Quickstart: Build and Deploy

This page shows you how to create a simple Hello World application, package it into a container image, upload the container image to Container Registry, and then deploy the container image to Cloud Run. The sample is shown in several languages, but note that you can use other languages in addition to the ones shown.

You can also follow this quickstart with a demo account on Qwiklabs.

Before you begin

1. Sign in to your Google Account.

   If you don't already have one, sign up for a new account.

2. In the Cloud Console, on the project selector page, select or create a Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   Go to the project selector page

3. Make sure that billing is enabled for your Google Cloud project. Learn how to confirm billing is enabled for your project.

4. Install and initialize the Cloud SDK.

Writing the sample application

For instructions on creating a sample hello world application that runs on Cloud Run, click the tab for your language:

Go

1. Create a new directory named helloworld-go and change directory into it:

   mkdir helloworld-go
   cd helloworld-go
   

2. Initialize a go.mod file to declare the go module:

   docs/serving/samples/hello-world/helloworld-go/go.mod

   module github.com/knative/docs/docs/serving/samples/hello-world/helloworld-go
   
   go 1.13
   

3. Create a new file named helloworld.go and paste the following code into it:

   docs/serving/samples/hello-world/helloworld-go/helloworld.go

   package main
   
   import (
   	"fmt"
   	"log"
   	"net/http"
   	"os"
   )
   
   func handler(w http.ResponseWriter, r *http.Request) {
   	log.Print("helloworld: received a request")
   	target := os.Getenv("TARGET")
   	if target == "" {
   		target = "World"
   	}
   	fmt.Fprintf(w, "Hello %s!\n", target)
   }
   
   func main() {
   	log.Print("helloworld: starting server...")
   
   	http.HandleFunc("/", handler)
   
   	port := os.Getenv("PORT")
   	if port == "" {
   		port = "8080"
   	}
   
   	log.Printf("helloworld: listening on port %s", port)
   	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
   }
   

   This code creates a basic web server that listens on the port defined by the PORT environment variable.

Your app is finished and ready to be containerized and uploaded to Container Registry.

Node.js

1. Create a new directory named helloworld-nodejs and change directory into it:

   mkdir helloworld-nodejs
   cd helloworld-nodejs
   

2. Create a package.json file with the following contents:

   docs/serving/samples/hello-world/helloworld-nodejs/package.json

   {
     "name": "knative-serving-helloworld",
     "version": "1.0.0",
     "description": "Simple hello world sample in Node",
     "main": "index.js",
     "scripts": {
       "start": "node index.js"
     },
     "author": "",
     "license": "Apache-2.0",
     "dependencies": {
       "express": "^4.16.4"
     }
   }
   

3. In the same directory, create a index.js file, and copy the following lines into it:

   docs/serving/samples/hello-world/helloworld-nodejs/index.js

   const express = require('express');
   const app = express();
   
   app.get('/', (req, res) => {
     console.log('Hello world received a request.');
   
     const target = process.env.TARGET || 'World';
     res.send(`Hello ${target}!`);
   });
   
   const port = process.env.PORT || 8080;
   app.listen(port, () => {
     console.log('Hello world listening on port', port);
   });
   

   This code creates a basic web server that listens on the port defined by the PORT environment variable.

Your app is finished and ready to be containerized and uploaded to Container Registry.

Python

1. Create a new directory named helloworld-python and change directory into it:

   mkdir helloworld-python
   cd helloworld-python
   

2. Create a file named app.py and paste the following code into it:

   docs/serving/samples/hello-world/helloworld-python/app.py

   import os
   
   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route('/')
   def hello_world():
       target = os.environ.get('TARGET', 'World')
       return 'Hello {}!\n'.format(target)
   
   if __name__ == "__main__":
       app.run(debug=True,host='0.0.0.0',port=int(os.environ.get('PORT', 8080)))
   

   This code responds to requests with our "Hello World" greeting. HTTP handling is done by a Gunicorn web server in the container. When directly invoked for local use, this code creates a basic web server that listens on the port defined by the PORT environment variable.

Your app is finished and ready to be containerized and uploaded to Container Registry.

Java

Create a Spring Boot application.

1. From the console, create a new empty web project using the cURL and unzip commands:

   curl https://start.spring.io/starter.zip \
       -d dependencies=web \
       -d javaVersion=1.8 \
       -d bootVersion=2.1.3.RELEASE \
       -d name=helloworld \
       -d artifactId=helloworld \
       -d baseDir=helloworld \
       -o helloworld.zip
   unzip helloworld.zip
   cd helloworld
   

   This creates a Spring Boot project.

