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This article mainly introduces the automatically generated code controller tool how to use the relevant knowledge, the content is detailed and easy to understand, the operation is simple and fast, has a certain reference value, I believe you will have something to gain after reading this automatically generated code controller tool article, let's take a look at it.

Controller-tools

Controller-tools can mainly help us to automatically generate the content needed by types.go and automatically generate crd for us.

Again, first clone it locally:

$git clone https://github.com/kubernetes-sigs/controller-tools.git

Under the cmd directory of the project, we can see that there are three tools: controller-gen, helpgen and type-scaffold.

Type-scaffold can be used to generate the types.go files we need, and controller-gen can generate zz_xxx.deepcopy.go files and crd files.

We use go install for installation:

$cd controller-gen$ go install. / cmd/ {controller-gen,type-scaffold}

After the installation is complete, we can check it under the bin directory under GOPATH.

Then we can create a new project to automatically generate code for us using the tools provided by controller-tools.

$mkdir controller-test & & cd controller-test$ go mod init controller-test$ mkdir-p pkg/apis/example.com/v1 $tree. ├── go.mod └── pkg └── apis example.com └── v14 directories, 1 file

Then we can use the tool to generate the code we need. First, we generate the content needed by types.go. Since type-scaffold does not support importing text, we need to copy it to the types.go file after generation:

$type-scaffold-- kind Foo// FooSpec defines the desired state of Footype FooSpec struct {/ / INSERT ADDITIONAL SPEC FIELDS-- desired state of cluster} / / FooStatus defines the observed state of Foo.// It should always be reconstructable from the state of the cluster and/or outside world.type FooStatus struct {/ / INSERT ADDITIONAL STATUS FIELDS-- observed state of cluster} / / + k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object// Foo is the Schema for the foos API// + k8s: Openapi-gen=truetype Foo struct {metav1.TypeMeta `json: " Inline "`metav1.ObjectMeta `json:" metadata,omitempty "`Spec FooSpec `json:" spec,omitempty "`Status FooStatus `json:" status,omitempty "`} / + k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object// FooList contains a list of Footype FooList struct {metav1.TypeMeta `json:", inline "`metav1.ListMeta `json:" metadata,omitempty "`Items [] Foo `json:" items "`}.

Then add the import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" to the types.go file.

Of course, automatic generation is just a template, and we still need to fill in the details, such as filling in FooSpec.

The resource type is defined, so how can we get client-go to identify our resource? it needs to be registered here. We can define GV (Group Version) in register.go and specify groupName through tags.

/ / register.go// + groupName=example.compackage v1import ("k8s.io/apimachinery/pkg/runtime"k8s.io/apimachinery/pkg/runtime/schema"k8s.io/apimachinery/pkg/runtime/serializer") var (Scheme = runtime.NewScheme () GroupVersion = schema.GroupVersion {Group: "example.com", Version: "v1" } Codec = serializer.NewCodecFactory (Scheme))

You can call the Scheme.AddKnownTypes method in types.go:

/ / types.gopackage v1import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" / / FooSpec defines the desired state of Footype FooSpec struct {/ / INSERT ADDITIONAL SPEC FIELDS-- desired state of cluster Name string `json: "name" `Replicas int32 `json: "replicas" `} / / FooStatus defines the observed state of Foo.// It should always be reconstructable from the state of the cluster and/or outside world.type FooStatus struct {/ / INSERT ADDITIONAL STATUS FIELDS-- Observed state of cluster} / / + k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object// Foo is the Schema for the foos API// + k8s:openapi-gen=truetype Foo struct {metav1.TypeMeta `json: " Inline "`metav1.ObjectMeta `json:" metadata,omitempty "`Spec FooSpec `json:" spec,omitempty "`Status FooStatus `json:" status,omitempty "`} / / + k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object// FooList contains a list of Footype FooList struct {metav1.TypeMeta `json:", inline "`metav1.ListMeta `json:" metadata Omitempty "`Items [] Foo `json:" items "`} func init () {Scheme.AddKnownTypes (GroupVersion, & Foo {}, & FooList {})}

Next, you need to generate the deepcopy.go file:

$controller-gen object paths=./pkg/apis/example.com/v1/types.go

Again, we use controller-gen to generate crd:

$mkdir config$ go mod tidy$ controller-gen crd paths=./... Output:crd:dir=config/crd

At this point, we look at the project structure:

. ├── config │ └── crd │ └── example.com_foos.yaml ├── go.mod ├── go.sum └── pkg └── apis └── example.com └── v1 ├── register.go ├── types.go └── zz_generated.deepcopy.go6 directories, 6 files

Finally, let's verify that we first create a cr:

ApiVersion: example.com/v1kind: Foometadata: name: crd-testspec: name: test replicas: 2

After adding crd and cr to the cluster, let's write a main.go file to verify:

Package mainimport ("context" v1 "controller-test/pkg/apis/example.com/v1"fmt"k8s.io/client-go/rest"k8s.io/client-go/tools/clientcmd"log") func main () {config, err: = clientcmd.BuildConfigFromFlags ("") Clientcmd.RecommendedHomeFile) if err! = nil {log.Fatalln (err)} / / here you need to use the original RESTClient config.APIPath = "/ apis/" config.NegotiatedSerializer = v1.Codec config.GroupVersion = & v1.GroupVersion client Err: = rest.RESTClientFor (config) if err! = nil {log.Fatalln (err)} foo: = & v1.Foo {} err = client.Get (). Namespace ("default"). Resource ("foos"). Name ("crd-test") .Do (context.TODO ()) .into (foo) if err! = nil {log.Fatalln (err)} newObj: = foo.DeepCopy () newObj.Spec.Name = "test2" fmt.Println (foo.Spec.Name) fmt.Println (newObj.Spec.Name)} / / = / / output result testtest2 on "how to use automatically generated Code controller tool" is introduced here. Thank you for reading! I believe that everyone has a certain understanding of the knowledge of "automatically generated code controller tool how to use". If you want to learn more, you are welcome to follow the industry information channel.

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