Script to dump goroutine stack traces from Pods in Kubernetes.

dump-pod-goroutines.sh

#!/usr/bin/env zsh

if [ "$#" -ne 2 ]; then
    echo "dump-pod-goroutines <labels> <port>"
    exit 1
fi

labels="$1"
port="$2"

mkdir -p pods

# collect pod names with specific "app" label
all_pods=$(kubectl get pods -l "$labels" --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')

echo "$all_pods" | while read -r pod; do
    # port-forward to the pod
    kubectl port-forward $pod $port:$port &
    pid=$!

    # wait for port to come alive
    while ! nc -z localhost $port; do   
        sleep 0.1
    done
    local_url="http://localhost:$port/debug/pprof/goroutine?debug=2"
    curl "$local_url" > "pods/$pod.txt"

    # stop port-forwarding
    kill $pid
done