I am migrating my current service to Kubernetes. Currently back end services are resolved via mod_cluster. mod cluster manager runs on httpd and mod_cluster clients auto register their web contexts with httpd/mod_cluster manager on startup
user-->ingress-rule--> httpd [running mod_cluster manager]--> Jboss[mod_cluster clients]
I resolve my UI via the following ingress rule
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: httpd
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
nginx.ingress.kubernetes.io/ssl-passthrough: "true"
spec:
rules:
- host: myk8s.myath.myserv.com
http:
paths:
- path: /
backend:
serviceName: httpd
servicePort: 443
tls:
- hosts:
- myk8s.myath.myserv.com
This works well, resolves UI, can log in and resolve all static content etc.
Mod cluster exposes services such as myservice. I disabled mod_cluster and created a Kubernetes service myservice that resolved to the back-end Pod thinking that the Ingress rule would get the request as far as httpd and then httpd would be able to resolve the backend service via Kubernetes but i get 404s as I am unable to resolve myservice
Service can be resolved via Reverse proxy rules such as below, but this is not preferred solution
# Redirect to myjbossserv
ProxyPass /myservice/services/command/ http://myjbossserv:8080/myservice/services/command/ <-----myjbossserv is a service registered in kubernetes
ProxyPassReverse /myservice/services/command/ http://myjbossserv:8080/myservice/services/command/
Any help much appreciated
The simplest way to solve this...catering for all HA and robustness use cases was to use reverse proxy rules. There are multiple ways to configure these such as at image build time or via config maps...
# Redirect to myjbossserv
ProxyPass /myservice/services/command/ http://myjbossserv:8080/myservice/services/command/ <-----myjbossserv is a service registered in kubernetes
ProxyPassReverse /myservice/services/command/ http://myjbossserv:8080/myservice/services/command/
Related
I am running Azure AKS with Kubenet networking, in which I have deployed several services, exposed on several ports.
I have configured a URL based routing and it seems to work for the services I could test.
I found out the following:
sending URL and URL:80, returns the desired web page, but the URL displayed in the browser's address bar is removing the port, if I send it. Looks like http://URL/
When I try accessing other web pages or services, I get a strange phenomena: Calling the URL with the port number, is waiting until the browser says it's unreachable. Fiddler returns "time out".
When I access the service (1 of 3 I could check visibly) and not provide the port, the Ingress rules I applied answer the request and I get the resulting web page, which is exposed on the internal service port.
i'm using this YAML, for rabbit management page:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: rabbit-admin-on-ingress
namespace: mynamespace
spec:
rules:
- host: rabbit.my.local
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: rabbitmq
port:
number: 15672
ingressClassName: nginx
and also, apply this config (using kubectl apply -f config.file.yaml):
apiVersion: v1
kind: ConfigMap
metadata:
name: tcp-services
namespace: ingress-nginx
data:
15672: "mynamespace/rabbitmq:15672"
What happens is:
http://rabbit.my.local gets the rabbit admin page
http://rabbit.my.local:15672 get a time out and I get frustrated
It seems this is also happening on another service I have running on port 8085 and perhaps even the DB running on the usual SQL port (might be a TCP only connection)
Both are configured the same as the rabbitmq service in the yaml rules and config file, with their respected service names, namespaces and ports.
Please help me to figure out how I can make Ingress accept the URLs with the :PORT attached to it and answer them. Save me.
A quick reminder - :80 works fine. Perhaps because it's one of the defaults for Ingress
Thank you so much in advance.
Moshe
I have a fairly simple setup in my kubernetes cluster, with two zones:
Low trust (public facing)
Medium trust (non public)
Both zones have Istio enabled, with:
Ingress gateway with SSL enabled. For testing within my local docker desktop, I use port 443 for the public facing, and port 443 for medium trust
Virtual service
Destination rule
I am deploying apache HTTPD - acting as a reverse proxy within the low trust. The plan is for the HTTPD to then forward the traffic to istio ingress gateway in the medium trust.
Within the medium trust is a Spring boot application.
So, lets say, user is accessing https://lowtrust.avengers.local/avengers. This request will be serviced by the ingress gateway in the lowtrust, and will end up in the HTTPD, which then forward the request to ingress gateway in mediumtrust.
LOWTRUST MEDIUMTRUST
| GW--> VS-->HTTPD Pod|======>| GW --> VS -->Java Pod|
I have created a github repo to demonstrate this:
https://github.com/alexwibowo/avengersKubernetes
The HTTP proxy configuration is here: https://github.com/alexwibowo/avengersKubernetes/blob/main/httpd/conf/proxy.conf.
