I have a Kubernetes template file that contains multiple temples inside for example:
apiVersion: v1
kind: ConfigMap
metadata:
name: logstash-config
namespace: elastic-foo
data:
logstash.yml: |
http.host: "0.0.0.0"
path.config: /usr/share/logstash/pipeline
logstash.conf: |
# all input will come from filebeat, no local logs
input {
}
filter {
}
output {
}
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: logstash-deployment
namespace: elastic-foo
spec:
replicas: 1
selector:
matchLabels:
app: logstash
template:
metadata:
labels:
app: logstash
spec:
containers:
- name: logstash
image: docker.elastic.co/logstash/logstash:7.10.1
env:
ports:
- containerPort: 5044
volumeMounts:
- name: config-volume
mountPath: /usr/share/logstash/config
- name: logstash-pipeline-volume
mountPath: /usr/share/logstash/pipeline
volumes:
- name: config-volume
configMap:
name: logstash-config
items:
- key: logstash.yml
path: logstash.yml
- name: logstash-pipeline-volume
configMap:
name: logstash-config
items:
- key: logstash.conf
path: logstash.conf
---
kind: Service
apiVersion: v1
metadata:
name: logstash-service
namespace: elastic-foo
spec:
selector:
app: logstash
ports:
- protocol: TCP
port: 5044
targetPort: 5044
type: ClusterIP
My question is, how can I execute only one template by name
for example :
kubectl create -f Service or Deployment or ConfigMap -f my_config.yml
That is not a feature of Kubectl. You can split them into different files or pipe through a tool like yq and use kubectl create -f -.
Related
I have a mongo yaml and web-app(NodeJS) yaml set up like this:
mongo-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: mongo-config
data:
mongo-url: mongo-service
mongo-secret.yaml
apiVersion: v1
kind: Secret
metadata:
name: mongo-secret
type: Opaque
data:
mongo-user: bW9uZ291c2Vy
mongo-password: bW9uZ29wYXNzd29yZA==
mongo.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: mongo-deployment
labels:
app: mongo
spec:
replicas: 1
selector:
matchLabels:
app: mongo
# blueprint for pods, creates pods with mongo:5.0 image
template:
metadata:
labels:
app: mongo
spec:
containers:
- name: mongodb
image: mongo:5.0
ports:
- containerPort: 27017
env:
- name: MONGO_INITDB_ROOT_USERNAME
valueFrom:
secretKeyRef:
name: mongo-secret
key: mongo-user
- name: MONGO_INITDB_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mongo-secret
key: mongo-password
---
# kind: service
# name: any
# selector: select pods to forward the requests to
apiVersion: v1
kind: Service
metadata:
name: mongo-service
spec:
selector:
app: mongo
ports:
- protocol: TCP
port: 8080
targetPort: 27017
and the webapp.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: webapp-deployment
labels:
app: webapp
spec:
replicas: 1
selector:
matchLabels:
app: webapp
# blueprint for pods, creates pods with mongo:5.0 image
template:
metadata:
labels:
app: webapp
spec:
containers:
- name: webapp
image: nanajanashia/k8s-demo-app:v1.0
ports:
- containerPort: 3000
env:
- name: USER_NAME
valueFrom:
secretKeyRef:
name: mongo-secret
key: mongo-user
- name: USER_PWD
valueFrom:
secretKeyRef:
name: mongo-secret
key: mongo-password
- name: DB_URL
valueFrom:
configMapKeyRef:
name: mongo-config
key: mongo-url
---
# kind: service
# name: any
# selector: select pods to forward the requests to
apiVersion: v1
kind: Service
metadata:
name: webapp-service
spec:
# default ClusterIP
# nodeport = external service
type: NodePort
selector:
app: webapp
ports:
- protocol: TCP
port: 3000
targetPort: 3000
nodePort: 30100
I ran the commands for each file
kubectl apply -f
i checked the status of the webapp which returned:
app listening on port 3000!
