I have a Wordpress pod that doesn't connect to my SQL DB pod. The wordpress mysql deployment is called wordpress-mysql so the referencing is correct. This is the message that appears.
Complete! WordPress has been successfully copied to /var/www/html
Warning: mysqli::mysqli(): php_network_getaddresses: getaddrinfo
failed: Name or service not known in - on line 22
Warning: mysqli::mysqli(): (HY000/2002): php_network_getaddresses:
getaddrinfo failed: Name or service not known in - on line 22
MySQL Connection Error: (2002) php_network_getaddresses: getaddrinfo
failed: Name or service not known
This is the code for the wordpress.yaml file:
apiVersion: v1
kind: Service
metadata:
name: frontend
spec:
selector:
app: wordpress
ports:
- name: web
port: 80
targetPort: 80
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: wp-pv-claim
labels:
app: nginx
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
storageClassName: do-block-storage
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: frontend
spec:
rules:
- host: test.example.services
http:
paths:
- path: /
backend:
serviceName: frontend
servicePort: web
---
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
name: wordpress
labels:
app: wordpress
spec:
selector:
matchLabels:
app: wordpress
tier: frontend
strategy:
type: Recreate
template:
metadata:
labels:
app: wordpress
tier: frontend
spec:
containers:
- image: wordpress:4.8-apache
name: wordpress
env:
- name: WORDPRESS_DB_HOST
value: wordpress-mysql
- name: WORDPRESS_DB_PASSWORD
valueFrom:
secretKeyRef:
name: mysql-pass
key: password
ports:
- containerPort: 80
name: wordpress
volumeMounts:
- name: wordpress-persistent-storage
mountPath: /var/www/html
volumes:
- name: wordpress-persistent-storage
persistentVolumeClaim:
claimName: wp-pv-claim
The following is an output from kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
frontend ClusterIP 10.245.131.56 <none> 80/TCP 4m25s
kubernetes ClusterIP 10.245.0.1 <none> 443/TCP 9m46s
wordpress-mysql ClusterIP None <none> 3306/TCP 5m16s
MySQL Service YAML:
apiVersion: v1
kind: Service
metadata:
name: wordpress-mysql
labels:
app: wordpress
spec:
ports:
- port: 3306
selector:
app: wordpress
tier: mysql
clusterIP: None
Related
I have several microservices, each one with its own mongodb deployment. I would like to start with getting my auth service working with a persistent volume. I have watched courses where postgresql is used and read a lot in the kubernetes docs but am having trouble getting this to work for mongodb.
When I run skaffold dev the PVC is created with no errors. kubectl shows the PVC is in Bound status, and running describe on the PVC shows my mongo deployment as the user.
However, when I visit my client service in the browser, I signup, logout, signin again with no problem and then if I restart skaffold so it deletes and recreates the containers my data is gone and I have to signup again.
Here are my files
auth-mongo-depl.yaml
# auth-mongo service base deployment configuration
apiVersion: apps/v1
kind: Deployment
metadata:
name: auth-mongo-depl
spec:
replicas: 1
selector:
matchLabels:
app: auth-mongo
template:
metadata:
labels:
app: auth-mongo
spec:
volumes:
- name: auth-mongo-data
persistentVolumeClaim:
claimName: auth-mongo-pvc
containers:
- name: auth-mongo
image: mongo
ports:
- containerPort: 27017
name: 'auth-mongo-port'
volumeMounts:
- name: auth-mongo-data
mountPath: '/data/db'
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-mongo-ip-srv
spec:
selector:
app: auth-mongo
type: ClusterIP
ports:
- name: auth-mongo-db
protocol: TCP
port: 27017
targetPort: 27017
---
# Persistent Volume Claim
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: auth-mongo-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 500Mi
auth-depl.yaml
# auth service base deployment configuration
apiVersion: apps/v1
kind: Deployment
metadata:
name: auth-depl
spec:
replicas: 1
selector:
matchLabels:
app: auth
template:
metadata:
labels:
app: auth
spec:
containers:
- name: auth
image: isimmons33/ticketing-auth
env:
- name: MONGO_URI
value: 'mongodb://auth-mongo-ip-srv:27017/auth'
- name: JWT_KEY
valueFrom:
secretKeyRef:
name: jwt-secret
key: JWT_KEY
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-ip-srv
spec:
selector:
app: auth
type: ClusterIP
ports:
- name: auth
protocol: TCP
port: 3000
targetPort: 3000
api/users portion of my ingress-srv.yaml
- path: /api/users/?(.*)
pathType: Prefix
backend:
service:
name: auth-ip-srv
port:
number: 3000
My client fires off a post request to /api/users/auth with which I can successfully signup or signin as long as I don't restart skaffold.
