While running a kubernetes on local with docker with the following command
kubectl -s http://localhost:8080 run-container nginx --image=nginx --port=80
following error is generated
Error from server: the server could not find the requested resource (post replicationControllers)
Could someone give me some pointers on how to resolve the problem.
Your help is highly appreciated
Firstly check docker service and apiserver is working correctly.
For apiserver: Use
curl http://localhost:8080/api/
Output:
{
"versions": [
"v1"
]
}
And, use
kubectl -s http://localhost:8080 run-container nginx -image=nginx:latest --port=80
or
kubectl -s http://localhost:8080 run-container nginx --image=nginx --port=80 --api-version="v1"
Add your own api-version on the last flag
Related
I'm creating a kind cluster with kind create cluster --name kind and I want to access it from another docker container but when I try to apply a Kubernetes file from a container (kubectl apply -f deployment.yml) I got this error:
The connection to the server 127.0.0.1:6445 was refused - did you specify the right host or port?
Indeed when I try to curl kind control-plane from a container, it's unreachable.
> docker run --entrypoint curl curlimages/curl:latest 127.0.0.1:6445
curl: (7) Failed to connect to 127.0.0.1 port 6445 after 0 ms: Connection refused
However kind control-plane is publishing to the right port but only to the localhost.
> docker ps --format "table {{.Image}}\t{{.Ports}}"
IMAGE PORTS
kindest/node:v1.23.4 127.0.0.1:6445->6443/tcp
Currently the only solution I found is to set the host network mode.
> docker run --network host --entrypoint curl curlimages/curl:latest 127.0.0.1:6445
Client sent an HTTP request to an HTTPS server.
This solution don't look to be the most secure. Is there another way like connecting the kind network to my container or something like that that I missed ?
Don't have enough rep to comment on the other answer, but wanted to comment on what ultimately worked for me.
Takeaways
Kind cluster running in it own bridge network kind
Service with kubernetes client running in another container with a mounted kube config volume
As described above the containers need to be in the same network unless you want your service to run in the host network.
The server address for the kubeconfig is the container name + internal port e.g. kind-control-plane:6443. The port is NOT the exposed port in the example below 6443 NOT 38669
CONTAINER ID IMAGE PORTS
7f2ee0c1bd9a kindest/node:v1.25.3 127.0.0.1:38669->6443/tcp
Kube config for the container
# path/to/some/kube/config
apiVersion: v1
clusters:
- cluster:
insecure-skip-tls-verify: true # Don't use in Prod equivalent of --insecure on cli
server: https://<kind-control-plane container name>:6443 # NOTE port is internal container port
name: kind-kind # or whatever
contexts:
- context:
cluster: kind-kind
user: <some-service-account>
name: kind-kind # or whatever
current-context: kind-kind
kind: Config
preferences: {}
users:
- name: <some-service-account>
user:
token: <TOKEN>
Docker container stuff
If using docker-compose you can add the kind network to the container such as:
#docker-compose.yml
services:
foobar:
build:
context: ./.config
networks:
- kind # add this container to the kind network
volumes:
- path/to/some/kube/config:/somewhere/in/the/container
networks:
kind: # define the kind network
external: true # specifies that the network already exists in docker
If running a new container:
docker run --network kind -v path/to/some/kube/config:/somewhere/in/the/container <image>
Container already running?
