Add Keda Deployer #3386

creydr · 2026-01-22T13:22:40Z

Changes

🎁 Add the possibility to deploy a function with a Keda HTTP scaler

Currently only exposes the function cluster internally. Issue to make the externally available is #3391.

/kind enhancement

Flow

flowchart TD
    U(User/other service) -->|accesses| A
    A[Entrypoint - Bridge Service] -->|forwards request| B
    B[Keda HTTP add-on interceptor-proxy] -->|forwards request| C
    B -.->|reads| E
    B -.->|scales| D
    C[App service] -->|forwards request| D
    D[Deployment]
    E{HTTPScaledObject}

Test procedure:

Build the func-cli with those changes
make build
Clone a repo with a function
e.g. cd /tmp & git clone https://github.com/creydr/func-go-hello-world

Make sure you have Keda with the HTTP-add-on installed

kubectl apply --server-side -f https://github.com/kedacore/keda/releases/download/v2.17.0/keda-2.17.0.yaml
kubectl apply --server-side -f https://github.com/kedacore/keda/releases/download/v2.17.0/keda-2.17.0-core.yaml


kubectl apply --server-side -f https://github.com/kedacore/http-add-on/releases/download/v0.11.1/keda-add-ons-http-0.11.1-crds.yaml
kubectl apply --server-side -f https://github.com/kedacore/http-add-on/releases/download/v0.11.1/keda-add-ons-http-0.11.1.yaml

Deploy the function with the keda deployer:

<path to built-func-binary> deploy --registry <your registry> --deployer keda
Building function image
Still building
Still building
Yes, still building
🙌 Function built: quay.io/creydr/func-go-hello-world/func-go-hello-world:latest
Pushing function image to the registry "quay.io" using the "creydr" user credentials
✅ Function deployed in namespace "default" and exposed at URL: 
   http://func-go-hello-world-interceptor-bridge.default.svc:8080

Check for the created resources:

kubectl get httpscaledobject                            
NAME                  TARGETWORKLOAD                           TARGETSERVICE            MINREPLICAS   MAXREPLICAS   AGE     ACTIVE
func-go-hello-world   apps/v1/Deployment/func-go-hello-world   func-go-hello-world:80   0             10            2m48s   True

kubectl get svc
NAME                                    TYPE           CLUSTER-IP     EXTERNAL-IP                                                  PORT(S)    AGE
func-go-hello-world                     ClusterIP      10.96.245.62   <none>                                                       80/TCP     3m48s
func-go-hello-world-interceptor-bridge   ExternalName   <none>         keda-add-ons-http-interceptor-proxy.keda.svc.cluster.local   8080/TCP   3m41s

Start a load test and see the pods getting scaled by Keda:

cat <<-EOF | kubectl apply -f  -                                        
apiVersion: batch/v1              
kind: Job     
metadata:
  name: hey-load-test
spec:    
  template:                                                     
    spec:  
      containers:                           
      - name: hey 
        image: quay.io/creydr/hey:latest
        args:
          - "-n"     
          - "1000000"
          - "-c"
          - "100"
          - "http://func-go-hello-world-interceptor-bridge:8080"
      restartPolicy: Never
  backoffLimit: 1
EOF

kubectl get po
NAME                                   READY   STATUS    RESTARTS   AGE
func-go-hello-world-6b895b8b59-8x2wz   1/1     Running   0          58s
func-go-hello-world-6b895b8b59-bhgzd   1/1     Running   0          43s
func-go-hello-world-6b895b8b59-dg4q9   1/1     Running   0          58s
func-go-hello-world-6b895b8b59-dgp92   1/1     Running   0          43s
func-go-hello-world-6b895b8b59-h8pzh   1/1     Running   0          27s
func-go-hello-world-6b895b8b59-j6zwd   1/1     Running   0          43s
func-go-hello-world-6b895b8b59-k5rkd   1/1     Running   0          63s
func-go-hello-world-6b895b8b59-n4582   1/1     Running   0          43s
func-go-hello-world-6b895b8b59-rh56x   1/1     Running   0          27s
func-go-hello-world-6b895b8b59-vfxtj   1/1     Running   0          58s
hey-load-test-t4mwp                    1/1     Running   0          68s

Release Note

Add keda deployer

codecov · 2026-01-22T14:13:44Z

Codecov Report

❌ Patch coverage is 52.81174% with 193 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.56%. Comparing base (7d24048) to head (08635b5).

