Merge pull request #1 from metacontroller/setup

chore: Initial commit

Author: grzesuav

.gitignore

@@ -0,0 +1 @@
+thing-controller

Dockerfile

@@ -0,0 +1,9 @@
+FROM golang:1.19 AS build
+
+COPY . /go/src/thing-controller
+WORKDIR /go/src/thing-controller
+RUN go mod vendor && go build -o /go/bin/thing-controller
+
+FROM debian:stretch-slim
+
+COPY --from=build /go/bin/thing-controller /usr/bin/thing-controller

Makefile

@@ -0,0 +1,15 @@
+PWD := ${CURDIR}
+ADDITIONAL_BUILD_ARGUMENTS?=""
+
+PKG		:= metacontroller
+API_GROUPS := metacontroller/v1alpha1
+
+CODE_GENERATOR_VERSION="v0.24.3"
+
+all: generate_crds
+
+.PHONY: generate_crds
+generate_crds:
+	@echo "+ Generating crds"
+	@go install sigs.k8s.io/controller-tools/cmd/controller-gen@latest
+	@controller-gen +crd:generateEmbeddedObjectMeta=true +paths="./api/..." +output:crd:stdout > crdv1.yaml

README.md

@@ -0,0 +1,69 @@
+## Example Go Controller
+
+This controller doesn't do anything useful.
+It's just an example skeleton for writing Metacontroller hooks with Go.
+
+**WARNING**
+
+There's a [known issue](https://github.com/GoogleCloudPlatform/metacontroller/issues/76)
+that makes it difficult to produce JSON according to the rules that Metacontroller
+requires if you import the official Go structs for Kubernetes APIs.
+In particular, some fields will always be emitted, even if you never set them,
+which goes against Metacontroller's [apply semantics](https://metacontroller.github.io/metacontroller/api/apply/).
+
+### Prerequisites
+
+* [Install Metacontroller](https://metacontroller.github.io/metacontroller/guide/install.html)
+
+### Install Thing Controller
+
+```sh
+kubectl apply -f crdv1.yaml
+kubectl apply -f thing-controller.yaml
+```
+
+### Create a Thing
+
+```sh
+kubectl apply -f my-thing.yaml
+```
+
+Look at the thing:
+
+```sh
+kubectl get thing -o yaml
+```
+
+Look at the thing the thing created:
+
+```sh
+kubectl get pod thing-1 -a
+```
+
+Look at what the thing the thing created said:
+
+```sh
+kubectl logs thing-1
+```
+
+### Clean up
+
+```sh
+kubectl delete -f thing-controller.yaml
+```
+
+### Building
+
+You don't need to build to run the example above,
+but if you make changes:
+
+```sh
+go mod vendor
+go build -o thing-controller
+```
+
+Or just make a new container image:
+
+```sh
+docker build . -t thing-controller
+```

api/types.go

@@ -0,0 +1,35 @@
+/*
+ *
+ * Copyright 2022. Metacontroller authors.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * /
+ */
+
+// +groupName=ctl.enisoc.com
+package v1
+
+import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+type ThingSpec struct {
+	message string `json:"message"`
+}
+
+// Thing
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+// +kubebuilder:subresource:status
+// +kubebuilder:resource:path=things,scope=Namespaced
+type Thing struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata"`
+
+	Spec ThingSpec `json:"spec"`
+}

crdv1.yaml

@@ -0,0 +1,49 @@
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.10.0
+  creationTimestamp: null
+  name: things.ctl.enisoc.com
+spec:
+  group: ctl.enisoc.com
+  names:
+    kind: Thing
+    listKind: ThingList
+    plural: things
+    singular: thing
+  scope: Namespaced
+  versions:
+  - name: v1
+    schema:
+      openAPIV3Schema:
+        description: Thing
+        properties:
+          apiVersion:
+            description: 'APIVersion defines the versioned schema of this representation
+              of an object. Servers should convert recognized schemas to the latest
+              internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#resources'
+            type: string
+          kind:
+            description: 'Kind is a string value representing the REST resource this
+              object represents. Servers may infer this from the endpoint the client
+              submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds'
+            type: string
+          metadata:
+            type: object
+          spec:
+            properties:
+              message:
+                type: string
+            required:
+            - message
+            type: object
+        required:
+        - metadata
+        - spec
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}

go.mod

@@ -0,0 +1,22 @@
+module thing-controller
+
+go 1.19
+
+require (
+	k8s.io/api v0.0.0-20180308023924-fd252c3a3e1d
+	k8s.io/apimachinery v0.0.0-20180302183502-e9ff529c66f8
+)
+
+require (
+	github.com/ghodss/yaml v1.0.0 // indirect
+	github.com/gogo/protobuf v1.0.0 // indirect
+	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b // indirect
+	github.com/google/gofuzz v1.0.0 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/spf13/pflag v1.0.0 // indirect
+	github.com/stretchr/testify v1.8.1 // indirect
+	golang.org/x/net v0.0.0-20180308154319-d0aafc73d5cd // indirect
+	golang.org/x/text v0.3.0 // indirect
+	gopkg.in/inf.v0 v0.9.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)