I got the IP address by
minikube ip
and the port was 30100
Why cannot not I access this web app?
I get a site cant be reached error.
If you are on Mac, check your minikube driver. I had to stop, delete minikube, then restart while specifying the hyperkit driver like so.
minikube stop
minikube delete
docker start --vm-driver=hyperkit
The information listed here is pretty useful too.
I deployed a logstash by statefulset kind with 3 replicas in k8s. Using filebeat to send data to it.
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: logstash-nginx
spec:
serviceName: "logstash"
selector:
matchLabels:
app: logstash
updateStrategy:
type: RollingUpdate
replicas: 3
template:
metadata:
labels:
app: logstash
spec:
containers:
- name: logstash
image: docker.elastic.co/logstash/logstash:7.10.0
resources:
limits:
memory: 2Gi
ports:
- containerPort: 5044
volumeMounts:
- name: config-volume
mountPath: /usr/share/logstash/config
- name: logstash-pipeline-volume
mountPath: /usr/share/logstash/pipeline
command: ["/bin/sh","-c"]
args:
- bin/logstash -f /usr/share/logstash/pipeline/logstash.conf;
volumes:
- name: config-volume
configMap:
name: logstash-configmap
items:
- key: logstash.yml
path: logstash.yml
- name: logstash-pipeline-volume
configMap:
name: logstash-configmap
items:
- key: logstash.conf
path: logstash.conf
Logstash's service
---
apiVersion: v1
kind: Service
metadata:
labels:
app: logstash
name: logstash
spec:
ports:
- name: "5044"
port: 5044
targetPort: 5044
selector:
app: logstash
Filebeat's daemonset configmap
---
apiVersion: v1
kind: ConfigMap
metadata:
name: filebeat-config
labels:
k8s-app: filebeat
data:
filebeat.yml: |-
...
output.logstash:
hosts: ["logstash.default.svc.cluster.local:5044"]
loadbalance: true
bulk_max_size: 1024
When run real data. Most data went to the second logstash's pod. Sometimes data also can go to the first and the third pods but very little occurs.
Use another way to set LB from filebeat
---
apiVersion: v1
kind: ConfigMap
metadata:
name: filebeat-config
labels:
k8s-app: filebeat
data:
filebeat.yml: |-
...
output.logstash:
hosts: ["logstash-nginx-0.logstash.default.svc.cluster.local:5044", "logstash-nginx-1.logstash.default.svc.cluster.local:5044", "logstash-nginx-2.logstash.default.svc.cluster.local:5044"]
loadbalance: true
bulk_max_size: 1024
Logstash's configmap
---
apiVersion: v1
kind: ConfigMap
metadata:
name: logstash-configmap
data:
logstash.yml: |
http.host: "0.0.0.0"
path.config: /usr/share/logstash/pipeline
xpack.monitoring.enabled: false
From the filebeat pod, it can access URIs by curl:
logstash-nginx-0.logstash.default.svc.cluster.local:5044
logstash-nginx-1.logstash.default.svc.cluster.local:5044
logstash-nginx-2.logstash.default.svc.cluster.local:5044
But the data can't be sent by filebeat to logstash's 3 pods at all. No traffic in the logstash's output logs. Where is wrong?
I don't see an option to mount a configMap as volume in the statefulset , as per https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.17/#statefulset-v1-apps only PVC can be associated with "StatefulSet" . But PVC does not have option for configMaps.
Here is a minimal example:
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: example
spec:
selector:
matchLabels:
app: example
serviceName: example
template:
metadata:
labels:
app: example
spec:
containers:
- name: example
image: nginx:stable-alpine
volumeMounts:
- mountPath: /config
name: example-config
volumes:
- name: example-config
configMap:
name: example-configmap
---
apiVersion: v1
kind: ConfigMap
metadata:
name: example-configmap
data:
a: "1"
b: "2"
In the container, you can find the files a and b under /config, with the contents 1 and 2, respectively.