The Istio ingress gateway for lowtrust:
https://github.com/alexwibowo/avengersKubernetes/blob/main/kubernetes/avengers/charts/avengers-istio/templates/istio-httpd.yaml
and istio ingress gateway for mediumtrust:
https://github.com/alexwibowo/avengersKubernetes/blob/main/kubernetes/avengers/charts/avengers-istio/templates/istio-app.yaml
As you can see, both gateways have their own certs configured. At the moment, I kind of 'cheat' by modifying my /etc/host file to have the following:
127.0.0.1 lowtrust.avengers.local
<CLUSTER_IP_ADDRESS> mediumtrust.avengers.local
By doing this, when HTTPD pod making request to 'mediumtrust.avengers.local', it will get directed to the istio ingress gateway (thats my understanding anyway).
I've heard that you can actually set up a mutual TLS for the scenario I've described above. With this approach, I wont need to setup the certificate in my mediumtrust ingress gateway - and just use 'ISTIO_MUTUAL'. I think for this, I will also need to set up a 'proxy' service & virtual service in the lowtrust namespace. The virtual service will then manage the communication between lowtrust & mediumtrust. But I'm not 100% how to do this.
Any help / advice is much appreciated!
Edit 1 (2021/07/01)
I've been reading more about this topic. So another option, is to have Service of type 'ExternalName' within the 'lowtrust' namespace.
Which, if I might use the analogy, will act like a 'proxy' for connecting to the service on the other namespace.
e.g.:
apiVersion: v1
kind: Service
metadata:
name: cr1-avengers-app
namespace: "lowtrust"
spec:
type: ExternalName
externalName: "cr1-avengers-app.mediumtrust.svc.cluster.local
ports:
- port: 8081
targetPort: 8080
protocol: TCP
name: http
But by using this, I will effectively bypass the Istio VirtualService, DestinationRule that I've defined on the mediumtrust namespace.
The way I've managed to solve this locally is by having an entry in my windows hostfile.
E.g.:
127.0.0.1 lowtrust.avengers.local
10.109.161.243 mediumtrust.avengers.local
10.109.161.243 is the Cluster IP address for my istio-ingressgateway. I got this by running kubectl get svc -n istio-system from command line.
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
istio-ingressgateway LoadBalancer 10.109.161.243 localhost 15021:30564/TCP,80:31834/TCP,443:31828/TCP,445:32700/TCP,15012:30459/TCP,15443:30397/TCP 21d
I was also missing 'SSLProxyEngine' flag in my reverse proxy configuration. So in the end my VirtualHost configuration looks like below:
E.g.:
<VirtualHost *:7000>
ProxyRequests Off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>
SSLProxyEngine on
ProxyPass /avengers https://mediumtrust.avengers.local/avengers
ProxyPassReverse /avengers https://mediumtrust.avengers.local/avengers
CustomLog "/tmp/access.log" common
ErrorLog /tmp/error.log
</VirtualHost>
I am learning Kubernetes and i run into trouble reaching an API in my local Minikube (Docker driver).
I have a pod running an angluar-client which tries to reach a backend pod. The frontend Pod is exposed by a NodePort Service. The backend pod is exposed to the Cluster by a ClusterIP Service.
But when i try to reach the clusterip service from the frontend the dns transpile-svc.default.svc.cluster.local cannot get resolved.
error message in the client
the dns should work properly. i followed this https://kubernetes.io/docs/tasks/administer-cluster/dns-debugging-resolution/ and deployed a dnsutils pod from where i can nslookup.
winpty kubectl exec -i -t dnsutils -- nslookup transpile-svc.default
Server: 10.96.0.10
Address: 10.96.0.10#53
Name: transpile-svc.default.svc.cluster.local
Address: 10.99.196.82
This is the .yaml file for the clusterIP Service
apiVersion: v1
kind: Service
metadata:
name: transpile-svc
labels:
app: transpile
spec:
selector:
app: transpile
ports:
- port: 80
targetPort: 80
Even if i hardcode the IP into the request of the frontend i am getting an empty response.
I verified, that the backend pod is working correctly and when i expose it as a NodePort i can reach the api with my browser.
What am i missing here? Im stuck with this problems for quite some time now and i dont find any solution.
Since your frontend application is calling your application from outside the cluster you need to expose your backend application to outside network too.
