Publish messages to Google Cloud Pub/Sub from mobile/client applications

This is not an officially supported Google product.

Copyright 2019 Google LLC

Introduction

This repository provides sample implementation of a proxy service which enables client-side apps to publish messages to Google Cloud Pub/Sub. The proxy service:

• Authenticates incoming end user requests.
• Forwards authenticated requests to Pub/Sub using appropriate Cloud IAM permissions

The detailed steps to run this proxy on GCP is covered in the tutorial available here.

Google Cloud Products Used or Referenced:

• Cloud PubSub
• Compute Engine
• Cloud Build
• Cloud Endpoints
• Container Registry

Local Deployment & Testing

For production grade deployments, refer to the detailed solution post.

Clone repository:

git clone https://github.com/GoogleCloudPlatform/solutions-pubsub-proxy-rest
cd solutions-pubsub-proxy-rest

Set environment variables:

export SERVICE_ACCOUNT_NAME=proxy-test-sa
export SERVICE_ACCOUNT_DEST=sa.json
export TOPIC=test-topic
export GOOGLE_APPLICATION_CREDENTIALS=$(pwd)/sa.json
export PROJECT=$(gcloud info --format='value(config.project)')

Create Pub/Sub topic:

gcloud pubsub topics create $TOPIC

Create service account:

gcloud iam service-accounts create \
   $SERVICE_ACCOUNT_NAME \
   --display-name $SERVICE_ACCOUNT_NAME

SA_EMAIL=$(gcloud iam service-accounts list \
   --filter="displayName:$SERVICE_ACCOUNT_NAME" \
   --format='value(email)')

gcloud projects add-iam-policy-binding $PROJECT \
   --member serviceAccount:$SA_EMAIL \
   --role roles/pubsub.publisher

mkdir -p $(dirname $SERVICE_ACCOUNT_DEST) && \
gcloud iam service-accounts keys create \
   $SERVICE_ACCOUNT_DEST \
   --iam-account $SA_EMAIL

Run Proxy Without Containerizing

To execute test cases and package, run:

mvn clean compile assembly:assembly package

To skip test cases, run:

mvn clean compile assembly:assembly package -DskipTests

On a new terminal, start the proxy after changing to the directory where pubsub-proxy was cloned:

export GOOGLE_APPLICATION_CREDENTIALS=$(pwd)/sa.json
java -jar target/pubsub-proxy-0.0.1-SNAPSHOT-jar-with-dependencies.jar 

Back on the original terminal, publish a message to Cloud Pub/Sub via proxy.

curl -i -X POST localhost:8080/publish \
   -H "Content-Type: application/json" \
   -d '{"topic": "'$TOPIC'", "messages": [ {"attributes": {"key1": "value1", "key2" : "value2"}, "data": "test data"}]}'

On the terminal running the proxy, check the logs to verify if the message was successfully published to Pub/Sub.

Deploy Proxy on GKE

Detailed steps to run this proxy on GCP is covered in the tutorial here.

Cleaning Up

Remove the private key:

rm -rf $SERVICE_ACCOUNT_DEST