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Choosing the right application framework and technology is critical to successfully building a robust, highly responsive web app. Enterprise developers regularly struggle to identify the best application build practices. According to the 2021 Java Developer Productivity Report, 62% of surveyed developers use Spring Boot as their main framework technology. The ever-increasing demand for microservices within the Java community is driving this significant adoption.
Source ~ The 2021 Java Developer productivity Report

Spring Boot is the world’s leading Java web framework. It’s open source, microservices-based, and helps developers to build scalable Java apps. Developers love Spring because of its auto-configuration, embedded servers, and simplified dependency management. It helps development teams create services faster and more efficiently. Accordingly, users spend very little time on initial setup. That includes downloading essential packages or application servers.
The biggest challenge that developers face with Spring Boot is concurrency — or the need to do too many things simultaneously. Spring Boot may also unnecessarily increase the deployment binary size with unused dependencies. This creates bloated JARs that may increase your overall application footprint while impacting performance. Other challenges include a high learning curve and complexity while building a customized logging mechanism.
How can you offset these drawbacks? Docker simplifies and accelerates your workflows by letting you freely innovate with your choice of tools, application stacks, and deployment environments for each project. You can run your Spring Boot artifact directly within Docker containers. This is useful when you need to quickly create microservices. Let’s see this process in action.
Building Your Application
This walkthrough will show you how to accelerate your application development using Spring Boot.
First, we’ll create a simple web app with Spring Boot, without using Docker. Next, we’ll build a Docker image just for that application. You’ll also learn how Docker Compose can help you rapidly deploy your application within containers. Let’s get started.
Key Components

JDK 17+
Spring Boot CLI (optional)
Microsoft Visual Studio Code
Docker Desktop

Getting Started
Once you’ve installed the Maven and OpenJDK package in your system, follow these steps to build a simple web application using Spring Boot.
Starting with Spring Initializr
Spring Initializr is a quickstart generator for Spring projects. It provides an extensible API to generate JVM-based projects with implementations for several common concepts — like basic language generation for Java, Kotlin, and Groovy. Spring Initializr also supports build-system abstraction with implementations for Apache Maven and Gradle. Additionally, It exposes web endpoints to generate an actual project and serve its metadata in a well-known format. This lets third-party clients provide assistance where it’s needed.
Open this pre-initialized project in order to generate a ZIP file. Here’s how that looks:

For this demonstration, we’ve paired Maven build automation with Java, a Spring Web dependency, and Java 17 for our metadata.

Click “Generate” to download “spring-boot-docker.zip”. Use the unzip command to extract your files.
Project Structure
Once you unzip the file, you’ll see the following project directory structure:

tree spring-boot-docker
spring-boot-docker
├── HELP.md
├── mvnw
├── mvnw.cmd
├── pom.xml
└── src
├── main
│ ├── java
│ │ └── com
│ │ └── example
│ │ └── springbootdocker
│ │ └── SpringBootDockerApplication.java
│ └── resources
│ ├── application.properties
│ ├── static
│ └── templates
└── test
└── java
└── com
└── example
└── springbootdocker
└── SpringBootDockerApplicationTests.java

The src/main/java directory contains your project’s source code, the src/test/java directory contains the test source, and the pom.xml file is your project’s Project Object Model (POM).
The pom.xml file is the core of a Maven project’s configuration. It’s a single configuration file that contains most of the information needed to build a customized project. The POM is huge and can seem daunting. Thankfully, you don’t yet need to understand every intricacy to use it effectively. Here’s your project’s POM:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.5.13</version>
<relativePath/> <!– lookup parent from repository –>
</parent>
<groupId>com.example</groupId>
<artifactId>spring-boot-docker</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-boot-docker</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

The SpringbootDockerApplication.java file starts by declaring your com.example.springbootdocker package and importing necessary Spring frameworks. Many Spring Boot developers like their apps to use auto-configuration, component scanning, and extra configuration definitions to their “application class.” You can use a single @SpringBootApplication annotation to enable those features. That same annotation also triggers component scanning for your current package and its sub-packages. You can configure this and even move it elsewhere by manually specifying the base package.
Let’s create a simple RESTful web service that displays “Hello World!” by annotating classic controllers as shown in the following example:.

