I have read a couple of blog posts on how to run a Spring Boot application on Amazon AWS EBS. I haven’t found any tutorial regarding how to install Sprint Boot on EC2.
Deploying Spring Boot on EBS of course is easier and offers many advantages but it hides many details a developers should know to understand how things works under the hood.
So I wrote this tutorial which I think will be very useful to developers who just started to work on Amazon AWS and Spring Boot.
In this tutorial I will assume you have already got an Amazon AWS account. You can use free tier only to run the tutorial.
Step 1: Create a Key Pair
To access the AMI (Amazon Machine Image) we will need a key pair. Amazon EC2 stores the public key only, and you store the private key. Anyone who possesses your private key can decrypt your login information, so it’s important that you store your private keys in a secure place. The keys that Amazon EC2 uses are 2048-bit SSH-2 RSA keys. You can have up to five thousand key pairs per region.
On the left menu of the console go to Key Pairs and then Create Key Pair.
Give a name to the pair, you will need it later.
Then the Fingerprint column will show a RSA key. The RSA key is a short sequence of bytes used to identify a longer public key. It is based on the host’s public key, usually based on “/etc/ssh/ssh_host_rsa_key.pub”. It is used for identification/verification of the host we are connecting to.
Step 2: Choose and configure AMI
We will now chose an Amazon Machine Image were we will install the software.
Step 2.1: Amazon Linux 2
I have chosen the Amazon Linux 2 AMI. It has been released from few month and it is the next generation of Amazon Linux, a Linux server operating system from Amazon Web Services (AWS).
It finally includes the systemd “System and Service Manager”, an initsystem used to bootstrap the user space and to manage system processes after booting. One of the main goals of systemd is the unification of basic configuration and service behaviors across Linux distributions. Since at least 2015, the majority of Linux distributions have adopted systemd, and it is considered a de facto standard.[3]
Step 2.2: create a t2.micro instance
To be eligible for a free tier usage we will choice a t2.micro instance. It will be enough for our learning purposes
Step 2.3 Configure Instace Details
In this step we can change and configure many parameters/value of the VM, such as the network configuration or the number of VMs to launch. For now, keep the defaults,
Step 2.4: Add Storage
There are different options for storing data on AWS. For now, accept all the default values provided
Step 2.5: Add Tags
Tags are important to keep everything in order. I will add a key named “name” and its value will be “spring-boot-1” indicating that this is my first machine running a spring boot instance.
Step 2.6 Configure Security Group
Add here SSH and HTTP protocol. I will use SSH to admin the instance and HTTP as interface to run services.
Select the key pair created before to be able to access the AMI with the private key we stored somewhere.
Clicking on Launch Instances will make the OS of the VM to start running.
In the console, under Instances it is possible to see the Instance State, Instance ID and the Public DNA which we will use later.
Step 2.7 Connect to the instance through ssh client
It is now possible to connect to the instance just created through an ssh client. I will use here a command line client in a ubuntu linux installation.
First, get the ID of your instance using the Amazon EC2 console (please look at the picture above). Also the Public DNS (IPv4) is important, store it somewhere.
Run the following command on your ssh client:
ssh -i SpringBootKey.pem ec2-user@ec2-34-202-9-171.compute-1.amazonaws.com
In the above command:
- SpringBootKey.pem is our private key. Please be sure you launch the ssh command in the same directory where the key is placed (otherwise write the correct path to the key)
- ec2-user is the user for an Amazon Linux AMI 2
- ec2-3-83-213-44.compute-1.amazonaws.com is the public ip address of our instance
The result of this command will be:
The authenticity of host ' ec2-3-83-213-44.compute-1.amazonaws.com (3.83.213.44' can't be established.
RSA key fingerprint is a3:8b:10:bd:b6:f5:a3:3f:f1:be:b7:bd:b4:e8:fe:05:00:aa:9c:fc.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ec2-34-202-9-171.compute-1.amazonaws.com,34.202.9.171' (RSA) to the list of known hosts.
__| __|_ )
_| ( / Amazon Linux 2 AMI
___|\___|___|
https://aws.amazon.com/amazon-linux-2/
15 package(s) needed for security, out of 16 available
Run "sudo yum update" to apply all updates.
We answered yes, confirming this is a fingerprint we recognize. This is stored somewhere in our laptop and checked for every new connection we will establish to our instance. Please be aware that when we stop and the restart our instance, public ip will change and so will do the public key.
We are in our Amazon Linux 2 AMI! We ca execute cat /proc/cpuinfo and free -m to see information about the machine’s capabilities:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 63
model name : Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz
stepping : 2
microcode : 0x3d
cpu MHz : 2400.211
cache size : 30720 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
[…]
total used free shared buff/cache available
Mem: 985 45 782 0 158 794
Swap: 0 0 0
Step 3 Installing Java & Maven
We will install OpenJDK, the reference implementation of Java which is fully open source while Oracle Java contains some proprietary code. Most Java applications will work fine with either.
