-
Notifications
You must be signed in to change notification settings - Fork 67
/
message.go
223 lines (195 loc) · 6.24 KB
/
message.go
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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/*
Copyright 2021 The Knative Authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package rabbit
import (
"bytes"
"context"
"fmt"
nethttp "net/http"
"strings"
"go.uber.org/zap"
sourcesv1alpha1 "knative.dev/eventing-rabbitmq/pkg/apis/sources/v1alpha1"
"github.com/NeowayLabs/wabbit"
cloudevents "github.com/cloudevents/sdk-go/v2"
"github.com/cloudevents/sdk-go/v2/binding"
"github.com/cloudevents/sdk-go/v2/binding/format"
"github.com/cloudevents/sdk-go/v2/binding/spec"
"github.com/cloudevents/sdk-go/v2/protocol/http"
"k8s.io/apimachinery/pkg/util/uuid"
)
const (
prefix = "ce-"
contentTypeHeader = "content-type"
specversionHeader = "specversion"
traceparent = "traceparent"
tracestate = "tracestate"
)
var specs = spec.WithPrefix(prefix)
// Message holds a rabbitmq message.
// this message *can* be read several times safely
type Message struct {
Value []byte
Headers map[string][]byte
ContentType string
format format.Format
version spec.Version
}
// Check if rabbit.Message implements binding.Message
var _ binding.Message = (*Message)(nil)
var _ binding.MessageMetadataReader = (*Message)(nil)
func ConvertMessageToHTTPRequest(
ctx context.Context,
sourceName, namespace, queueName string,
msg wabbit.Delivery,
req *nethttp.Request,
logger *zap.Logger) error {
msgBinding := NewMessageFromDelivery(sourceName, namespace, queueName, msg)
defer func() {
err := msgBinding.Finish(nil)
if err != nil {
logger.Error("Something went wrong while trying to finalizing the message", zap.Error(err))
}
}()
// if the msg is a cloudevent send it as it is to http
if msgBinding.ReadEncoding() != binding.EncodingUnknown {
return http.WriteRequest(cloudevents.WithEncodingBinary(ctx), msgBinding, req)
}
// if the rabbitmq msg is not a cloudevent transform it into one
event := cloudevents.NewEvent()
err := ConvertToCloudEvent(&event, msg, namespace, sourceName, queueName)
if err != nil {
logger.Error("Error converting RabbitMQ msg to CloudEvent", zap.Error(err))
return err
}
return http.WriteRequest(ctx, binding.ToMessage(&event), req)
}
// NewMessageFromDelivery returns a binding.Message that holds the provided RabbitMQ Message.
// The returned binding.Message *can* be read several times safely
func NewMessageFromDelivery(sourceName, namespace, queueName string, msg wabbit.Delivery) *Message {
headers := make(map[string][]byte, len(msg.Headers()))
for key, val := range msg.Headers() {
if key == traceparent || key == tracestate {
continue
}
k := strings.ToLower(key)
headers[strings.TrimPrefix(k, prefix)] = []byte(fmt.Sprint(val))
}
if _, ok := headers["source"]; !ok {
headers["source"] = []byte(sourcesv1alpha1.RabbitmqEventSource(namespace, sourceName, queueName))
}
return NewMessage(msg.Body(), msg.ContentType(), headers)
}
// NewMessage returns a binding.Message that holds the provided rabbitmq message components.
// The returned binding.Message *can* be read several times safely
func NewMessage(value []byte, contentType string, headers map[string][]byte) *Message {
if ft := format.Lookup(contentType); ft != nil {
return &Message{
Value: value,
ContentType: contentType,
Headers: headers,
format: ft,
}
} else if v := specs.Version(string(headers[specversionHeader])); v != nil {
return &Message{
Value: value,
ContentType: contentType,
Headers: headers,
version: v,
}
}
return &Message{
Value: value,
ContentType: contentType,
Headers: headers,
}
}
func (m *Message) ReadEncoding() binding.Encoding {
if m.version != nil {
return binding.EncodingBinary
}
if m.format != nil {
return binding.EncodingStructured
}
return binding.EncodingUnknown
}
func (m *Message) ReadBinary(ctx context.Context, encoder binding.BinaryWriter) (err error) {
if m.version == nil {
return binding.ErrNotBinary
}
var contentTypeSet bool
for k, v := range m.Headers {
if k == contentTypeHeader {
contentTypeSet = true
err = encoder.SetAttribute(m.version.AttributeFromKind(spec.DataContentType), string(v))
// avoid converting any RabbitMQ related headers to the CloudEvent
} else if !strings.HasPrefix(k, "x-") {
attr := m.version.Attribute(prefix + k)
if err == nil {
if attr != nil {
err = encoder.SetAttribute(attr, string(v))
} else {
err = encoder.SetExtension(k, string(v))
}
}
}
if !contentTypeSet && err == nil {
err = encoder.SetAttribute(m.version.AttributeFromKind(spec.DataContentType), m.ContentType)
}
if err != nil {
return
}
}
if m.Value != nil {
err = encoder.SetData(bytes.NewBuffer(m.Value))
}
return
}
func (m *Message) ReadStructured(ctx context.Context, encoder binding.StructuredWriter) error {
if m.format != nil {
return encoder.SetStructuredEvent(ctx, m.format, bytes.NewReader(m.Value))
}
return binding.ErrNotStructured
}
func (m *Message) GetAttribute(k spec.Kind) (spec.Attribute, interface{}) {
attr := m.version.AttributeFromKind(k)
if attr != nil {
return attr, string(m.Headers[attr.PrefixedName()])
}
return nil, nil
}
func (m *Message) GetExtension(name string) interface{} {
return string(m.Headers[name])
}
func (m *Message) Finish(error) error {
return nil
}
func ConvertToCloudEvent(event *cloudevents.Event, msg wabbit.Delivery, namespace, sourceName, queueName string) error {
if msg.MessageId() != "" {
event.SetID(msg.MessageId())
} else {
event.SetID(string(uuid.NewUUID()))
}
if event.Type() == "" {
event.SetType(sourcesv1alpha1.RabbitmqEventType)
}
if event.Source() == "" {
event.SetSource(sourcesv1alpha1.RabbitmqEventSource(namespace, sourceName, queueName))
}
event.SetSubject(event.ID())
event.SetTime(msg.Timestamp())
err := event.SetData(msg.ContentType(), msg.Body())
if err != nil {
return err
}
return nil
}