Shuffle around code and use rancher/apiserver

pkg/resources/common/dynamiccolumns.go

@@ -0,0 +1,104 @@
+package common
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/rancher/apiserver/pkg/types"
+	"github.com/rancher/steve/pkg/attributes"
+	"github.com/rancher/wrangler/pkg/ratelimit"
+	"k8s.io/apimachinery/pkg/apis/meta/internalversion"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	metav1beta1 "k8s.io/apimachinery/pkg/apis/meta/v1beta1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+	"k8s.io/client-go/rest"
+)
+
+type DynamicColumns struct {
+	client *rest.RESTClient
+}
+
+type ColumnDefinition struct {
+	metav1.TableColumnDefinition `json:",inline"`
+	Field                        string `json:"field,omitempty"`
+}
+
+func NewDynamicColumns(config *rest.Config) (*DynamicColumns, error) {
+	c, err := newClient(config)
+	if err != nil {
+		return nil, err
+	}
+	return &DynamicColumns{
+		client: c,
+	}, nil
+}
+
+func (d *DynamicColumns) SetColumns(ctx context.Context, schema *types.APISchema) error {
+	if attributes.Columns(schema) != nil {
+		return nil
+	}
+
+	gvr := attributes.GVR(schema)
+	if gvr.Resource == "" {
+		return nil
+	}
+
+	r := d.client.Get()
+	if gvr.Group == "" {
+		r.Prefix("api")
+	} else {
+		r.Prefix("apis", gvr.Group)
+	}
+	r.Prefix(gvr.Version)
+	r.Prefix(gvr.Resource)
+	r.VersionedParams(&metav1.ListOptions{
+		Limit: 1,
+	}, metav1.ParameterCodec)
+
+	obj, err := r.Do(ctx).Get()
+	if err != nil {
+		attributes.SetTable(schema, false)
+		return nil
+	}
+	t, ok := obj.(*metav1.Table)
+	if !ok {
+		return nil
+	}
+
+	if len(t.ColumnDefinitions) > 0 {
+		var cols []ColumnDefinition
+		for i, colDef := range t.ColumnDefinitions {
+			cols = append(cols, ColumnDefinition{
+				TableColumnDefinition: colDef,
+				Field:                 fmt.Sprintf("$.metadata.fields[%d]", i),
+			})
+		}
+		attributes.SetColumns(schema, cols)
+	}
+
+	return nil
+}
+
+func newClient(config *rest.Config) (*rest.RESTClient, error) {
+	scheme := runtime.NewScheme()
+	if err := internalversion.AddToScheme(scheme); err != nil {
+		return nil, err
+	}
+	if err := metav1.AddMetaToScheme(scheme); err != nil {
+		return nil, err
+	}
+	if err := metav1beta1.AddMetaToScheme(scheme); err != nil {
+		return nil, err
+	}
+
+	config = rest.CopyConfig(config)
+	config.RateLimiter = ratelimit.None
+	config.UserAgent = rest.DefaultKubernetesUserAgent()
+	config.AcceptContentTypes = "application/json;as=Table;v=v1;g=meta.k8s.io"
+	config.GroupVersion = &schema.GroupVersion{}
+	config.NegotiatedSerializer = serializer.NewCodecFactory(scheme)
+	config.APIPath = "/"
+	return rest.RESTClientFor(config)
+}