package com.example.springbootdocker;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@SpringBootApplication
public class SpringBootDockerApplication {

@RequestMapping("/")
public String home() {
return "Hello World!";
}

public static void main(String[] args) {
SpringApplication.run(SpringBootDockerApplication.class, args);
}

}

@RestControler and @RequestMapping are two other popular annotations. The @RestController annotation simplifies the creation of RESTful web services. It conveniently combines @Controller and @ResponseBody — which eliminates the need to annotate every request-handling method of the controller class with the @ResponseBody annotation. Meanwhile, the @RequestMapping annotation maps web requests to Spring Controller methods.
First, we can flag a class as a @SpringBootApplication and as a @RestController, letting Spring MVC harness it for web requests. @RequestMapping maps / to the home() method, which sends a Hello World response. The main() method uses Spring Boot’s SpringApplication.run() method to launch an application.
The following command takes your compiled code and packages it into a distributable format, like a JAR:
./mvnw package

[INFO] Scanning for projects…
[INFO]
[INFO] ——————-&lt; com.example:spring-boot-docker &gt;——————-
[INFO] Building spring-boot-docker 0.0.1-SNAPSHOT
[INFO] ——————————–[ jar ]———————————
[INFO]
[INFO] — maven-resources-plugin:3.2.0:resources (default-resources) @ spring-boot-docker —
[INFO] Using ‘UTF-8′ encoding to copy filtered resources.
[INFO] Using ‘UTF-8′ encoding to copy filtered properties files.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] — maven-compiler-plugin:3.8.1:compile (default-compile) @ spring-boot-docker —
[INFO] Nothing to compile – all classes are up to date
[INFO]
[INFO] — maven-resources-plugin:3.2.0:testResources (default-testResources) @ spring-boot-docker —
[INFO] Using ‘UTF-8′ encoding to copy filtered resources.
[INFO] Using ‘UTF-8′ encoding to copy filtered properties files.
[INFO] skip non existing resourceDirectory /Users/johangiraldohurtado/Downloads/spring-boot-docker/src/test/resources
[INFO]
[INFO] — maven-compiler-plugin:3.8.1:testCompile (default-testCompile) @ spring-boot-docker —
[INFO] Changes detected – recompiling the module!
[INFO] Compiling 1 source file to /Users/johangiraldohurtado/Downloads/spring-boot-docker/target/test-classes
[INFO]
[INFO] — maven-surefire-plugin:2.22.2:test (default-test) @ spring-boot-docker —
…
…
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 4.37 s – in com.example.springbootdocker.SpringBootDockerApplicationTests
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO]
[INFO] — maven-jar-plugin:3.2.2:jar (default-jar) @ spring-boot-docker —
[INFO] Building jar: /Users/johangiraldohurtado/Downloads/spring-boot-docker/target/spring-boot-docker-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] — spring-boot-maven-plugin:2.5.13:repackage (repackage) @ spring-boot-docker —
[INFO] Replacing main artifact with repackaged archive
[INFO] ——
[INFO] BUILD SUCCESS
[INFO] ————————————————————————
[INFO] Total time: 11.461 s
[INFO] Finished at: 2022-05-12T12:50:12-05:00
[INFO] ————————————————————————

Running app Packages as a JAR File
After successfully building your JAR, it’s time to run the app package as a JAR file:
java -jar target/spring-boot-docker-0.0.1-SNAPSHOT.jar
Here are the results:

. ____ _ __ _ _
/ / ___’_ __ _ _(_)_ __ __ _
( ( )___ | ‘_ | ‘_| | ‘_ / _` |
/ ___)| |_)| | | | | || (_| | ) ) ) )
‘ |____| .__|_| |_|_| |___, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.5.13)