Some explanation:
You do not need a PVC to mount the configmap as a volume to your pods. PersistentVolumeClaims are persistent drives, which you can read from/write to. An example for their usage is a database, such as Postgres.
ConfigMaps on the other hand are read-only key-value structures that are stored inside Kubernetes (in its etcd store), which are to store the configuration for your application. Their values can be mounted as environment variables or as files, either individually or altogether.
I have done it in this way.
apiVersion: v1
kind: ConfigMap
metadata:
name: rabbitmq-configmap
namespace: default
data:
enabled_plugins: |
[rabbitmq_management,rabbitmq_shovel,rabbitmq_shovel_management].
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: rabbitmq
labels:
component: rabbitmq
spec:
serviceName: "rabbitmq"
replicas: 1
selector:
matchLabels:
component: rabbitmq
template:
metadata:
labels:
component: rabbitmq
spec:
initContainers:
- name: "rabbitmq-config"
image: busybox:1.32.0
volumeMounts:
- name: rabbitmq-config
mountPath: /tmp/rabbitmq
- name: rabbitmq-config-rw
mountPath: /etc/rabbitmq
command:
- sh
- -c
- cp /tmp/rabbitmq/rabbitmq.conf /etc/rabbitmq/rabbitmq.conf && echo '' >> /etc/rabbitmq/rabbitmq.conf;
cp /tmp/rabbitmq/enabled_plugins /etc/rabbitmq/enabled_plugins
volumes:
- name: rabbitmq-config
configMap:
name: rabbitmq-configmap
optional: false
items:
- key: enabled_plugins
path: "enabled_plugins"
- name: rabbitmq-config-rw
emptyDir: {}
containers:
- name: rabbitmq
image: rabbitmq:3.8.5-management
env:
- name: RABBITMQ_DEFAULT_USER
value: "username"
- name: RABBITMQ_DEFAULT_PASS
value: "password"
- name: RABBITMQ_DEFAULT_VHOST
value: "vhost"
ports:
- containerPort: 15672
name: ui
- containerPort: 5672
name: api
volumeMounts:
- name: rabbitmq-data-pvc
mountPath: /var/lib/rabbitmq/mnesia
volumeClaimTemplates:
- metadata:
name: rabbitmq-data-pvc
spec:
accessModes: [ "ReadWriteOnce" ]
resources:
requests:
storage: 2Gi
---
apiVersion: v1
kind: Service
metadata:
name: rabbitmq
spec:
selector:
component: rabbitmq
ports:
- protocol: TCP
port: 15672
targetPort: 15672
name: ui
- protocol: TCP
port: 5672
targetPort: 5672
name: api
type: ClusterIP
I'm trying to implement an ElasticStack in Kubernetes via Minikube. I've barely started, as I'm writing basically everything from scratch to get a better understand of K8s and because the provided yml's from Elastic don't offer any explanation as to what is done why, so I'm doing my own thing.
The problem I've ran into is that my Kibana-pod cannot communicate with my ElasticSearch-pod, although I've set up the necessary services and ports on my pods.
Where it gets weird is that
kubectl port-forward services/elastic-http 9200
works flawlessly and lets me get information from my ElasticSearch pod. However, when I enter a pod via
kubectl exec -it <pod-name> -- /bin/bash
and try to use curl to get the same information my browser just showed me, the connection is being refused and my pods won't talk to one another.
My configs look as follows.
