I'm supposed to make a StatefulSet with a Headless Service but when I make the Headless Service and create the StatefulSet only one pod gets made but with Error status and I get this error when trying to use kubectl log:
serviceName environment variable doesn't exist! Fix your specification.
Here is my code:
apiVersion: v1
kind: Service
metadata:
name: svc-hl-xyz
spec:
clusterIP: None
selector:
app: svc-hl-xyz
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: sts-xyz
spec:
replicas: 3
serviceName: "svc-hl-xyz"
selector:
matchLabels:
app: svc-hl-xyz
template:
metadata:
labels:
app: svc-hl-xyz
spec:
containers:
- name: ctr-sts-xyz
image: XXX/XXX/XXX
command: ["XXX", "XXX","XXX"]
My specification seems to follow the Kubernetes documentation for StatefulSet so I'm not sure why it doesn't work. All I can think of is that the command or the image I'm trying to use is causing this somehow.
The container logs (serviceName environment variable doesn't exist! Fix your specification.) tell you that the serviceName environment variable is missing.
Add it to the container spec in your statefulset:
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: sts-xyz
spec:
replicas: 3
serviceName: "svc-hl-xyz"
selector:
matchLabels:
app: svc-hl-xyz
template:
metadata:
labels:
app: svc-hl-xyz
spec:
containers:
- name: ctr-sts-xyz
image: quay.io/myafk/interactive:stable
command: ["interactive", "workloads","-t=first"]
env:
- name: serviceName
value: svc-hl-xyz
More information about env variables on Pods can be found in the docs
After setup my kubernetes cluster on GCP i used command kubectl scale deployment superappip--replicas=30 from google console to scale my deployments, but what should be added in my deployment file myip-service.yaml to do the same?
The following is an example of a Deployment. It creates a ReplicaSet to bring up three nginx Pods
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
you can follow more here.
I'm trying to deploy this yaml in my kubernetes cluster into one of my nodes
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-1
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
But when I try to deploy it with the command, I get this error message
pi#k8s-master-rasp4:~ $ kubectl apply -f despliegue-nginx.yaml -l kubernetes.io/hostname=k8s-worker-1
error: no objects passed to apply
Anyone knows where the problem could be?
Thanks
You are not allowed to use label selector (-l) with kubectl apply....
Use nodeSelector to assign pods to specific nodes:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment-1
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
nodeSelector:
kubernetes.io/hostname: k8s-worker-1 # <-- updated here!
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
I am setting up the kubernetes setup for django webapp.
I am passing environment variable while creating deployment as below
kubectl create -f deployment.yml -l key1=value1
I am getting error as below
error: no objects passed to create
Able to create the deployment successfully, If i remove the env variable -l key1=value1 while creating deployment.
deployment.yaml as below
#Deployment
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
service: sigma-service
name: $key1
What will be the reason for causing the above error while creating deployment?
I used envsubst (https://www.gnu.org/software/gettext/manual/html_node/envsubst-Invocation.html) for this. Create a deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: $NAME
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
Then:
export NAME=my-test-nginx
envsubst < deployment.yaml | kubectl apply -f -
Not sure what OS are you using to run this. On macOS, envsubst installed like:
brew install gettext
brew link --force gettext
This isn't a right way to use the deployment, you can't provide half details in yaml and half in kubectl commands. If you want to pass environment variables in your deployment you should add those detail in the deployment spec.template.spec:
You should add following block to your deployment.yaml
spec:
containers:
- env:
- name: var1
value: val1
This will export your environment variables inside the container.
The other way to export the environment variable is use kubectl run (not advisable) as it is going to be depreciated very soon. You can use following command:
kubectl run nginx --image=nginx --restart=Always --replicas=1 --env=var1=val1
The above command will create a deployment nginx with replica 1 and environment variable var1=val1
You cannot pass variables to "kubectl create -f". YAML files should be complete manifests without variables. Also you cannot use "-l" flag to "kubectl create -f".