2022-05-12 13:02:35.591 INFO 3594 — [ main] c.e.s.SpringBootDockerApplication : Starting SpringBootDockerApplication v0.0.1-SNAPSHOT using Java 17.0.2 on Johans-MacBook-Air.local with PID 3594 (/Users/johangiraldohurtado/Downloads/spring-boot-docker/target/spring-boot-docker-0.0.1-SNAPSHOT.jar started by johangiraldohurtado in /Users/johangiraldohurtado/Downloads/spring-boot-docker)
2022-05-12 13:02:35.597 INFO 3594 — [ main] c.e.s.SpringBootDockerApplication : No active profile set, falling back to 1 default profile: "default"
2022-05-12 13:02:37.958 INFO 3594 — [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-05-12 13:02:37.979 INFO 3594 — [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-05-12 13:02:37.979 INFO 3594 — [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.62]
2022-05-12 13:02:38.130 INFO 3594 — [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-05-12 13:02:38.130 INFO 3594 — [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2351 ms
2022-05-12 13:02:39.015 INFO 3594 — [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ”
2022-05-12 13:02:39.050 INFO 3594 — [ main] c.e.s.SpringBootDockerApplication : Started SpringBootDockerApplication in 4.552 seconds (JVM running for 5.486)

You can now access your “Hello World” page through your web browser at http://localhost:8080, or via this curl command:

curl localhost:8080
Hello World

Click here to access the code previously developed for this example.
Containerizing the Spring Boot Application
Docker helps you containerize your Java app — letting you bundle together your complete Spring application, runtime, configuration, and OS-level dependencies. This includes everything needed to ship a cross-platform, multi-architecture web application.
Let’s assess how you can easily run this app inside a Docker container using a Docker Official Image. First, you’ll need to download Docker Desktop. Docker Desktop accelerates the image-building process while making useful images more discoverable. Complete the installation process once your download is finished.
Docker uses a Dockerfile to specify each image’s “layers.” Each layer stores important changes stemming from the base image’s standard configuration. Create the following empty Dockerfile in your Spring Boot project.
touch Dockerfile
Use your favorite text editor to open this Dockerfile. You’ll then need to define your base image.
Whenever you are creating a Docker image to run a Java program, it’s always recommended to use a smaller base image that helps in speeding up the build process and launching containers at a faster pace. Also, for executing a simple program, we just need to use JRE instead of JDK since there is no development or compilation of the code required.
The upstream Java JDK doesn’t distribute an official JRE package. Hence, we will leverage the popular eclipse-temurin:17-jdk-focal Docker image available in Docker Hub. The Eclipse Temurin project provides code and processes that support the building of runtime binaries and associated technologies that are high performance, enterprise-caliber & cross-platform.
FROM eclipse-temurin:17-jdk-focal
Next, let’s quickly create a directory to house our image’s application code. This acts as the working directory for your application:
WORKDIR /app
The following COPY instruction copies the Maven wrappers and pom file from the host machine to the container image.The pom.xml file contains information of project and configuration information for the maven to build the project such as dependencies, build directory, source directory, test source directory, plugin, goals etc.
COPY .mvn/ ./mvn
COPY mvnw pom.xml ./
The following RUN instructions trigger a goal that resolves all project dependencies including plugins and reports and their dependencies.
RUN ./mvnw dependency:go-offline
Next, we need to copy the most important directory of the maven project – /src. It includes java source code and pre-environment configuration files of the artifact.
COPY src ./src
The Spring Boot Maven plugin includes a run goal which can be used to quickly compile and run your application. The last line tells Docker to compile and run your app packages.
CMD [“./mvnw”, “spring-boot:run”]
Here’s your complete Dockerfile:

FROM eclipse-temurin:17-jdk-focal

WORKDIR /app

COPY .mvn/ .mvn
COPY mvnw pom.xml ./
RUN ./mvnw dependency:go-offline

COPY src ./src

CMD ["./mvnw", "spring-boot:run"]

Building Your Docker Image
Next, you’ll need to build your Docker image. Enter the following command to kickstart this process, which produces an output soon after:
docker build –platform linux/amd64 -t spring-helloworld .

docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
spring-helloworld latest 4cf762a7b96d 4 minutes ago 124MB

Docker Desktop’s intuitive dashboard lets you manage your containers, applications, and images directly from within Docker Desktop. The GUI enables this with only a few clicks. While still possible, you won’t need to use the CLI to perform these core actions.
Select Dashboard from the top whale menu icon to access the Docker Dashboard:

Click on Images. The Images view displays a list of your Docker images, and lets you run images as functional containers.

Additionally, you can push your images directly to Docker Hub for easy sharing and collaboration.

