feat: Simulated Provider for running IT

.ci/test

@@ -36,7 +36,10 @@ function test_with_coverage() {
   local output_dir=test/output
   local coverprofile_file=coverprofile.out
   mkdir -p test/output
-  ginkgo $GINKGO_COMMON_FLAGS --coverprofile ${coverprofile_file} -covermode=set -output-dir ${output_dir} ${TEST_PACKAGES}
+  ginkgo $GINKGO_COMMON_FLAGS \
+         --coverprofile ${coverprofile_file} -covermode=set \
+         --skip-package ${SKIP_PACKAGES} \
+         -output-dir ${output_dir} ${TEST_PACKAGES}
 
   sed -i -e '/mode: set/d' ${output_dir}/${coverprofile_file}
   {( echo "mode: set"; cat ${output_dir}/${coverprofile_file} )} > ${output_dir}/${coverprofile_file}.temp
@@ -47,18 +50,22 @@ function test_with_coverage() {
 ###############################################################################
 
 if [[ "${SKIP_UNIT_TESTS}" != "" ]]; then
-  echo ">>>>>Skipping unit tests"
+  echo ">>>>> Skipping unit tests"
 else
   echo ">>>>> Invoking unit tests"
   TEST_PACKAGES="cmd pkg"
-  GINKGO_COMMON_FLAGS="-r -timeout=1h0m0s --randomize-all --randomize-suites --fail-on-pending  --show-node-events"
+  SKIP_PACKAGES="simulatedprovider/test/integration"
+  GINKGO_COMMON_FLAGS="-r -timeout=1h0m0s --randomize-all --randomize-suites --fail-on-pending  --show-node-events --poll-progress-after=300s --poll-progress-interval=60s"
   test_with_coverage
   echo ">>>>> Finished executing unit tests"
 fi
 
-# Integration tests here will always be skipped.
 if [[ "${SKIP_INTEGRATION_TESTS}" != "" ]]; then
   echo ">>>>> Skipping integration tests"
+else
+  echo ">>>>> Invoking integration tests with the simulated provider"
+	ginkgo -v --show-node-events --poll-progress-after=300s --poll-progress-interval=60s pkg/simulatedprovider/test/integration/controller
+  echo ">>>>> Finished executing integration tests"
 fi
 
 #TODO: return success failure properly

.gitignore

@@ -6,6 +6,7 @@
 /test
 /logs
 /hack/tools/bin
+/pkg/simulatedprovider/bin
 
 *.html
 .vscode
@@ -20,12 +21,17 @@ kubectl
 .cache_ggshield
 
 # Binary files of MCM
+./machine-controller
 ./machine-controller-manager
 ./managevm
 
 # Output of the go coverage tool, specifically when used with LiteIDE
 *coverprofile.out*
 
+# Output of MCM IT logs
+**/*.log
+**/*.log.*
+
 # Autogen tags
 tags
 

docs/development/integration_tests.md

@@ -21,7 +21,19 @@ Integration tests for `machine-controller-manager-provider-{provider-name}` can
  - In case of non-gardener setup (control cluster is not a gardener seed), the name of the machineclass must be `test-mc-v1` and the value of `providerSpec.secretRef.name` should be `test-mc-secret`.
  - In case of azure, `TARGET_CLUSTER_NAME` must be same as the name of the Azure ResourceGroup for the cluster.
  - If you are deploying the secret manually, a `Secret` named `test-mc-secret` (that contains the provider secret and cloud-config) in the `default` namespace of the Control Cluster should be created.
-3. The controllers log files (`mcm_process.log` and `mc_process.log`) are stored in `.ci/controllers-test/logs` repo and can be used later.
+3. The controllers log files (`mcm_process.log` and `mc_process.log`) are stored in `.ci/controllers-test/logs` directory and can be used later.
+
+### With the Simulated Provider
+
+Before running the simulated provider, please ensure that there's no old `kwokctl` versions present on your system since the cluster creation installs the required version. But that only happens if there's no existing installation present.
+
+To run the integration tests against the simulated provider, rather than running the `test-integration` target from the provider repository, just run it on the project root.
+That is, `machine-controller-manager/Makefile` provides the same helper target that runs IT with the simulated provider.
+```
+make test-integration
+```
+No additional inputs are required. The logs are stored in `pkg/simulatedprovider/test/integration/controller/logs` directory.
+
 ## Adding Integration Tests for new providers
 
