Forum Discussion
michaelgardner
Altocumulus
AltocumulusHow to rewrite a path to a backend service dropping the prefix and passing the remaining path?
Hello,
I am not sure whether my posting is appropriate in this area, so please delete it if there is a violation of posting rules...
This must be a common task, but I cannot figure out how to do the following fanout rewrite in our nginx ingress:
http://abcccc.com/httpbin/anything -> /anything (the httpbin backend service)
When I create the following ingress with a path of '/' and send the query, I receive a proper response.
curl -I -k http://abczzz.com/anything
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: mikie-ingress
namespace: mikie
spec:
ingressClassName: nginx
rules:
- host: abczzz.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: httpbin-service
port:
number: 8999
What I really need is to be able to redirect to different services off of this single host, so I changed the ingress to the following, but the query always fails with a 404. Basically, I want the /httpbin to disappear and pass the path onto the backend service, httpbin.
curl -I -k http://abczzz.com/httpbin/anything
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: mikie-ingress
namespace: mikie
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
ingressClassName: nginx
rules:
- host: abczzz.com
http:
paths:
- path: /httpbin(/|$)(.*)
pathType: Prefix
backend:
service:
name: httpbin-service
port:
number: 8999
Thank you for your time and interest,
Mike
- Rebecca_Moloney
Admin
Just popping in with more NGINX Ingress related content in case you're interested:
michaelgardnerHi guys, Just checking in... Any news?
- JRahm
you see BrianEhlert and JSON-Williams_NGIИX 's posts below?
- michaelgardner
Since haproxy is based upon nginx, I set up the same environment and test in a new cluster at Digital Ocean. Unfortunately, the tests failed as with the commercial version. Attached is an updated compressed file including the haproxy work.
- michaelgardner
So, I started from scratch at Digital Ocean... I created two Kubernetes clusters using their default configuration:
* aboh-cluster is the community version of nginx ingnress
* abitofhelp-cluster is the commercial version of nginix ingressNginx community: helm 4.1.3, ingress-nginx 1.21, nginx 1.19.10
Nginx commercial: helm 2.2.2, ingress 1.22
Unfortunately, the outcome is the same as in my previous test. The community version works with the deployment/service and ingress manifests. The commercial version with 404 errors using the same manifests and curl commands.
I have captured the following in the attached compressed file:* Descriptions of the services and ingresses;
* Manifests for the deployments, services, and ingresses;
* Logs capturing the curl command and the resultI am not sure where to go from here... We want to use the commercial version with support, but cannot seem to get it to work.
Thanks for any hints or help,
Mike
- BrianEhlert
Employee
Hey Michael
The first thing that I will mention is that annotations are unique to each implementation.
The annotations specific to the community ingress controller are not implemented by other projects. This is probably the first hurdle you are hitting.
This block here:nginx.ingress.kubernetes.ioDefines that your annotation is specific to the community project.
Rewrites for the NGINX Inc ingress controller project have an example here for the Ingress object: https://github.com/nginxinc/kubernetes-ingress/tree/main/examples/rewrites
And an example here using the project specific CRDs: https://github.com/nginxinc/kubernetes-ingress/tree/main/examples/custom-resources/rewrites
JSON-Williams_NGIИXRob_Michel As BrianEhlert mentioned, you need to change your annotation and Ingress resource slightly to match the commercial version of NGINX Ingress controller.
You can try something like this:
apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: cafe-ingress annotations: nginx.org/rewrites: "serviceName=httpbin-service rewrite=/" spec: rules: - host: cat.abitofhelp.io http: paths: - path: /httpbin/ pathType: Prefix backend: service: name: httpbin-service port: number: 8999Make sure you adjust accordingly to match your environment.
- michaelgardner
Hello xuwen & JRahm,
Thank you fo your quick responses and help. After a break, I adjusted the path, as below, and was able to successfully route to httpbin and preserve the path after the prefix. Hopefully, this will help others... 🙂
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: mikie-ingress
namespace: mikie
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
ingressClassName: nginx
rules:
- host: abczzz.com
http:
paths:
- backend:
service:
name: httpbin-service
port:
number: 8999
path: /httpbin/(.*)
pathType: Prefix- michaelgardner
In order to compare my issues, I deployed nginx-ingress, which we will be using for our deployment, and the community edition, to two separate Kubernetes clusters. When I reported success a few minutes ago, it was with the community edition. However, with nginx-ingress and the same manifests used for the community edition, the rewrites are not succeeding... 404s... Arggg...
I've attached my deployment scripts, which I was documenting for our team. Could you please take a look at them to see whether you spot any reasons that they wouldn't work, as expected? I am going to dig back in when I get back into the office in the morning and will report what I find. I've left the httpbin backend services running, in case you want to play with anything. No issues with your access, if desired.
Thank you for your help and support,
Mike
- JRahm
I'll try to track down some help for you, michaelgardner. In the meantime, can you clarify if you are using the kuburnetes flavor of nginx ingress, or the nginx ingress for kubernetes? Clear as mud, I know...this might help: https://www.nginx.com/blog/guide-to-choosing-ingress-controller-part-4-nginx-ingress-controller-options/.
Examples of rewrites from the nginx ingress BY nginx: https://github.com/nginxinc/kubernetes-ingress/tree/v2.2.2/examples/rewrites
- JRahm
That seems to match the syntax on the ingress example. A quick search on stack seems to also support the same syntax. Are you on at least ingress controller 2.0 and kubernetes 1.22? the referenced API version doesn't seem to be compatible earlier.
- xuwen
Cumulonimbus
when HTTP_REQUEST { set uri [HTTP::uri] if { $uri contains "anything" } { HTTP::uri "/[join [lrange [split $uri "/"] 2 end] "/"]" } }