The Image view also includes the Inspect option. This unveils environmental variables, port information, and more. Crucially, the Image view lets you run your container directly from your image. Simply specify the container’s name, exposed ports, and mounted volumes as required.

Run Your Spring Boot Docker Container
Docker runs processes in isolated containers. A container is a process that runs on a host, which is either local or remote. When an operator executes docker run, the container process that runs is isolated with its own file system, networking, and separate process tree from the host.
The following docker run command first creates a writeable container layer over the specified image, and then starts it.
docker run -p 8080:8080 -t spring-helloworld
Here’s your result:

2022-05-12 18:31:38.770 INFO 1 — [ main] c.e.s.SpringBootDockerApplication : Starting SpringBootDockerApplication v0.0.1-SNAPSHOT using Java 17.0.2 on 3196593a534f with PID 1 (/app.jar started by root in /)
2022-05-12 18:31:38.775 INFO 1 — [ main] c.e.s.SpringBootDockerApplication : No active profile set, falling back to 1 default profile: "default"
2022-05-12 18:31:39.434 INFO 1 — [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-05-12 18:31:39.441 INFO 1 — [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-05-12 18:31:39.442 INFO 1 — [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.62]
2022-05-12 18:31:39.535 INFO 1 — [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-05-12 18:31:39.535 INFO 1 — [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 682 ms
2022-05-12 18:31:39.797 INFO 1 — [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ”
2022-05-12 18:31:39.805 INFO 1 — [ main] c.e.s.SpringBootDockerApplication : Started SpringBootDockerApplication in 1.365 seconds (JVM running for 1.775)

Go to Docker Dashboard and open your app in your browser:

Next, click Logs to observe your app’s behavior:

Docker Dashboard’s Stats tab lets you view CPU consumption, memory usage, disk read vs. write, and network use:

You can also confirm your containerized application’s functionality via the URL http://localhost:8080:

curl localhost:8080
Hello Developers From Docker!

Want to explore alternative ways to get started with Spring Boot? Check out this Docker image built for developers like you.
Building Multi-Container Spring Boot Apps with Docker Compose
We’ve effectively learned how to build a sample Spring Boot app and create associated Docker images. Next, let’s build a multi-container Spring Boot app using Docker Compose.
For this demonstration, you’ll leverage the popular awesome-compose repository.
Cloning the Repository

git clone https://github.com/docker/awesome-compose

Change your directory to match the spring-postgres project and you’ll see the following project directory structure:

.
├── README.md
├── backend
│ ├── Dockerfile
│ ├── pom.xml
│ └── src
│ └── main
│ ├── java
│ │ └── com
│ │ └── company
│ │ └── project
│ │ ├── Application.java
│ │ ├── controllers
│ │ │ └── HomeController.java
│ │ ├── entity
│ │ │ └── Greeting.java
│ │ └── repository
│ │ └── GreetingRepository.java
│ └── resources
│ ├── application.properties
│ ├── data.sql
│ ├── schema.sql
│ └── templates
│ └── home.ftlh
├── db
│ └── password.txt
└── docker-compose.yaml

13 directories, 13 files

Let’s also take a peak at our docker compose file:

services:
backend:
build: backend
ports:
– 8080:8080
environment:
– POSTGRES_DB=example
networks:
– spring-postgres
db:
image: postgres
restart: always
secrets:
– db-password
volumes:
– db-data:/var/lib/postgresql/data
networks:
– spring-postgres
environment:
– POSTGRES_DB=example
– POSTGRES_PASSWORD_FILE=/run/secrets/db-password
expose:
– 5432
volumes:
db-data:
secrets:
db-password:
file: db/password.txt
networks:
spring-postgres:

The compose file defines an application with two services: backend and db. While deploying the application, docker compose maps port 8080 of the backend service container to port 8080 of the host, per your file. Make sure port 8080 on the host isn’t already in use.
Through your compose file, it’s possible to determine environment variables. For example, you can specify connected databases in the backend service. With a database, you can define the name, password, and parameters of your database.
Thanks to our compose file’s behavior — which lets us recreate containers from indicated services — it’s important to define volumes that store critical information.
Start your application by running docker compose command:
docker compose up -d
Your container list should show two containers running and their port mappings, as seen below:

docker compose ps
Name Command State Ports
——————————————————————————————-
spring-postgres_backend_1 java -cp app:app/lib/* com … Up 0.0.0.0:8080-&gt;8080/tcp
spring-postgres_db_1 docker-entrypoint.sh postgres Up 5432/tcp

