Curl: Check web server with hostname and IP

A nice way to check if the server is responding for a particular hostname. In this case, we attach the host parameter of the HTTP, and the hostname + port.

If you are sending traffic to IP with a different Host entry, it will not connect to the right service and will serve default-backend.

Try:

curl -H 'Host: aws-dns-name.org' IP_Address

Example:

curl -H 'Host: dashboard.com' ec2-18-207-220-253.compute-1.amazonaws.com:30100

Expose a nginx pod on ec2, just for testing

Deploy the nginx pod:

kubectl run nginx --image=nginx

Expose pod port with a service:

kubectl expose pod/nginx --port 80 --type NodePort

Check the services:

kubectl get services

NAME                TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE

kubernetes          ClusterIP      10.96.0.1       <none>        443/TCP          2d2h

nginx               NodePort       10.102.83.199   <none>        80:31545/TCP     8s

Forward public traffic to minikube cluster

We’ll be forwarding traffic using iptables tool as follows 

-Identify instance private network interface. Its IP address should correlate with the one shown from the instance main page (the default should be called enX0.
-Identify the minikube bridge network interface using ifconfig command, looking for an interface starting with br-, and copy its IP address aside.
-Identify the nginx service port generated by service creation.
kubectl get services



Then add the rules to forward the traffic of enX0 to the Minikube bridge

sudo iptables -A PREROUTING -t nat -i enX0 -p tcp --dport 31545 -j DNAT --to-destination 192.168.49.2:31545

sudo iptables -A FORWARD -p tcp -d 192.168.49.2 --dport 31545 -j ACCEPT

Add the rules on the ec2 security group to accept the traffic coming with destination por 31545.

Then test the app, something like this:

http://ec2-18-207-220-253.compute-1.amazonaws.com:31545/

Then if you want clean things from the cluster:

kubectl delete service nginx

service "nginx" deleted

kubectl delete pod nginx

pod "nginx" deleted

Add an ingress for the kubernetes dashboard

Run the following command to install the dashboard:

[ec2-user@ip-172-31-80-45 k8s-demo]minikube dashboard

Enable the ingress controller:

[ec2-user@ip-172-31-80-45 ~]$ minikube addons enable ingress

💡  ingress is an addon maintained by Kubernetes. For any concerns contact minikube on GitHub.

You can view the list of minikube maintainers at: https://github.com/kubernetes/minikube/blob/master/OWNERS

    ▪ Using image registry.k8s.io/ingress-nginx/controller:v1.11.2

    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.4.3

    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.4.3

🔎  Verifying ingress addon...

🌟  The 'ingress' addon is enabled

Create a YAML file:

apiVersion: networking.k8s.io/v1

kind: Ingress

metadata:

name: dashboard-ingress

namespace: kubernetes-dashboard

spec:

defaultBackend:

service:

name: kubernetes-dashboard

port:

number: 80

Apply the ingress to the cluster:

[ec2-user@ip-172-31-80-45 k8s-demo]$ kubectl apply -f dashboard-ingress.yaml 

ingress.networking.k8s.io/dashboard-ingress created

Check the namespaces:

[ec2-user@ip-172-31-80-45 ~]$ kubectl get ns

NAME                   STATUS   AGE

default                Active   2d22h

ingress-nginx          Active   2d15h

kube-node-lease        Active   2d22h

kube-public            Active   2d22h

kube-system            Active   2d22h

kubernetes-dashboard   Active   41h

Check the ingress service for the namespace:

[ec2-user@ip-172-31-80-45 k8s-demo]$ kubectl get ingress -n kubernetes-dashboard

NAME                CLASS   HOSTS   ADDRESS        PORTS   AGE

dashboard-ingress   nginx   *       192.168.49.2   80      40h

Add proper iptables rules to forward the traffic:

