Add otel4k8s script (#146)

Author: svrnm

scripts/otel4k8s.sh

@@ -0,0 +1,145 @@
+#!/bin/bash
+# This script assumes that you are using a k8s environment and have deployed an application simulation already.
+#
+# It has been tested with the following setup instructions for the cluster:
+# minikube start --cpus 6 --memory 10g --network-plugin=cni --cni=false && cilium install && cilium status --wait
+#
+# With the simulation deployed into the k8s namespace "my-simulation", run it as follows:
+#
+# ./otel4k8s.sh "my-simulation"
+#
+# This will deploy cert manager, otel operater, a LGTM-stack in a single container and the instrumentation instructions
+# for your applications. The last step will restart all pods that belong to the simulation.
+#
+# For a more detailed configuration run
+#
+# ./otel4k8s.sh --help
+# 
+# NOTE: Currently only java will be auto instrumented, other languages will be added soon
+
+CERT_MANAGER_VERSION=1.16.3
+O11Y_NAMESPACE=o11y
+APP_NAMESPACE=""
+
+WITH_CERT_MANAGER=1
+WITH_OTEL_OPERATOR=1
+WITH_LGTM_CONTAINER=1
+
+KUBECTL="kubectl"
+
+# Function to display help
+show_help() {
+	echo "Usage: otel4k8s.sh [OPTION]"
+	echo "Deploy cert manager, OpenTelemetry operator, a LGTM-stack in a single container and automatic instrumentation for a running app simulation"
+	echo
+	echo "Options:"
+	echo "  --patch   Increase the patch number by 1."
+	echo "  (no option) Display the current version."
+}
+
+if [[ $# -eq 1 && ${1} != --* ]]; then
+    APP_NAMESPACE=${1}
+else
+
+for ARG in "$@"; do
+	case "$ARG" in
+	--help)
+		show_help
+		exit 0
+		;;
+	--app-namespace=*)
+		APP_NAMESPACE="${ARG#*=}"
+		shift
+		;;
+  --o11y-namespace=*)
+    O11Y_NAMESPACE="${ARG#*=}"
+		shift
+		;;
+  --no-cert-manager)
+    WITH_CERT_MANAGER=0
+    shift
+    ;;
+  --no-lgtm)
+    WITH_LGTM_CONTAINER=0
+    shift
+    ;;
+  --no-otel-operator)
+    WITH_OTEL_OPERATOR=0
+    shift
+    ;;
+  --dry-run)
+    KUBECTL="echo kubectl"
+    shift
+    ;;
+  *)
+		echo "Unknown option: $ARG"
+		show_help
+		exit 1
+		;;
+	esac
+done
+
+fi
+
+# helper function that will rerun commands until they are successful
+retry_until_success() {
+    local delay=5         # Seconds to wait between retries
+    local max_attempts=0   # 0 means unlimited retries
+    local attempt=0
+
+    while true; do
+        "$@" && return 0   # Run the command; if it succeeds, return success
+        
+        attempt=$((attempt + 1))
+        echo "Attempt $attempt failed. Retrying in $delay seconds..."
+
+        if [[ $max_attempts -gt 0 && $attempt -ge $max_attempts ]]; then
+            echo "Maximum retry attempts reached. Giving up."
+            return 1
+        fi
+
+        sleep "$delay"
+    done
+}
+
+# Install Cert Manager
+if [[ ${WITH_CERT_MANAGER} -eq 1 ]]; then
+  retry_until_success ${KUBECTL} apply -f "https://github.com/cert-manager/cert-manager/releases/download/v${CERT_MANAGER_VERSION}/cert-manager.yaml"
+fi
+
+# Install the OTel operator
+if [[ ${WITH_OTEL_OPERATOR} -eq 1 ]]; then
+  retry_until_success ${KUBECTL} apply -f https://github.com/open-telemetry/opentelemetry-operator/releases/latest/download/opentelemetry-operator.yaml
+fi
+
+# Install LGTM in one container
+  if [[ ${WITH_LGTM_CONTAINER} -eq 1 ]]; then
+  ${KUBECTL} create namespace ${O11Y_NAMESPACE}
+  retry_until_success ${KUBECTL} apply -f https://raw.githubusercontent.com/grafana/docker-otel-lgtm/refs/heads/main/k8s/lgtm.yaml --namespace "${O11Y_NAMESPACE}"
+fi
+
+add_otel_instrumentation() {
+  ${KUBECTL} apply --namespace "${APP_NAMESPACE}" -f - <<EOF
+apiVersion: opentelemetry.io/v1alpha1
+kind: Instrumentation
+metadata:
+  name: my-instrumentation
+spec:
+  exporter:
+    endpoint: http://lgtm.${O11Y_NAMESPACE}.svc.cluster.local:4317
+  sampler:
+    type: always_on
+EOF
+}
+
+retry_until_success add_otel_instrumentation
+
+# TODO: This is currently only injecting the java automatic instrumentation, we need a way to identify the language and inject the right one
+# see https://github.com/cisco-open/app-simulator/issues/147
+for deployment in $(kubectl get deployments -n "${APP_NAMESPACE}" -o jsonpath='{.items[*].metadata.name}'); do
+    ${KUBECTL} patch deployment ${deployment} -n "${APP_NAMESPACE}" -p '{"spec": {"template":{"metadata":{"annotations":{"instrumentation.opentelemetry.io/inject-java":"true"}}}} }'
+done
+
+${KUBECTL} rollout restart deployment -n "${APP_NAMESPACE}"
+
+${KUBECTL} port-forward service/lgtm 3000:3000 4317:4317 4318:4318 --namespace ${O11Y_NAMESPACE} &