2. Update the HelloworldApplication class in src/main/java/com/example/helloworld/HelloworldApplication.java by adding a @RestController to handle the / mapping and also add a @Value field to provide the TARGET environment variable:

   docs/serving/samples/hello-world/helloworld-java-spring/src/main/java/com/example/helloworld/HelloworldApplication.java

   package com.example.helloworld;
   
   import org.springframework.beans.factory.annotation.Value;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   import org.springframework.web.bind.annotation.GetMapping;
   import org.springframework.web.bind.annotation.RestController;
   
   @SpringBootApplication
   public class HelloworldApplication {
   
     @Value("${TARGET:World}")
     String target;
   
     @RestController
     class HelloworldController {
       @GetMapping("/")
       String hello() {
         return "Hello " + target + "!";
       }
     }
   
     public static void main(String[] args) {
       SpringApplication.run(HelloworldApplication.class, args);
     }
   }
   

   This code creates a basic web server that listens on the port defined by the PORT environment variable.

Your app is finished and ready to be containerized and uploaded to Container Registry.

To deploy Java to Cloud Run with other frameworks, review the Knative samples for Spark and Vert.x.

C#

1. Install .NET Core SDK 3.1. Note that we only need to do this to create the new web project in the next step: the Dockerfile, which is described later, will load all dependencies into the container.

2. From the console, create a new empty web project using the dotnet command:

   dotnet new web -o helloworld-csharp
   

3. Change directory to helloworld-csharp.

4. Update the CreateHostBuilder definition in Program.cs to listen on the port defined by the PORT environment variable:

   docs/serving/samples/hello-world/helloworld-csharp/Program.cs

   using System;
   using Microsoft.AspNetCore.Hosting;
   using Microsoft.Extensions.Hosting;
   
   namespace helloworld_csharp
   {
       public class Program
       {
           public static void Main(string[] args)
           {
               CreateHostBuilder(args).Build().Run();
           }
   
           public static IHostBuilder CreateHostBuilder(string[] args)
           {
               string port = Environment.GetEnvironmentVariable("PORT") ?? "8080";
               string url = String.Concat("http://0.0.0.0:", port);
   
               return Host.CreateDefaultBuilder(args)
                   .ConfigureWebHostDefaults(webBuilder =>
                   {
                       webBuilder.UseStartup<Startup>().UseUrls(url);
                   });
           }
       }
   }

   This code creates a basic web server that listens on the port defined by the PORT environment variable.

5. Create a file named Startup.cs and paste the following code into it:

   docs/serving/samples/hello-world/helloworld-csharp/Startup.cs

   using System;
   using Microsoft.AspNetCore.Builder;
   using Microsoft.AspNetCore.Hosting;
   using Microsoft.AspNetCore.Http;
   using Microsoft.Extensions.DependencyInjection;
   using Microsoft.Extensions.Hosting;
   
   namespace helloworld_csharp
   {
       public class Startup
       {
           // This method gets called by the runtime. Use this method to add services to the container.
           // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
           public void ConfigureServices(IServiceCollection services)
           {
           }
   
           // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
           public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
           {
               if (env.IsDevelopment())
               {
                   app.UseDeveloperExceptionPage();
               }
   
               app.UseRouting();
   
               app.UseEndpoints(endpoints =>
               {
                   endpoints.MapGet("/", async context =>
                   {
                       var target = Environment.GetEnvironmentVariable("TARGET") ?? "World";
                       await context.Response.WriteAsync($"Hello {target}!\n");
                   });
               });
           }
       }
   }

   This code responds to requests with our "Hello World" greeting.

Your app is finished and ready to be containerized and uploaded to Container Registry.

PHP

1. Create a new directory named helloworld-php and change directory into it:

   mkdir helloworld-php
   cd helloworld-php
   

2. Create a file named index.php and paste the following code into it:

   docs/serving/samples/hello-world/helloworld-php/index.php

   <?php
   $target = getenv('TARGET', true) ?: 'World';
   echo sprintf("Hello %s!", $target);
   

   This code responds to requests with our "Hello World" greeting. HTTP handling is done by an Apache web server in the container.

Your app is finished and ready to be containerized and uploaded to Container Registry.

Ruby

1. Create a new directory named helloworld-ruby and change directory into it:

   mkdir helloworld-ruby
   cd helloworld-ruby
   

2. Create a file named app.rb and paste the following code into it:

   docs/serving/samples/hello-world/helloworld-ruby/app.rb

   require 'sinatra'
   
   set :bind, '0.0.0.0'
   
   get '/' do
     target = ENV['TARGET'] || 'World'
     "Hello #{target}!\n"
   end
   

   This code creates a basic web server that listens on the port defined by the PORT environment variable.