I even used kubectl to get a shell into my mongo deployment and queried to see the new user account there as it should be. But of course it is gone after restarting skaffold.
I am on Windows 10 but am running everything through WSL2 (Ubuntu)
Thanks for any help
It is highly recommended to use StatefulSets for running databases in Kubernetes. In Deployment if your pod crashes for some reason and creates new one, it's not guaranteed the pod will get patched to the same PV, hence the you loose the data.
Have a look on this https://kubernetes.io/blog/2017/01/running-mongodb-on-kubernetes-with-statefulsets
The solution as pointed out by raghu_manne was to use StatefulSets. But because the link posted is extremely old, here is the full solution that worked for me.
Also here is a youtube video I just found that explains StatefulSet and volumeClaimTemplates quite well.
How to run MongoDB with StatefulSets in Kubernetes
auth-mongo-depl.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: auth-mongo-depl
spec:
replicas: 1
serviceName: auth-mongo
selector:
matchLabels:
app: auth-mongo
template:
metadata:
labels:
app: auth-mongo
spec:
containers:
- name: auth-mongo
image: mongo
ports:
- containerPort: 27017
volumeMounts:
- name: auth-mongo-data
mountPath: /data/db
volumeClaimTemplates:
- metadata:
name: auth-mongo-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 500Mi
---
# ClusterIp Service
apiVersion: v1
kind: Service
metadata:
name: auth-mongo-ip-srv
spec:
selector:
app: auth-mongo
type: ClusterIP
ports:
- name: auth-mongo-db
protocol: TCP
port: 27017
targetPort: 27017
I have created a kubernetes project in visual studio 2019, with the default template. This template creates a WeatherForecast controller.
After that I have published it to my ARC.
I used this command to create the AKS:
az aks create -n $MYAKS -g $MYRG --generate-ssh-keys --z 1 -s Standard_B2s --attach-acr /subscriptions/mysubscriptionguid/resourcegroups/$MYRG/providers/Microsoft.ContainerRegistry/registries/$MYACR
And I enabled HTTP application routing via the azure portal.
I have deployed it to azure kubernetes (Standard_B2s), with the following deployment.yaml:
# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: kubernetes1-deployment
labels:
app: kubernetes1-deployment
spec:
replicas: 2
selector:
matchLabels:
app: kubernetes1
template:
metadata:
labels:
app: kubernetes1
spec:
containers:
- name: kubernetes1
image: mycontainername.azurecr.io/kubernetes1:latest
ports:
- containerPort: 80
service.yaml:
#service.yaml
apiVersion: v1
kind: Service
metadata:
name: kubernetes1
spec:
type: ClusterIP
selector:
app: kubernetes1
ports:
- port: 80 # SERVICE exposed port
name: http # SERVICE port name
protocol: TCP # The protocol the SERVICE will listen to
targetPort: http # Port to forward to in the POD
ingress.yaml:
#ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: kubernetes1
annotations:
kubernetes.io/ingress.class: addon-http-application-routing
spec:
rules:
- host: kubernetes1.<uuid (removed for this post)>.westeurope.aksapp.io # Which host is allowed to enter the cluster
http:
paths:
- backend: # How the ingress will handle the requests
service:
name: kubernetes1 # Which service the request will be forwarded to
port:
name: http # Which port in that service
path: / # Which path is this rule referring to
pathType: Prefix # See more at https://kubernetes.io/docs/concepts/services-networking/ingress/#path-types
But when I go to kubernetes1..westeurope.aksapp.io or kubernetes1..westeurope.aksapp.io/WeatherForecast I get the following error:
503 Service Temporarily Unavailable
nginx/1.15.3
It's working now. For other people who have the same problem. I have updated my deployment config from:
# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: kubernetes1-deployment
labels:
app: kubernetes1-deployment
spec:
replicas: 2
selector:
matchLabels:
app: kubernetes1
template:
metadata:
labels:
app: kubernetes1
spec:
containers:
- name: kubernetes1
image: mycontainername.azurecr.io/kubernetes1:latest
ports:
- containerPort: 80
to:
# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: kubernetes1
spec:
selector: # Define the wrapping strategy
matchLabels: # Match all pods with the defined labels
app: kubernetes1 # Labels follow the `name: value` template
template: # This is the template of the pod inside the deployment
metadata:
labels:
app: kubernetes1
spec:
nodeSelector:
kubernetes.io/os: linux
containers:
- image: mycontainername.azurecr.io/kubernetes1:latest
name: kubernetes1
resources:
requests:
cpu: 100m
memory: 128Mi
limits:
cpu: 250m
memory: 256Mi
ports:
- containerPort: 80
name: http
I don't know exactly which line solved the problem. Feel free to comment it if you know which line the problem was.
