Add startup-script to install Ops Agent

resources/scripts/startup-script/examples/install_cloud_ops_agent.sh

@@ -0,0 +1,91 @@
+#!/bin/bash
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+LEGACY_MONITORING_PACKAGE='stackdriver-agent'
+LEGACY_LOGGING_PACKAGE='google-fluentd'
+OPSAGENT_PACKAGE='google-cloud-ops-agent'
+
+fail() {
+	echo >&2 "[$(date +'%Y-%m-%dT%H:%M:%S%z')] $*"
+	exit 1
+}
+
+handle_debian() {
+	is_legacy_monitoring_installed() {
+		dpkg-query --show --showformat 'dpkg-query: ${Package} is installed\n' ${LEGACY_MONITORING_PACKAGE} |
+			grep "${LEGACY_MONITORING_PACKAGE} is installed"
+	}
+
+	is_legacy_logging_installed() {
+		dpkg-query --show --showformat 'dpkg-query: ${Package} is installed\n' ${LEGACY_LOGGING_PACKAGE} |
+			grep "${LEGACY_LOGGING_PACKAGE} is installed"
+	}
+
+	is_legacy_installed() {
+		is_legacy_monitoring_installed || is_legacy_logging_installed
+	}
+
+	is_opsagent_installed() {
+		dpkg-query --show --showformat 'dpkg-query: ${Package} is installed\n' ${OPSAGENT_PACKAGE} |
+			grep "${OPSAGENT_PACKAGE} is installed"
+	}
+
+	install_opsagent() {
+		curl -s https://dl.google.com/cloudagents/add-google-cloud-ops-agent-repo.sh | bash -s -- --also-install
+	}
+}
+
+handle_redhat() {
+	is_legacy_monitoring_installed() {
+		rpm --query --queryformat 'package %{NAME} is installed\n' ${LEGACY_MONITORING_PACKAGE} |
+			grep "${LEGACY_MONITORING_PACKAGE} is installed"
+	}
+
+	is_legacy_logging_installed() {
+		rpm --query --queryformat 'package %{NAME} is installed\n' ${LEGACY_LOGGING_PACKAGE} |
+			grep "${LEGACY_LOGGING_PACKAGE} is installed"
+	}
+
+	is_legacy_installed() {
+		is_legacy_monitoring_installed || is_legacy_logging_installed
+	}
+
+	is_opsagent_installed() {
+		rpm --query --queryformat 'package %{NAME} is installed\n' ${OPSAGENT_PACKAGE} |
+			grep "${OPSAGENT_PACKAGE} is installed"
+	}
+
+	install_opsagent() {
+		curl -s https://dl.google.com/cloudagents/add-google-cloud-ops-agent-repo.sh | bash -s -- --also-install
+	}
+}
+
+main() {
+	if [ -f /etc/debian_version ]; then
+		handle_debian
+	elif [ -f /etc/redhat-release ]; then
+		handle_redhat
+	else
+		fail "Unsupported platform."
+	fi
+
+	if is_legacy_installed || is_opsagent_installed; then
+		fail "Legacy or Ops Agent is already installed."
+	fi
+
+	install_opsagent
+}
+
+main