Support in cluster context

[ConnorsApps]

Adds the ability to run knsiff in a Kubernetes pod.

Testing

manifest.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: sniff-service-account
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: sniff-cluster-role
rules:
- apiGroups: [""]
  resources: ["*"]
  verbs: ["*"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: sniff-cluster-role-binding
subjects:
- kind: ServiceAccount
  name: sniff-service-account
  namespace: default
roleRef:
  kind: ClusterRole
  name: sniff-cluster-role
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: Pod
metadata:
  name: sniff
spec:
  serviceAccountName: sniff-service-account
  containers:
  - name: sniff
    image: golang:1-alpine
    command: ["tail", "-f", "/dev/null"]
  restartPolicy: Never

# create pod with overly permissive rbac rules
kubectl apply -f manifest.yaml

# Copy local repo
kubectl cp . sniff:/app -c sniff

kubectl exec sniff -c sniff -- sh -c "cd /app && go mod download"

kubectl exec sniff -c sniff -- sh -c "cd /app && go run cmd/kubectl-sniff.go pod-name -c container -n my-namespace -p -o -"