After the application starts, navigate to http://localhost:8080 in your web browser. You can also run the following curl to form your webpage:

$ curl localhost:8080
<!DOCTYPE HTML>
<html>
<head>
<title>Getting Started: Serving Web Content</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<p>Hello from Docker!</p>
</body>

Stop and Remove Your Containers
You’ve successfully built your sample application—congratulations! However, it’s now time to take things offline. You can do this quickly and easily with the following command:

$ docker compose down
Stopping spring-postgres_db_1 … done
Stopping spring-postgres_backend_1 … done
Removing spring-postgres_db_1 … done
Removing spring-postgres_backend_1 … done
Removing network spring-postgres_default

Alternatively, navigate to the Containers / Apps section from Docker Desktop’s sidebar, hover over each active container, and click the square Stop button. The process takes roughly 10 seconds — shutting your containers down elegantly.
Conclusion
We’ve demonstrated how to containerize our Spring Boot application, and why that’s so conducive to smoother deployment. We’ve also harnessed Docker Compose to construct a simple, two-layered web application. This process is quick and lets you devote precious time to other development tasks — especially while using Docker Desktop. No advanced knowledge of containers or even Docker is needed to succeed.
References:

Getting Started with Java
Build your Java image
Spring Boot development with Docker

Quelle: https://blog.docker.com/feed/

4. Juni 2022

da Agency

Deploying Web Applications Quicker and Easier with Caddy 2

Follow along as we dissect an awesome method for accelerating your web application server deployment. Huge thanks to Chris Maki for his help in putting this guide together!

Today’s web applications — and especially enterprise variants — have numerous moving parts that need continual upkeep. These tasks can easily overwhelm developers who already have enough on their plates. You might have to grapple with:

TLS certificate management and termination
Web server setup and maintenance
Application firewalls and proxies
API gateway integration
Caching
Logging

Consequently, the task of building, deploying, and maintaining a web application has become that much more complicated. Developers must worry about performance, access delegation, and security.
Lengthy development times reflect this. It takes 4.5 months on average to build a complete web app — while creating a viable backend can take two to three months. There’s massive room for improvement. Web developers need simpler solutions that dramatically reduce deployment time.
First, we’ll briefly highlight a common deployment pipeline. Second, we’ll explore an easier way to get things up and running with minimal maintenance. Let’s jump in.
Cons of Server Technologies Like NGINX
There are many ways to deploy a web application backend. Upwards of 60% of the web server market is collectively dominated by NGINX and Apache. While these options are tried and true, they’re not 100% ready to use out of the box.
Let’s consider one feature that’s becoming indispensable across web applications: HTTPS. If you’re accustomed to NGINX web servers, you might know that these servers are HTTP-enabled right away. However, If SSL is required for you and your users, you’ll have to manually configure your servers to support it. Here’s what that process looks like from NGINX’s documentation:

server {
listen 443 ssl;
server_name www.example.com;
ssl_certificate www.example.com.crt;
ssl_certificate_key www.example.com.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers HIGH:!aNULL:!MD5;
…
}

Additionally, NGINX shares that “the ssl parameter must be enabled on listening sockets in the server block, and the locations of the server certificate and private key files should be specified.”
You’re tasked with these core considerations and determining best practices through your configurations. Additionally, you must properly optimize your web server to handle these HTTPS connections — without introducing new bottlenecks based on user activity, resource consumption, and timeouts. Your configuration files slowly grow with each customization:

worker_processes auto;

http {
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 10m;

server {
listen 443 ssl;
server_name www.example.com;
keepalive_timeout 70;

ssl_certificate www.example.com.crt;
ssl_certificate_key www.example.com.key;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers HIGH:!aNULL:!MD5;
…

It’s worth remembering this while creating your web server. Precise, finely-grained control over server behavior is highly useful but has some drawbacks. Configurations can be time consuming. They may also be susceptible to coding conflicts introduced elsewhere. On the certificate side, you’ll often have to create complex SSL certificate chains to ensure maximum cross-browser compatibility:

