Nest+Dapr

A NestJS module for Dapr along with a reference application.

• Dapr
• NestJS
• NX

See the module documentation to install just the package.

Getting started

Requirements

• MacOS (Windows not supported yet)
• Docker

Running the project

# This will install dependencies and Dapr before running the application
./bin/start.sh

Testing various components

Pubsub

Topic subscription

# Mimics a publish to the "pubsub" topic
$> curl -X POST http://localhost:3101/v1.0/publish/pubsub/orders -H "Content-Type: application/json" -d '{"orderId": "100"}'

# You should see some messages in the backend logs like:
== APP == [Nest] 11745  - 09/10/2024, 7:41:17 PM     LOG [PubsubDemo] handleOrdersTopic: {"orderId":"100"}
== APP == [Nest] 11745  - 09/10/2024, 7:41:17 PM     LOG [PubsubDemo] handleOrderCompleteTopic 1725997277402

Topic subscription with error handling

Currently configured to retry messages 3 times before publishing the message to the deadletter topic "dead-letter-topic"

# Handler for this message will throw an error
$> curl -X POST http://localhost:3101/v1.0/publish/pubsub/flaky-topic -H "Content-Type: application/json" -d '{"shouldError": true}'

# You should see some messages in the backend logs like:
== APP == [Nest] 12542  - 09/10/2024, 7:43:01 PM     LOG [PubsubErrorHandlingDemo] handleFlakyTopic: {"shouldError":true}
== APP == [Nest] 12542  - 09/10/2024, 7:43:01 PM   ERROR [DaprPubsub(pubsub)] Handler errored with Error: wtf. Using fail method "RETRY".
== APP == [Nest] 12542  - 09/10/2024, 7:43:04 PM     LOG [PubsubErrorHandlingDemo] handleFlakyTopic: {"shouldError":true}
== APP == [Nest] 12542  - 09/10/2024, 7:43:04 PM   ERROR [DaprPubsub(pubsub)] Handler errored with Error: wtf. Using fail method "RETRY".
== APP == [Nest] 12542  - 09/10/2024, 7:43:07 PM     LOG [PubsubErrorHandlingDemo] handleFlakyTopic: {"shouldError":true}
== APP == [Nest] 12542  - 09/10/2024, 7:43:07 PM   ERROR [DaprPubsub(pubsub)] Handler errored with Error: wtf. Using fail method "RETRY".
== APP == [Nest] 12542  - 09/10/2024, 7:43:10 PM     LOG [PubsubErrorHandlingDemo] handleFlakyTopic: {"shouldError":true}
== APP == [Nest] 12542  - 09/10/2024, 7:43:10 PM   ERROR [DaprPubsub(pubsub)] Handler errored with Error: wtf. Using fail method "RETRY".
== APP == [Nest] 12542  - 09/10/2024, 7:43:11 PM   ERROR [PubsubErrorHandlingDemo] handleFlakyTopicDlt: {"shouldError":true}

State store

# Set the state for entity 1
$> curl -X POST http://localhost:3000/api/client-demo/entity/1 --header "Content-Type: application/json" --data '{"hello": "world"}'

# Fetch the state
$> curl http://localhost:3000/api/client-demo/entity/1
{"hello":"world"}

Distributed lock

# Obtain the lock with ID 1
$> curl -X POST http://localhost:3000/api/client-demo/lock/1/obtain
{"result":"Lock 1 obtained"}

# Attempts to obtain it again will fail
$> curl -X POST http://localhost:3000/api/client-demo/lock/1/obtain
{"result":"Lock 1 not available"}

# Release the lock
$> curl -X POST http://localhost:3000/api/client-demo/lock/1/release
{"result":"Lock 1 released"}

# Attempts to release a non-existing lock will fail
$> curl -X POST http://localhost:3000/api/client-demo/lock/1/release
{"result":"Lock 1 does not exist"}