Update k8s to 1.36 and build with go 1.26

Signed-off-by: Niklas Ott <niklas.ott@unwired.at>

Author: ceriath

.github/workflows/build.yaml

@@ -23,7 +23,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
           cache-dependency-path: |
             **/go.sum
             **/go.mod

.github/workflows/release.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - uses: fluxcd/flux2/action@main
       - uses: sigstore/cosign-installer@cad07c2e89fa2edd6e2d7bab4c1aa38e53f76003 # v4.1.1
       - name: Prepare

.github/workflows/scan.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Initialize CodeQL
         uses: github/codeql-action/init@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4.35.2
         with:

Dockerfile

@@ -1,4 +1,4 @@
-ARG GO_VERSION=1.25
+ARG GO_VERSION=1.26
 ARG XX_VERSION=1.6.1
 
 FROM --platform=$BUILDPLATFORM tonistiigi/xx:${XX_VERSION} AS xx

Dockerfile.loadtester

@@ -1,4 +1,4 @@
-FROM golang:1.25-alpine AS builder
+FROM golang:1.26-alpine AS builder
 
 ARG TARGETPLATFORM
 ARG TARGETARCH

Makefile

@@ -6,7 +6,7 @@ build:
 	CGO_ENABLED=0 go build -a -o ./bin/flagger ./cmd/flagger
 
 tidy:
-	rm -f go.sum; go mod tidy -compat=1.25
+	rm -f go.sum; go mod tidy -compat=1.26
 
 vet:
 	go vet ./...

docs/gitbook/dev/dev-guide.md

@@ -8,7 +8,7 @@ Flagger is written in Go and uses Go modules for dependency management.
 
 On your dev machine install the following tools:
 
-* go >= 1.25
+* go >= 1.26
 * kubectl >= 1.30
 * kustomize >= 5.0
 * helm >= 3.0

go.mod

@@ -1,6 +1,6 @@
 module github.com/fluxcd/flagger
 
-go 1.25.0
+go 1.26.0
 
 require (
 	cloud.google.com/go/monitoring v1.27.0
@@ -22,16 +22,16 @@ require (
 	google.golang.org/api v0.276.0
 	google.golang.org/genproto v0.0.0-20260414002931-afd174a4e478
 	google.golang.org/grpc v1.80.0
-	google.golang.org/protobuf v1.36.11
+	google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af
 	gopkg.in/h2non/gock.v1 v1.1.2
 	gopkg.in/inf.v0 v0.9.1
-	k8s.io/api v0.35.4
-	k8s.io/apimachinery v0.35.4
-	k8s.io/client-go v0.35.4
-	k8s.io/code-generator v0.35.4
+	k8s.io/api v0.36.1
+	k8s.io/apimachinery v0.36.1
+	k8s.io/client-go v0.36.1
+	k8s.io/code-generator v0.36.1
 	k8s.io/klog/v2 v2.140.0
-	k8s.io/metrics v0.35.4
-	k8s.io/utils v0.0.0-20260319190234-28399d86e0b5
+	k8s.io/metrics v0.36.1
+	k8s.io/utils v0.0.0-20260507154919-ff6756f316d2
 	knative.dev/serving v0.46.6
 )
 
@@ -43,7 +43,7 @@ require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/blendle/zapdriver v1.3.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
-	github.com/emicklei/go-restful/v3 v3.12.2 // indirect
+	github.com/emicklei/go-restful/v3 v3.13.0 // indirect
 	github.com/evanphx/json-patch/v5 v5.9.11 // indirect
 	github.com/fxamacker/cbor/v2 v2.9.0 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
@@ -98,11 +98,11 @@ require (
 	gopkg.in/evanphx/json-patch.v4 v4.13.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/gengo/v2 v2.0.0-20250922181213-ec3ebc5fd46b // indirect
-	k8s.io/kube-openapi v0.0.0-20250910181357-589584f1c912 // indirect
+	k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a // indirect
 	knative.dev/networking v0.0.0-20250902160145-7dad473f6351 // indirect
 	knative.dev/pkg v0.0.0-20250909011231-077dcf0d00e8 // indirect
 	sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 // indirect
 	sigs.k8s.io/randfill v1.0.0 // indirect
-	sigs.k8s.io/structured-merge-diff/v6 v6.3.0 // indirect
+	sigs.k8s.io/structured-merge-diff/v6 v6.3.2 // indirect
 	sigs.k8s.io/yaml v1.6.0 // indirect
 )

