feat(source/istio): support version 1.25+

[ivankatliarchuk]

What does it do ?

• Added support for currently supported version 1.22 - 1.25, 1.26 https://istio.io/latest/docs/releases/supported-releases/
• fixed istio.md with pre-commit-hook

Note; tested with 1.22 and 1.25 versions. Works without issues

Currently supported version is 1.25, as 1.22 end of life is Jan 22, 2025

Stored versions

# istio 1.22
❯❯ kubectl get crd virtualservices.networking.istio.io -ojsonpath='{.status.storedVersions}'
["v1beta1"]%

❯❯ kubectl get crd gateways.networking.istio.io -ojsonpath='{.status.storedVersions}'
["v1beta1"]%

# istio 1.26
❯❯ kubectl get crd virtualservices.networking.istio.io -ojsonpath='{.status.storedVersions}'
["v1beta1"]%

❯❯ kubectl get crd gateways.networking.istio.io -ojsonpath='{.status.storedVersions}'
["v1beta1"]%

It is safe to usev1, but I think we should support v1beta while v1beta is current storage version

Motivation

Fixes: #4473, #2798

Follow-up:

• istio-virtualservice in some occasions incorrectly identify RecordType cname instead of a record
• improve performance WIP chore(source): istio informers index service objects #5547

More

• Yes, this PR title follows Conventional Commits
• Yes, I added unit tests
• Yes, I updated end user documentation accordingly

Smoke test for kind: Gateway

Arguments

go run main.go \
    --provider=aws \
    --registry=txt \
    --source=service \
    --log-level=info \
    --source=istio-gateway \
    --policy=sync \
    --fqdn-template="{{ .Kind | toLower }}-{{ .APIVersion | replace \"networking.istio.io/\" \"\"}}-{{.Name}}.local.tld" \
    --combine-fqdn-annotation \
    --domain-filter=local.tld

# https://istio.io/latest/docs/reference/config/networking/gateway/
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: httpbin-gateway
  namespace: extdns-istio
  annotations:
    external-dns.alpha.kubernetes.io/target : 10.172.1.12
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "httpbin.local.ltd"

Create

Delete

Virtual Service

go run main.go \
    --provider=aws \
    --interval=30s \
    --registry=txt \
    --log-level=info \
    --source=istio-virtualservice \
    --policy=sync

Manifest files

---
# https://istio.io/latest/docs/reference/config/networking/gateway/
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: httpbin-gateway
  namespace: extdns-istio
  annotations:
    external-dns.alpha.kubernetes.io/target : 10.172.1.256
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "httpbin-test.local.tld"
---
# https://istio.io/latest/docs/reference/config/networking/virtual-service/
# Configure routes for traffic entering via the Gateway
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: httpbin-vservice
  namespace: extdns-istio
spec:
  hosts:
  - "httpbin-test.local.tld"
  gateways:
  - extdns-istio/httpbin-gateway
  http:
  - match:
    - uri:
        prefix: /status
    - uri:
        prefix: /delay
    route:
    - destination:
        port:
          number: 8000
        host: httpbin

Create

Delete

[ivankatliarchuk]

Hi @mthemis-provenir, @simonostendorf and @stevehipwell can you confirm that this PR fixes your issue ? If needed, see how to test a PR ?. This will require golang to be installed.

[mthemis-provenir]

Would it not make more sense to target support of Istio 1.26, given that only 1.25 and 1.26 are supported versions? Resources are stored as v1 in 1.26, so I doubt v1beta1 support will change anything.

[ivankatliarchuk]

Everything is stored in v1beta, you could execute a command kubectl get crd gateways.networking.istio.io -ojsonpath='{.status.storedVersions}' or similar. v1 returned by the API at the moment.

I will try 1.25 as yep, 1.22 is end of life in Jan 2025.

You could try 1.26, it most likely will work as well. If not, I'll create a patch

[mthemis-provenir]

Everything is stored in v1beta, you could execute a command kubectl get crd gateways.networking.istio.io -ojsonpath='{.status.storedVersions}' or similar. v1 returned by the API at the moment.

I will try 1.25 as yep, 1.22 is end of life in Jan 2025.

You could try 1.26, it most likely will work as well. If not, I'll create a patch

Strange, you are correct - gateways and virtualservices are stored as v1beta1, but describing resources themselves show as v1. In that case yes this most likely will work I guess.

[mloiseleur]

/lgtm

[mthemis-provenir]

Any chance of an approval / merge here, guys? Would be good to get external-dns supporting Istio releases that aren't EOL.
cc @mloiseleur @szuecs

[ivankatliarchuk]

I have no issues merging this; the change is approved. However, please be aware that the next release is likely to occur in September due to summer holiday period

[ivankatliarchuk]

/approve

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[ivankatliarchuk]

Staging image: https://console.cloud.google.com/gcr/images/k8s-staging-external-dns/global/external-dns@sha256:23a740fe0a0e244b9570565a86b6daf8189a4dfead8f462e1e6a60f150f5984b/details?inv=1&invt=Ab2Itw&tab=vulnz

docker pull gcr.io/k8s-staging-external-dns/external-dns:v20250707-v0.18.0-25-g252a5e01