engine for Kubernetes (OKE) deployment. My application, which is based on Spring Boot 2.5 and uses gRPC for service communication, has started throwing a `CrashLoopBackOff` status for one of the pods after deploying the latest changes. The pod logs indicate that the application want to connect to the gRPC service hosted on another pod. Here's the relevant part of my `deployment.yaml` configuration: ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: my-app spec: replicas: 3 selector: matchLabels: app: my-app template: metadata: labels: app: my-app spec: containers: - name: my-app-container image: myregistry/my-app:latest ports: - containerPort: 8080 env: - name: GRPC_SERVER_URL value: "my-grpc-service:50051" ``` I have verified that `my-grpc-service` is running and accessible from my application pod using the command `kubectl exec -it $(kubectl get pods --selector=app=my-app -o jsonpath='{.items[0].metadata.name}') -- curl my-grpc-service:50051`. The response I get is as expected, yet my application fails to start with the following behavior in the logs: ``` Exception in thread "main" io.grpc.StatusRuntimeException: UNAVAILABLE: Failed to connect to the server ``` I also have the appropriate Network Security Groups and the Kubernetes service defined as: ```yaml apiVersion: v1 kind: Service metadata: name: my-grpc-service spec: type: ClusterIP ports: - port: 50051 targetPort: 50051 selector: app: my-grpc-service ``` Additionally, I ensured that the DNS resolution is working within the cluster by checking for any issues with CoreDNS. I even tried redeploying the `my-grpc-service` and clearing the cache, but still, the question continues. Are there any specific configurations or best practices I might be missing regarding gRPC service integration on OKE? I'm working on a API that needs to handle this. Am I missing something obvious? I'm working on a web app that needs to handle this. Cheers for any assistance! Thanks for taking the time to read this! This is for a web app running on CentOS.