Files with missing lines	Patch %	Lines
pkg/keda/deployer.go	58.01%	73 Missing and 16 partials ⚠️
pkg/keda/describer.go	50.00%	28 Missing and 8 partials ⚠️
pkg/keda/lister.go	56.14%	18 Missing and 7 partials ⚠️
pkg/keda/remover.go	32.43%	20 Missing and 5 partials ⚠️
cmd/client.go	30.00%	7 Missing ⚠️
cmd/deploy.go	25.00%	3 Missing ⚠️
pkg/keda/client.go	50.00%	2 Missing and 1 partial ⚠️
pkg/keda/wait.go	62.50%	2 Missing and 1 partial ⚠️
cmd/completion_util.go	0.00%	1 Missing ⚠️
pkg/deployer/testing/integration_test_helper.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3386      +/-   ##
==========================================
- Coverage   54.61%   54.56%   -0.05%     
==========================================
  Files         173      179       +6     
  Lines       19814    20216     +402     
==========================================
+ Hits        10821    11031     +210     
- Misses       7861     8015     +154     
- Partials     1132     1170      +38

Flag	Coverage Δ
e2e	`38.55% <7.14%> (-0.75%)`	⬇️
e2e go	`32.73% <4.03%> (-0.68%)`	⬇️
e2e node	`28.51% <4.03%> (-0.59%)`	⬇️
e2e python	`32.26% <4.03%> (-0.67%)`	⬇️
e2e quarkus	`28.66% <4.03%> (-0.57%)`	⬇️
e2e rust	`28.08% <4.03%> (-0.58%)`	⬇️
e2e springboot	`26.55% <4.03%> (-0.54%)`	⬇️
e2e typescript	`28.62% <4.03%> (-0.59%)`	⬇️
integration	`17.54% <65.01%> (+0.99%)`	⬆️
unit macos-14	`42.27% <1.23%> (-0.88%)`	⬇️
unit macos-latest	`42.27% <1.23%> (-0.88%)`	⬇️
unit ubuntu-24.04-arm	`42.61% <0.97%> (-0.87%)`	⬇️
unit ubuntu-latest	`43.16% <1.23%> (-0.90%)`	⬇️
unit windows-latest	`42.29% <1.23%> (-0.88%)`	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

gauron99 · 2026-01-22T15:13:56Z

/test all

creydr · 2026-01-23T11:28:48Z

pkg/keda/deployer.go

+			CooldownPeriod: ptr.To(int32(300)),
+			ScalingMetric: &httpv1alpha1.ScalingMetricSpec{
+				Rate: &httpv1alpha1.RateMetricSpec{
+					TargetValue: 100,
+					Window: metav1.Duration{
+						Duration: time.Minute,
+					},
+					Granularity: metav1.Duration{
+						Duration: time.Second,
+					},
+				},
+			},


@linkvt do you have any recommendations for those metrics? I mostly took them from the example 🙃

creydr · 2026-01-23T11:54:51Z

/cc @gauron99 @lkingland @matejvasek

linkvt · 2026-01-24T19:30:26Z

go.mod


+// Override invalid k8s.io/client-go v1.5.2 requirement from keda http-add-on
+// keda uses a replace directive internally, but those don't propagate to dependents
+replace k8s.io/client-go => k8s.io/client-go v0.34.3


PR to resolve this in the KHA is open and will probably be released next week, just need to fix CI, see kedacore/http-add-on#1424

Awesome. Thanks a lot

hack/component-versions.sh

schema/func_yaml-schema.json

pkg/k8s/deployer.go

pkg/keda/deployer.go

matejvasek · 2026-01-27T16:50:01Z

https://github.com/knative/func/pull/3386/files#diff-de5ffd1deebc759567528bb5daaae836c26cd37338fce587cb54276caf9291e0R111-R114
Missing keda value in the enum in the JSON schema file?
The file is generated so fix has to be done elsewhere.

func/pkg/functions/function.go

Line 213 in 8206b24

Deployer string `yaml:"deployer,omitempty" jsonschema:"enum=knative,enum=raw"`

pkg/keda/client.go

pkg/deployer/testing/integration_test_helper.go

# Conflicts: # go.mod # go.sum

creydr · 2026-01-29T10:46:01Z

infra issue
/test unit-tests

matejvasek · 2026-01-29T14:32:30Z

go.mod

 module knative.dev/func

-go 1.24.4
+go 1.25.5


Is inclusion of the patch version necessary (can't we just have 1.25)?

Also what dependency required 1.25?

This came when I added the keda http-addon. This is on 1.25.5 (https://github.com/kedacore/http-add-on/blob/8f2e332219c3949d5b0098b9700fd3014c6c6429/go.mod#L3)

I dont think we can bump if midstream is 1.24. This missmatch caused trouble in the past

matejvasek · 2026-01-29T14:59:01Z

pkg/deployer/testing/integration_test_helper.go

+	case keda.KedaDeployerName:
+		// use same in-cluster dialer as Kubernetes Deployer
+		fallthrough
 	case k8s.KubernetesDeployerName:


Nit: I think this could be little bit verbose using comma:

case keda.KedaDeployerName, k8s.KubernetesDeployerName:

gauron99 · 2026-01-29T20:51:27Z

I haven't found anything to change. Once the standing questions/discussions are resolved -- lgtm

matejvasek · 2026-01-30T15:35:54Z

/approve
/lgtm
/hold for others

knative-prow · 2026-01-30T15:36:00Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: creydr, matejvasek