I read the following kubernetes docs which resulted in the following yaml's to run postgresql & pgadmin in a cluster:
--- pgadmin-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: pgadmin-deployment
spec:
replicas: 1
selector:
matchLabels:
app: pgadmin-pod
template:
metadata:
labels:
app: pgadmin-pod
spec:
containers:
- name: pgadmin-container
image: dpage/pgadmin4
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 80
env:
- name: PGADMIN_DEFAULT_EMAIL
value: email#example.com
- name: PGADMIN_DEFAULT_PASSWORD
value: password
--- pgadmin-service.yaml
apiVersion: v1
kind: Service
metadata:
name: pgadmin-service
spec:
type: NodePort
ports:
- port: 30000
targetPort: 80
selector:
app: pgadmin-pod
--- postgres-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres-deployment
spec:
replicas: 1
selector:
matchLabels:
app: postgres-pod
template:
metadata:
labels:
app: postgres-pod
spec:
containers:
- name: postgres-container
image: postgres:9.6-alpine
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
env:
- name: POSTGRES_DB
value: database
- name: POSTGRES_PASSWORD
value: password
- name: POSTGRES_USER
value: username
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgrepvc
volumes:
- name: postgrepvc
persistentVolumeClaim:
claimName: postgres-pv-claim
--- postgres-service.yaml
apiVersion: v1
kind: Service
metadata:
name: postgres-service
spec:
type: NodePort
ports:
- port: 30001
targetPort: 5432
selector:
app: postgres-pod
--- postgres-storage.yaml
postgres-storage.yaml
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: manual
capacity:
storage: 5Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: manual
accessModes:
- ReadWriteMany
resources:
requests:
storage: 5Gi
I then run the following command kubectl create -f ./ which results in the following:
kubernetes pods / svc's
Then I try to access pgAdmin on 10.43.225.170:30000 from outside of the cluster, but I get "10.43.225.170 took too long to respond." no matter what I try.
So how do I expose pgAdmin & postgress to the outside world, and is there a way to give them static ip's so I don't have to update ip's in connection strings each time I re-deploy on kubernetes, or do I have to use statefulset for this?
Problems here
you are trying to reach node internal ip 10.43.225.170 instead of external one.
nodePort service configured incorrectly. In addition you are trying to call incorrect port
You haven't specified what platform you use. I'm using GKE, so in my case its easier because I have external IP's automatically assigned during cluster node creation. But I had to manually create ingress firewall rule to allow access from outside to nodes and required ports (30000,30001)
In any case, to be able to use nodePort - you should have external IP address assigned to one of the nodes in cluster and a Firewall rule that allows ingress traffic to that port
Going next. You are trying to call <NodeIP>:spec.ports[*].port.
