How to fetch configmap from kubernetes pod - kubernetes

Question

I have one spring boot microservice running on docker container, below is the Dockerfile
FROM java:8-jre
MAINTAINER <>
WORKDIR deploy/
#COPY config/* /deploy/config/
COPY ./ms.console.jar /deploy/
CMD chmod +R 777 ./ms.console.jar
CMD ["java","-jar","/deploy/ms.console.jar","console"]
EXPOSE 8384
here my configuration stores in external folder, i.e /config/console-server.yml and when I started the application, internally it will load the config (spring boot functionality).
Now I want to separate this configuration using configmap, for that I simply created one configmap and storing all the configuration details.
kubectl create configmap console-configmap
--from-file=./config/console-server.yml
kubectl describe configmap console-configmap
below are the description details:
Name: console-configmap
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
console-server.yml:
----
server:
http:
port: 8385
compression:
enabled: true
mime-types: application/json,application/xml,text/html,text/xml,text/plain,text/css,application/javascript
min-response-size: 2048
---
spring:
thymeleaf:
prefix: classpath:/static
application:
name: console-service
profiles:
active: native
servlet:
multipart:
max-file-size: 30MB
max-request-size: 30MB
---
host:
gateway: http://apigateway:4000
webhook: http://localhost:9000
my deployment yml is:
apiVersion: apps/v1 # for versions before 1.8.0 use apps/v1beta1
kind: Deployment
metadata:
name: consoleservice1
spec:
selector:
matchLabels:
app: consoleservice
replicas: 1 # tells deployment to run 3 pods matching the template
template: # create pods using pod definition in this template
metadata:
labels:
app: consoleservice
spec:
containers:
- name: consoleservice
image: ms-console
ports:
- containerPort: 8384
imagePullPolicy: Always
envFrom:
- configMapRef:
name: console-configmap
imagePullSecrets:
- name: regcresd
My doubt is, I commented config folder in the Dockerfile, so while running pods, it's throwing exception because of no configuration, how I will inject this console-configmap to my deployment, what I tried already shared, but getting same issues.

Answer 1

First of all, how are you consuming the .yml file in your application? If you consume your yml file contents as environment variables, your config should just work fine. But I suspect that you want to consume the contents from the config file inside the container. If that is the case you have to create a volume out of the configmap as follows:
apiVersion: apps/v1 # for versions before 1.8.0 use apps/v1beta1
kind: Deployment
metadata:
name: consoleservice1
spec:
selector:
matchLabels:
app: consoleservice
replicas: 1 # tells deployment to run 3 pods matching the template
template: # create pods using pod definition in this template
metadata:
labels:
app: consoleservice
spec:
containers:
- name: consoleservice
image: ms-console
ports:
- containerPort: 8384
imagePullPolicy: Always
volumeMounts:
- mountPath: /app/config
name: config
volumes:
- name: config
configMap:
name: console-configmap
imagePullSecrets:
- name: regcresd
The file will be available in the path /app/config/console-server.yml. You have to modify it as per your needs.

Answer 2

do you need to load key:value pairs from the config file as environment variables then below spec would work
envFrom:
- configMapRef:
name: console-configmap
if you need the config as a file inside pod then mount the configmap as volume. following link would be helpful
https://kubernetes.io/docs/tutorials/configuration/configure-redis-using-configmap/