3. Create a file nameGemfile and copy the following into it:

   docs/serving/samples/hello-world/helloworld-ruby/Gemfile

   source 'https://rubygems.org'
   
   gem 'sinatra'
   gem 'rack', '>= 2.0.6'
   

4. If you don't have Bundler 2.0 or greater installed, install Bundler.

5. Generate a Gemfile.lock file by running:

   bundle install

Your app is finished and ready to be containerized and uploaded to Container Registry.

Shell

1. Create a new directory named helloworld-shell and change directory into it:

   mkdir helloworld-shell
   cd helloworld-shell
   

2. Create a script.sh file with the following contents:

   docs/serving/samples/hello-world/helloworld-shell/script.sh

   #!/bin/sh
   echo Hello ${TARGET:=World}!
   
   
   

   In order to execute this shell script on every incoming requests, this sample uses a small Go program that starts a basic web server and listen on the port defined by the PORT environment variable.

3. Create a invoke.go file with the following contents:

   docs/serving/samples/hello-world/helloworld-shell/invoke.go

   package main
   
   import (
   	"fmt"
   	"log"
   	"net/http"
   	"os"
   	"os/exec"
   )
   
   func handler(w http.ResponseWriter, r *http.Request) {
   	log.Print("helloworld: received a request")
   
   	cmd := exec.CommandContext(r.Context(), "/bin/sh", "script.sh")
   	cmd.Stderr = os.Stderr
   	out, err := cmd.Output()
   	if err != nil {
   		w.WriteHeader(500)
   	}
   	w.Write(out)
   }
   
   func main() {
   	log.Print("helloworld: starting server...")
   
   	http.HandleFunc("/", handler)
   
   	port := os.Getenv("PORT")
   	if port == "" {
   		port = "8080"
   	}
   
   	log.Printf("helloworld: listening on %s", port)
   	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
   }
   

Your app is finished and ready to be containerized and uploaded to Container Registry.

Other

Cloud Run supports most languages. For simple samples in languages other than the ones in this table, see the following:

• Kotlin
• Swift
• Dart
• Rust
• Elixir
• C++
• Other

However, in all of these samples, ignore and omit the material about service.yaml and Docker Hub, because Cloud Run does not use these.

Containerizing an app and uploading it to Container Registry

To containerize the sample app, create a new file named Dockerfile in the same directory as the source files, and copy the following content:

Go

docs/serving/samples/hello-world/helloworld-go/Dockerfile

# Use the official Golang image to create a build artifact.
# This is based on Debian and sets the GOPATH to /go.
# https://hub.docker.com/_/golang
FROM golang:1.13 as builder

# Create and change to the app directory.
WORKDIR /app

# Retrieve application dependencies using go modules.
# Allows container builds to reuse downloaded dependencies.
COPY go.* ./
RUN go mod download

# Copy local code to the container image.
COPY . ./

# Build the binary.
# -mod=readonly ensures immutable go.mod and go.sum in container builds.
RUN CGO_ENABLED=0 GOOS=linux go build -mod=readonly -v -o server

# Use the official Alpine image for a lean production container.
# https://hub.docker.com/_/alpine
# https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
FROM alpine:3
RUN apk add --no-cache ca-certificates

# Copy the binary to the production image from the builder stage.
COPY --from=builder /app/server /server

# Run the web service on container startup.
CMD ["/server"]

Node.js

docs/serving/samples/hello-world/helloworld-nodejs/Dockerfile

# Use the official lightweight Node.js 12 image.
# https://hub.docker.com/_/node
FROM node:12-slim

# Create and change to the app directory.
WORKDIR /usr/src/app

# Copy application dependency manifests to the container image.
# A wildcard is used to ensure both package.json AND package-lock.json are copied.
# Copying this separately prevents re-running npm install on every code change.
COPY package*.json ./

# Install production dependencies.
RUN npm install --only=production

# Copy local code to the container image.
COPY . ./

# Run the web service on container startup.
CMD [ "npm", "start" ]

Add a .dockerignore file to exclude files from your container image. To exclude files from being uploaded to Cloud Build, add an additional .gcloudignore file.