[ec2-user@ip-172-31-80-45 k8s-demo]$ sudo iptables -A PREROUTING -t nat -i enX0 -p tcp --dport 80 -j DNAT --to-destination 192.168.49.2:80

sudo iptables -A FORWARD -p tcp -d 192.168.49.2 --dport 80 -j ACCEPT

[ec2-user@ip-172-31-80-45 ~]$ kubectl describe ingress dashboard-ingress -n kubernetes-dashboard

Name:             dashboard-ingress

Labels:           <none>

Namespace:        kubernetes-dashboard

Address:          192.168.49.2

Ingress Class:    nginx

Default backend:  kubernetes-dashboard:80 (10.244.0.40:9090)

Rules:

  Host        Path  Backends

  ----        ----  --------

  *           *     kubernetes-dashboard:80 (10.244.0.40:9090)

Annotations:  <none>

Events:

  Type    Reason  Age                    From                      Message

  ----    ------  ----                   ----                      -------

  Normal  Sync    8m29s (x3 over 9m29s)  nginx-ingress-controller  Scheduled for sync

After that you can access with the web browser using the public dns name.

After you test it, you can remove the ingress:

[ec2-user@ip-172-31-80-45 ~]$ kubectl delete ingress dashboard-ingress -n kubernetes-dashboard

ingress.networking.k8s.io "dashboard-ingress" deleted

Configure ingress controller kubernetes

 This automatically starts the Nginx ingress controller.

[ec2-user@ip-172-31-80-45 ~]$ minikube addons enable ingress

💡  ingress is an addon maintained by Kubernetes. For any concerns contact minikube on GitHub.

You can view the list of minikube maintainers at: https://github.com/kubernetes/minikube/blob/master/OWNERS

    ▪ Using image registry.k8s.io/ingress-nginx/controller:v1.11.2

    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.4.3

    ▪ Using image registry.k8s.io/ingress-nginx/kube-webhook-certgen:v1.4.3

🔎  Verifying ingress addon...

🌟  The 'ingress' addon is enabled

[ec2-user@ip-172-31-80-45 ~]$ kubectl get pod -n kube-system

NAME                               READY   STATUS    RESTARTS        AGE

coredns-6f6b679f8f-d9wl9           1/1     Running   1 (5h50m ago)   7h56m

etcd-minikube                      1/1     Running   1 (5h51m ago)   7h56m

kube-apiserver-minikube            1/1     Running   1 (3h51m ago)   7h56m

kube-controller-manager-minikube   1/1     Running   1 (5h51m ago)   7h56m

kube-proxy-qnpdq                   1/1     Running   1 (5h51m ago)   7h56m

kube-scheduler-minikube            1/1     Running   1 (5h51m ago)   7h56m

storage-provisioner                1/1     Running   3 (3h50m ago)   7h56m

[ec2-user@ip-172-31-80-45 ~]$ kubectl get ns

NAME              STATUS   AGE

default           Active   7h57m

ingress-nginx     Active   4m31s

kube-node-lease   Active   7h57m

kube-public       Active   7h57m

kube-system       Active   7h57m

Check the status of kubernetes

To check current pods:

[ec2-user@ip-172-31-80-45 ~]$ kubectl get pod
NAME                                 READY   STATUS    RESTARTS       AGE
mongo-deployment-77f8f85dc8-cvz9j    1/1     Running   1 (126m ago)   139m
webapp-deployment-655ff6696b-vw5lw   1/1     Running   1 (7m1s ago)   138m

To check all pods, services and deployments:
[ec2-user@ip-172-31-80-45 ~]$ kubectl get all
NAME                                     READY   STATUS    RESTARTS       AGE
pod/mongo-deployment-77f8f85dc8-cvz9j    1/1     Running   1 (132m ago)   145m
pod/webapp-deployment-655ff6696b-vw5lw   1/1     Running   1 (13m ago)    144m
NAME                     TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
service/kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP          4h17m
service/mongo-service    ClusterIP   10.103.48.93    <none>        8080/TCP         155m
service/webapp-service   NodePort    10.109.94.172   <none>        3000:30100/TCP   144m
NAME                                READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/mongo-deployment    1/1     1            1           145m
deployment.apps/webapp-deployment   1/1     1            1           144m
NAME                                           DESIRED   CURRENT   READY   AGE
replicaset.apps/mongo-deployment-77f8f85dc8    1         1         1       145m
replicaset.apps/webapp-deployment-655ff6696b   1         1         1       144m