docker network connect kind <container name>
I don't know exactly why you want to do this. but no problem I think this could help you:
first, lets pull your docker image:
❯ docker pull curlimages/curl
In my kind cluster I got 3 control plane nodes and 3 worker nodes. Here are the pod of my kind cluster:
❯ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39dbbb8ca320 kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 127.0.0.1:35327->6443/tcp so-cluster-1-control-plane
62b5538275e9 kindest/haproxy:v20220207-ca68f7d4 "haproxy -sf 7 -W -d…" 7 days ago Up 7 days 127.0.0.1:35625->6443/tcp so-cluster-1-external-load-balancer
9f189a1b6c52 kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 127.0.0.1:40845->6443/tcp so-cluster-1-control-plane3
4c53f745a6ce kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 127.0.0.1:36153->6443/tcp so-cluster-1-control-plane2
97e5613d2080 kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 0.0.0.0:30081->30080/tcp so-cluster-1-worker2
0ca64a907707 kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 0.0.0.0:30080->30080/tcp so-cluster-1-worker
9c5d26caee86 kindest/node:v1.23.5 "/usr/local/bin/entr…" 7 days ago Up 7 days 0.0.0.0:30082->30080/tcp so-cluster-1-worker3
The container that is interesting for us here is the haproxy one (kindest/haproxy:v20220207-ca68f7d4) which have the role of loadbalancing the enterring traffic to the nodes (and, in our example, especially the control plane nodes.) we can see that the port 35625 of our host machine is mapped to the port 6443 of the haproxy container. (127.0.0.1:35625->6443/tcp)
so, our cluster endpoint is https://127.0.0.1:35625, we can confirm this in our kubeconfig file (~/.kube/config):
❯ cat .kube/config
apiVersion: v1
kind: Config
preferences: {}
users:
- name: kind-so-cluster-1
user:
client-certificate-data: <base64data>
client-key-data: <base64data>
clusters:
- cluster:
certificate-authority-data: <certificate-authority-dataBase64data>
server: https://127.0.0.1:35625
name: kind-so-cluster-1
contexts:
- context:
cluster: kind-so-cluster-1
user: kind-so-cluster-1
namespace: so-tests
name: kind-so-cluster-1
current-context: kind-so-cluster-1
let's run the curl container in background:
❯ docker run -d --network host curlimages/curl sleep 3600
ba183fe2bb8d715ed1e503a9fe8096dba377f7482635eb12ce1322776b7e2366
as expected, we cant HTTP request the endpoint that listen on an HTTPS port:
❯ docker exec -it ba curl 127.0.0.1:35625
Client sent an HTTP request to an HTTPS server.
we can try to use the certificate that is in the field "certificate-authority-data" in our kubeconfig to check if that change something (it should):
Lets create a file named my-ca.crt that contain the stringData of the certificate:
base64 -d <<< <certificate-authority-dataBase64dataFromKubeConfig> > my-ca.crt
since the working directory of the curl docker image is "/" lets copy our cert to this location in the container and verify that it is actually there:
docker cp my-ca.crt ba183fe:/
❯ docker exec -it ba sh
/ $ ls my-ca.crt
my-ca.crt
Let's try again our curl request but with the certificate:
❯ docker exec -it ba curl --cacert my-ca.crt https://127.0.0.1:35625
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
"reason": "Forbidden",
"details": {},
"code": 403
}
YOU, can get the same result by adding the "--insecure" flag to your curl request:
❯ docker exec -it ba curl https://127.0.0.1:35625 --insecure
{
"kind": "Status",
"apiVersion": "v1",
"metadata": {},
"status": "Failure",
"message": "forbidden: User \"system:anonymous\" cannot get path \"/\"",
"reason": "Forbidden",
"details": {},
"code": 403
}
However, we can't access our cluster with anonymous user ! So lets get a token from kubernetes (cf https://kubernetes.io/docs/tasks/administer-cluster/access-cluster-api/):
# Create a secret to hold a token for the default service account
kubectl apply -f - <<EOF
apiVersion: v1
kind: Secret
metadata:
name: default-token
annotations:
kubernetes.io/service-account.name: default
type: kubernetes.io/service-account-token
EOF
Once the token controller has populated the secret with a token:
# Get the token value
❯ kubectl get secret default-token -o jsonpath='{.data.token}' | base64 --decode
eyJhbGciOiJSUzI1NiIsImtpZCI6InFSTThZZ05lWHFXMWExQlVSb1hTcHNxQ3F6Z2Z2aWpUaUYwd2F2TGdVZ0EifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJzby10ZXN0cyIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJkZWZhdWx0LXRva2VuIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImRlZmF1bHQiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiIzYzY0OTg1OS0xNzkyLTQzYTQtOGJjOC0zMDEzZDgxNjRmY2IiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6c28tdGVzdHM6ZGVmYXVsdCJ9.VLfjuym0fohYTT_uoLPwM0A6u7dUt2ciWZF2K9LM_YvQ0UZT4VgkM8UBVOQpWjTmf9s2B5ZxaOkPu4cz_B4xyDLiiCgqiHCbUbjxE9mphtXGKQwAeKLvBlhbjYnHb9fCTRW19mL7VhqRgfz5qC_Tae7ysD3uf91FvqjjxsCyzqSKlsq0T7zXnzQ_YQYoUplGa79-LS_xDwG-2YFXe0RfS9hkpCILpGDqhLXci_gwP9DW0a6FM-L1R732OdGnb9eCPI6ReuTXQz7naQ4RQxZSIiNd_S7Vt0AYEg-HGvSkWDl0_DYIyHShMeFHu1CtfTZS5xExoY4-_LJD8mi
Now lets execute the curl command directly with the token !
