SDK Examples

Your existing GCP SDK code works with LocalCloud — just set environment variables. Below are examples for the most common services.

Cloud Storage

Python

from google.cloud import storage

client = storage.Client(project="local-project")

# Create bucket and upload
bucket = client.create_bucket("my-bucket")
blob = bucket.blob("data.txt")
blob.upload_from_string("Hello from LocalCloud!")
print(blob.download_as_text())

Node.js

const { Storage } = require("@google-cloud/storage");

const storage = new Storage({ projectId: "local-project" });

async function main() {
  await storage.createBucket("my-bucket");
  const bucket = storage.bucket("my-bucket");
  await bucket.file("data.txt").save("Hello from LocalCloud!");
  const [content] = await bucket.file("data.txt").download();
  console.log(content.toString());
}
main();

Go

package main

import (
    "context"
    "fmt"
    "io"

    "cloud.google.com/go/storage"
)

func main() {
    ctx := context.Background()
    client, _ := storage.NewClient(ctx)
    defer client.Close()

    bucket := client.Bucket("my-bucket")
    bucket.Create(ctx, "local-project", nil)

    w := bucket.Object("data.txt").NewWriter(ctx)
    fmt.Fprint(w, "Hello from LocalCloud!")
    w.Close()

    r, _ := bucket.Object("data.txt").NewReader(ctx)
    data, _ := io.ReadAll(r)
    fmt.Println(string(data))
}

Java

import com.google.cloud.storage.*;

public class Example {
    public static void main(String[] args) {
        Storage storage = StorageOptions.newBuilder()
            .setProjectId("local-project")
            .build().getService();

        storage.create(BucketInfo.of("my-bucket"));

        BlobId blobId = BlobId.of("my-bucket", "data.txt");
        storage.create(BlobInfo.newBuilder(blobId).build(),
            "Hello from LocalCloud!".getBytes());

        byte[] content = storage.readAllBytes(blobId);
        System.out.println(new String(content));
    }
}

Pub/Sub

Python

from google.cloud import pubsub_v1

publisher = pubsub_v1.PublisherClient()
subscriber = pubsub_v1.SubscriberClient()

topic_path = publisher.topic_path("local-project", "my-topic")
sub_path = subscriber.subscription_path("local-project", "my-sub")

# Create topic and subscription
publisher.create_topic(request={"name": topic_path})
subscriber.create_subscription(request={"name": sub_path, "topic": topic_path})

# Publish
publisher.publish(topic_path, b"Hello, Pub/Sub!")

# Pull
response = subscriber.pull(request={"subscription": sub_path, "max_messages": 10})
for msg in response.received_messages:
    print(msg.message.data.decode())
    subscriber.acknowledge(request={"subscription": sub_path, "ack_ids": [msg.ack_id]})

Node.js

const { PubSub } = require("@google-cloud/pubsub");

const pubsub = new PubSub({ projectId: "local-project" });

async function main() {
  const [topic] = await pubsub.createTopic("my-topic");
  const [subscription] = await topic.createSubscription("my-sub");

  await topic.publishMessage({ data: Buffer.from("Hello, Pub/Sub!") });

  subscription.on("message", (message) => {
    console.log(message.data.toString());
    message.ack();
  });
}
main();

BigQuery

Python

from google.cloud import bigquery

client = bigquery.Client(project="local-project")

# Create dataset and table
client.create_dataset("analytics")
schema = [
    bigquery.SchemaField("name", "STRING"),
    bigquery.SchemaField("age", "INTEGER"),
]
table = bigquery.Table("local-project.analytics.users", schema=schema)
client.create_table(table)

# Insert and query
rows = [{"name": "Alice", "age": 30}, {"name": "Bob", "age": 25}]
client.insert_rows_json("local-project.analytics.users", rows)

query = "SELECT name, age FROM analytics.users WHERE age > 20"
for row in client.query(query):
    print(f"{row.name}: {row.age}")

Node.js

const { BigQuery } = require("@google-cloud/bigquery");

const bigquery = new BigQuery({ projectId: "local-project" });

async function main() {
  await bigquery.createDataset("analytics");
  const [rows] = await bigquery.query("SELECT 1 + 1 AS result");
  console.log(rows);
}
main();

Environment Setup

Remember to set the emulator environment variables before running any examples:

eval "$(curl -s http://localhost:8080/_localcloud/env?format=shell)"

Or set them manually:

export STORAGE_EMULATOR_HOST=http://localhost:4443
export PUBSUB_EMULATOR_HOST=localhost:8085
export BIGQUERY_EMULATOR_HOST=http://localhost:9050
export GOOGLE_CLOUD_PROJECT=local-project