Monitoring Go applications in Kubernetes environment

Before you monitor Go applications in Kubernetes environment, you must connect the data collector to the server by creating a secret. Then, you update your application deployment to monitor the Go applications.

Before you begin

Check whether your service account has access to Kubernetes resources. For more information, see Authorizing the data collector to access Kubernetes resources.
Ensure that you downloaded the configuration package to obtain the server information. For more information, see Obtaining the server configuration information.
Check whether you downloaded the Go data collector package from Passport Advantage. For more information, see Downloading the Go data collector.

About this task

To enable the Go data collector, you need to update the application code to import the Go data collector package, rebuild the application with the vendor files of the Go data collector, and create the secret based on the configuration package.

Procedure

Update the Go application by importing the Go data collector module in the application main file.
```
import (
    _ "github.ibm.com/APM/godc"
)
```
Rebuild the Go application with vendor files of the Go data collector.
1. Extract the Go data collector package file go_datacollector.tgz:
```
tar xzf go_datacollector.tgz
```
2. Merge the vendor files with the vendor files of the application.
3. Build the application with new vendor files.
```
go build -mod=vendor
```
4. Create the Kubernetes secret based on the configuration package. Go to the ibm-cloud-apm-dc-configpack directory where you extract the configuration package in Obtaining the server configuration information, and run the following command to create a secret to connect to the server, for example, name it as icam-server-secret.
```
kubectl -n my_namespace create secret generic icam-server-secret \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/keyfile.jks \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/keyfile.p12 \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/keyfile.kdb \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/ca.pem \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/cert.pem \
 --from-file=ibm-cloud-apm-dc-configpack/keyfiles/key.pem \
 --from-file=ibm-cloud-apm-dc-configpack/global.environment
```

Update the application yaml file to mount the secret. See the following example.

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: MyGoApp
  labels:
    app: MyGoApp
spec:
  selector:
    matchLabels:
      app: MyGoApp
      pod: MyGoApp
  replicas: 1
  template:
    metadata:
      name: MyGoApp
      labels:
        app: MyGoApp
        pod: MyGoApp
    spec:
      containers:
      - name: MyGoApp
        image: mycluster.icp:8500/default/MyGoApp:v1
        imagePullPolicy: Always
        ports:
        - containerPort: 3000
          protocol: TCP
        env:
        - name: APPLICATION_NAME
          value: "MyGoApp"
        volumeMounts:
        - name: global-environment
          mountPath: /opt/ibm/apm/serverconfig
      volumes:
      - name: global-environment
        secret:
          secretName: icam-server-secret 
          optional: true

Redeploy the Go application.