github.com/erdrix/operator-sdk@v0.8.2/pkg/k8sutil/k8sutil.go (about)

     1  // Copyright 2018 The Operator-SDK Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package k8sutil
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"io/ioutil"
    21  	"os"
    22  	"strings"
    23  
    24  	corev1 "k8s.io/api/core/v1"
    25  	discovery "k8s.io/client-go/discovery"
    26  	crclient "sigs.k8s.io/controller-runtime/pkg/client"
    27  	logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"
    28  )
    29  
    30  var log = logf.Log.WithName("k8sutil")
    31  
    32  // GetWatchNamespace returns the namespace the operator should be watching for changes
    33  func GetWatchNamespace() (string, error) {
    34  	ns, found := os.LookupEnv(WatchNamespaceEnvVar)
    35  	if !found {
    36  		return "", fmt.Errorf("%s must be set", WatchNamespaceEnvVar)
    37  	}
    38  	return ns, nil
    39  }
    40  
    41  // errNoNS indicates that a namespace could not be found for the current
    42  // environment
    43  var ErrNoNamespace = fmt.Errorf("namespace not found for current environment")
    44  
    45  // GetOperatorNamespace returns the namespace the operator should be running in.
    46  func GetOperatorNamespace() (string, error) {
    47  	nsBytes, err := ioutil.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
    48  	if err != nil {
    49  		if os.IsNotExist(err) {
    50  			return "", ErrNoNamespace
    51  		}
    52  		return "", err
    53  	}
    54  	ns := strings.TrimSpace(string(nsBytes))
    55  	log.V(1).Info("Found namespace", "Namespace", ns)
    56  	return ns, nil
    57  }
    58  
    59  // GetOperatorName return the operator name
    60  func GetOperatorName() (string, error) {
    61  	operatorName, found := os.LookupEnv(OperatorNameEnvVar)
    62  	if !found {
    63  		return "", fmt.Errorf("%s must be set", OperatorNameEnvVar)
    64  	}
    65  	if len(operatorName) == 0 {
    66  		return "", fmt.Errorf("%s must not be empty", OperatorNameEnvVar)
    67  	}
    68  	return operatorName, nil
    69  }
    70  
    71  // ResourceExists returns true if the given resource kind exists
    72  // in the given api groupversion
    73  func ResourceExists(dc discovery.DiscoveryInterface, apiGroupVersion, kind string) (bool, error) {
    74  	apiLists, err := dc.ServerResources()
    75  	if err != nil {
    76  		return false, err
    77  	}
    78  	for _, apiList := range apiLists {
    79  		if apiList.GroupVersion == apiGroupVersion {
    80  			for _, r := range apiList.APIResources {
    81  				if r.Kind == kind {
    82  					return true, nil
    83  				}
    84  			}
    85  		}
    86  	}
    87  	return false, nil
    88  }
    89  
    90  // GetPod returns a Pod object that corresponds to the pod in which the code
    91  // is currently running.
    92  // It expects the environment variable POD_NAME to be set by the downwards API.
    93  func GetPod(ctx context.Context, client crclient.Client, ns string) (*corev1.Pod, error) {
    94  	podName := os.Getenv(PodNameEnvVar)
    95  	if podName == "" {
    96  		return nil, fmt.Errorf("required env %s not set, please configure downward API", PodNameEnvVar)
    97  	}
    98  
    99  	log.V(1).Info("Found podname", "Pod.Name", podName)
   100  
   101  	pod := &corev1.Pod{}
   102  	key := crclient.ObjectKey{Namespace: ns, Name: podName}
   103  	err := client.Get(ctx, key, pod)
   104  	if err != nil {
   105  		log.Error(err, "Failed to get Pod", "Pod.Namespace", ns, "Pod.Name", podName)
   106  		return nil, err
   107  	}
   108  
   109  	// .Get() clears the APIVersion and Kind,
   110  	// so we need to set them before returning the object.
   111  	pod.TypeMeta.APIVersion = "v1"
   112  	pod.TypeMeta.Kind = "Pod"
   113  
   114  	log.V(1).Info("Found Pod", "Pod.Namespace", ns, "Pod.Name", pod.Name)
   115  
   116  	return pod, nil
   117  }