As per Type NodePort documentation:
Service is visible as <NodeIP>:spec.ports[*].nodePort
You need explicitly specify nodePort
I have changed a bit your deployment, can access pgAdmin after deploying it and opening corresponding ports in firewall.
apiVersion: apps/v1
kind: Deployment
metadata:
name: pgadmin-deployment
spec:
replicas: 1
selector:
matchLabels:
app: pgadmin-pod
template:
metadata:
labels:
app: pgadmin-pod
spec:
containers:
- name: pgadmin-container
image: dpage/pgadmin4
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 80
env:
- name: PGADMIN_DEFAULT_EMAIL
value: email#example.com
- name: PGADMIN_DEFAULT_PASSWORD
value: password
---
apiVersion: v1
kind: Service
metadata:
name: pgadmin-service
spec:
type: NodePort
ports:
- nodePort: 30000
targetPort: 80
port: 80
selector:
app: pgadmin-pod
--- postgres-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres-deployment
spec:
replicas: 1
selector:
matchLabels:
app: postgres-pod
template:
metadata:
labels:
app: postgres-pod
spec:
containers:
- name: postgres-container
image: postgres:9.6-alpine
imagePullPolicy: "IfNotPresent"
ports:
- containerPort: 5432
env:
- name: POSTGRES_DB
value: database
- name: POSTGRES_PASSWORD
value: password
- name: POSTGRES_USER
value: username
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgrepvc
volumes:
- name: postgrepvc
persistentVolumeClaim:
claimName: postgres-pv-claim
---
apiVersion: v1
kind: Service
metadata:
name: postgres-service
spec:
type: NodePort
ports:
- nodePort: 30001
targetPort: 5432
port: 5432
selector:
app: postgres-pod
---
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: manual
capacity:
storage: 5Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: manual
accessModes:
- ReadWriteMany
resources:
requests:
storage: 5Gi
Check:
kubectl apply -f pg_my.yaml
deployment.apps/pgadmin-deployment created
service/pgadmin-service created
service/postgres-service created
persistentvolume/postgres-pv-volume created
persistentvolumeclaim/postgres-pv-claim created
#In my case I take node external ip from any node from `kubectl get nodes -o wide` output:
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP
gke-cluster-1-default-pool-*******-***** Ready <none> 20d v1.18.16-gke.502 10.186.0.7 *.*.*.*
curl *.*.*.*:30000
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>Redirecting...</title>
<h1>Redirecting...</h1>
<p>You should be redirected automatically to target URL: /login?next=%2F.
I am developing a simple web app with web service and persistent layer. Web persistent layer is Cockroach db. I am trying to deploy my app with single command:
kubectl apply -f my-app.yaml
App is deployed successfully. However when backend has to store something in db the following error appears:
dial tcp: lookup web-service-cockroach on 192.168.65.1:53: no such host
When I start my app I provide the following connection string to cockroach db and connection is successful but when I try to store something in db the above error appears:
postgresql://root#web-service-db:26257/defaultdb?sslmode=disable
For some reason web pod can not talk with db pod. My whole configuration is:
# Service for web application
apiVersion: v1
kind: Service
metadata:
name: web-service
spec:
selector:
app: web-service
type: NodePort
ports:
- protocol: TCP
port: 8080
targetPort: http
nodePort: 30103
externalIPs:
- 192.168.1.9 # < - my local ip
---
# Deployment of web app
apiVersion: apps/v1
kind: Deployment
metadata:
name: web-service
spec:
selector:
matchLabels:
app: web-service
replicas: 1
template:
metadata:
labels:
app: web-service
spec:
hostNetwork: true
containers:
- name: web-service
image: my-local-img:latest
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 8080
hostPort: 8080
env:
- name: DB_CONNECT_STRING
value: "postgresql://root#web-service-db:26257/defaultdb?sslmode=disable"
---
### Kubernetes official doc PersistentVolume
apiVersion: v1
kind: PersistentVolume
metadata:
name: cockroach-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/tmp/my-local-volueme"
---
### Kubernetes official doc PersistentVolumeClaim
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: cockroach-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 4Gi
---
# Cockroach used by web-service
apiVersion: v1
kind: Service
metadata:
name: web-service-cockroach
labels:
app: web-service-cockroach
spec:
selector:
app: web-service-cockroach
type: NodePort
ports:
- protocol: TCP
port: 26257
targetPort: 26257
nodePort: 30104
---
# Cockroach stateful set used to deploy locally
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: web-service-cockroach
spec:
serviceName: web-service-cockroach
replicas: 1
selector:
matchLabels:
app: web-service-cockroach
template:
metadata:
labels:
app: web-service-cockroach
spec:
volumes:
- name: cockroach-pv-storage
persistentVolumeClaim:
claimName: cockroach-pv-claim
containers:
- name: web-service-cockroach
image: cockroachdb/cockroach:latest
command:
- /cockroach/cockroach.sh
- start
- --insecure
volumeMounts:
- mountPath: "/tmp/my-local-volume"
name: cockroach-pv-storage
ports:
- containerPort: 26257
After deployment everything looks good.
