github.com/kaisenlinux/docker.io@v0.0.0-20230510090727-ea55db55fac7/engine/client/container_wait.go (about)

     1  package client // import "github.com/docker/docker/client"
     2  
     3  import (
     4  	"context"
     5  	"encoding/json"
     6  	"net/url"
     7  
     8  	"github.com/docker/docker/api/types/container"
     9  	"github.com/docker/docker/api/types/versions"
    10  )
    11  
    12  // ContainerWait waits until the specified container is in a certain state
    13  // indicated by the given condition, either "not-running" (default),
    14  // "next-exit", or "removed".
    15  //
    16  // If this client's API version is before 1.30, condition is ignored and
    17  // ContainerWait will return immediately with the two channels, as the server
    18  // will wait as if the condition were "not-running".
    19  //
    20  // If this client's API version is at least 1.30, ContainerWait blocks until
    21  // the request has been acknowledged by the server (with a response header),
    22  // then returns two channels on which the caller can wait for the exit status
    23  // of the container or an error if there was a problem either beginning the
    24  // wait request or in getting the response. This allows the caller to
    25  // synchronize ContainerWait with other calls, such as specifying a
    26  // "next-exit" condition before issuing a ContainerStart request.
    27  func (cli *Client) ContainerWait(ctx context.Context, containerID string, condition container.WaitCondition) (<-chan container.ContainerWaitOKBody, <-chan error) {
    28  	if versions.LessThan(cli.ClientVersion(), "1.30") {
    29  		return cli.legacyContainerWait(ctx, containerID)
    30  	}
    31  
    32  	resultC := make(chan container.ContainerWaitOKBody)
    33  	errC := make(chan error, 1)
    34  
    35  	query := url.Values{}
    36  	query.Set("condition", string(condition))
    37  
    38  	resp, err := cli.post(ctx, "/containers/"+containerID+"/wait", query, nil, nil)
    39  	if err != nil {
    40  		defer ensureReaderClosed(resp)
    41  		errC <- err
    42  		return resultC, errC
    43  	}
    44  
    45  	go func() {
    46  		defer ensureReaderClosed(resp)
    47  		var res container.ContainerWaitOKBody
    48  		if err := json.NewDecoder(resp.body).Decode(&res); err != nil {
    49  			errC <- err
    50  			return
    51  		}
    52  
    53  		resultC <- res
    54  	}()
    55  
    56  	return resultC, errC
    57  }
    58  
    59  // legacyContainerWait returns immediately and doesn't have an option to wait
    60  // until the container is removed.
    61  func (cli *Client) legacyContainerWait(ctx context.Context, containerID string) (<-chan container.ContainerWaitOKBody, <-chan error) {
    62  	resultC := make(chan container.ContainerWaitOKBody)
    63  	errC := make(chan error)
    64  
    65  	go func() {
    66  		resp, err := cli.post(ctx, "/containers/"+containerID+"/wait", nil, nil, nil)
    67  		if err != nil {
    68  			errC <- err
    69  			return
    70  		}
    71  		defer ensureReaderClosed(resp)
    72  
    73  		var res container.ContainerWaitOKBody
    74  		if err := json.NewDecoder(resp.body).Decode(&res); err != nil {
    75  			errC <- err
    76  			return
    77  		}
    78  
    79  		resultC <- res
    80  	}()
    81  
    82  	return resultC, errC
    83  }