英文:
How to deserialize Kubernetes YAML file
问题
你可以使用client-go
库中的yaml
包来将Kubernetes的YAML文件反序列化为Go结构体。以下是一个示例代码:
package main
import (
"fmt"
"k8s.io/apimachinery/pkg/util/yaml"
)
type Deployment struct {
APIVersion string `yaml:"apiVersion"`
Kind string `yaml:"kind"`
Metadata struct {
Name string `yaml:"name"`
} `yaml:"metadata"`
Spec struct {
Replicas int `yaml:"replicas"`
Template struct {
Metadata struct {
Labels struct {
Run string `yaml:"run"`
} `yaml:"labels"`
} `yaml:"metadata"`
Spec struct {
Containers []struct {
Name string `yaml:"name"`
Image string `yaml:"image"`
Ports []struct {
ContainerPort int `yaml:"containerPort"`
} `yaml:"ports"`
} `yaml:"containers"`
} `yaml:"spec"`
} `yaml:"template"`
} `yaml:"spec"`
}
func main() {
service := `
apiVersion: apps/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
`
var deployment Deployment
err := yaml.Unmarshal([]byte(service), &deployment)
if err != nil {
panic(err)
}
fmt.Printf("%#v\n", deployment)
}
这个示例代码定义了一个与你提供的YAML文件结构相匹配的Go结构体Deployment
。你可以使用yaml.Unmarshal
函数将YAML文件反序列化为该结构体。
请注意,你需要在代码中导入k8s.io/apimachinery/pkg/util/yaml
包来使用yaml.Unmarshal
函数。
希望这可以帮助到你!
英文:
How can I deserialize a Kubernetes YAML file into an Go struct? I took a look into the kubectl
code, but somehow I get an error for every YAML file:
no kind "Deployment" is registered for version "apps/v1beta1"
This is an MWE:
package main
import (
"fmt"
"k8s.io/client-go/pkg/api"
)
var service = `
apiVersion: apps/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
`
func main() {
decode := api.Codecs.UniversalDecoder().Decode
//decode := api.Codecs.UniversalDeserializer().Decode
obj, _, err := decode([]byte(service), nil, nil)
if err != nil {
panic(err)
}
fmt.Printf("%#v\n", obj)
}
I am using client version 2.0.0
. The glide.yaml
looks like this:
package: test/stackoverflow
import:
- package: k8s.io/client-go
version: ^2.0.0
These are the references to kubectl
:
- https://github.com/kubernetes/kubernetes/blob/43ac38e29e6ecf83e78bc7c5d9f804310b051c95/pkg/kubectl/cmd/apply.go#L637
- https://github.com/kubernetes/kubernetes/blob/43ac38e29e6ecf83e78bc7c5d9f804310b051c95/pkg/kubectl/cmd/util/factory_client_access.go#L205-L213
Unfortunately, the docs are very confusing to me, so I have no idea how to tackle this problem.
Edit:
This problem also exists with other resource types:
no kind "Service" is registered for version "v1"
答案1
得分: 5
你需要导入_ "k8s.io/client-go/pkg/apis/extensions/install"
,否则模式为空,另请参阅文档。
完整的工作示例如下:
$ go get -u github.com/golang/dep/cmd/dep
$ dep init
$ go run main.go
使用以下main.go
:
package main
import (
"fmt"
"k8s.io/client-go/pkg/api"
_ "k8s.io/client-go/pkg/api/install"
_ "k8s.io/client-go/pkg/apis/extensions/install"
)
var deployment = `
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
`
func main() {
// decode := api.Codecs.UniversalDecoder().Decode
decode := api.Codecs.UniversalDeserializer().Decode
obj, _, err := decode([]byte(deployment), nil, nil)
if err != nil {
fmt.Printf("%#v", err)
}
fmt.Printf("%#v\n", obj)
}
请注意,我还为您导入了_ "k8s.io/client-go/pkg/api/install"
,这样您就可以使用v1
中的对象,例如pods或services。
编辑:感谢我的同事Stefan Schimanski提出了最初的解决方案。
英文:
You need to import _ "k8s.io/client-go/pkg/apis/extensions/install"
otherwise the schema is empty, see also docs.
