condfigmap.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: uf-config
data:
  deploymentclient.conf: |  
    [deployment-client]
    clientName=foo
    [target-broker:deploymentServer]
    targetUri=deploymentserver.splunk.mycompany.com:8089

ufsidecar.yaml

apiVersion: v1
kind: Pod
metadata:
  name: sidecar-container-demo
spec:
  containers:
  - name: main-container
    image: nginx
    resources: {}
    ports:
      - containerPort: 80
    volumeMounts:
    - name: var-logs
      mountPath: /var/log      
  #https://docs.splunk.com/Documentation/Forwarder/8.1.2/Forwarder/DeployandrunauniversalforwarderinsideaDockercontainer
  - name: splunkUF-sidecar
    image: splunk/universalforwarder:latest
    env:
      - name: SPLUNK_START_ARGS
        value: '--accept-license'
      - name: SPLUNK_PASSWORD
        value: 'Chang3d!'
      
    resources: {}
    volumeMounts:
    - name: var-logs
      mountPath: /var/log
    - name: uf-config
      mountPath: /opt/splunkforwarder/etc/apps/_k8s/local
  dnsPolicy: Default
  volumes:
  - name: var-logs
    emptyDir: {}
  - name: uf-config
    configMap:
      # Provide the name of the ConfigMap you want to mount.
      name: uf-config
      # An array of keys from the ConfigMap to create as files
      items:
      - key: "deploymentclient.conf"
        path: "deploymentclient.conf"