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Java Spring Active profile in kubernetes Cluster

i want to start Java spring app with active profile...
I build Docker image in Gitlab CI/CD using maven wrapper ,
./mvnw compile jib:build -Dimage=image/sms-service:1
after that i deploy app in k8s....
now i want to run with active profile , what is best way? how can i define in k8s to run specific user
apiVersion: apps/v1
kind: Deployment
metadata:
name: sms-service
namespace: sms-service
spec:
selector:
matchLabels:
app: sms-service
replicas: 4 # tells deployment to run 2 pods matching the template
template:
metadata:
labels:
app: sms-service
spec:
template:
spec:
containers:
- name: sms-service
image: image/sms-service:1
imagePullPolicy: Always
ports:
- containerPort: 8080
imagePullSecrets:
- name: sms-service

Set the SPRING_PROFILES_ACTIVE environment variable to the profile(s) you want to run.
You can set it in the deployment yaml or at build time in your image but usually better to add it to deployment.

Create a new file, named configmap.yaml under the k8s config folder and add the following lines:
apiVersion: v1
kind: ConfigMap
metadata:
name: blabla
namespace: bla
data:
application.yaml: |
spring:
profiles:
active: prod (here goes the profile)
This tells Kubernetes to set this configuration when starting the container

Reading Kube Secrets from Java Program

I'm working on a library to read secrets from a given directory that I've got easily up and running with Docker Swarm by using the /run/secrets directory as the defined place to read secrets from. I'd like to do the same for a Kubernetes deployment but looking online I see many guides that advise using various Kubernetes APIs and libraries. Is it possible to simply read from disk as it is with Docker Swarm? If so, what is the directory that these are stored in?

Please read the documentation
I see 2 practical ways to access the k8s secrets:
Mount the secret as a file
apiVersion: v1
kind: Pod
metadata:
name: mypod
spec:
containers:
- name: mypod
image: redis
volumeMounts:
- name: foo
mountPath: "/etc/foo"
readOnly: true
volumes:
- name: foo
secret:
secretName: mysecret
Expose the secret as an environmental variable
apiVersion: v1
kind: Pod
metadata:
name: secret-env-pod
spec:
containers:
- name: mycontainer
image: redis
env:
- name: SECRET_USERNAME
valueFrom:
secretKeyRef:
name: mysecret
key: username
- name: SECRET_PASSWORD
valueFrom:
secretKeyRef:
name: mysecret
key: password

Dockerized Spring Boot app not using mounted Kubernetes ConfigMap (application.properties)

I have a problem where in my dockerized Spring Boot application is not using the application.properties I stored in a configMap.
However, I can see and confirm that my configMap has been mounted properly in the right directory of my Spring Boot app when I enter the pod's shell.
Note that I have an application.properties by default wherein Kubernetes mounts / overwrites it later on.
It seems that the Spring Boot uses the first application.properties and when k8s overwrites it, apparently, it doesn't use it.
It seems that, apparently, what happens is:
run the .jar file inside the Dockerized Spring Boot app
use the first/default application.properties file on runtime
Kubernetes proceeds to mount the configMap
mount / overwrite success, but how will Spring Boot use this one since it's already running?
Here is the Dockerfile of my Spring Boot / Docker image for reference:
FROM maven:3.5.4-jdk-8-alpine
# Copy whole source code to the docker image
# Note of .dockerignore, this ensures that folders such as `target` is not copied
WORKDIR /usr/src/myproject
COPY . /usr/src/myproject/
RUN mvn clean package -DskipTests
WORKDIR /usr/src/my-project-app
RUN cp /usr/src/myproject/target/*.jar ./my-project-app.jar
EXPOSE 8080
CMD ["java", "-jar", "my-project-app.jar"]
Here's my Kubernetes deployment .yaml file for reference:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-project-api
namespace: my-cluster
labels:
app: my-project-api
spec:
replicas: 1
selector:
matchLabels:
app: my-project-api
strategy:
type: RollingUpdate
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
template:
metadata:
labels:
app: my-project-api
spec:
containers:
- name: my-project-api
image: "my-project:latest"
imagePullPolicy: Always
env:
.
.
.
volumeMounts:
- name: my-project-config
mountPath: /usr/src/my-project/my-project-service/src/main/resources/config/application.properties
ports:
- containerPort: 8080
name: my-project-api
protocol: TCP
volumes:
# Name of the volume
- name: my-project-config
# Get a ConfigMap with this name and attach to this volume
configMap:
name: my-project-config
And my configMap for reference:
kind: ConfigMap
apiVersion: v1
data:
application.properties: |-
# This comment means that this is coming from k8s ConfigMap. Nice!
server.port=8999
.
.
.
.
metadata:
name: my-project-config
namespace: my-cluster
Any help is greatly appreciated... Thank you so much.. :)