The complete working example is:
$ go get -u github.com/golang/dep/cmd/dep
$ dep init
$ go run main.go
With the following main.go
:
package main
import (
"fmt"
"k8s.io/client-go/pkg/api"
_ "k8s.io/client-go/pkg/api/install"
_ "k8s.io/client-go/pkg/apis/extensions/install"
)
var deployment = `
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-nginx
spec:
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
`
func main() {
// decode := api.Codecs.UniversalDecoder().Decode
decode := api.Codecs.UniversalDeserializer().Decode
obj, _, err := decode([]byte(deployment), nil, nil)
if err != nil {
fmt.Printf("%#v", err)
}
fmt.Printf("%#v\n", obj)
}
Note that I also imported _ "k8s.io/client-go/pkg/api/install"
for you so that you can use objects in v1
such as pods or services.
EDIT: Kudos to my colleague Stefan Schimanski who proposed the initial solution.
答案2
得分: 1
我一直在使用api machinery的k8s.io/apimachinery/pkg/util/yaml
来解码Kubernetes的部署和服务清单。
import (
"fmt"
"bytes"
appsv1 "k8s.io/api/apps/v1"
k8Yaml "k8s.io/apimachinery/pkg/util/yaml"
)
...
d := &appsv1.Deployment{}
dec := k8Yaml.NewYAMLOrJSONDecoder(bytes.NewReader([]byte(deploymentManifest)), 1000)
if err := dec.Decode(&d); err != nil {
return nil, err
}
fmt.Printf("%+v", d)
英文:
I've been using api machinery'sk8s.io/apimachinery/pkg/util/yaml
to decode kubernete's deployment and service manifests.
import (
"fmt"
"bytes"
appsv1 "k8s.io/api/apps/v1"
k8Yaml "k8s.io/apimachinery/pkg/util/yaml"
)
...
d := &appsv1.Deployment{}
dec := k8Yaml.NewYAMLOrJSONDecoder(bytes.NewReader([]byte(deploymentManifest)), 1000)
if err := dec.Decode(&d); err != nil {
return nil, err
}
fmt.Printf("%+v", d)
答案3
得分: 0
import (
"fmt"
"gopkg.in/yaml.v2"
"log"
//corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/runtime/serializer/json"
"k8s.io/client-go/kubernetes/scheme"
v1alpha1 "github.com/argoproj/argo-cd/pkg/apis/application/v1alpha1"
)
....
func ParseYaml2(yaml []byte) (v1alpha1.Application, error) {
// 创建一个YAML序列化器。JSON是YAML的子集,所以也支持。
s := json.NewYAMLSerializer(json.DefaultMetaFactory, scheme.Scheme,
scheme.Scheme)
// 将YAML解码为对象。
var app v1alpha1.Application
_, _, err := s.Decode(yaml, nil, &app)
if err != nil {
panic(err)
}
//fmt.Printf("%#v\n", app)
return app, err
}
---
go.mod
// https://github.com/argoproj/argo-cd/issues/4055
replace github.com/argoproj/argo-cd => github.com/argoproj/argo-cd v1.5.5
var yaml2 = []byte(`
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
...
var app v1alpha1.Application
app,err := ParseYaml2(yaml2)
// Types from https://github.com/argoproj/argo-cd/blob/master/pkg/apis/application/v1alpha1/types.go
fmt.Printf("--- t:\n%s\n\n", app.Spec.Source.Path)
fmt.Printf("--- t:\n%s\n\n", app.Spec.Source.Helm.ValueFiles)
----
<details>
<summary>英文:</summary>
import (
"fmt"
"gopkg.in/yaml.v2"
"log"
//corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/runtime/serializer/json"
"k8s.io/client-go/kubernetes/scheme"
v1alpha1 "github.com/argoproj/argo-cd/pkg/apis/application/v1alpha1"
)
....
func ParseYaml2(yaml []byte) (v1alpha1.Application, error) {
// Create a YAML serializer. JSON is a subset of YAML, so is supported too.
s := json.NewYAMLSerializer(json.DefaultMetaFactory, scheme.Scheme,
scheme.Scheme)
// Decode the YAML to an object.
var app v1alpha1.Application
_, _, err := s.Decode(yaml, nil, &app)
if err != nil {
panic(err)
}
//fmt.Printf("%#v\n", app)
return app, err
}
go.mod
// https://github.com/argoproj/argo-cd/issues/4055
replace github.com/argoproj/argo-cd => github.com/argoproj/argo-cd v1.5.5
var yaml2 = []byte(`
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
...
var app v1alpha1.Application
app,err := ParseYaml2(yaml2)
// Types from https://github.com/argoproj/argo-cd/blob/master/pkg/apis/application/v1alpha1/types.go
fmt.Printf("--- t:\n%s\n\n", app.Spec.Source.Path)
fmt.Printf("--- t:\n%s\n\n", app.Spec.Source.Helm.ValueFiles)
</details>
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