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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package crio
    15  
    16  import (
    17  	"context"
    18  	"encoding/json"
    19  	"errors"
    20  	"fmt"
    21  	"net"
    22  	"net/http"
    23  	"syscall"
    24  	"time"
    25  )
    26  
    27  const (
    28  	InspectContainersEndpoint = "/containers"
    29  
    30  	crioProtocolPrefix    = "cri-o://"
    31  	maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
    32  )
    33  
    34  // CrioClient can get information from docker
    35  type CrioClient struct {
    36  	client     *http.Client
    37  	socketPath string
    38  }
    39  
    40  // FormatContainerID strips protocol prefix from the container ID
    41  func (c CrioClient) FormatContainerID(ctx context.Context, containerID string) (string, error) {
    42  	if len(containerID) < len(crioProtocolPrefix) {
    43  		return "", fmt.Errorf("container id %s is not a crio container id", containerID)
    44  	}
    45  	if containerID[0:len(crioProtocolPrefix)] != crioProtocolPrefix {
    46  		return "", fmt.Errorf("expected %s but got %s", crioProtocolPrefix, containerID[0:len(crioProtocolPrefix)])
    47  	}
    48  	return containerID[len(crioProtocolPrefix):], nil
    49  }
    50  
    51  // most of these implementations are copied from https://github.com/cri-o/cri-o/blob/master/internal/client/client.go
    52  
    53  // GetPidFromContainerID fetches PID according to container id
    54  func (c CrioClient) GetPidFromContainerID(ctx context.Context, containerID string) (uint32, error) {
    55  	id, err := c.FormatContainerID(ctx, containerID)
    56  	if err != nil {
    57  		return 0, err
    58  	}
    59  
    60  	req, err := c.getRequest(ctx, InspectContainersEndpoint+"/"+id)
    61  	if err != nil {
    62  		return 0, err
    63  	}
    64  	resp, err := c.client.Do(req)
    65  	if err != nil {
    66  		return 0, err
    67  	}
    68  	defer resp.Body.Close()
    69  	cInfo := make(map[string]interface{})
    70  	if err := json.NewDecoder(resp.Body).Decode(&cInfo); err != nil {
    71  		return 0, err
    72  	}
    73  
    74  	pid := cInfo["pid"]
    75  	if pid, ok := pid.(float64); ok {
    76  		return uint32(pid), nil
    77  	}
    78  
    79  	return 0, errors.New("fail to get pid from container info")
    80  }
    81  
    82  // ContainerKillByContainerID kills container according to container id
    83  func (c CrioClient) ContainerKillByContainerID(ctx context.Context, containerID string) error {
    84  	pid, err := c.GetPidFromContainerID(ctx, containerID)
    85  	if err != nil {
    86  		return err
    87  	}
    88  	return syscall.Kill(int(pid), syscall.SIGKILL)
    89  }
    90  
    91  func New(socketPath string) (*CrioClient, error) {
    92  	tr := new(http.Transport)
    93  	if err := configureUnixTransport(tr, "unix", socketPath); err != nil {
    94  		return nil, err
    95  	}
    96  	c := &http.Client{
    97  		Transport: tr,
    98  	}
    99  	return &CrioClient{
   100  		client:     c,
   101  		socketPath: socketPath,
   102  	}, nil
   103  }
   104  
   105  func configureUnixTransport(tr *http.Transport, proto, addr string) error {
   106  	if len(addr) > maxUnixSocketPathSize {
   107  		return fmt.Errorf("unix socket path %q is too long", addr)
   108  	}
   109  	// No need for compression in local communications.
   110  	tr.DisableCompression = true
   111  	tr.DialContext = func(_ context.Context, _, _ string) (net.Conn, error) {
   112  		return net.DialTimeout(proto, addr, 32*time.Second)
   113  	}
   114  	return nil
   115  }
   116  
   117  func (c *CrioClient) getRequest(ctx context.Context, path string) (*http.Request, error) {
   118  	req, err := http.NewRequest("GET", path, nil)
   119  	if err != nil {
   120  		return nil, err
   121  	}
   122  	// For local communications over a unix socket, it doesn't matter what
   123  	// the host is. We just need a valid and meaningful host name.
   124  	req.Host = "crio"
   125  	req.URL.Host = c.socketPath
   126  	req.URL.Scheme = "http"
   127  	req = req.WithContext(ctx)
   128  	return req, nil
   129  }
   130