To check the current configmap:

[ec2-user@ip-172-31-80-45 ~]$ kubectl get configmap
NAME               DATA   AGE
game-demo          1      170m
kube-root-ca.crt   1      4h32m
mongo-config       1      164m

To check the current secrets:
[ec2-user@ip-172-31-80-45 ~]$ kubectl get secrets
NAME           TYPE     DATA   AGE
mongo-secret   Opaque   2      170m

To check the service's data:

[ec2-user@ip-172-31-80-45 ~]$ kubectl describe service webapp-service
Name: webapp-service
Namespace: default
Labels: <none>
Annotations: <none>
Selector: app=webapp
Type: NodePort
IP Family Policy: SingleStack
IP Families: IPv4
IP: 10.109.94.172
IPs: 10.109.94.172
Port: <unset> 3000/TCP
TargetPort: 3000/TCP
NodePort: <unset> 30100/TCP
Endpoints: 10.244.0.6:3000
Session Affinity: None
External Traffic Policy: Cluster
Internal Traffic Policy: Cluster
Events: <none>

To check the pod's data:

[ec2-user@ip-172-31-80-45 ~]$ kubectl describe pod mongo-deployment-77f8f85dc8-cvz9j
Name: mongo-deployment-77f8f85dc8-cvz9j
Namespace: default
Priority: 0
Service Account: default
Node: minikube/192.168.49.2
Start Time: Tue, 17 Sep 2024 20:42:27 +0000
Labels: app=mongo
pod-template-hash=77f8f85dc8
Annotations: <none>
Status: Running
IP: 10.244.0.7
IPs:
IP: 10.244.0.7
Controlled By: ReplicaSet/mongo-deployment-77f8f85dc8
Containers:
mongo:
Container ID: docker://9b4e7fc09ae6ac02df14283196c57c5826afcf00659e51e8fb37e92ced31fdc0
Image: mongo:5.0
Image ID: docker-pullable://mongo@sha256:fd08cf3c5aae3268a032a7064c60a4bc0fb468ee9a7b6b1b45b9b2335e4fda3e
Port: 27017/TCP
Host Port: 0/TCP
State: Running
Started: Tue, 17 Sep 2024 22:54:42 +0000
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Tue, 17 Sep 2024 20:42:37 +0000
Finished: Tue, 17 Sep 2024 20:54:48 +0000
Ready: True
Restart Count: 1
Environment:
MONGO_INITD_ROOT_USERNAME: <set to the key 'mongo-user' in secret 'mongo-secret'> Optional: false
MONGO_INITD_ROOT_PASSWORD: <set to the key 'mongo-password' in secret 'mongo-secret'> Optional: false
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-pm8q8 (ro)
Conditions:
Type Status
PodReadyToStartContainers True

Initialized True

Ready True

ContainersReady True

PodScheduled True

Volumes:
kube-api-access-pm8q8:
Type: Projected (a volume that contains injected data from multiple sources)
TokenExpirationSeconds: 3607
ConfigMapName: kube-root-ca.crt
ConfigMapOptional: <nil>
DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 178m default-scheduler Successfully assigned default/mongo-deployment-77f8f85dc8-cvz9j to minikube
Normal Pulling 178m kubelet Pulling image "mongo:5.0"
Normal Pulled 177m kubelet Successfully pulled image "mongo:5.0" in 8.868s (8.868s including waiting). Image size: 723535501 bytes.
Normal Created 177m kubelet Created container mongo
Normal Started 177m kubelet Started container mongo
Normal SandboxChanged 45m kubelet Pod sandbox changed, it will be killed and re-created.
Normal Pulled 45m kubelet Container image "mongo:5.0" already present on machine
Normal Created 45m kubelet Created container mongo
Normal Started 45m kubelet Started container mongo

