Notificações de eventos do S3
Configure o S3 para publicar eventos no Lambda, SQS ou SNS sempre que ações específicas ocorrerem nos objetos, permitindo fluxos de trabalho reativos avançados.
Notificações de eventos do S3 é uma aula grátis de AWS for Backend Developers (EC2, S3, RDS, Lambda) no CoddyKit. Esta é a aula 3 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de AWS for Backend Developers (EC2, S3, RDS, Lambda), e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de AWS for Backend Developers (EC2, S3, RDS, Lambda) inclui 4 aulas no total.
Partes desta aula ainda não foram traduzidas e aparecem em inglês.
Intro to S3 Event Notifications
Welcome to this lesson on S3 Event Notifications! This powerful feature allows your S3 buckets to automatically notify other AWS services when specific actions occur.
Think of it as setting up an alert system for your data. When a file is uploaded, deleted, or modified, S3 can tell another service to take action.
The Event Flow
S3 event notifications work by publishing an event message whenever a configured action happens in your bucket. These messages contain details about the event, such as the bucket name, object key, and event time.
- Object Created: When a new file is uploaded.
- Object Deleted: When a file is removed.
- Object Restore: When an archived object is restored.
These events enable powerful, reactive workflows for your applications.
Common Event Destinations
S3 can send these event notifications to several AWS services. The most common destinations are:
- AWS Lambda: For running custom code in response to events (e.g., resizing images, processing data).
- Amazon SQS (Simple Queue Service): For queuing events reliably for later processing by other applications.
- Amazon SNS (Simple Notification Service): For fanning out notifications to multiple subscribers (e.g., sending emails, triggering other services).
Choosing the right destination depends on your specific use case.
Setting Up Notifications
Configuring S3 event notifications is done at the bucket level. You define which event types you want to monitor and which destination service should receive the notifications.
You can also apply filters to only trigger notifications for objects with specific prefixes (folders) or suffixes (file extensions).
Example: Notifying on New Objects
A very common use case is triggering an event when new objects are created (uploaded) to an S3 bucket. This can kick off an automated process.
For instance, if users upload profile pictures, an s3:ObjectCreated:Put event can trigger a Lambda function to resize the image and store different versions.
Lambda for Processing Events
AWS Lambda is an excellent choice for processing S3 events because it's serverless. You only pay when your code runs, and it scales automatically.
When S3 sends an event to Lambda, the event details are passed as an input to your Lambda function, allowing your code to react specifically to what happened.
Lambda Event Handler
Here's a simple Python Lambda function that receives and logs an S3 event. This is the entry point for your custom logic.
Try running it to see how the event structure looks!
import json
def lambda_handler(event, context):
print("Received S3 event:")
print(json.dumps(event, indent=2))
# Extract bucket and key from the event
for record in event['Records']:
bucket_name = record['s3']['bucket']['name']
object_key = record['s3']['object']['key']
print(f"Object '{object_key}' in bucket '{bucket_name}' was {record['eventName']}")
return {
'statusCode': 200,
'body': json.dumps('Event processed successfully!')
}Linking S3 to Lambda
To connect your S3 bucket to a Lambda function, you configure the notification settings in the S3 console or via AWS CLI/SDK.
You'll select the event types (e.g., 'All object create events'), choose 'Lambda Function' as the destination, and specify your function's ARN. You can also add prefix and suffix filters here.
SQS & SNS for Events
While Lambda is great for immediate code execution, SQS and SNS offer different benefits:
- SQS: Ideal for buffering events, decoupling components, and ensuring messages are processed even if the consumer is temporarily unavailable.
- SNS: Perfect for fan-out scenarios, where one event needs to trigger multiple subscribers (e.g., sending an email notification AND triggering a Lambda function).
They provide flexibility for complex architectures.
Event Notification Check
Let's test your understanding of S3 Event Notifications.
S3 Events Recap
Great job! You've learned about S3 Event Notifications, a powerful feature for creating reactive, event-driven architectures.
- S3 publishes events for actions like object creation or deletion.
- These events can be sent to Lambda, SQS, or SNS.
- You can use filters (prefix/suffix) to control which events trigger notifications.
This allows you to automate tasks and build dynamic applications based on changes in your S3 buckets!
Perguntas Frequentes
A aula “Notificações de eventos do S3” é grátis?
Sim — o texto completo de “Notificações de eventos do S3” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de AWS for Backend Developers (EC2, S3, RDS, Lambda), atualize para CoddyKit PRO. O curso de AWS for Backend Developers (EC2, S3, RDS, Lambda) inclui 4 aulas no total.
O que vou aprender em “Notificações de eventos do S3”?
Configure o S3 para publicar eventos no Lambda, SQS ou SNS sempre que ações específicas ocorrerem nos objetos, permitindo fluxos de trabalho reativos avançados. Você pratica AWS for Backend Developers (EC2, S3, RDS, Lambda) com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.
Preciso ter experiência prévia para começar AWS for Backend Developers (EC2, S3, RDS, Lambda)?
Nenhuma experiência prévia é necessária. AWS for Backend Developers (EC2, S3, RDS, Lambda) no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 3 de 4.
Quanto tempo leva a aula “Notificações de eventos do S3”?
A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.
Posso escrever e executar código nesta aula de AWS for Backend Developers (EC2, S3, RDS, Lambda)?
Sim. Cada aula de AWS for Backend Developers (EC2, S3, RDS, Lambda) inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.
Todas as aulas deste curso
- Replicação entre regiões do S3
- Hospedagem de sites estáticos no S3
- Notificações de eventos do S3
- Políticas de ciclo de vida e classes de armazenamento do S3