If you want to pass environment variables to pod you should do like that:
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
env:
- name: MY_VAT
value: MY_VALUE
ports:
- containerPort: 80
Read more here: https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/
Follow the below steps
create test-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: MYAPP
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
using sed command you can update the deployment name at deployment time
sed -e 's|MYAPP|my-nginx|g' test-deploy.yaml | kubectl apply -f -
File: ./deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: MYAPP
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
File: ./service.yaml
apiVersion: v1
kind: Service
metadata:
name: MYAPP
labels:
app: nginx
spec:
type: ClusterIP
ports:
- port: 80
selector:
app: nginx
File: ./kustomization.yaml
resources:
- deployment.yaml
- service.yaml
If you're using https://kustomize.io/, you can do this trick in a CI:
sh '( echo "images:" ; echo " - name: $IMAGE" ; echo " newTag: $VERSION" ) >> ./kustomization.yaml'
sh "kubectl apply --kustomize ."
I chose yq since it is yaml aware and gives a precise control where text substitutions happen.
To set an image from bash env var:
export IMAGE="your_image:latest"
yq eval '.spec.template.spec.containers[0].image = "'$IMAGE'"' manifests/daemonset.yaml | kubectl apply -f -
yq is available on MacPorts (as of 19/04/21 v4.4.1) with sudo port install yq
I was facing the same problem. I created a python script to change simple/complex or add values to the YAML file.
This became very handy in a similar situation that you describe. Also, switching to the python domain can allow for more complex scenarios.
The code and how to use it are available at this gist.
https://gist.github.com/washraf/f81153270c80b0b4ecf90a53872abde7
Please try following
apiVersion: apps/v1
kind: Deployment
metadata:
namespace: kdpd00201
name: frontend
labels:
app: nginx
spec:
replicas: 6
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: frontend
image: ifccncf/nginx:1.14.2
ports:
- containerPort: 8001
env:
- name: NGINX_PORT
value: "8001"
My solution is then
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: frontend
name: frontend
namespace: kdpd00201
spec:
replicas: 4
selector:
matchLabels:
app: frontend
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: frontend
spec:
containers:
- env: # modified level
- name: NGINX_PORT
value: "8080"
image: lfccncf/nginx:1.13.7
name: nginx
ports:
- containerPort: 8080
I need to hard code the address of a couchDB instance to another server in my kubernetes cluster. I'm not super familiar with kubernetes but I know that IP will change each time the cluster is rebuilt or the pod is rebuilt. So I can't use that.
What is the URL to this kubernetes service/what should I hard code into my Server Docker Image so it will alway find the CouchDB server in the system. I think it will be in this format
<service-name>.<namespace>.svc.cluster.local:<service-port>
# YAML for launching the server
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: kino-couch
labels:
app: kino-couch
spec:
serviceName: orderer
# Single instance of the Orderer Pod is needed
replicas: 1
selector:
matchLabels:
app: kino-couch
template:
metadata:
labels:
app: kino-couch
spec:
containers:
- name: kino-couch
ports:
- containerPort: 5984
# Image used
image: dpacchain/development:dpaccouch
If "wget 172.17.0.2:5984" works what should "172.17.0.2" be replaced with
The following is not correct
wget kino-couch-0.couch-service.default.svc.cluster.local:5984
wget kino-couch-0.couch-service.default.svc.cluster.local:5984
wget kino-couch-0.kino-couch.default.svc.cluster.local:5984
wget kino-couch-0.kino-couchdb.default.svc.cluster.local:5984
wget kino-couch-0.kino-couchdb.svc.cluster.local:5984
For StatefulSet you need to create a Headless service to be responsible for the network identity of the Pods proving stable DNS entries. Notice clusterIP: None in below example.
apiVersion: v1
kind: Service
metadata:
name: couch-service
labels:
app: kino-couch
spec:
ports:
- port: 5984
clusterIP: None
selector:
app: kino-couch
The statefulset need to refer to the above service in serviceName. So the statefulset yaml would look like below
# YAML for launching the server
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: kino-couch
labels:
app: kino-couch
spec:
serviceName: couch-service
# Single instance of the Orderer Pod is needed
replicas: 1
selector:
matchLabels:
app: kino-couch
template:
metadata:
labels:
app: kino-couch
spec:
containers:
- name: kino-couch
ports:
- containerPort: 5984
# Image used
image: dpacchain/development:dpaccouch
Then as a client you can access it using couch-service.<namespace>.svc.cluster.local:5984 to connect to a any of the CouchDB pods.
If you want to connect to a specific pod then use kino-couch-0.couch-service.<namespace>.svc.cluster.local:5984. This is typically needed for connecting the couchDB pods between themselves to create a cluster.