Kibana.yml
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: my-kb
namespace: default
spec:
selector:
matchLabels:
app: kibana
template:
metadata:
name: kibana
labels:
app: kibana
spec:
containers:
- name: kibana
image: docker.elastic.co/kibana/kibana:7.3.0
ports:
- containerPort: 5601
name: kibana-web
volumeMounts:
- name: kb-conf
mountPath: /usr/share/kibana/config/kibana.yml
subPath: kibana.yml
volumes:
- name: kb-conf
configMap:
name: kibana-config
items:
- key: kibana.yml
path: kibana.yml
---
kind: Service
apiVersion: v1
metadata:
name: kibana-http
namespace: default
spec:
selector:
app: kibana
ports:
- protocol: TCP
port: 5601
name: kibana-web
---
kind: ConfigMap
apiVersion: v1
metadata:
name: kibana-config
namespace: default
data:
kibana.yml: |
elasticsearch.hosts: ["http://elastic-http.default.svc:9200"]
ElasticSearch.yml
kind: PersistentVolume
apiVersion: v1
metadata:
name: elastic-pv
namespace: default
spec:
capacity:
storage: 15Gi
accessModes:
- ReadWriteOnce
hostPath:
path: /data
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: elastic-pv-claim
namespace: default
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 15Gi
---
kind: Deployment
apiVersion: extensions/v1beta1
metadata:
name: elastic-deploy
namespace: default
spec:
selector:
matchLabels:
app: elasticsearch
template:
metadata:
name: elasticsearch
labels:
app: elasticsearch
spec:
containers:
- name: elasticsearch
image: docker.elastic.co/elasticsearch/elasticsearch:7.3.0
ports:
- containerPort: 9200
name: elastic-http
protocol: TCP
- containerPort: 9300
name: node-sniffer
protocol: TCP
#readinessProbe:
# httpGet:
# port: 9200
# periodSeconds: 5
volumeMounts:
- name: elastic-conf
mountPath: /usr/share/elasticsearch/config/elasticsearch.yml
subPath: elasticsearch.yml
- name: elastic-data
mountPath: /var/data
securityContext:
privileged: true
initContainers:
- name: sysctl-adj
image: busybox
command: ['sysctl', '-w', 'vm.max_map_count=262144']
securityContext:
privileged: true
volumes:
- name: elastic-data
persistentVolumeClaim:
claimName: elastic-pv-claim
- name: elastic-conf
configMap:
name: elastic-config
items:
- key: elasticsearch.yml
path: elasticsearch.yml
---
kind: Service
apiVersion: v1
metadata:
name: elastic-http
namespace: default
spec:
selector:
app: elasticsearch
ports:
- port: 9200
targetPort: elastic-http
name: elastic-http
- port: 9300
targetPort: node-sniffer
name: node-finder
---
kind: ConfigMap
apiVersion: v1
metadata:
name: elastic-config
namespace: default
data:
elasticsearch.yml: |
xpack.security.enabled: false
node.master: true
path.data: /var/data
http.port: 9200
I think you are having clusterIP service type and if you want to see it in browser one of the option is to have service type as NodePort.
You can see more details here
I'm not sure about this part in service:
targetPort: elastic-http
targetPort: node-sniffer
could you try to remove them and try again
I have an angular app and some node containers for backend, in my deployment file, how i can get container backed for connect my front end.
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: frontend
spec:
replicas: 1
template:
metadata:
labels:
app: frontend
spec:
containers:
- name: frontend
image: container_imaer_backend
env:
- name: IP_BACKEND
value: here_i_need_my_container_ip_pod
ports:
- containerPort: 80
protocol: TCP
I would recommend instead of using the IP to use the DNS Name there's more info here: https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/
But basically it's http://metadata-name.namespace.svc.cluster.local so in the case for that deployment it's http://frontend.default.svc.cluster.local
It's better this way because the local IP address can change.
You could use Pod field values for environment(ref: here). That way you can set POD IP in environment variable.
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: mysql
name: mysql
namespace: default
spec:
replicas: 1
selector:
matchLabels:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: mysql
image: mysql:5.6
imagePullPolicy: IfNotPresent
env:
- name: MYSQL_ROOT_PASSWORD
value: root
- name: POD_IP
valueFrom:
fieldRef:
apiVersion: v1
fieldPath: status.podIP
ports:
- containerPort: 3306
name: mysql
protocol: TCP
volumeMounts:
- mountPath: /var/lib/mysql
name: data
volumes:
- name: data
emptyDir: {}