client.go

Documentation: github.com/chaos-mesh/chaos-mesh/pkg/chaosdaemon/crclients/crio

     1  // Copyright 2021 Chaos Mesh 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  
    16  package crio
    17  
    18  import (
    19  	"context"
    20  	"encoding/json"
    21  	"errors"
    22  	"fmt"
    23  	"net"
    24  	"net/http"
    25  	"syscall"
    26  	"time"
    27  )
    28  
    29  const (
    30  	InspectContainersEndpoint = "/containers"
    31  
    32  	crioProtocolPrefix    = "cri-o://"
    33  	maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
    34  )
    35  
    36  // CrioClient can get information from docker
    37  type CrioClient struct {
    38  	client     *http.Client
    39  	socketPath string
    40  }
    41  
    42  // FormatContainerID strips protocol prefix from the container ID
    43  func (c CrioClient) FormatContainerID(ctx context.Context, containerID string) (string, error) {
    44  	if len(containerID) < len(crioProtocolPrefix) {
    45  		return "", fmt.Errorf("container id %s is not a crio container id", containerID)
    46  	}
    47  	if containerID[0:len(crioProtocolPrefix)] != crioProtocolPrefix {
    48  		return "", fmt.Errorf("expected %s but got %s", crioProtocolPrefix, containerID[0:len(crioProtocolPrefix)])
    49  	}
    50  	return containerID[len(crioProtocolPrefix):], nil
    51  }
    52  
    53  // most of these implementations are copied from https://github.com/cri-o/cri-o/blob/master/internal/client/client.go
    54  
    55  // GetPidFromContainerID fetches PID according to container id
    56  func (c CrioClient) GetPidFromContainerID(ctx context.Context, containerID string) (uint32, error) {
    57  	id, err := c.FormatContainerID(ctx, containerID)
    58  	if err != nil {
    59  		return 0, err
    60  	}
    61  
    62  	req, err := c.getRequest(ctx, InspectContainersEndpoint+"/"+id)
    63  	if err != nil {
    64  		return 0, err
    65  	}
    66  	resp, err := c.client.Do(req)
    67  	if err != nil {
    68  		return 0, err
    69  	}
    70  	defer resp.Body.Close()
    71  	cInfo := make(map[string]interface{})
    72  	if err := json.NewDecoder(resp.Body).Decode(&cInfo); err != nil {
    73  		return 0, err
    74  	}
    75  
    76  	pid := cInfo["pid"]
    77  	if pid, ok := pid.(float64); ok {
    78  		return uint32(pid), nil
    79  	}
    80  
    81  	return 0, errors.New("fail to get pid from container info")
    82  }
    83  
    84  // ContainerKillByContainerID kills container according to container id
    85  func (c CrioClient) ContainerKillByContainerID(ctx context.Context, containerID string) error {
    86  	pid, err := c.GetPidFromContainerID(ctx, containerID)
    87  	if err != nil {
    88  		return err
    89  	}
    90  	return syscall.Kill(int(pid), syscall.SIGKILL)
    91  }
    92  
    93  func New(socketPath string) (*CrioClient, error) {
    94  	tr := new(http.Transport)
    95  	if err := configureUnixTransport(tr, "unix", socketPath); err != nil {
    96  		return nil, err
    97  	}
    98  	c := &http.Client{
    99  		Transport: tr,
   100  	}
   101  	return &CrioClient{
   102  		client:     c,
   103  		socketPath: socketPath,
   104  	}, nil
   105  }
   106  
   107  func configureUnixTransport(tr *http.Transport, proto, addr string) error {
   108  	if len(addr) > maxUnixSocketPathSize {
   109  		return fmt.Errorf("unix socket path %q is too long", addr)
   110  	}
   111  	// No need for compression in local communications.
   112  	tr.DisableCompression = true
   113  	tr.DialContext = func(_ context.Context, _, _ string) (net.Conn, error) {
   114  		return net.DialTimeout(proto, addr, 32*time.Second)
   115  	}
   116  	return nil
   117  }
   118  
   119  func (c *CrioClient) getRequest(ctx context.Context, path string) (*http.Request, error) {
   120  	req, err := http.NewRequest("GET", path, nil)
   121  	if err != nil {
   122  		return nil, err
   123  	}
   124  	// For local communications over a unix socket, it doesn't matter what
   125  	// the host is. We just need a valid and meaningful host name.
   126  	req.Host = "crio"
   127  	req.URL.Host = c.socketPath
   128  	req.URL.Scheme = "http"
   129  	req = req.WithContext(ctx)
   130  	return req, nil
   131  }
   132