To check the logs of a pod:

[ec2-user@ip-172-31-80-45 ~]$ kubectl logs pod/mongo-deployment-77f8f85dc8-cvz9j

{"t":{"$date":"2024-09-17T22:54:43.121+00:00"},"s":"I", "c":"CONTROL", "id":23285, "ctx":"-","msg":"Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'"}
{"t":{"$date":"2024-09-17T22:54:43.136+00:00"},"s":"I", "c":"NETWORK", "id":4915701, "ctx":"-","msg":"Initialized wire specification","attr":{"spec":{"incomingExternalClient":{"minWireVersion":0,"maxWireVersion":13},"incomingInternalClient":{"minWireVersion":0,"maxWireVersion":13},"outgoing":{"minWireVersion":0,"maxWireVersion":13},"isInternalClient":true}}}
{"t":{"$date":"2024-09-17T22:54:43.147+00:00"},"s":"W", "c":"ASIO", "id":22601, "ctx":"main","msg":"No TransportLayer configured during NetworkInterface startup"}


{"t":{"$date":"2024-09-17T22:54:43.149+00:00"},"s":"I", "c":"NETWORK", "id":4648601, "ctx":"main","msg":"Implicit TCP FastOpen unavailable. If TCP FastOpen is required, set tcpFastOpenServer, tcpFastOpenClient, and tcpFastOpenQueueSize."}

To check the service:

[ec2-user@ip-172-31-80-45 ~]$ kubectl get service
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
kubernetes       ClusterIP   10.96.0.1       <none>        443/TCP          4h54m
mongo-service    ClusterIP   10.103.48.93    <none>        8080/TCP         3h11m
webapp-service   NodePort    10.109.94.172   <none>        3000:30100/TCP   3h

To see the Minikube ip:
[ec2-user@ip-172-31-80-45 ~]$ minikube ip
192.168.49.2

If you are using a deployment of kubernetes, you can check date of the node:
[ec2-user@ip-172-31-80-45 ~]$ kubectl get node -o wide
NAME       STATUS   ROLES           AGE     VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION                    CONTAINER-RUNTIME
minikube   Ready    control-plane   4h55m   v1.31.0   192.168.49.2   <none>        Ubuntu 22.04.4 LTS   6.1.109-118.189.amzn2023.x86_64   docker://27.2.0

To check the endpoints
[ec2-user@ip-172-31-80-45 ~]$ kubectl get endpoints
NAME ENDPOINTS AGE
kubernetes 192.168.49.2:8443 5h40m
mongo-service 10.244.0.7:27017 3h57m
webapp-service 10.244.0.6:3000 3h46m

Minikube on Amazon Linux 2023

 

Download the latest Minikube version

[ec2-user@ip-172-31-32-118 ~]$ curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-latest.x86_64.rpm

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current

                                 Dload  Upload   Total   Spent    Left  Speed

100 36.2M  100 36.2M    0     0  48.4M      0 --:--:-- --:--:-- --:--:-- 48.4M

Install minikube

[ec2-user@ip-172-31-32-118 ~]$ sudo rpm -Uvh minikube-latest.x86_64.rpm

Verifying...                          ################################# [100%]

Preparing...                          ################################# [100%]

package minikube-1.34.0-0.x86_64 is already installed

If you try to start Minikube you will have the following error.
[ec2-user@ip-172-31-32-118 ~]$ minikube start

😄  minikube v1.34.0 on Amazon 2023.5.20240916 (xen/amd64)

👎  Unable to pick a default driver. Here is what was considered, in preference order:

    ▪ docker: Not healthy: "docker version --format {{.Server.Os}}-{{.Server.Version}}:{{.Server.Platform.Name}}" exit status 1: permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.44/version": dial unix /var/run/docker.sock: connect: permission denied

    ▪ docker: Suggestion: Add your user to the 'docker' group: 'sudo usermod -aG docker $USER && newgrp docker' <https://docs.docker.com/engine/install/linux-postinstall/>

💡  Alternatively you could install one of these drivers:

    ▪ kvm2: Not installed: exec: "virsh": executable file not found in $PATH

    ▪ podman: Not installed: exec: "podman": executable file not found in $PATH

    ▪ qemu2: Not installed: exec: "qemu-system-x86_64": executable file not found in $PATH

    ▪ virtualbox: Not installed: unable to find VBoxManage in $PATH

❌  Exiting due to DRV_NOT_HEALTHY: Found driver(s) but none were healthy. See above for suggestions how to fix installed drivers.

