Edit config file inside image before deployment/pod creation - kubernetes

Question

I am running grafana as a pod inside my Kubernetes cluster. Once Grafana is initialized, it create a DB on localhost and saves all data there. This means that whenever a pod is destroyed and recreated, the whole DB is reinitialized and I lose all previous Data.
The grafana config inside the Pod for DB is ::
#################################### Database ####################################
[database]
# Either "mysql", "postgres" or "sqlite3", it's your choice
;type = sqlite3
;host = 127.0.0.1:3306
;name = grafana
;user = root
;password =
Inorder to get rid of this problem, I have to create an external DB and point my Grafana to use that DB instance everytime I create the Grafana Pod. My current default implementation to create the Grafana pod is ::
apiVersion: v1
kind: Service
metadata:
name: lb-grafana-service
spec:
ports:
- port: 4545
targetPort: 4545
protocol: TCP
clusterIP: 10.100.10.100
----
apiVersion: v1
kind: Service
metadata:
annotations:
prometheus.io/scrape: 'true'
labels:
app: grafana
name: grafana
name: grafana
spec:
ports:
- name: scrape
port: 4545
nodePort: 30999
protocol: TCP
type: NodePort
selector:
app: grafana
----
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: grafana
spec:
replicas: 1
selector:
matchLabels:
app: grafana
template:
metadata:
name: grafana
labels:
app: grafana
spec:
containers:
- name: grafana
image: grafana/grafana:develop
env:
- name: Prometheus_SERVICE_URL
value: http://172.29.219.105:30901
- name: GF_SECURITY_ADMIN_PASSWORD
value: "grafana"
- name: GF_SERVER_HTTP_PORT
value: "4545"
ports:
- containerPort: 9101
volumeMounts:
- mountPath: /var
name: grafana-storage
volumes:
- name: grafana-storage
emptyDir: {}
So what I want to do is overwrite the /etc/grafana/grafana.ini file before Grafana pod comes online OR just rewrite the current file with new values. I have no idea how I can do that right now. A little guidance will be much appreciated.

Answer 1

In general, you could use ConfigMaps like the comment said.
The Grafana image itself provides the ability to provide all configuration parameters via environment variables. This is only mentioned in the GitHub readme.
This way you could set the environment variables with Kubernetes, like:
spec:
template:
spec:
containers:
- name: grafana
image: grafana/grafana:4.1.1
env:
- name: "GF_SERVER_ROOT_URL"
value: "http://grafana.{{.clusterDomain}}"
- name: "GF_DATABASE_TYPE"
value: "{{.gfDatabaseType}}"
- name: "GF_DATABASE_HOST"
value: "{{.gfDatabaseHost}}"
- name: "GF_DATABASE_NAME"
value: "{{.gfDatabaseName}}"
- name: "GF_DATABASE_USER"
value: "{{.gfDatabaseUser}}"
- name: "GF_DATABASE_PASSWORD"
value: "{{.gfDatabasePassword}}"
- name: "GF_DATABASE_SSL_MODE"
value: "disable"
- name: "GF_AUTH_ANONYMOUS_ENABLED"
value: "true"