 For a new provider, Running Integration tests works with no changes. But for the orphan resource test cases to work correctly, the provider-specific API calls and the Resource Tracker Interface (RTI) should be implemented. Please check [`machine-controller-manager-provider-aws`](https://github.com/gardener/machine-controller-manager-provider-aws/blob/master/test/integration/provider/) for reference.

go.mod

@@ -47,7 +47,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
 	github.com/prometheus/common v0.66.1 // indirect
 	github.com/prometheus/procfs v0.16.1 // indirect

go.sum

@@ -90,8 +90,9 @@ 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/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h0RJWRi/o0o=
 github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=

kubernetes/crds.go

@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: 2026 SAP SE or an SAP affiliate company and Gardener contributors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package kubernetes
+
+import (
+	_ "embed"
+
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	sigyaml "sigs.k8s.io/yaml"
+)
+
+func mustUnmarshal(raw []byte) *apiextensionsv1.CustomResourceDefinition {
+	t := new(apiextensionsv1.CustomResourceDefinition)
+	err := sigyaml.Unmarshal(raw, &t)
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+var (
+	//go:embed crds/machine.sapcloud.io_machineclasses.yaml
+	// MachineClassCRD represents the raw bytes for MachineClass resource.
+	MachineClassCRD []byte
+	//go:embed crds/machine.sapcloud.io_machinedeployments.yaml
+	// MachineDeploymentCRD represents the raw bytes for MachineDeployment resource.
+	MachineDeploymentCRD []byte
+	//go:embed crds/machine.sapcloud.io_machinesets.yaml
+	// MachineSetCRD represents the raw bytes for MachineSet resource.
+	MachineSetCRD []byte
+	//go:embed crds/machine.sapcloud.io_machines.yaml
+	// MachineCRD represents the raw bytes for Machine resource.
+	MachineCRD []byte
+
+	// CRDs is a list of all machine-controller-manager CRDs.
+	CRDs = []*apiextensionsv1.CustomResourceDefinition{
+		mustUnmarshal(MachineClassCRD),
+		mustUnmarshal(MachineDeploymentCRD),
+		mustUnmarshal(MachineSetCRD),
+		mustUnmarshal(MachineCRD),
+	}
+)

pkg/simulatedprovider/Makefile

@@ -0,0 +1,49 @@
+# SPDX-FileCopyrightText: 2026 SAP SE or an SAP affiliate company and Gardener contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+PKG_ROOT      := $(shell dirname "$(realpath $(lastword $(MAKEFILE_LIST)))")
+PKG_DIR       := $(shell dirname "$(PKG_ROOT)")
+REPO_ROOT     := $(shell dirname "$(PKG_DIR)")
+TOOLS_BIN_DIR := $(REPO_ROOT)/hack/tools/bin
+
+KWOKCTL       ?= $(TOOLS_BIN_DIR)/kwokctl
+KWOK_VERSION  ?= v0.8.0
+
+$(KWOKCTL): $(TOOLS_BIN_DIR)
+	GOBIN=$(abspath $(TOOLS_BIN_DIR)) go install sigs.k8s.io/kwok/cmd/{kwok,kwokctl}@$(KWOK_VERSION)
+
+
+.PHONY: build
+build:
+	@mkdir -p bin
+	go build -v -o bin/machine-controller cmd/machine-controller/main.go
+
+.PHONY: start
+start:
+	@GO111MODULE=on go run \
+			cmd/machine-controller/main.go \
+			--control-kubeconfig=$(CONTROL_KUBECONFIG) \
+			--target-kubeconfig=$(TARGET_KUBECONFIG) \
+			--namespace=$(CONTROL_NAMESPACE) \
+			--machine-creation-timeout=20m \
+			--machine-drain-timeout=5m \
+			--machine-health-timeout=10m \
+			--machine-pv-detach-timeout=2m \
+			--machine-safety-apiserver-statuscheck-timeout=30s \
+			--machine-safety-apiserver-statuscheck-period=1m \
+			--machine-safety-orphan-vms-period=30m \
+			--leader-elect=$(LEADER_ELECT) \
+			--v=3
+
+.PHONY: start-simulated-cluster
+start-simulated-cluster: $(KWOKCTL)
+	$(KWOKCTL) create cluster --name "test-cluster" --config ./cluster/kwok-config.yaml
+
+.PHONY: stop-simulated-cluster
+stop-simulated-cluster: $(KWOKCTL)
+	$(KWOKCTL) delete cluster --name "test-cluster"
+
+.PHONY: test-integration
+test-integration:
+	@(cd test/integration/controller; ginkgo -v --show-node-events --poll-progress-after=300s --poll-progress-interval=60s)