❯ docker exec -it ba curl -X GET https://127.0.0.1:35625/api --header "Authorization: Bearer eyJhbGciOiJSUzI1NiIsImtpZCI6InFSTThZZ05lWHFXMWExQlVSb1hTcHNxQ3F6Z2Z2aWpUaUYwd2F2TGdVZ0EifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJzby10ZXN0cyIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJkZWZhdWx0LXRva2VuIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImRlZmF1bHQiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiIzYzY0OTg1OS0xNzkyLTQzYTQtOGJjOC0zMDEzZDgxNjRmY2IiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6c28tdGVzdHM6ZGVmYXVsdCJ9.VLfjuym0fohYTT_uoLPwM0A6u7dUt2ciWZF2K9LM_YvQ0UZT4VgkM8UBVOQpWjTmf9s2B5ZxaOkPu4cz_B4xyDLiiCgqiHCbUbjxE9mphtXGKQwAeKLvBlhbjYnHb9fCTRW19mL7VhqRgfz5qC_Tae7ysD3uf91FvqjjxsCyzqSKlsq0T7zXnzQ_YQYoUplGa79-LS_xDwG-2YFXe0RfS9hkpCILpGDqhLXci_gwP9DW0a6FM-L1R732OdGnb9eCPI6ReuTXQz7naQ4RQxZSIiNd_S7Vt0AYEg-HGvSkWDl0_DYIyHShMeFHu1CtfTZS5xExoY4-_LJD8mi" --insecure
{
"kind": "APIVersions",
"versions": [
"v1"
],
"serverAddressByClientCIDRs": [
{
"clientCIDR": "0.0.0.0/0",
"serverAddress": "172.18.0.5:6443"
}
]
}
It works !
I still don't know why you want to do this but I hope that this helped you.
Since It's not what you wanted because here I use host network, You can use this : How to communicate between Docker containers via "hostname" as proposed #SergioSantiago thanks for your comment !
bguess
1.)
Execute the following command to generate a random number which is used in the later steps
NUMBER=$[ ( $RANDOM % 1000 ) + 1 ]
echo $NUMBER
Note: Replace the sentence your random number with the number that you have generated wherever you have found the sentence.
Your task is to start a Kubernetes Engine managed by Kubernetes Cluster with the name mycluster-your random number and configure it to run 2 nodes.
2.)
Run and Deploy a Container
Here, you need to launch a single instance of the Nginx container (with version 1.10.0) from the cloud shell.
Execute the following command to view the pod that is running in the nginx container.**
3.)
First, you need to expose the Nginx container to the internet.
Kubernetes will create a service with an external load balancer with a public IP address. You can view your service by executing the following command.
kubectl get services
Now, you will get the external IP address of the Nginx cluster. Open the new web browser tab and paste the Cluster External IP address. You should get the default home page of the Nginx browser.
I have used the below code so far, but the lb is not working:
gcloud container clusters create mycluster-5 --zone=us-central1-a
kubectl create deployment mycluster --image=gcr.io/cloud-marketplace/google/nginx1
kubectl set image deployment nginx nginx=nginx:1.9.1
kubectl expose deployment mycluster-727 --type LoadBalancer --port 80 --target-port 8080
service/mycluster-727 exposed
The reason it's not working because the port is not exposed by the Pod. Please run the below command instead of the second command.
kubectl run mycluster --image=gcr.io/cloud-marketplace/google/nginx1 --port=80
This command should create the deployment and exposed the containerPort on 80 as well which your service would be able to hit.
