Adding APM Insight Node.js agent in a Kubernetes environment via init containers
The below steps will guide you through the process of integrating the APM Insight Node.js agent into your Kubernetes deployment using init containers. During the application startup, Kubernetes init containers are used to incorporate the Node.js agent binaries into the application container.
Prerequisite
Node.js version 8 or above is required, since it has support for the NODE_OPTIONS environment variable.
Create a Node.js application image
Create a Node.js application image by incorporating the application binaries and dependencies, excluding any Node.js agent binaries or configurations in the image.
Include the init container in the deployment spec
The sample code snippet given below describes the required volumes, volumeMounts, and initContainer definitions, which have to be updated in your deployment spec section.
initContainers:
- name: init-npm
image: node:14
command: ["/bin/sh", "-c"]
args: ["mkdir -p /apm/ && cd /apm && npm install apminsight --silent"]
volumeMounts:
- mountPath: /apm
name: app-volume
Code illustration
In the code snippet given above, an init container named init-npm is defined within the Kubernetes configuration. This container utilizes a Node.js 14 Docker image. In the container, we are creating a directory named /apm and installing the apminsight package into that directory using the NPM (Node Package Manager). The installation command used is npm install apminsight --silent. Subsequently, the /apm directory is mounted to the container under the volume name app-volume.
containers:
env:
- name: NODE_OPTIONS
value: "--require /apm/node_modules/apminsight"
- name: APMINSIGHT_LICENSE_KEY
value: "<license-key>"
- name: APMINSIGHT_APP_NAME
value: "<application-name>"
- name: APMINSIGHT_APP_PORT
value: "<application-port>"
volumeMounts:
- mountPath: /apm
name: app-volume Code illustration
To integrate the APM Insight agent, modifications have been made by setting the NODE_OPTIONS environment variable, which includes the instruction --require /apm/node_modules/apminsight.
Additionally, specific configuration values such as the license key, application name, and application port are now provided through environment variables APMINSIGHT_LICENSE_KEY, APMINSIGHT_APP_NAME, and APMINSIGHT_APP_PORT respectively.
Sample Kubernetes deployment YAML file
The below sample code snippet assumes the Node.js application image has been published to myrepository/sample-nodejs-app:latest.
apiVersion: apps/v1
kind: Deployment
metadata:
name: sample-deployment
spec:
replicas: 1
selector:
matchLabels:
app: sample-app
template:
metadata:
labels:
app: sample-app
spec:
initContainers:
- name: init-npm
image: node:14
command: ["/bin/sh", "-c"]
args: ["mkdir -p /apm/ && cd /apm && npm install apminsight --silent"]
volumeMounts:
- mountPath: /apm
name: app-volume
containers:
- name: main-container
image: myrepository/sample-nodejs-app:latest
env:
- name: NODE_OPTIONS
value: "--require /apm/node_modules/apminsight"
- name: APMINSIGHT_LICENSE_KEY
value: "<license-key>"
- name: APMINSIGHT_APP_NAME
value: "<application-name>"
- name: APMINSIGHT_APP_PORT
value: "<application-port>"
volumeMounts:
- mountPath: /apm
name: app-volume
volumes:
- name: app-volume
emptyDir: {}Related articles
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