So proceed to check for updates and install docker.
[ec2-user@ip-172-31-32-118 ~]$ sudo yum update -y

Last metadata expiration check: 0:44:48 ago on Tue Sep 17 17:37:47 2024.

Dependencies resolved.

Nothing to do.

Complete!

[ec2-user@ip-172-31-32-118 ~]$ sudo yum install -y docker

Last metadata expiration check: 0:45:13 ago on Tue Sep 17 17:37:47 2024.

Package docker-25.0.6-1.amzn2023.0.2.x86_64 is already installed.

Dependencies resolved.

Nothing to do.

Complete!

Add the user ec2-user to the docker group

[ec2-user@ip-172-31-32-118 ~]$ sudo usermod -aG docker $USER && newgrp docker

[ec2-user@ip-172-31-32-118 ~]$ sudo systemctl start docker && sudo systemctl enable docker

Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service.

Check for the current version

[ec2-user@ip-172-31-32-118 ~]$ curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt

v1.31.0

Use the following version to download the kubectl

[ec2-user@ip-172-31-32-118 ~]$ curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.31.0/bin/linux/amd64/kubectl

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current

                                 Dload  Upload   Total   Spent    Left  Speed

100 53.7M  100 53.7M    0     0  61.0M      0 --:--:-- --:--:-- --:--:-- 60.9M

[ec2-user@ip-172-31-32-118 ~]$ sudo chmod +x ./kubectl

[ec2-user@ip-172-31-32-118 ~]$ sudo mv ./kubectl /usr/local/bin/kubectl

[ec2-user@ip-172-31-32-118 ~]$ minikube start

😄  minikube v1.34.0 on Amazon 2023.5.20240916 (xen/amd64)

✨  Automatically selected the docker driver. Other choices: ssh, none

📌  Using Docker driver with root privileges

👍  Starting "minikube" primary control-plane node in "minikube" cluster

🚜  Pulling base image v0.0.45 ...

💾  Downloading Kubernetes v1.31.0 preload ...

    > preloaded-images-k8s-v18-v1...:  326.69 MiB / 326.69 MiB  100.00% 39.54 M

    > gcr.io/k8s-minikube/kicbase...:  487.89 MiB / 487.90 MiB  100.00% 38.87 M

🔥  Creating docker container (CPUs=2, Memory=2200MB) ...

🐳  Preparing Kubernetes v1.31.0 on Docker 27.2.0 ...

    ▪ Generating certificates and keys ...

    ▪ Booting up control plane ...

    ▪ Configuring RBAC rules ...

🔗  Configuring bridge CNI (Container Networking Interface) ...

🔎  Verifying Kubernetes components...

    ▪ Using image gcr.io/k8s-minikube/storage-provisioner:v5

🌟  Enabled addons: storage-provisioner, default-storageclass

🏄  Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default

The Minikube is installed.

[ec2-user@ip-172-31-32-118 ~]$ kubectl get pod -A

NAMESPACE     NAME                               READY   STATUS    RESTARTS   AGE

kube-system   coredns-6f6b679f8f-28vqp           1/1     Running   0          19s

kube-system   etcd-minikube                      1/1     Running   0          26s

kube-system   kube-apiserver-minikube            1/1     Running   0          24s

kube-system   kube-controller-manager-minikube   1/1     Running   0          24s

kube-system   kube-proxy-m4pcg                   1/1     Running   0          19s

kube-system   kube-scheduler-minikube            1/1     Running   0          24s

kube-system   storage-provisioner                1/1     Running   0          23s