There are two ways: either expose it directly by changing transpile-svc service to loadbalancer type or introduce an ingress controller(eg Nginx ingress controller with an Ingres object) which will handle all redirections
Steps to expose service as loadbalancer in minikube
1.Change your service transpile-svc type to LoadBalancer
2.Run command minikube service transpile-svc to expose the service ie an IP will be allocated.
3. Run kubectl get services to get external IP assigned. Use IP:POST to call from frontend application
DNS hostnames *.*.svc.cluster.local is only resolvable from within the kubernetes cluster. You should use http://NODEIP:NODEPORT or url provided by minikube service transpile-svc --url in the frontend javascript code which is running in a browser outside the kubernetes cluster.
If the frontend pod is nginx then you can configure the backend service name as below in the nginx configuration file as described in the docs
upstream transpile {
server transpile;
}
server {
listen 80;
location / {
proxy_pass http://transpile-svc;
}
}
I am building a microservice full stack web application as (so far) :
ReactJS (client microservice) : listens on 3000
Authentication (Auth microservice) : listens on 3000 // accidently assigned the same port
Technically, what I have heard/learned so far is that we cannot have two Pods running on the same port.
I am really confused how am I able to run the application (perfectly) like this with same ports on different applications/pods?
ingress-nginx config:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress-service
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/use-regex: 'true'
spec:
## our custom routing rules
rules:
- host: ticketing.dev
http:
paths:
- path: /api/users/?(.*)
backend:
serviceName: auth-srv
servicePort: 3000
- path: /?(.*)
backend:
serviceName: client-srv
servicePort: 3000
I am really curious, am I missing something here?
Each Pod has its own network namespace and its own IP address, though the Pod-specific IP addresses aren't reachable from outside the cluster and aren't really discoverable inside the cluster. Since each Pod has its own IP address, you can have as many Pods as you want all listening to the same port.
Each Service also has its own IP address; again, not reachable from outside the cluster, though they have DNS names so applications can find them. Since each Service has its own IP address, you can have as many Services as you want all listening to the same port. The Service ports can be the same or different from the Pod ports.
The Ingress controller is reachable from outside the cluster via HTTP. The Ingress specification you show defines HTTP routing rules. If I set up a DNS service with a .dev TLD and define an A record for ticketing.dev that points at the ingress controller, then http://ticketing.dev/api/users/anything gets forwarded to http://auth-srv.default.svc.cluster.local:3000/ within the cluster, and http://ticketing.dev/otherwise goes to http://client-srv.default.svc.cluster.local:3000/. Those in turn will get forwarded to whatever Pods they're connected to.
There's no particular prohibition against multiple Pods or Services having the same port. I tend to like setting all of my HTTP Services to listen on port 80 since it's the standard HTTP port, even if the individual Pods are listening on port 3000 or 8000 or 8080 or whatever else.
You have two different services in the backend: auth-srv and client-srv. Therefore, you have two different addresses and then can use any port you want in each of it. that means you can get the same port in the two different services.
I am running a restfull service behind self signed cert thru NGINX in google cloud kubernetes infrastructure.
Kubernetes service loader exposes 443 and routes the traffic those containers. All is working just fine as expected other than asking internal clients to ignore the self sign cert warning!
It is time for to move to CA cert thus only option as far as I see is https loader but I couldnt figure out how we can reroute the traffic to service loader or directly to pods as service loader(http loader)
Any help apprecaited
Update Firewall Rules for:
IP: 130.211.0.0/22
tcp:30000-32767
Create NodePort type service:
apiVersion: v1
kind: Service
metadata:
name: yourservicenodeport
labels:
name: your-service-node-port
spec:
type: NodePort
ports:
- port: 80
nodePort: 30001
selector:
name: yourpods
Create health check.
For the nodeport which is in this case: 30001
Create an ingress service:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: youTheking-ingress-service
spec:
backend:
serviceName: yourservice
servicePort: 80
Wait for few minutes, be patient.
Change the health check on http load balancer.
a. Go to the Load Balancing on Networking Tab.
b. Click Advance menu.
c. Go Backend Services and Edit.
d. Update health check option and use the one created for nodeport service.
Repeat step 5 for instance group to be recognized health.
SSL is needed, go back to the load balancer, edit, click Frontend Configuration, then add https with cert.
You are ready to roll.
I'm not sure I fully understand you question but I'll try to answer it anyway.
You have two options for exposing your service using a cert signed by a trusted CA:
Do what you are doing today but with the real cert. You will probably want to put the cert into a secret and point your nginx configuration at it to load the cert.
Replace nginx with the google L7 load balancer. You would upload your certificate to google, configure the L7 balancer to terminate HTTPS and forward traffic to your backends.