go.sum

@@ -0,0 +1,45 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/ghodss/yaml v1.0.0 h1:wQHKEahhL6wmXdzwWG11gIVCkOv05bNOh+Rxn0yngAk=
+github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
+github.com/gogo/protobuf v1.0.0 h1:2jyBKDKU/8v3v2xVR2PtiWQviFUyiaGk2rpfyFT8rTM=
+github.com/gogo/protobuf v1.0.0/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b h1:VKtxabqXZkF25pY9ekfRL6a582T4P37/31XEstQ5p58=
+github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
+github.com/google/gofuzz v1.0.0 h1:A8PeW59pxE9IoFRqBp37U+mSNaQoZ46F1f0f863XSXw=
+github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
+github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OHLH3mGKHDcjJRFFRrJa6eAM5H+CtDdOsPc=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
+github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+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/spf13/pflag v1.0.0 h1:oaPbdDe/x0UncahuwiPxW1GYJyilRAdsPnq3e1yaPcI=
+github.com/spf13/pflag v1.0.0/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+golang.org/x/net v0.0.0-20180308154319-d0aafc73d5cd h1:GNzbLJRy/nHOFS5m5780xbL4nia5w6cyb8exQGYw3Z4=
+golang.org/x/net v0.0.0-20180308154319-d0aafc73d5cd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/inf.v0 v0.9.0 h1:3zYtXIO92bvsdS3ggAdA8Gb4Azj0YU+TVY1uGYNFA8o=
+gopkg.in/inf.v0 v0.9.0/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
+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 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+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 v0.0.0-20180308023924-fd252c3a3e1d h1:82NkfZsgXdPC9a1nq0FsgF7OzZn8rWf/Vn8nv1XQYh4=
+k8s.io/api v0.0.0-20180308023924-fd252c3a3e1d/go.mod h1:iuAfoD4hCxJ8Onx9kaTIt30j7jUFS00AXQi6QMi99vA=
+k8s.io/apimachinery v0.0.0-20180302183502-e9ff529c66f8 h1:asJjRiuBvuXsmTKz/8u9DombWmog9pdhOpyfk0n1agc=
+k8s.io/apimachinery v0.0.0-20180302183502-e9ff529c66f8/go.mod h1:ccL7Eh7zubPUSh9A3USN90/OzHNSVN6zxzde07TDCL0=

main.go

@@ -0,0 +1,124 @@
+/*
+ *
+ * Copyright 2022. Metacontroller authors.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"io/ioutil"
+	"log"
+	"net/http"
+
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/json"
+)
+
+type Controller struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata"`
+	Spec              ControllerSpec   `json:"spec"`
+	Status            ControllerStatus `json:"status"`
+}
+
+type ControllerSpec struct {
+	Message string `json:"message"`
+}
+
+type ControllerStatus struct {
+	Replicas  int `json:"replicas"`
+	Succeeded int `json:"succeeded"`
+}
+
+type SyncRequest struct {
+	Parent   Controller          `json:"parent"`
+	Children SyncRequestChildren `json:"children"`
+}
+
+type SyncRequestChildren struct {
+	Pods map[string]*v1.Pod `json:"Pod.v1"`
+}
+
+type SyncResponse struct {
+	Status   ControllerStatus `json:"status"`
+	Children []runtime.Object `json:"children"`
+}
+
+func sync(request *SyncRequest) (*SyncResponse, error) {
+	response := &SyncResponse{}
+
+	// Compute status based on latest observed state.
+	for _, pod := range request.Children.Pods {
+		response.Status.Replicas++
+		if pod.Status.Phase == v1.PodSucceeded {
+			response.Status.Succeeded++
+		}
+	}
+
+	// Generate desired children.
+	pod := &v1.Pod{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: "v1",
+			Kind:       "Pod",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: request.Parent.Name,
+		},
+		Spec: v1.PodSpec{
+			RestartPolicy: v1.RestartPolicyOnFailure,
+			Containers: []v1.Container{
+				{
+					Name:    "hello",
+					Image:   "busybox",
+					Command: []string{"echo", request.Parent.Spec.Message},
+				},
+			},
+		},
+	}
+	response.Children = append(response.Children, pod)
+
+	return response, nil
+}
+
+func syncHandler(w http.ResponseWriter, r *http.Request) {
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	request := &SyncRequest{}
+	if err := json.Unmarshal(body, request); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	response, err := sync(request)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	body, err = json.Marshal(&response)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(body)
+}
+
+func main() {
+	http.HandleFunc("/sync", syncHandler)
+
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}

my-thing.yaml

@@ -0,0 +1,6 @@
+apiVersion: ctl.enisoc.com/v1
+kind: Thing
+metadata:
+  name: thing-1
+spec:
+  message: Hello, World!