summaryrefslogtreecommitdiff
path: root/pkg/api/handlers/compat/events.go
blob: 289bf4a2dd822d274cab4b38bbd6af48ca8ec6db (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
package compat

import (
	"encoding/json"
	"fmt"
	"net/http"
	"sync"

	"github.com/containers/podman/v2/libpod"
	"github.com/containers/podman/v2/libpod/events"
	"github.com/containers/podman/v2/pkg/api/handlers/utils"
	"github.com/containers/podman/v2/pkg/domain/entities"
	"github.com/gorilla/schema"
	jsoniter "github.com/json-iterator/go"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
)

// filtersFromRequests extracts the "filters" parameter from the specified
// http.Request.  The parameter can either be a `map[string][]string` as done
// in new versions of Docker and libpod, or a `map[string]map[string]bool` as
// done in older versions of Docker.  We have to do a bit of Yoga to support
// both - just as Docker does as well.
//
// Please refer to https://github.com/containers/podman/issues/6899 for some
// background.
func filtersFromRequest(r *http.Request) ([]string, error) {
	var (
		compatFilters map[string]map[string]bool
		filters       map[string][]string
		libpodFilters []string
		raw           []byte
	)

	if _, found := r.URL.Query()["filters"]; found {
		raw = []byte(r.Form.Get("filters"))
	} else {
		return []string{}, nil
	}

	// Backwards compat with older versions of Docker.
	if err := json.Unmarshal(raw, &compatFilters); err == nil {
		for filterKey, filterMap := range compatFilters {
			for filterValue, toAdd := range filterMap {
				if toAdd {
					libpodFilters = append(libpodFilters, fmt.Sprintf("%s=%s", filterKey, filterValue))
				}
			}
		}
		return libpodFilters, nil
	}

	if err := json.Unmarshal(raw, &filters); err != nil {
		return nil, err
	}

	for filterKey, filterSlice := range filters {
		for _, filterValue := range filterSlice {
			libpodFilters = append(libpodFilters, fmt.Sprintf("%s=%s", filterKey, filterValue))
		}
	}

	return libpodFilters, nil
}

// NOTE: this endpoint serves both the docker-compatible one and the new libpod
// one.
func GetEvents(w http.ResponseWriter, r *http.Request) {
	var (
		fromStart bool
		decoder   = r.Context().Value("decoder").(*schema.Decoder)
		runtime   = r.Context().Value("runtime").(*libpod.Runtime)
		json      = jsoniter.ConfigCompatibleWithStandardLibrary // FIXME: this should happen on the package level
	)

	// NOTE: the "filters" parameter is extracted separately for backwards
	// compat via `fitlerFromRequest()`.
	query := struct {
		Since  string `schema:"since"`
		Until  string `schema:"until"`
		Stream bool   `schema:"stream"`
	}{
		Stream: true,
	}
	if err := decoder.Decode(&query, r.URL.Query()); err != nil {
		utils.Error(w, "Failed to parse parameters", http.StatusBadRequest, errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String()))
		return
	}

	if len(query.Since) > 0 || len(query.Until) > 0 {
		fromStart = true
	}

	libpodFilters, err := filtersFromRequest(r)
	if err != nil {
		utils.Error(w, "Failed to parse parameters", http.StatusBadRequest, errors.Wrapf(err, "Failed to parse parameters for %s", r.URL.String()))
		return
	}

	eventChannel := make(chan *events.Event)
	errorChannel := make(chan error)

	// Start reading events.
	go func() {
		readOpts := events.ReadOptions{
			FromStart:    fromStart,
			Stream:       query.Stream,
			Filters:      libpodFilters,
			EventChannel: eventChannel,
			Since:        query.Since,
			Until:        query.Until,
		}
		errorChannel <- runtime.Events(r.Context(), readOpts)
	}()

	var coder *jsoniter.Encoder
	var writeHeader sync.Once

	for stream := true; stream; stream = query.Stream {
		select {
		case err := <-errorChannel:
			if err != nil {
				utils.InternalServerError(w, err)
				return
			}
		case evt := <-eventChannel:
			writeHeader.Do(func() {
				// Use a sync.Once so that we write the header
				// only once.
				w.Header().Set("Content-Type", "application/json")
				w.WriteHeader(http.StatusOK)
				if flusher, ok := w.(http.Flusher); ok {
					flusher.Flush()
				}
				coder = json.NewEncoder(w)
				coder.SetEscapeHTML(true)
			})

			if evt == nil {
				continue
			}

			e := entities.ConvertToEntitiesEvent(*evt)
			if err := coder.Encode(e); err != nil {
				logrus.Errorf("unable to write json: %q", err)
			}
			if flusher, ok := w.(http.Flusher); ok {
				flusher.Flush()
			}
		}

	}
}