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

~~OWNERS~~ [matejvasek]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

gauron99 · 2026-01-30T17:26:11Z

/lgtm

knative-prow bot added do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. kind/enhancement labels Jan 22, 2026

knative-prow bot requested review from dsimansk and jrangelramos January 22, 2026 13:22

knative-prow bot added the size/XXL Denotes a PR that changes 1000+ lines, ignoring generated files. label Jan 22, 2026

creydr force-pushed the keda-deployer branch from 2d7459c to 989fbf8 Compare January 22, 2026 14:01

knative-prow-robot added the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 22, 2026

creydr force-pushed the keda-deployer branch from 989fbf8 to a12ae90 Compare January 22, 2026 14:26

knative-prow-robot removed the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 22, 2026

creydr force-pushed the keda-deployer branch from 15a82c0 to ea2966e Compare January 23, 2026 11:07

creydr changed the title ~~[WIP] Add Keda Deployer~~ Add Keda Deployer Jan 23, 2026

knative-prow bot removed the do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. label Jan 23, 2026

creydr commented Jan 23, 2026

View reviewed changes

knative-prow bot requested review from gauron99, lkingland and matejvasek January 23, 2026 11:54

knative-prow-robot added the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 23, 2026

linkvt reviewed Jan 24, 2026

View reviewed changes

matejvasek reviewed Jan 26, 2026

View reviewed changes

hack/component-versions.sh Show resolved Hide resolved

matejvasek reviewed Jan 26, 2026

View reviewed changes

schema/func_yaml-schema.json Outdated Show resolved Hide resolved

matejvasek reviewed Jan 27, 2026

View reviewed changes

pkg/k8s/deployer.go Outdated Show resolved Hide resolved

matejvasek reviewed Jan 27, 2026

View reviewed changes

pkg/keda/deployer.go Outdated Show resolved Hide resolved

matejvasek reviewed Jan 27, 2026

View reviewed changes

pkg/keda/client.go Outdated Show resolved Hide resolved

matejvasek reviewed Jan 28, 2026

View reviewed changes

pkg/deployer/testing/integration_test_helper.go Outdated Show resolved Hide resolved

creydr added 2 commits January 28, 2026 18:05

Add Keda Deployer

d52b172

Run hack/update-codegen.sh

7a49d90

creydr added 7 commits January 28, 2026 18:08

Fix: add owner reference in bridge service too

4984e08

Run make schema-generate

135c86d

Update component-versions via component-versions.json

52a48ea

Remove cluster-domain flag and use cluster.local instead for now

95824be

Fix: add "keda" to deployer enum for jsonschema

3ea7855

Remove unneeded blank import

c62469c

Remove custom roundtripper for keda integration tests

e3f667b

creydr force-pushed the keda-deployer branch from e22bfe8 to e3f667b Compare January 28, 2026 17:27

knative-prow-robot removed the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 28, 2026

creydr added 3 commits January 28, 2026 18:34

Run ./hack/update-codegen.sh

0d76ef6

Fix linter issue

8b19fd2

Fix unit test for component version script

cf379c4

knative-prow-robot added the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 28, 2026

creydr added 2 commits January 29, 2026 11:32

Update to Keda HTTP Add-on 1.12

45189ab

Merge remote-tracking branch 'knative/main' into keda-deployer

a48fb70

# Conflicts: # go.mod # go.sum

knative-prow-robot removed the needs-rebase Indicates a PR cannot be merged because it has merge conflicts with HEAD. label Jan 29, 2026

creydr mentioned this pull request Jan 29, 2026

Clusterdomain is not configurable in Keda deployer #3403

Open

matejvasek reviewed Jan 29, 2026

View reviewed changes

Address review comments

08635b5

knative-prow bot assigned matejvasek Jan 30, 2026

knative-prow bot added do-not-merge/hold Indicates that a PR should not merge because someone has issued a /hold command. lgtm Indicates that a PR is ready to be merged. labels Jan 30, 2026

knative-prow bot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Jan 30, 2026

knative-prow bot assigned gauron99 Jan 30, 2026

Add Keda Deployer #3386

Are you sure you want to change the base?

Add Keda Deployer #3386

Uh oh!

Conversation

creydr commented Jan 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Changes

Flow

Test procedure:

Uh oh!

codecov bot commented Jan 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

gauron99 commented Jan 22, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

creydr commented Jan 23, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

matejvasek commented Jan 27, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

creydr commented Jan 29, 2026

Uh oh!

matejvasek Jan 29, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

gauron99 commented Jan 29, 2026

Uh oh!

matejvasek commented Jan 30, 2026

Uh oh!

knative-prow bot commented Jan 30, 2026

Uh oh!

gauron99 commented Jan 30, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

creydr commented Jan 22, 2026 •

edited

Loading

codecov bot commented Jan 22, 2026 •

edited

Loading

matejvasek commented Jan 27, 2026 •

edited

Loading

matejvasek Jan 29, 2026 •

edited

Loading