go.sum

@@ -26,8 +26,8 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/emicklei/go-restful/v3 v3.12.2 h1:DhwDP0vY3k8ZzE0RunuJy8GhNpPL6zqLkDf9B/a0/xU=
-github.com/emicklei/go-restful/v3 v3.12.2/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
+github.com/emicklei/go-restful/v3 v3.13.0 h1:C4Bl2xDndpU6nJ4bc1jXd+uTmYPVUwkD6bFY/oTyCes=
+github.com/emicklei/go-restful/v3 v3.13.0/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
 github.com/envoyproxy/go-control-plane v0.14.0 h1:hbG2kr4RuFj222B6+7T83thSPqLjwBIfQawTkC++2HA=
 github.com/envoyproxy/go-control-plane/envoy v1.36.0 h1:yg/JjO5E7ubRyKX3m07GF3reDNEnfOboJ0QySbH736g=
 github.com/envoyproxy/go-control-plane/envoy v1.36.0/go.mod h1:ty89S1YCCVruQAm9OtKeEkQLTb+Lkz0k8v9W0Oxsv98=
@@ -56,8 +56,6 @@ github.com/go-openapi/jsonreference v0.21.0 h1:Rs+Y7hSXT83Jacb7kFyjn4ijOuVGSvOdF
 github.com/go-openapi/jsonreference v0.21.0/go.mod h1:LmZmgsrTkVg9LG4EaHeY8cBDslNPMo06cago5JNLkm4=
 github.com/go-openapi/swag v0.23.0 h1:vsEVJDUo2hPJ2tu0/Xc+4noaxyEffXNIs3cOULZ+GrE=
 github.com/go-openapi/swag v0.23.0/go.mod h1:esZ8ITTYEsH1V2trKHjAN8Ai7xHb8RV+YSZ577vPjgQ=
-github.com/go-task/slim-sprig/v3 v3.0.0 h1:sUs3vkvUymDpBKi3qH1YSqBQk9+9D/8M2mN1vB6EwHI=
-github.com/go-task/slim-sprig/v3 v3.0.0/go.mod h1:W848ghGpv3Qj3dhTPRyJypKRiqCdHZiAzKg9hl15HA8=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/gnostic-models v0.7.0 h1:qwTtogB15McXDaNqTZdzPJRHvaVJlAl+HVQnLmJEJxo=
@@ -67,8 +65,6 @@ github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX
 github.com/google/go-containerregistry v0.20.3 h1:oNx7IdTI936V8CQRveCjaxOiegWwvM7kqkbXTpyiovI=
 github.com/google/go-containerregistry v0.20.3/go.mod h1:w00pIgBRDVUDFM6bq+Qx8lwNWK+cxgCuX1vd3PIBDNI=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
-github.com/google/pprof v0.0.0-20250403155104-27863c87afa6 h1:BHT72Gu3keYf3ZEu2J0b1vyeLSOYI8bm5wbJM/8yDe8=
-github.com/google/pprof v0.0.0-20250403155104-27863c87afa6/go.mod h1:boTsfXsheKC2y+lKOCMpSfarhxDeIzfZG1jqGcPl3cA=
 github.com/google/s2a-go v0.1.9 h1:LGD7gtMgezd8a/Xak7mEWL0PjoTQFvpRudN895yqKW0=
 github.com/google/s2a-go v0.1.9/go.mod h1:YA0Ei2ZQL3acow2O62kdp9UlnvMmU7kA6Eutn0dXayM=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
@@ -126,10 +122,6 @@ github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
 github.com/oapi-codegen/runtime v1.0.0 h1:P4rqFX5fMFWqRzY9M/3YF9+aPSPPB06IzP2P7oOxrWo=
 github.com/oapi-codegen/runtime v1.0.0/go.mod h1:LmCUMQuPB4M/nLXilQXhHw+BLZdDb18B34OO356yJ/A=
-github.com/onsi/ginkgo/v2 v2.27.2 h1:LzwLj0b89qtIy6SSASkzlNvX6WktqurSHwkk2ipF/Ns=