Welcome to Stack Overflow!
The commands you've posted are not working because you have a typo and the containers ports don't match.
Problem explanation:
Here you are creating a new deployment named mycluster but you are not exposing any port.
kubectl create deployment mycluster --image=gcr.io/cloud-marketplace/google/nginx1
Here you are exposing a deployment named mycluster-727 on port 80 and to target port 8080:
kubectl expose deployment mycluster-727 --type LoadBalancer --port 80 --target-port 8080
Here you are setting image on differents deployment nginx and with a different version that was asked 1.10.0:
kubectl set image deployment nginx nginx=nginx:1.9.1
Fixing the problem
I've checked, and the images gcr.io/cloud-marketplace/google/nginx1 and nginx:1.10.0 and both of them use port 80 to expose the application, so instead use --targer-port=8080 you need use port 80, but you also need to expose the container por when creating the deployment.
Based on #nischay goayl answer, the following command will create a deployment and expose on port 80:
kubectl run mycluster --image=nginx:1.10.0 --port=80
Then, create a service exposing the application:
kubectl expose deployment mycluster --type LoadBalancer --port 80 --target-port 80
Wait for EXTERANL-IP and try to reach your application.
If you want to test internally, use a test pod with curl image to reach the service:
apiVersion: v1
kind: Pod
metadata:
name: curl
namespace: default
spec:
containers:
- name: curl
image: curlimages/curl
command:
- sleep
- "3600"
imagePullPolicy: IfNotPresent
restartPolicy: Always
And then use the command:
kubectl exec -it curl -- curl -IL http://mycluster
response:
HTTP/1.1 200 OK
Server: nginx/1.10.0
Date: Mon, 30 Mar 2020 09:30:07 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 26 Apr 2016 15:17:57 GMT
Connection: keep-alive
ETag: "571f86a5-264"
Accept-Ranges: bytes
What happened:
I have been following this guidelines: https://kubernetes.io/docs/setup/minikube/ and I have the "connection refused" issue when trying to curl the application. Here are the steps I did
~~> minikube status
minikube: Stopped
cluster:
kubectl:
~~> minikube start
Starting local Kubernetes v1.10.0 cluster...
Starting VM...
Getting VM IP address...
Moving files into cluster...
Setting up certs...
Connecting to cluster...
Setting up kubeconfig...
Starting cluster components...
Kubectl is now configured to use the cluster.
Loading cached images from config file.
~~> kubectl run hello-minikube --image=k8s.gcr.io/echoserver:1.10 --port=9500
deployment.apps/hello-minikube created
~~> kubectl expose deployment hello-minikube --type=NodePort
service/hello-minikube exposed
~~> kubectl get pod
NAME READY STATUS RESTARTS AGE
hello-minikube-79577c5997-24gt8 1/1 Running 0 39s
~~> curl $(minikube service hello-minikube --url)
curl: (7) Failed to connect to 192.168.99.100 port 31779: Connection refused
What I expect to happen:
When I curl the pod, it should give a proper reply (like in the quickstart: https://kubernetes.io/docs/setup/minikube/)
minikube logs: https://docs.google.com/document/d/1o2-ebiZTsoCzQNSn_rQSkcuVzOJABmwT2KKzGoUQNiQ/edit
Not sure where you got the port 9500 from but that's the reason it doesn't work. NGINX serves on port 8080. This should work (it does for me, at least):
$ kubectl expose deployment hello-minikube \
--type=NodePort \
--port=8080 --target-port=8080
$ curl $(minikube service hello-minikube --url)
Hostname: hello-minikube-79577c5997-tf49z
Pod Information:
-no pod information available-
Server values:
server_version=nginx: 1.13.3 - lua: 10008
Request Information:
client_address=172.17.0.1
method=GET
real path=/
query=
request_version=1.1
request_scheme=http
request_uri=http://192.168.64.11:8080/
Request Headers:
accept=*/*
host=192.168.64.11:32141
user-agent=curl/7.54.0
Request Body:
-no body in request-
Im running OpenShift.
