k8s的自定义资源代码生成详解

为什么下这篇文章呢，在代码生成这一块跌了两次跟头，说白了只知道照抄，并不知道里面到底是干什么的，要做到知其然并知其所以然，也是为以后在自动生成代码的时候做一个参考。

生成的项目目录结构如下

.
├── go.mod
├── go.sum
├── hack
│   ├── boilerplate.go.txt
│   ├── update-codegen.sh
│   └── verify-codegen.sh
└── pkg├── apis│   └── mycontroller│       ├── register.go│       └── v1alpha1│           ├── doc.go│           ├── register.go│           ├── types.go│           └── zz_generated.deepcopy.go└── client├── clientset│   └── versioned│       ├── clientset.go│       ├── doc.go│       ├── fake│       │   ├── clientset_generated.go│       │   ├── doc.go│       │   └── register.go│       ├── scheme│       │   ├── doc.go│       │   └── register.go│       └── typed│           └── mycontroller│               └── v1alpha1│                   ├── doc.go│                   ├── fake│                   │   ├── doc.go│                   │   ├── fake_mycontroller_client.go│                   │   └── fake_website.go│                   ├── generated_expansion.go│                   ├── mycontroller_client.go│                   └── website.go├── informers│   └── externalversions│       ├── factory.go│       ├── generic.go│       ├── internalinterfaces│       │   └── factory_interfaces.go│       └── mycontroller│           ├── interface.go│           └── v1alpha1│               ├── interface.go│               └── website.go└── listers└── mycontroller└── v1alpha1├── expansion_generated.go└── website.go

代码生成需要的文件

├── go.mod
├── go.sum
├── hack
│   ├── boilerplate.go.txt
│   ├── update-codegen.sh
│   └── verify-codegen.sh
└── pkg├── apis└── mycontroller├── register.go└── v1alpha1├── doc.go├── register.go├── types.go

hack目录下面的文件和代码生成有关
1、update-codegen.sh文件详解

#!/usr/bin/env bash# Copyright 2017 The Kubernetes 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
#
#     http://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.set -o errexit
set -o nounset
set -o pipefailSCRIPT_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
CODEGEN_PKG=${CODEGEN_PKG:-$(cd ${SCRIPT_ROOT}; ls -d -1 .k8s.io/code-generator 2>/dev/null || echo ../code-generator)}# generate the code with:
# - --output-base because this script should also be able to run inside the vendor dir of
#   k8s.io/kubernetes. The output-base is needed for the generators to output into the vendor dir
#   instead of the $GOPATH directly. For normal projects this can be dropped.
# "$(dirname "${BASH_SOURCE[0]}")"/../generate-internal-groups.sh all \
#  k8s.io/code-generator/_examples/apiserver k8s.io/code-generator/_examples/apiserver/apis k8s.io/code-generator/_examples/apiserver/apis \
#  "example:v1 example2:v1 example3.io:v1" \
#  --output-base "$(dirname "${BASH_SOURCE[0]}")/../../.." \
#  --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt"
# "$(dirname "${BASH_SOURCE[0]}")"/../generate-groups.sh all \
#  k8s.io/code-generator/_examples/crd k8s.io/code-generator/_examples/crd/apis \
#  "example:v1 example2:v1" \
#  --output-base "$(dirname "${BASH_SOURCE[0]}")/../../.." \
#  --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt"
# "$(dirname "${BASH_SOURCE[0]}")"/../generate-groups.sh all \
#  k8s.io/code-generator/_examples/MixedCase k8s.io/code-generator/_examples/MixedCase/apis \
#  "example:v1" \
#  --output-base "$(dirname "${BASH_SOURCE[0]}")/../../.." \
#  --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt"
# "$(dirname "${BASH_SOURCE[0]}")"/../generate-groups.sh all \
#  k8s.io/code-generator/_examples/HyphenGroup k8s.io/code-generator/_examples/HyphenGroup/apis \
#  "example:v1" \
#  --output-base "$(dirname "${BASH_SOURCE[0]}")/../../.." \
#  --go-header-file "${SCRIPT_ROOT}/hack/boilerplate.go.txt"
${CODEGEN_PKG}/generate-groups.sh "deepcopy,client,informer,lister" \website/pkg/client website/pkg/apis \mycontroller:v1alpha1 \--output-base "$GOPATH/src" \--go-header-file ${SCRIPT_ROOT}/hack/boilerplate.go.txt

