pod.go

Documentation: k8s.io/kubernetes/pkg/util/pod

     1  /*
     2  Copyright 2018 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package pod
    18  
    19  import (
    20  	"bytes"
    21  	"context"
    22  	"encoding/json"
    23  	"fmt"
    24  
    25  	v1 "k8s.io/api/core/v1"
    26  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    27  	"k8s.io/apimachinery/pkg/types"
    28  	"k8s.io/apimachinery/pkg/util/strategicpatch"
    29  	clientset "k8s.io/client-go/kubernetes"
    30  	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
    31  )
    32  
    33  // PatchPodStatus patches pod status. It returns true and avoids an update if the patch contains no changes.
    34  func PatchPodStatus(ctx context.Context, c clientset.Interface, namespace, name string, uid types.UID, oldPodStatus, newPodStatus v1.PodStatus) (*v1.Pod, []byte, bool, error) {
    35  	patchBytes, unchanged, err := preparePatchBytesForPodStatus(namespace, name, uid, oldPodStatus, newPodStatus)
    36  	if err != nil {
    37  		return nil, nil, false, err
    38  	}
    39  	if unchanged {
    40  		return nil, patchBytes, true, nil
    41  	}
    42  
    43  	updatedPod, err := c.CoreV1().Pods(namespace).Patch(ctx, name, types.StrategicMergePatchType, patchBytes, metav1.PatchOptions{}, "status")
    44  	if err != nil {
    45  		return nil, nil, false, fmt.Errorf("failed to patch status %q for pod %q/%q: %v", patchBytes, namespace, name, err)
    46  	}
    47  	return updatedPod, patchBytes, false, nil
    48  }
    49  
    50  func preparePatchBytesForPodStatus(namespace, name string, uid types.UID, oldPodStatus, newPodStatus v1.PodStatus) ([]byte, bool, error) {
    51  	oldData, err := json.Marshal(v1.Pod{
    52  		Status: oldPodStatus,
    53  	})
    54  	if err != nil {
    55  		return nil, false, fmt.Errorf("failed to Marshal oldData for pod %q/%q: %v", namespace, name, err)
    56  	}
    57  
    58  	newData, err := json.Marshal(v1.Pod{
    59  		ObjectMeta: metav1.ObjectMeta{UID: uid}, // only put the uid in the new object to ensure it appears in the patch as a precondition
    60  		Status:     newPodStatus,
    61  	})
    62  	if err != nil {
    63  		return nil, false, fmt.Errorf("failed to Marshal newData for pod %q/%q: %v", namespace, name, err)
    64  	}
    65  
    66  	patchBytes, err := strategicpatch.CreateTwoWayMergePatch(oldData, newData, v1.Pod{})
    67  	if err != nil {
    68  		return nil, false, fmt.Errorf("failed to CreateTwoWayMergePatch for pod %q/%q: %v", namespace, name, err)
    69  	}
    70  	return patchBytes, bytes.Equal(patchBytes, []byte(fmt.Sprintf(`{"metadata":{"uid":%q}}`, uid))), nil
    71  }
    72  
    73  // ReplaceOrAppendPodCondition replaces the first pod condition with equal type or appends if there is none
    74  func ReplaceOrAppendPodCondition(conditions []v1.PodCondition, condition *v1.PodCondition) []v1.PodCondition {
    75  	if i, _ := podutil.GetPodConditionFromList(conditions, condition.Type); i >= 0 {
    76  		conditions[i] = *condition
    77  	} else {
    78  		conditions = append(conditions, *condition)
    79  	}
    80  	return conditions
    81  }
    82
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