OpenShift Master: v3.3.1.7
Kubernetes Master: v1.3.0+52492b4
But am having problems trying to run a build in Jenkins (running in a pod). This is not a problem with the java code that I'm trying to build, but is a problem in the Kubernetes/Openshift setup.
The builds fail with:
Caused by: java.net.UnknownHostException: kubernetes.default: Name does not resolve
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
at java.net.InetAddress.getAllByName0(InetAddress.java:1276)
at java.net.InetAddress.getAllByName(InetAddress.java:1192)
at java.net.InetAddress.getAllByName(InetAddress.java:1126)
at okhttp3.Dns$1.lookup(Dns.java:39)
...
Does anyone know how to fix this?
First confirm that DNS is actually working with:
› kubectl run -i -t busybox --image=busybox --restart=Never
Waiting for pod default/busybox to be running, status is Pending, pod ready: false
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes.default
Server: 192.168.60.10
Address 1: 192.168.60.10 kube-dns.kube-system.svc.cluster.local
Name: kubernetes.default
Address 1: 192.168.60.1 kubernetes.default.svc.cluster.local
If that doesn't work check if the DNS pods are running:
kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
Will respond sth like:
NAME READY STATUS RESTARTS AGE
kube-dns-v14-3u5zi 3/3 Running 36 166d
Finally checking the related logs is worth a try:
kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name) -c kube-dns
kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name) -c dnsmasq
kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name) -c healthz
Full instructions can be found on kubernetes.io
Please check on manage jenkins -> Configure Global Security -> Agent port is 50000 and Fixed
I'm newbie of the Kubernetes while I'm using Google Cloud Container. I just follow the tutorials as belows:
https://cloud.google.com/container-engine/docs/tutorials/http-balancer
http://kubernetes.io/docs/hellonode/#create-your-pod
In these tutorials, I'll get the replicacontroller after I run the "kubectl run" but there is no replicacontrollers so that I cannot run the command of "kubectl expose rc" in order to open a port.
Here is my result of the commands:
ChangMatthews-MacBook-Pro:frontend changmatthew$ kubectl run nginx --image=nginx --port=80
deployment "nginx" created
ChangMatthews-MacBook-Pro:frontend changmatthew$ kubectl expose rc nginx --target-port=80 --type=NodePort
Error from server: replicationcontrollers "nginx" not found
Here is my result when I run "kubectl get rc,svc,ingress,deployments,pods":
ChangMatthews-MacBook-Pro:frontend changmatthew$ kubectl get rc,svc,ingress,deployments,pods
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.3.240.1 <none> 443/TCP 12m
NAME RULE BACKEND ADDRESS AGE
basic-ingress - nginx:80 107.178.247.247 12m
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
nginx 1 1 1 1 11m
NAME READY STATUS RESTARTS AGE
nginx-198147104-zgo7m 1/1 Running 0 11m
One of my solution is to create yaml file which define the replicacontroller. But is there any way to create replicacontroller via kubectl run command like above tutorials?
Thanks,
Now that kubectl run creates a deployment, you specify that the type being exposed in a deployment rather than a replication controller:
kubectl expose deployment nginx --target-port=80 --type=NodePort
The team might still be updating the docs to reflect 1.2. Note the output you got:
$ kubectl run nginx --image=nginx --port=80
deployment "nginx" created
kubectl run now creates a deployemtn+replica-set.
To view these you can do kubectl get deployment, and get rs respectively.
Deployments are essentially a nicer way to perform rolling update server side, but there's a little more to it. See docs: http://kubernetes.io/docs/user-guide/deployments/
In version 1.15.0, it works as follows.
root#k8smaster ~]# kubectl run guestbook --image=coolguy/k8s_guestbook:1.0 --port=8080 --generator=run/v1
kubectl run --generator=run/v1 is DEPRECATED and will be removed in a future version. Use kubectl run --generator=run-pod/v1 or kubectl create
instead.
***replicationcontroller/guestbook created***
In version 1.19.0:
[root#k8smaster ~]# kubectl run guestbook --image=dmsong2008/k8s_guestbook:1.0 --port=8080 --generator=run/v1
***Flag --generator has been deprecated, has no effect and will be removed in the future.***
pod/guestbook created