The thing is that /src/main/resources/application.properties that your application uses is the one that is inside the jar file by default. If you open your jar, you should see it there.
That being said, your expectations to mount a /src/main/resources directory where your jar is are not going to be fulfilled, unfortunately.
These are the docs you should be looking at.
I won't go into much detail as it's explained pretty good in the docs but I will say that you are better off explicitly declaring your config location so that new people on the project know from where the config is coming from right off the bat.
You can do something like this:
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-project-api
labels:
app: my-project-api
spec:
selector:
matchLabels:
app: my-project-api
template:
metadata:
labels:
app: my-project-api
spec:
containers:
- name: my-project-api
image: "my-project:latest"
imagePullPolicy: Always
env:
- name: JAVA_OPTS
value: "-Dspring.config.location=/opt/config"
.
.
.
volumeMounts:
- name: my-project-config
mountPath: /opt/config
ports:
- containerPort: 8080
volumes:
- name: my-project-config
configMap:
name: my-project-config
Hope that helps,
Cheers!

I did slightly differently. I made sure I have mounted application.properties at config/. i.e; below is my example mounted application.properties (below commands show the values in pod - i.e; after kubectl exec -it into the pod)
/ # pwd
/
/ # cat config/application.properties
logback.access.enabled=false
management.endpoints.web.exposure.include=health, loggers, beans, configprops, env
Basically, the trick is based on the link in the above answer. Below is an excerpt from the link in which it does say application.properties will be picked from config/. So, I made sure my environment (dev, test, prod) specific config map was mounted at config/. Do note there is precedence for the below list (per the link: locations higher in the list override lower items)
A /config subdir of the current directory.
The current directory
A classpath /config package
The classpath root
Below is the config map definition (just pasted data section)
data:
application.properties: |+
logback.access.enabled={{.Values.logacbkAccessEnabled}}
management.endpoints.web.exposure.include=health, loggers, beans, configprops, env
And you can also see from actuator/env endpoint SpringBootApp did pick those values.
{
"name": "Config resource 'file [config/application.properties]' via location 'optional:file:./config/'",
"properties": {
"logback.access.enabled": {
"value": "false",
"origin": "URL [file:config/application.properties] - 1:24"
},
"management.endpoints.web.exposure.include": {
"value": "health, loggers, beans, configprops, env",
"origin": "URL [file:config/application.properties] - 2:43"
}
}
},

kubernetes failed to start pod due to ContainerCannotRun

I am new to kubernetes. Recently set up kubernetes cluster with 1 master and 1 node.
I am able to start a docker container by running
sudo docker run <docker-image> in my node machine.
But i failed to start docker container as a pod using kubernetes yml file.
by running sudo kubectl create -f deployment.yml
I describe the pod information and saw this error message.
Last State: Terminated
Reason: ContainerCannotRun
Message: OCI runtime create failed: container_linux.go:345: starting container process caused "exec: \"HOSTNAME\": executable file not found in $PATH": unknown
Exit Code: 128
docker container supposes to start a java executable.
this is my deployment file
kind: Service
apiVersion: v1
metadata:
name: service1-service
spec:
selector:
app: service1
ports:
- protocol: "TCP"
# Port accessible inside cluster
port: 26666
# Port to forward to inside the pod
targetPort: 26666
# Port accessible outside cluster
nodePort: 26666
type: LoadBalancer
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: service1-depolyment
spec:
selector:
matchLabels:
app: service1
replicas: 1
template:
metadata:
labels:
app: service1
spec:
containers:
- name: service1
image: service1-docker-image
imagePullPolicy: Never
ports:
- containerPort: 26666
# args: ["HOSTNAME", "KUBERNETES_PORT"]
In this deployment file, I try to create a nginx and one java web applicaition service.
It is because i defined wrong apiVersion and kind ?
Any help would be appreciated.

Look at this error exec: \"HOSTNAME\": executable file not found in $PATH
I had a similar error since the container could not locate the docker "CMD" binary since I gave it the wrong path. Check the path to the file and that should do the trick.

Programmatically get the name of the pod that a container belongs to in Kubernetes?

Is there a way to programmatically get the name of the pod that a container belongs to in Kubernetes? If so how? I'm using fabric8's java client but curl or something similar will be fine as well.
Note that I don't want to find the pod using a specific label since then (I assume) I may not always find the right pod if it's scaled with a replication controller.

You can tell Kubernetes to put the pod name in an environment variable of your choice using the downward API.
For example:
apiVersion: v1
kind: Pod
metadata:
name: dapi-test-pod
spec:
containers:
- name: test-container
image: gcr.io/google_containers/busybox
command: [ "/bin/sh", "-c", "env" ]
env:
- name: MY_POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: MY_POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: MY_POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
restartPolicy: Never

The pod name is written to /etc/hostname so it's possible to read it from there. In Java (which I'm using) you can also get the hostname (and thus the name of the pod) by calling System.getenv("HOSTNAME").