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

     1  package client // import "github.com/docker/docker/client"
     2  
     3  import (
     4  	"context"
     5  	"encoding/json"
     6  	"net/url"
     7  	"time"
     8  
     9  	"github.com/docker/docker/api/types"
    10  	"github.com/docker/docker/api/types/events"
    11  	"github.com/docker/docker/api/types/filters"
    12  	timetypes "github.com/docker/docker/api/types/time"
    13  )
    14  
    15  // Events returns a stream of events in the daemon. It's up to the caller to close the stream
    16  // by cancelling the context. Once the stream has been completely read an io.EOF error will
    17  // be sent over the error channel. If an error is sent all processing will be stopped. It's up
    18  // to the caller to reopen the stream in the event of an error by reinvoking this method.
    19  func (cli *Client) Events(ctx context.Context, options types.EventsOptions) (<-chan events.Message, <-chan error) {
    20  
    21  	messages := make(chan events.Message)
    22  	errs := make(chan error, 1)
    23  
    24  	started := make(chan struct{})
    25  	go func() {
    26  		defer close(errs)
    27  
    28  		query, err := buildEventsQueryParams(cli.version, options)
    29  		if err != nil {
    30  			close(started)
    31  			errs <- err
    32  			return
    33  		}
    34  
    35  		resp, err := cli.get(ctx, "/events", query, nil)
    36  		if err != nil {
    37  			close(started)
    38  			errs <- err
    39  			return
    40  		}
    41  		defer resp.body.Close()
    42  
    43  		decoder := json.NewDecoder(resp.body)
    44  
    45  		close(started)
    46  		for {
    47  			select {
    48  			case <-ctx.Done():
    49  				errs <- ctx.Err()
    50  				return
    51  			default:
    52  				var event events.Message
    53  				if err := decoder.Decode(&event); err != nil {
    54  					errs <- err
    55  					return
    56  				}
    57  
    58  				select {
    59  				case messages <- event:
    60  				case <-ctx.Done():
    61  					errs <- ctx.Err()
    62  					return
    63  				}
    64  			}
    65  		}
    66  	}()
    67  	<-started
    68  
    69  	return messages, errs
    70  }
    71  
    72  func buildEventsQueryParams(cliVersion string, options types.EventsOptions) (url.Values, error) {
    73  	query := url.Values{}
    74  	ref := time.Now()
    75  
    76  	if options.Since != "" {
    77  		ts, err := timetypes.GetTimestamp(options.Since, ref)
    78  		if err != nil {
    79  			return nil, err
    80  		}
    81  		query.Set("since", ts)
    82  	}
    83  
    84  	if options.Until != "" {
    85  		ts, err := timetypes.GetTimestamp(options.Until, ref)
    86  		if err != nil {
    87  			return nil, err
    88  		}
    89  		query.Set("until", ts)
    90  	}
    91  
    92  	if options.Filters.Len() > 0 {
    93  		//nolint:staticcheck // ignore SA1019 for old code
    94  		filterJSON, err := filters.ToParamWithVersion(cliVersion, options.Filters)
    95  		if err != nil {
    96  			return nil, err
    97  		}
    98  		query.Set("filters", filterJSON)
    99  	}
   100  
   101  	return query, nil
   102  }