package awspubsub

import "gocloud.dev/pubsub/awspubsub"

Package awspubsub provides an implementation of pubsub that uses AWS SNS (Simple Notification Service) and SQS (Simple Queueing Service).

Escaping

Go CDK supports all UTF-8 strings; to make this work with providers lacking full UTF-8 support, strings must be escaped (during writes) and unescaped (during reads). The following escapes are required for awspubsub:

• Metadata keys: Characters other than "a-zA-z0-9_-.", and additionally "." when it's at the start of the key or the previous character was ".", are escaped using "__0x<hex>__". These characters were determined by experimentation.
• Metadata values: Escaped using URL encoding.
• Message body: AWS SNS/SQS only supports UTF-8 strings. See the BodyBase64Encoding enum in TopicOptions for strategies on how to send non-UTF-8 message bodies. By default, non-UTF-8 message bodies are base64 encoded.

As

awspubsub exposes the following types for As:

• Topic: *sns.SNS
• Subscription: *sqs.SQS
• Message: *sqs.Message
• Error: awserror.Error

Index ¶

• func OpenSubscription(ctx context.Context, client *sqs.SQS, qURL string, opts *SubscriptionOptions) *pubsub.Subscription
• func OpenTopic(ctx context.Context, client *sns.SNS, topicARN string, opts *TopicOptions) *pubsub.Topic
• type BodyBase64Encoding
• type SubscriptionOptions
• type TopicOptions

Functions ¶

func OpenSubscription ¶

func OpenSubscription(ctx context.Context, client *sqs.SQS, qURL string, opts *SubscriptionOptions) *pubsub.Subscription

OpenSubscription opens a on AWS SQS for the given SQS client and queue URL. The queue is assumed to be subscribed to some SNS topic, though there is no check for this.

func OpenTopic ¶

func OpenTopic(ctx context.Context, client *sns.SNS, topicARN string, opts *TopicOptions) *pubsub.Topic

OpenTopic opens the topic on AWS SNS for the given SNS client and topic ARN.

Types ¶

type BodyBase64Encoding ¶

type BodyBase64Encoding int

BodyBase64Encoding is an enum of strategies for when to base64 message bodies.

const (
	// NonUTF8Only means that message bodies that are valid UTF-8 encodings are
	// sent as-is. Invalid UTF-8 message bodies are base64 encoded, and a
	// MessageAttribute with key "base64encoded" is added to the message.
	// When receiving messages, the "base64encoded" attribute is used to determine
	// whether to base64 decode, and is then filtered out.
	NonUTF8Only BodyBase64Encoding = 0
	// Always means that all message bodies are base64 encoded.
	// A MessageAttribute with key "base64encoded" is added to the message.
	// When receiving messages, the "base64encoded" attribute is used to determine
	// whether to base64 decode, and is then filtered out.
	Always BodyBase64Encoding = 1
	// Never means that message bodies are never base64 encoded. Non-UTF-8
	// bytes in message bodies may be modified by SNS/SQS.
	Never BodyBase64Encoding = 2
)

type SubscriptionOptions ¶

type SubscriptionOptions struct{}

SubscriptionOptions will contain configuration for subscriptions.

type TopicOptions ¶

type TopicOptions struct {
	// BodyBase64Encoding determines when message bodies are base64 encoded.
	// The default is NonUTF8Only.
	BodyBase64Encoding BodyBase64Encoding
}

TopicOptions contains configuration options for topics.

Source Files ¶

awspubsub.go