docs/serving/samples/hello-world/helloworld-nodejs/.dockerignore

Dockerfile
README.md
node_modules
npm-debug.log

Python

The Python Dockerfile starts a Gunicorn web server that listens on the port defined by the PORT environment variable:

docs/serving/samples/hello-world/helloworld-python/Dockerfile

# Use the official lightweight Python image.
# https://hub.docker.com/_/python
FROM python:3.7-slim

# Copy local code to the container image.
ENV APP_HOME /app
WORKDIR $APP_HOME
COPY . ./

# Install production dependencies.
RUN pip install Flask gunicorn

# Run the web service on container startup. Here we use the gunicorn
# webserver, with one worker process and 8 threads.
# For environments with multiple CPU cores, increase the number of workers
# to be equal to the cores available.
CMD exec gunicorn --bind :$PORT --workers 1 --threads 8 --timeout 0 app:app

Add a .dockerignore file to exclude files from your container image. To exclude files from being uploaded to Cloud Build, add an additional .gcloudignore file.

docs/serving/samples/hello-world/helloworld-python/.dockerignore

Dockerfile
README.md
*.pyc
*.pyo
*.pyd
__pycache__

Java

docs/serving/samples/hello-world/helloworld-java-spring/Dockerfile

# Use the official maven/Java 8 image to create a build artifact.
# https://hub.docker.com/_/maven
FROM maven:3.5-jdk-8-alpine as builder

# Copy local code to the container image.
WORKDIR /app
COPY pom.xml .
COPY src ./src

# Build a release artifact.
RUN mvn package -DskipTests

# Use AdoptOpenJDK for base image.
# It's important to use OpenJDK 8u191 or above that has container support enabled.
# https://hub.docker.com/r/adoptopenjdk/openjdk8
# https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
FROM adoptopenjdk/openjdk8:jdk8u202-b08-alpine-slim

# Copy the jar to the production image from the builder stage.
COPY --from=builder /app/target/helloworld-*.jar /helloworld.jar

# Run the web service on container startup.
CMD ["java", "-Djava.security.egd=file:/dev/./urandom", "-jar", "/helloworld.jar"]

C#

docs/serving/samples/hello-world/helloworld-csharp/Dockerfile

# Use Microsoft's official build .NET image.
# https://hub.docker.com/_/microsoft-dotnet-core-sdk/
FROM mcr.microsoft.com/dotnet/core/sdk:3.1-alpine AS build
WORKDIR /app

# Install production dependencies.
# Copy csproj and restore as distinct layers.
COPY *.csproj ./
RUN dotnet restore

# Copy local code to the container image.
COPY . ./
WORKDIR /app

# Build a release artifact.
RUN dotnet publish -c Release -o out


# Use Microsoft's official runtime .NET image.
# https://hub.docker.com/_/microsoft-dotnet-core-aspnet/
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-alpine AS runtime
WORKDIR /app
COPY --from=build /app/out ./

# Run the web service on container startup.
ENTRYPOINT ["dotnet", "helloworld-csharp.dll"]

To exclude files produced via local dotnet build operations from upload to Cloud Build add a .gcloudignore file in the same directory as the sample app's source files:

run/.gcloudignore

**/obj/
**/bin/

If these lines are in a .gitignore file, you can skip this step because .gitignore is a default source for .gcloudignore configuration.

Copy these lines to a .dockerignore file for local container builds with the docker CLI.

PHP

The PHP Dockerfile starts an Apache web server that listens on the port defined by the PORT environment variable:

docs/serving/samples/hello-world/helloworld-php/Dockerfile

# Use the official PHP 7.3 image.
# https://hub.docker.com/_/php
FROM php:7.3-apache

# Copy local code to the container image.
COPY index.php /var/www/html/

# Use the PORT environment variable in Apache configuration files.
RUN sed -i 's/80/${PORT}/g' /etc/apache2/sites-available/000-default.conf /etc/apache2/ports.conf

# Configure PHP for development.
# Switch to the production php.ini for production operations.
# RUN mv "$PHP_INI_DIR/php.ini-production" "$PHP_INI_DIR/php.ini"
# https://hub.docker.com/_/php#configuration
RUN mv "$PHP_INI_DIR/php.ini-development" "$PHP_INI_DIR/php.ini"

Add a .dockerignore file to exclude files from your container image. To exclude files from being uploaded to Cloud Build, add an additional .gcloudignore file.

docs/serving/samples/hello-world/helloworld-php/.dockerignore

Dockerfile
README.md
vendor

Ruby

docs/serving/samples/hello-world/helloworld-ruby/Dockerfile

# Use the official lightweight Ruby image.
# https://hub.docker.com/_/ruby
FROM ruby:2.6-slim

# Install production dependencies.
WORKDIR /usr/src/app
COPY Gemfile Gemfile.lock ./
ENV BUNDLE_FROZEN=true
RUN gem install bundler && bundle install