$ openssl s_client -connect www.godaddy.com:443
…
Certificate chain
0 s:/C=US/ST=Arizona/L=Scottsdale/1.3.6.1.4.1.311.60.2.1.3=US
/1.3.6.1.4.1.311.60.2.1.2=AZ/O=GoDaddy.com, Inc
/OU=MIS Department/CN=www.GoDaddy.com
/serialNumber=0796928-7/2.5.4.15=V1.0, Clause 5.(b)
i:/C=US/ST=Arizona/L=Scottsdale/O=GoDaddy.com, Inc.
/OU=http://certificates.godaddy.com/repository
/CN=Go Daddy Secure Certification Authority
/serialNumber=07969287
1 s:/C=US/ST=Arizona/L=Scottsdale/O=GoDaddy.com, Inc.
/OU=http://certificates.godaddy.com/repository
/CN=Go Daddy Secure Certification Authority
/serialNumber=07969287
i:/C=US/O=The Go Daddy Group, Inc.
/OU=Go Daddy Class 2 Certification Authority
2 s:/C=US/O=The Go Daddy Group, Inc.
/OU=Go Daddy Class 2 Certification Authority
i:/L=ValiCert Validation Network/O=ValiCert, Inc.
/OU=ValiCert Class 2 Policy Validation Authority
/CN=http://www.valicert.com//emailAddress=info@valicert.com
…

Spinning up your server therefore takes multiple steps. You must also take these tasks and scale them to include proxying, caching, logging, and API gateway setup. The case is similar for module-based web servers like Apache.
We don’t say this to knock either web server (in fact, we maintain official images for both Apache and NGINX). However — as a backend developer — you’ll want to weigh those development-and-deployment efforts vs. their collective benefits. That’s where a plug-and-play solution comes in handy. This is perfect for those without deep backend experience or those strapped for time.
Pros of Using Caddy 2
Written in Go, Caddy 2 (which we’ll simply call “Caddy” throughout this guide) acts as an enterprise-grade web server with automatic HTTPS. Other servers don’t share this same feature out of the box.
Additionally, Caddy 2 offers some pretty cool benefits:

Automatic TLS certificate renewals
OCSP stapling, to speed up SSL handshakes through request consolidation
Static file serving for scripts, CSS, and images that enrich web applications
Reverse proxying for scalability, load balancing, health checking, and circuit breaking
Kubernetes (K8s) ingress, which interfaces with K8s’ Go client and SharedInformers
Simplified logging, caching, API gateway, and firewall support
Configurable, shared Websocket and proxy support with HTTP/2

This is not an exhaustive list, by any means. However, these baked-in features alone can cut deployment time significantly. We’ll explore how Caddy 2 works, and how it makes server setup more enjoyable. Let’s hop in.
Here’s How Caddy Works
One Caddy advantage is its approachability for developers of all skill levels. It also plays nicely with external configurations.
Have an existing web server configuration that you want to migrate over to Caddy? No problem. Native adapters convert NGINX, TOML, Caddyfiles, and other formats into Caddy’s JSON format. You won’t have to reinvent the wheel nor start fresh to deploy Caddy in a containerized fashion.
Here’s how your Caddyfile structure might appear:

example.com

# Templates give static sites some dynamic features
templates

# Compress responses according to Accept-Encoding headers
encode gzip zstd

# Make HTML file extension optional
try_files {path}.html {path}

# Send API requests to backend
reverse_proxy /api/* localhost:9005

# Serve everything else from the file system
file_server

Note that this Caddyfile is even considered complex by Caddy’s own standards (since you’re defining extra functionality). What if you want to run WordPress with fully-managed HTTPS? The following Caddyfile enables this:

example.com

root * /var/www/wordpress
php_fastcgi unix//run/php/php-version-fpm.sock
file_server

That’s it! Basic files can produce some impressive results. Each passes essential instructions to your server and tells it how to run. Caddy’s reference documentation is also extremely helpful should you want to explore further.
Quick Commands
Before tackling your image, Caddy has shared some rapid, one-line commands that perform some basic tasks. You’ll enter these through the Caddy CLI:

To create a quick, local file server:
$ caddy file-server
To create a public file server over HTTPS:
$ caddy file-server –domain yoursampleapp.com
To perform an HTTPS reverse proxy:
$ caddy reverse-proxy –from example.com –to localhost:9000
To run a Caddyfile-backed server in an existing working directory:
$ caddy run

Caddy notes that these commands are tested and approved for production deployments. They’re safe, easy, and reliable. Want to learn many more useful commands and subcommands? Check out Caddy’s CLI documentation to streamline your workflows.
Leveraging the Caddy Container Image
Caddy bills itself as a web-server solution with fewer moving parts, and therefore fewer management demands. Its static binary compiles for any platform. Since Caddy has no dependencies, it can run practically anywhere — and within containers. This makes it a perfect match for Docker, which is why developers have downloaded Caddy’s Docker Official Image over 100 million times. You can find our Caddy image on Docker Hub.

We’ll discuss how to use this image to deploy your web applications faster, and share some supporting Docker mechanisms that can help streamline those processes. You don’t even need libc, either.
Prerequisites

A free Docker Hub account – for complete push/pull registry access to our Caddy Official Image
The latest version of Docker Desktop, tailored to your OS and CPU (for macOS users)
Your preferred IDE, though VSCode is popular

Docker Desktop unlocks greater productivity around container, image, and server management. Although the CLI remains available, we’re leveraging the GUI while running important tasks.
Pull Your Caddy Image
Getting started with Docker’s official Caddy image is easy. Enter the docker pull caddy:latest command to download the image locally on your machine. You can also specify a Caddy image version using a number of available tags.
Entering docker pull caddy:latest grabs Caddy’s current version, while docker pull caddy:2.5.1 requests an image running Caddy v2.5.1 (for example).
Using :latest is okay during testing but not always recommended in production. Ideally, you’ll aim to thoroughly test and vet any image from a security standpoint before using it. Pulling caddy:latest (or any image tagged similarly) may invite unwanted gremlins into your deployment.
Since Docker automatically grabs the newest release, it’s harder to pre-inspect that image or notice that changes have been made. However, :latest images can include the most up-to-date vulnerability and bug fixes. Image release notes are helpful here.
You can confirm your successful image pull within Docker Desktop:

After pulling caddy:latest, you can enter the docker image ls command to view its size. Caddy is even smaller than both NGINX and Apache’s httpd images:

Need to inspect the contents of your Caddy image? Docker Desktop lets you summon a Docker Software Bill of Materials (SBOM) — which lists all packages contained within your designated image. Simply enter the docker sbom caddy:latest command (or use any container image:tag):

You’ll see that your 43.1MB caddy:latest image contains 129 packages. These help Caddy run effectively cross-platform.
Run Your Caddy Image
Your image is ready to go! Next, run your image to confirm that Caddy is working properly with the following command:
docker run –rm -d -p 8080:80 –name web caddy

Each portion of this command serves a purpose:

–rm removes the container when it exits or when the daemon exits (whichever comes first)
-d runs your Caddy container in the background
-p designates port connections between host and container
–name lets you assign a non-random name to your image
web is an argument to the –name flag, and is the descriptive name of your running container
caddy is your image’s name, which was automatically assigned during your initial docker pull command

Since you’ve established a port connection, navigate to localhost:8080 in your browser. Caddy should display a webpage:

You’ll see some additional instructions for setting up Caddy 2. Scrolling further down the page also reveals more details, plus some handy troubleshooting tips.
Time to Customize
These next steps will help you customize your web application and map it into the container. Caddy uses the /var/www/html path to store your critical static website files.
Here’s where you’ll store any CSS or HTML — or anything residing within your index.html file. Additionally, this becomes your root directory once your Caddyfile is complete.
Locate your Caddyfile at /etc/caddy/Caddyfile to make any important configuration changes. Caddy’s documentation provides a fantastic breakdown of what’s possible, while the Caddyfile Tutorial guides you step-by-step.
The steps mentioned above describe resources that’ll exist within your Caddy container, not those that exist on your local machine. Because of this, it’s often necessary to reload Caddy to apply any configuration changes, or otherwise. You can apply any new changes by entering systemctl reload caddy in your CLI, and visiting your site as confirmation. Running your Caddy server within a Docker container requires just one extra shell command:
$ docker exec -w /etc/caddy web caddy reload