-github.com/onsi/ginkgo/v2 v2.27.2/go.mod h1:ArE1D/XhNXBXCBkKOLkbsb2c81dQHCRcF5zwn/ykDRo=
-github.com/onsi/gomega v1.38.2 h1:eZCjf2xjZAqe+LeWvKb5weQ+NcPwX84kqJ0cZNxok2A=
-github.com/onsi/gomega v1.38.2/go.mod h1:W2MJcYxRGV63b418Ai34Ud0hEdTVXq9NW9+Sx6uXf3k=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
@@ -228,8 +220,8 @@ google.golang.org/genproto/googleapis/rpc v0.0.0-20260406210006-6f92a3bedf2d h1:
 google.golang.org/genproto/googleapis/rpc v0.0.0-20260406210006-6f92a3bedf2d/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
 google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
 google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
-google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
-google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
+google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af h1:+5/Sw3GsDNlEmu7TfklWKPdQ0Ykja5VEmq2i817+jbI=
+google.golang.org/protobuf v1.36.12-0.20260120151049-f2248ac996af/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
@@ -244,24 +236,24 @@ gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-k8s.io/api v0.35.4 h1:P7nFYKl5vo9AGUp1Z+Pmd3p2tA7bX2wbFWCvDeRv988=
-k8s.io/api v0.35.4/go.mod h1:yl4lqySWOgYJJf9RERXKUwE9g2y+CkuwG+xmcOK8wXU=
-k8s.io/apimachinery v0.35.4 h1:xtdom9RG7e+yDp71uoXoJDWEE2eOiHgeO4GdBzwWpds=
-k8s.io/apimachinery v0.35.4/go.mod h1:NNi1taPOpep0jOj+oRha3mBJPqvi0hGdaV8TCqGQ+cc=
-k8s.io/client-go v0.35.4 h1:DN6fyaGuzK64UvnKO5fOA6ymSjvfGAnCAHAR0C66kD8=
-k8s.io/client-go v0.35.4/go.mod h1:2Pg9WpsS4NeOpoYTfHHfMxBG8zFMSAUi4O/qoiJC3nY=
-k8s.io/code-generator v0.35.4 h1:i0FfiXAeUMBlHarjVk5ZWf6Wjsg3YJpNYmOg0nPk6r4=
-k8s.io/code-generator v0.35.4/go.mod h1:rwLDdemFgPK6dGlLFHPUieyekgAlV1x8IVafjAy/ELA=
+k8s.io/api v0.36.1 h1:XbL/EMj8K2aJpJtePmqUyQMsM0D4QI2pvl7YKJ20FTY=
+k8s.io/api v0.36.1/go.mod h1:KOWo4ey3TINlXjeHVuwB3i+tXXnu+UcwFBHlI/9dvEo=
+k8s.io/apimachinery v0.36.1 h1:G63Gjx2W+q0YD+72Vo8oY0nDnePVwnuzTmmy5ENrVSA=
+k8s.io/apimachinery v0.36.1/go.mod h1:ibYOR00vW/I1kzvi5SF0dRuJ52BvKtfvRdOn35GPQ+8=
+k8s.io/client-go v0.36.1 h1:FN/K8QIT2CEDt+2WB2HnWrUANZ50AP5GII43/SP2JR0=
+k8s.io/client-go v0.36.1/go.mod h1:s6rAnCtTGYDQnpNjEhSaISV+2O8jwruZ6m3QOYBFbtU=
+k8s.io/code-generator v0.36.1 h1:5bHQ7NbBcFFLHcoyo/hgU3m2tQV5RLz2nv4QNDlsbXc=
+k8s.io/code-generator v0.36.1/go.mod h1:oCv8WmrW2RGdcMyvSk1aYbBfSs51ggtSFQr1YNeuAuo=
 k8s.io/gengo/v2 v2.0.0-20250922181213-ec3ebc5fd46b h1:gMplByicHV/TJBizHd9aVEsTYoJBnnUAT5MHlTkbjhQ=
 k8s.io/gengo/v2 v2.0.0-20250922181213-ec3ebc5fd46b/go.mod h1:CgujABENc3KuTrcsdpGmrrASjtQsWCT7R99mEV4U/fM=
