graceful_shutdown_test.go

Documentation: k8s.io/kubernetes/test/integration/controlplane

     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 controlplane
    18  
    19  import (
    20  	"io"
    21  	"net/http"
    22  	"sync"
    23  	"testing"
    24  	"time"
    25  
    26  	"k8s.io/apimachinery/pkg/util/wait"
    27  	"k8s.io/client-go/rest"
    28  	kubeapiservertesting "k8s.io/kubernetes/cmd/kube-apiserver/app/testing"
    29  	"k8s.io/kubernetes/test/integration/framework"
    30  )
    31  
    32  func TestGracefulShutdown(t *testing.T) {
    33  	server := kubeapiservertesting.StartTestServerOrDie(t, nil, nil, framework.SharedEtcd())
    34  
    35  	tearDownOnce := sync.Once{}
    36  	defer tearDownOnce.Do(server.TearDownFn)
    37  
    38  	transport, err := rest.TransportFor(server.ClientConfig)
    39  	if err != nil {
    40  		t.Fatalf("unexpected error: %v", err)
    41  	}
    42  	client := http.Client{Transport: transport}
    43  
    44  	req, body, err := newBlockingRequest("POST", server.ClientConfig.Host+"/api/v1/namespaces")
    45  	if err != nil {
    46  		t.Fatal(err)
    47  	}
    48  	respErrCh := backgroundRoundtrip(transport, req)
    49  
    50  	t.Logf("server should be blocking request for data in body")
    51  	time.Sleep(time.Millisecond * 500)
    52  	select {
    53  	case respErr := <-respErrCh:
    54  		if respErr.err != nil {
    55  			t.Fatalf("unexpected error: %v", err)
    56  		}
    57  		bs, err := io.ReadAll(respErr.resp.Body)
    58  		if err != nil {
    59  			t.Fatal(err)
    60  		}
    61  		t.Fatalf("unexpected server answer: %d, body: %s", respErr.resp.StatusCode, string(bs))
    62  	default:
    63  	}
    64  
    65  	t.Logf("server should answer")
    66  	resp, err := client.Get(server.ClientConfig.Host + "/")
    67  	if err != nil {
    68  		t.Fatal(err)
    69  	}
    70  	resp.Body.Close()
    71  
    72  	t.Logf("shutting down server")
    73  	// We tear it down in the background to ensure that
    74  	// pending requests should work fine.
    75  	wg := sync.WaitGroup{}
    76  	wg.Add(1)
    77  	go func() {
    78  		defer wg.Done()
    79  		tearDownOnce.Do(server.TearDownFn)
    80  	}()
    81  
    82  	t.Logf("server should fail new requests")
    83  	if err := wait.Poll(time.Millisecond*100, wait.ForeverTestTimeout, func() (done bool, err error) {
    84  		resp, err := client.Get(server.ClientConfig.Host + "/")
    85  		if err != nil {
    86  			return true, nil
    87  		}
    88  		resp.Body.Close()
    89  		return false, nil
    90  	}); err != nil {
    91  		t.Fatalf("server did not shutdown")
    92  	}
    93  
    94  	t.Logf("server should answer pending request")
    95  	time.Sleep(time.Millisecond * 500)
    96  	if _, err := body.Write([]byte("garbage")); err != nil {
    97  		t.Fatal(err)
    98  	}
    99  	body.Close()
   100  	respErr := <-respErrCh
   101  	if respErr.err != nil {
   102  		t.Fatal(respErr.err)
   103  	}
   104  	defer respErr.resp.Body.Close()
   105  	bs, err := io.ReadAll(respErr.resp.Body)
   106  	if err != nil {
   107  		t.Fatal(err)
   108  	}
   109  	t.Logf("response: code %d, body: %s", respErr.resp.StatusCode, string(bs))
   110  
   111  	wg.Wait()
   112  }
   113  
   114  type responseErrorPair struct {
   115  	resp *http.Response
   116  	err  error
   117  }
   118  
   119  func backgroundRoundtrip(transport http.RoundTripper, req *http.Request) <-chan responseErrorPair {
   120  	ch := make(chan responseErrorPair)
   121  	go func() {
   122  		resp, err := transport.RoundTrip(req)
   123  		ch <- responseErrorPair{resp, err}
   124  	}()
   125  	return ch
   126  }
   127  
   128  func newBlockingRequest(method, url string) (*http.Request, io.WriteCloser, error) {
   129  	bodyReader, bodyWriter := io.Pipe()
   130  	req, err := http.NewRequest(method, url, bodyReader)
   131  	return req, bodyWriter, err
   132  }
   133
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