This gracefully reloads your content without a complete restart. That process is otherwise time consuming and disruptive.
Next, you can serve your updated index.html file by entering the following. You’ll create a working directory and run the following commands from that directory:

$ mkdir docker-caddy
$ cd docker-caddy
$ echo "hello world" > index.html
$ docker run -d -p 8080:80
-v $PWD/index.html:/usr/share/caddy/index.html
-v caddy_data:/data
caddy
…
$ curl http://localhost/
hello world

Want to quickly push new configurations to your Caddy server? Caddy provides a RESTful JSON API that lets you POST sets of changes with minimal effort. This isn’t necessary for our tutorial, though you may find this config structure useful in the future:

POST /config/

{
"apps": {
"http": {
"servers": {
"example": {
"listen": ["127.0.0.1:2080"],
"routes": [{
"@id": "demo",
"handle": [{
"handler": "file_server",
"browse": {}
}]
}]
}
}
}
}
}

No matter which route you take, any changes made through Caddy’s API are persisted on disk and continually usable after restarts. Caddy’s API docs explain this and more in greater detail.
Building Your Caddy-Based Dockerfile
Finally, half the magic of using Caddy and Docker rests with the Dockerfile. You don’t always want to mount your files within a container. Instead, it’s often better to COPY files or directories from a remote source and base your image on them:

FROM caddy:<version>

COPY Caddyfile /etc/caddy/Caddyfile
COPY site /srv

This adds your Caddyfile in using an absolute path. You can even add modules to your Caddy Dockerfile to extend your server’s functionality. Caddy’s :builder image streamlines this process significantly. Just note that this version is much larger than the standard Caddy image. To reduce bloat, the FROM instruction uses a binary overlay to save space:

FROM caddy:builder AS builder

RUN xcaddy build
–with github.com/caddyserver/nginx-adapter
–with github.com/hairyhenderson/caddy-teapot-module@v0.0.3-0

FROM caddy:<version>

COPY –from=builder /usr/bin/caddy /usr/bin/caddy

You’re also welcome to add any of Caddy’s available modules, which are free to download. Congratulations! You now have all the ingredients needed to deploy a functional Caddy 2 web application.
Quick Notes on Docker Compose
Though not required, you can use docker compose to run your Caddy-based stack. As a side note, Docker Compose V2 is also written in Go. You’d store this Compose content within a docker-compose.yml file, which looks like this:

version: "3.7"

services:
caddy:
image: caddy:<version>
restart: unless-stopped
ports:
– "80:80"
– "443:443"
volumes:
– $PWD/site:/srv
– caddy_data:/data
– caddy_config:/config

volumes:
caddy_data:
caddy_config:

Stopping and Reviving Your Containers
Want to stop your container? Simply enter docker stop web to shut it down within 10 seconds. If this process stalls, Docker will kill your container immediately. You can customize and extend this timeout with the following command:
docker stop –time=30 web

However, doing this is easier using Docker Desktop — and specifically the Docker Dashboard. In the sidebar, navigate to the Containers pane. Next, locate your Caddy server container titled “web” in the list, hover over it, and click the square Stop icon. This performs the same task from our first command above:

You’ll also see options to Open in Browser, launch the container CLI, Restart, or Delete.
Stop your Caddy container by accident, or want to spin up another? Navigate to the Images pane, locate caddy in the list, hover over it, and click the Run button that appears. Once the modal appears, expand the Optional Settings section. Next, do the following:

Name your new container something meaningful
Designate your Local Host port as 8080 and map it Container Port 80
Mount any volumes you want, though this isn’t necessary for this demo
Click the Run button to confirm

Finally, revisit the Containers pane, locate your new container, and click Open in Browser. You should see the very same webpage that your Caddy server rendered earlier, if things are working properly.
Conclusion
Despite the popularity of Apache and NGINX, developers have other server options at their disposal. Alternatives like Caddy 2 can save time, effort, and make the deployment process much smoother. Reduced dependencies, needed configurations, and even Docker integration help simplify each management step. As a bonus, you’re also supporting an open-source project.
Are you currently using Caddy 1 and want to upgrade to Caddy 2? Follow along with Caddy’s official documentation to understand the process.
Quelle: https://blog.docker.com/feed/