github.com/kim0/docker@v0.6.2-0.20161130212042-4addda3f07e7/client/events.go (about)

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