add KUBECTL_EXPLAIN_OPENAPIV3 envar to gate new explain implementation

update
This commit is contained in:
Alexander Zielenski 2022-10-12 08:37:41 -07:00
parent a9c093b165
commit 2f16cd4aea
No known key found for this signature in database
GPG Key ID: 754BC11B447F7843
2 changed files with 128 additions and 2 deletions

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@ -18,14 +18,17 @@ package explain
import (
"fmt"
"os"
"github.com/spf13/cobra"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/cli-runtime/pkg/genericclioptions"
"k8s.io/client-go/discovery"
cmdutil "k8s.io/kubectl/pkg/cmd/util"
"k8s.io/kubectl/pkg/explain"
explainv2 "k8s.io/kubectl/pkg/explain/v2"
"k8s.io/kubectl/pkg/util/i18n"
"k8s.io/kubectl/pkg/util/openapi"
"k8s.io/kubectl/pkg/util/templates"
@ -62,12 +65,25 @@ type ExplainOptions struct {
Mapper meta.RESTMapper
Schema openapi.Resources
// Toggles whether the OpenAPI v3 template-based renderer should be used to show
// output.
EnableOpenAPIV3 bool
// Name of the template to use with the openapiv3 template renderer. If
// `EnableOpenAPIV3` is disabled, this does nothing
OutputFormat string
// Client capable of fetching openapi documents from the user's cluster
DiscoveryClient discovery.DiscoveryInterface
}
func NewExplainOptions(parent string, streams genericclioptions.IOStreams) *ExplainOptions {
return &ExplainOptions{
IOStreams: streams,
CmdParent: parent,
IOStreams: streams,
CmdParent: parent,
EnableOpenAPIV3: os.Getenv("KUBECTL_EXPLAIN_OPENAPIV3") == "true",
OutputFormat: "plaintext",
}
}
@ -89,6 +105,12 @@ func NewCmdExplain(parent string, f cmdutil.Factory, streams genericclioptions.I
}
cmd.Flags().BoolVar(&o.Recursive, "recursive", o.Recursive, "Print the fields of fields (Currently only 1 level deep)")
cmd.Flags().StringVar(&o.APIVersion, "api-version", o.APIVersion, "Get different explanations for particular API version (API group/version)")
// Only enable --output as a valid flag if the feature is enabled
if o.EnableOpenAPIV3 {
cmd.Flags().StringVar(&o.OutputFormat, "output", o.OutputFormat, "Format in which to render the schema")
}
return cmd
}
@ -104,6 +126,15 @@ func (o *ExplainOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []
return err
}
// Only openapi v3 needs the discovery client.
if o.EnableOpenAPIV3 {
clientset, err := f.KubernetesClientSet()
if err != nil {
return err
}
o.DiscoveryClient = clientset.DiscoveryClient
}
o.args = args
return nil
}
@ -142,6 +173,17 @@ func (o *ExplainOptions) Run() error {
}
}
if o.EnableOpenAPIV3 {
return explainv2.PrintModelDescription(
fieldsPath,
o.Out,
o.DiscoveryClient.OpenAPIV3(),
fullySpecifiedGVR,
recursive,
o.OutputFormat,
)
}
gvk, _ := o.Mapper.KindFor(fullySpecifiedGVR)
if gvk.Empty() {
gvk, err = o.Mapper.KindFor(fullySpecifiedGVR.GroupResource().WithVersion(""))

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@ -0,0 +1,84 @@
/*
Copyright 2022 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.
*/
package v2
import (
"encoding/json"
"fmt"
"io"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/client-go/openapi"
)
// PrintModelDescription prints the description of a specific model or dot path.
// If recursive, all components nested within the fields of the schema will be
// printed.
func PrintModelDescription(
fieldsPath []string,
w io.Writer,
client openapi.Client,
gvr schema.GroupVersionResource,
recursive bool,
outputFormat string,
) error {
return printModelDescriptionWithGenerator(
NewGenerator(), fieldsPath, w, client, gvr, recursive, outputFormat)
}
// Factored out for testability
func printModelDescriptionWithGenerator(
generator *generator,
fieldsPath []string,
w io.Writer,
client openapi.Client,
gvr schema.GroupVersionResource,
recursive bool,
outputFormat string,
) error {
paths, err := client.Paths()
if err != nil {
return fmt.Errorf("failed to fetch list of groupVersions: %w", err)
}
var resourcePath string
if len(gvr.Group) == 0 {
resourcePath = fmt.Sprintf("api/%s", gvr.Version)
} else {
resourcePath = fmt.Sprintf("apis/%s/%s", gvr.Group, gvr.Version)
}
gv, exists := paths[resourcePath]
if !exists {
return fmt.Errorf("could not locate schema for %s", resourcePath)
}
openAPISchemaBytes, err := gv.Schema(runtime.ContentTypeJSON)
if err != nil {
return fmt.Errorf("failed to fetch openapi schema for %s: %w", resourcePath, err)
}
var parsedV3Schema map[string]interface{}
if err := json.Unmarshal(openAPISchemaBytes, &parsedV3Schema); err != nil {
return fmt.Errorf("failed to parse openapi schema for %s: %w", resourcePath, err)
}
return generator.Render(outputFormat, parsedV3Schema, gvr, fieldsPath, recursive, w)
}