I have containerized microservice built with Java. This application uses the default /config-volume directory when it searches for property files. Previously I manually deployed with Dockerfiles, and now I'm looking to automate this process with Kubernetes. The container image starts the microservice immediately so I need to get add properties to the config-volume folder immediately. I accomplished this in Docker with this simple Dockerfile
FROM ########.amazon.ecr.url.us-north-1.amazonaws.com/company/image-name:1.0.0
RUN mkdir /config-volume
COPY path/to/my.properties /config-volume
I'm trying to copy this type of behavior in a kubernetes deployment.yaml but I have found no way to do it.
I've tried performing a kubectl cp command immediately after applying the deployment and it sometimes works but it can results in a race condition which cause the microservice to fail at startup.
(I've redacted unnecessary parts)
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-service
spec:
replicas: 1
template:
spec:
containers:
- env:
image: ########.amazon.ecr.url.us-north-1.amazonaws.com/company/image-name:1.0.0
name: my-service
ports:
- containerPort: 8080
volumeMounts:
- mountPath: /config-volume
name: config-volume
volumes:
- name: config-volume
emptyDir: {}
status: {}Is there a way to copy files into a volume inside the deployment.yaml?
You are trying to emulate a ConfigMap using volumes. Instead, put your configuration into a ConfigMap, and mount that to your deployments. The documentation is there:
https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/
Once you have your configuration as a ConfigMap, mount it using something like this:
...
containers:
- name: mycontainer
volumeMounts:
- name: config-volume
mountPath: /config-volume
volumes:
- name: config-volume
configMap:
name: nameOfConfigMap