# Copy local code to the container image.
COPY . ./

# Run the web service on container startup.
CMD ["ruby", "./app.rb"]

Shell

docs/serving/samples/hello-world/helloworld-shell/Dockerfile

# Use the official Golang image to create a build artifact.
# This is based on Debian and sets the GOPATH to /go.
# https://hub.docker.com/_/golang
FROM golang:1.13 as builder

# Create and change to the app directory.
WORKDIR /app

# Retrieve application dependencies using go modules.
# Allows container builds to reuse downloaded dependencies.
COPY go.* ./
RUN go mod download

# Copy local code to the container image.
COPY invoke.go ./

# Build the binary.
# -mod=readonly ensures immutable go.mod and go.sum in container builds.
RUN CGO_ENABLED=0 GOOS=linux go build -mod=readonly -v -o server

# Use the official Alpine image for a lean production container.
# https://hub.docker.com/_/alpine
# https://docs.docker.com/develop/develop-images/multistage-build/#use-multi-stage-builds
FROM alpine:3
RUN apk add --no-cache ca-certificates

# Copy the binary to the production image from the builder stage.
COPY --from=builder /app/server /server
COPY script.sh ./

# Run the web service on container startup.
CMD ["/server"]

Other

Cloud Run supports most languages. For sample Dockerfiles in languages other than the ones in this table, see the following:

• Kotlin
• Swift
• Dart
• Rust
• Elixir
• C++
• Other

However, in those samples, ignore and omit the material about service.yaml and Docker Hub, because Cloud Run does not use these.

Build your container image using Cloud Build, by running the following command from the directory containing the Dockerfile:

gcloud builds submit --tag gcr.io/PROJECT-ID/helloworld

where PROJECT-ID is your GCP project ID. You can get it by running gcloud config get-value project.

Upon success, you will see a SUCCESS message containing the image name (gcr.io/PROJECT-ID/helloworld). The image is stored in Container Registry and can be re-used if desired.

Deploying to Cloud Run

To deploy the container image:

1. Deploy using the following command:

   gcloud run deploy --image gcr.io/PROJECT-ID/helloworld --platform managed

   Replace PROJECT-ID with your GCP project ID. You can view your project ID by running the command gcloud config get-value project.

   1. You will be prompted for the service name: press Enter to accept the default name, helloworld.
   2. You will be prompted for region: select the region of your choice, for example us-central1.
   3. You will be prompted to allow unauthenticated invocations: respond y .

   Then wait a few moments until the deployment is complete. On success, the command line displays the service URL.

2. Visit your deployed container by opening the service URL in a web browser.

Cloud Run locations

Cloud Run is regional, which means the infrastructure that runs your Cloud Run services is located in a specific region and is managed by Google to be redundantly available across all the zones within that region.

Meeting your latency, availability, or durability requirements are primary factors for selecting the region where your Cloud Run services are run. You can generally select the region nearest to your users but you should consider the location of the other Google Cloud products that are used by your Cloud Run service. Using Google Cloud products together across multiple locations can affect your service's latency as well as cost.

Cloud Run is available in the following regions:

• asia-east1 (Taiwan)
• asia-northeast1 (Tokyo)
• europe-north1 (Finland)
• europe-west1 (Belgium)
• europe-west4 (Netherlands)
• us-central1 (Iowa)
• us-east1 (South Carolina)
• us-east4 (Northern Virginia)
• us-west1 (Oregon)

If you already created a Cloud Run service, you can view the region in the Cloud Run dashboard in the Cloud Console.

OK

Congratulations! You have just deployed an application packaged in a container image to Cloud Run. Cloud Run automatically and horizontally scales your container image to handle the received requests, then scales down when demand decreases. You only pay for the CPU, memory, and networking consumed during request handling.

Clean up

Removing your test project

While Cloud Run does not charge when the service is not in use, you might still be charged for storing the container image in Container Registry. You can delete your image or delete your Cloud project to avoid incurring charges. Deleting your Cloud project stops billing for all the resources used within that project.

Caution: Deleting a project has the following effects:
• Everything in the project is deleted. If you used an existing project for this tutorial, when you delete it, you also delete any other work you've done in the project.
• Custom project IDs are lost. When you created this project, you might have created a custom project ID that you want to use in the future. To preserve the URLs that use the project ID, such as an appspot.com URL, delete selected resources inside the project instead of deleting the whole project.
1. In the Cloud Console, go to the Manage resources page.

   Go to the Manage resources page

2. In the project list, select the project that you want to delete and then click Delete .
3. In the dialog, type the project ID and then click Shut down to delete the project.

What's next

For more information on building a container from code source and pushing to Container Registry, see:

• Developing Cloud Run services
• Building Containers