CODEGEN_PKG的值到该是在k8s.io/code-generator
website/pkg/client website/pkg/apis:表示个是你要生成代码的目录，目录的名称是client
mycontroller:v1alpha1:表示的是应用组名:版本
–output-base:表示生成文件的输出位置

2、mycontroller下面的register.go

/*
Copyright 2017 The Kubernetes 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 athttp://www.apache.org/licenses/LICENSE-2.0Unless 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 mycontroller// GroupName is the group name used in this package// 上面那些注释啊，不能删啊，我搞了一下午，就是把上面的删除掉了
// 组名 mycontroller.xialee.io
const (GroupName = "mycontroller.xialee.io"
)

3、v1alpha1包下面的register.go文件

package v1alpha1import (metav1 "k8s.io/apimachinery/pkg/apis/meta/v1""k8s.io/apimachinery/pkg/runtime""k8s.io/apimachinery/pkg/runtime/schema""website/pkg/apis/mycontroller"
)var SchemeGroupVersion = schema.GroupVersion{Group:   mycontroller.GroupName,Version: "v1alpha1",
}// Kind takes an unqualified kind and returns back a Group qualified GroupKind
func Kind(kind string) schema.GroupKind {return SchemeGroupVersion.WithKind(kind).GroupKind()
}// Resource takes an unqualified resource and returns a Group qualified GroupResource
func Resource(resource string) schema.GroupResource {return SchemeGroupVersion.WithResource(resource).GroupResource()
}var (// SchemeBuilder initializes a scheme builderSchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)// AddToScheme is a global function that registers this API group & version to a schemeAddToScheme = SchemeBuilder.AddToScheme
)// Adds the list of known types to Scheme.
func addKnownTypes(scheme *runtime.Scheme) error {scheme.AddKnownTypes(SchemeGroupVersion,&Website{},&WebsiteList{},)metav1.AddToGroupVersion(scheme, SchemeGroupVersion)return nil
}

4、v1alpha1包下面的doc.go文件

// +k8s:deepcopy-gen=package
// +groupName=mycontroller.xialee.io// Package v1alpha1 is the v1alpha1 version of the API.
package v1alpha1

5、v1alpha1包下面的types.go文件

package v1alpha1import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"// +genclient
// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Objecttype Website struct {metav1.TypeMeta   `json:",inline"`metav1.ObjectMeta `json:"metadata,omitempty"`Spec   WebsiteSpec   `json:"spec"`Status WebsiteStatus `json:"status"`
}type WebsiteSpec struct {GitRepo        string `json:"gitRepo"`DeploymentName string `json:"deploymentName"`Replicas       *int32 `json:"replicas"`// TargetDeployment string `json:"targetDeployment"`// MinReplicas      int    `json:"minReplicas"`// MaxReplicas      int    `json:"maxReplicas"`// MetricType       string `json:"metricType"`// Step             int    `json:"step"`// ScaleUp          int    `json:"scaleUp"`// ScaleDown        int    `json:"scaleDown"`
}type WebsiteStatus struct {AvailableReplicas int32 `json:"availableReplicas"`
}// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Objecttype WebsiteList struct {metav1.TypeMeta `json:",inline"`metav1.ListMeta `json:"metadata,omitempty"`Items []Website `json:"items"`
}

谨记：上面的注释不要随便删除

执行自动生成代码脚本

1、首先将自己的项目上传到gopath下面的src里面，（前提go环境已经安装好了），进入website目录里面，执行go mod init,会生成一个go.mod文件，在里面添加依赖的包require ( k8s.io/api v0.0.0-20191031065753-b19d8caf39be k8s.io/apimachinery v0.0.0-20191105185716-00d39968b57e k8s.io/client-go v0.0.0-20191101230044-e9766ae82012 k8s.io/code-generator v0.0.0-20191029223907-9f431a56fdbc k8s.io/klog v1.0.0 k8s.io/sample-controller v0.0.0-20191101231324-472018681a2b )然后执行go mod download下载相关的依赖包，然后执行sh hack/update-codegen.sh,正常输出，则证明自动生成代码成功