 k8s.io/klog/v2 v2.140.0 h1:Tf+J3AH7xnUzZyVVXhTgGhEKnFqye14aadWv7bzXdzc=
 k8s.io/klog/v2 v2.140.0/go.mod h1:o+/RWfJ6PwpnFn7OyAG3QnO47BFsymfEfrz6XyYSSp0=
-k8s.io/kube-openapi v0.0.0-20250910181357-589584f1c912 h1:Y3gxNAuB0OBLImH611+UDZcmKS3g6CthxToOb37KgwE=
-k8s.io/kube-openapi v0.0.0-20250910181357-589584f1c912/go.mod h1:kdmbQkyfwUagLfXIad1y2TdrjPFWp2Q89B3qkRwf/pQ=
-k8s.io/metrics v0.35.4 h1:KFo3xFe5rzLDarHLNjZB0J1g1c5fvl6A5Kk/8KzIwOA=
-k8s.io/metrics v0.35.4/go.mod h1:5DO36o9esGC1VXylSpqJWmwhoopS/erADQcACz1tN3s=
-k8s.io/utils v0.0.0-20260319190234-28399d86e0b5 h1:kBawHLSnx/mYHmRnNUf9d4CpjREbeZuxoSGOX/J+aYM=
-k8s.io/utils v0.0.0-20260319190234-28399d86e0b5/go.mod h1:xDxuJ0whA3d0I4mf/C4ppKHxXynQ+fxnkmQH0vTHnuk=
+k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a h1:xCeOEAOoGYl2jnJoHkC3hkbPJgdATINPMAxaynU2Ovg=
+k8s.io/kube-openapi v0.0.0-20260317180543-43fb72c5454a/go.mod h1:uGBT7iTA6c6MvqUvSXIaYZo9ukscABYi2btjhvgKGZ0=
+k8s.io/metrics v0.36.1 h1:MQPb+G4RhrKEpt8NETPssbW8QgGUc4Jbqu1jx+kPqGk=
+k8s.io/metrics v0.36.1/go.mod h1:xqS8XcWLjDzo6E7DJm/GfjKpRKdN5/MtJAQFuV6nLUc=
+k8s.io/utils v0.0.0-20260507154919-ff6756f316d2 h1:wU4tMEhLGgIbLvXQb1cfN+EcM0wf7zC6CPF+C79jroc=
+k8s.io/utils v0.0.0-20260507154919-ff6756f316d2/go.mod h1:xDxuJ0whA3d0I4mf/C4ppKHxXynQ+fxnkmQH0vTHnuk=
 knative.dev/networking v0.0.0-20250902160145-7dad473f6351 h1:Gv/UqbN0AK+ORoT5e2Kg+3+uMW/y9CCdhpXKxYaVV6k=
 knative.dev/networking v0.0.0-20250902160145-7dad473f6351/go.mod h1:P/fAhhVDgmLt1ugFX8vBvdSDiUOw2P4SGcjbzoZ02Xw=
 knative.dev/pkg v0.0.0-20250909011231-077dcf0d00e8 h1:n0BMHXIem9MyDkK4vfA4Vzdxaf1e+EeLJ6k+8exCjjI=
@@ -272,7 +264,7 @@ sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730 h1:IpInykpT6ceI+QxKBbEflcR5E
 sigs.k8s.io/json v0.0.0-20250730193827-2d320260d730/go.mod h1:mdzfpAEoE6DHQEN0uh9ZbOCuHbLK5wOm7dK4ctXE9Tg=
 sigs.k8s.io/randfill v1.0.0 h1:JfjMILfT8A6RbawdsK2JXGBR5AQVfd+9TbzrlneTyrU=
 sigs.k8s.io/randfill v1.0.0/go.mod h1:XeLlZ/jmk4i1HRopwe7/aU3H5n1zNUcX6TM94b3QxOY=
-sigs.k8s.io/structured-merge-diff/v6 v6.3.0 h1:jTijUJbW353oVOd9oTlifJqOGEkUw2jB/fXCbTiQEco=
-sigs.k8s.io/structured-merge-diff/v6 v6.3.0/go.mod h1:M3W8sfWvn2HhQDIbGWj3S099YozAsymCo/wrT5ohRUE=
+sigs.k8s.io/structured-merge-diff/v6 v6.3.2 h1:kwVWMx5yS1CrnFWA/2QHyRVJ8jM6dBA80uLmm0wJkk8=
+sigs.k8s.io/structured-merge-diff/v6 v6.3.2/go.mod h1:M3W8sfWvn2HhQDIbGWj3S099YozAsymCo/wrT5ohRUE=
 sigs.k8s.io/yaml v1.6.0 h1:G8fkbMSAFqgEFgh4b1wmtzDnioxFCUgTZhlbj5P9QYs=
 sigs.k8s.io/yaml v1.6.0/go.mod h1:796bPqUfzR/0jLAl6XjHl3Ck7MiyVv8dbTdyT3/pMf4=