kubectl get service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 50m
web-service NodePort 10.111.85.64 192.168.1.9 8080:30103/TCP 6m17s
webs-service-cockroach NodePort 10.96.42.121 <none> 26257:30104/TCP 6m8s
kubectl get pods
NAME READY STATUS RESTARTS AGE
web-service-6cc74b5f54-jlvd6 1/1 Running 0 24m
web-service-cockroach-0 1/1 Running 0 24m
Thanks in advance!
Looks like you have a problem with DNS.
dial tcp: lookup web-service-cockroach on 192.168.65.1:53: no such host
Address 192.168.65.1 does not like a kube-dns service ip.
This could be explaind if you where using host network, and surprisingly you do.
When using hostNetwork: true, the default dns server used is the server that the host uses and that never is a kube-dns.
To solve it set:
spec:
dnsPolicy: ClusterFirstWithHostNet
It sets the dns server to the k8s one for the pod.
Have a look at kubernetes documentaion for more information about Pod's DNS Policy.
I am working on creating a nexus repo through kubernetes. By browesing i came across this site (https://blog.sonatype.com/kubernetes-recipe-sonatype-nexus-3-as-a-private-docker-registry) I was able to create a service and deployment and pod and everthing created without am issue. But i was not able to open it.
This is my nexus.yaml file
apiVersion: v1
kind: Namespace
metadata:
name: nexus
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: nexusvolume-local
namespace: nexus
labels:
app: nexus
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 3Gi
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nexus
namespace: nexus
spec:
replicas: 1
template:
metadata:
labels:
app: nexus
spec:
containers:
- image: sonatype/nexus3
imagePullPolicy: Always
name: nexus
ports:
- containerPort: 8081
- containerPort: 5000
volumeMounts:
- mountPath: /nexus-data
name: nexus-data-volume
volumes:
- name: nexus-data-volume
persistentVolumeClaim:
claimName: nexusvolume-local
---
apiVersion: v1
kind: Service
metadata:
name: nexus-service
namespace: nexus
spec:
ports:
- port: 80
targetPort: 8081
protocol: TCP
name: http
- port: 5000
targetPort: 5000
protocol: TCP
name: docker
selector:
app: nexus
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nexus-ingress
namespace: nexus
annotations:
ingress.kubernetes.io/proxy-body-size: 100m
kubernetes.io/tls-acme: "true"
kubernetes.io/ingress.class: "nginx"
spec:
tls:
- hosts:
# CHANGE ME
- docker.testnexusurl.com
- nexus.testnexusurl.com
secretName: nexus-tls
rules:
# CHANGE ME
- host: nexus.testnexusurl.com
http:
paths:
- path: /
backend:
serviceName: nexus-service
servicePort: 80
# CHANGE ME
- host: docker.testnexusurl.com
http:
paths:
- path: /
backend:
serviceName: nexus-service
servicePort: 5000
When i give
kubectl describe service nexus-service -n nexus
Name: nexus-service
Namespace: nexus
Labels: <none>
Annotations: <none>
Selector: app=nexus
Type: ClusterIP
IP: 10.111.212.3
Port: http 80/TCP
TargetPort: 8081/TCP
Endpoints: 172.17.0.11:8081
Port: docker 5000/TCP
TargetPort: 5000/TCP
Endpoints: 172.17.0.11:5000
Session Affinity: None
Events: <none>
I tried by giving the port and opening but i am getting a error it can reached.
Can someone help me on this???
Thanks in advance.
After looking at the above yml file, there you have written namespace as "nexus", try running by changing namespace to "default".