sudo yum install java-1.8.0-openjdk-devel
After successful install we can check the version installed:
[ec2-user@ip-172-31-41-75 ~]$ java -version openjdk version "1.8.0_191" OpenJDK Runtime Environment (build 1.8.0_191-b12) OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode)
We will then install maven:
[ec2-user@ip-172-31-41-75 ~]$ wget http://mirrors.sonic.net/apache/maven/maven-3/3.6.0/binaries/apache-maven-3.6.0-bin.zip [ec2-user@ip-172-31-41-75 ~]$ unzip apache-maven-3.6.0 [ec2-user@ip-172-31-41-75 ~]$ sudo mv apache-maven-3.6.0 /opt [ec2-user@ip-172-31-41-75 ~]$ sudo mv /opt/apache-maven-3.6.0/ /opt/maven
Create a file for updating path environment variable:
[ec2-user@ip-172-31-41-75 ~]$ Vi /etc/profile.d/maven.sh
And write the following line inside:
export PATH=/opt/maven/bin:${PATH}
then reload your environment variables
[ec2-user@ip-172-31-41-75 ~]$ source /etc/profile.d/maven.sh
And check everything is ok
[ec2-user@ip-172-31-41-75 ~]$ mvn -version Apache Maven 3.6.0 (97c98ec64a1fdfee7767ce5ffb20918da4f719f3; 2018-10-24T18:41:47Z) Maven home: /opt/maven Java version: 1.8.0_191, vendor: Oracle Corporation, runtime: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b12-0.amzn2.x86_64/jre Default locale: en_US, platform encoding: UTF-8 OS name: "linux", version: "4.14.88-88.73.amzn2.x86_64", arch: "amd64", family: "unix"
Step 4: Spring Boot install
Let’s create a directory as follows:
[ec2-user@ip-172-31-41-75 ~]$ cd /home/ec2-user [ec2-user@ip-172-31-41-75 ~]$ mkdir SpringBootProject [ec2-user@ip-172-31-41-75 ~]$ vi pom.xml
And insert the following text [2]. In the comments many lines are explained.
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>jtrainer.education</groupId>
<artifactId>SpringBootTutorial</artifactId>
<version>0.0.1-SNAPSHOT</version>
<!—This is the main class we will use as entry point -->
<properties>
<start-class>jtrainer.education.springboot.Application</start-class>
</properties>
<!-- Inherit defaults from Spring Boot -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.1.RELEASE</version>
</parent>
<!-- spring-boot-starter-web is the dependency for building web, including RESTful, applications using Spring MVC. Uses Tomcat as the default embedded container -->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<!-- Package as an executable jar so the application will be configured as a service -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Then write the following command:
[ec2-user@ip-172-31-41-75 ~]$ mvn clean package
This will produce a ./target directory with a SpringBootTutorial-0.0.1-SNAPSHOT.jar file ready to be executed:
[ec2-user@ip-172-31-41-75 ~]$ cd /home/ec2-user/target [ec2-user@ip-172-31-41-75 ~]$ java -jar SpringBootTutorial-0.0.1-SNAPSHOT.jar
Which of course will fail as we don’t have written any jtrainer.education.springboot.Application class.
Step 5: Our First Java Class with Spring Boot
Create the following directory structure:
/home/ec2-user/src/main/java/jtrainer/education/springboot
And within the springboot dir create the java class Application.java [1] as follows:
[ec2-user@ip-172-31-41-75 ~]$ vi Application.java
With the following content:
package jtrainer.education.springboot;
import java.util.Arrays;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Bean
public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
return args -> {
System.out.println("Let's inspect the beans provided by Spring Boot:");
String[] beanNames = ctx.getBeanDefinitionNames();
Arrays.sort(beanNames);
for (String beanName : beanNames) {
System.out.println(beanName);
}
};
}
}
I will then recompile and build the jar and execute it again:
[ec2-user@ip-172-31-41-75 ~]$ mvn clean package [ec2-user@ip-172-31-41-75 ~]$ java -jar SpringBootTutorial-0.0.1-SNAPSHOT.jar
This will produce a large output with the names of all beans defined in this Spring Application Context.
Spring Boot is now up and running!
Step 6: our first rest controller
In the file src/main/java/jtrainer/education/springboot/HelloController.java write the following class:
package jtrainer.education.springboot;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RequestMapping;
@RestController
public class HelloController {
@RequestMapping("/")
public String index() {
return "Greetings from Spring Boot@aws!";
}
}
Then recompile, build and execute:
[ec2-user@ip-172-31-41-75 ~]$ mvn clean package [ec2-user@ip-172-31-41-75 ~]$ java -jar SpringBootTutorial-0.0.1-SNAPSHOT.jar
Then from another shell type the following command:
[ec2-user@ip-172-31-41-75 ~]$ wget localhost:8080
Which will output:
--2018-12-29 14:09:58-- http://localhost:8080/ Resolving localhost (localhost)... 127.0.0.1 Connecting to localhost (localhost)|127.0.0.1|:8080... connected. HTTP request sent, awaiting response... 200 Length: 27 [text/plain] Saving to: ‘index.html’ 100%[======================================>] 27 --.-K/s in 0s 2018-12-29 14:09:58 (5.12 MB/s) - ‘index.html’ saved [27/27]
Where index.html content is
Greetings from Spring Boot@aws!
Step 7: is this a service deployed on AWS?
Add a new rule in your security group as follows:
The type in your browser:
http://ec2-3-81-1-223.compute-1.amazonaws.com:8080/
you will see the message:
Greetings from Spring Boot@aws!
You can now access the service in HelloController from anywhere in the world!
References
[1] – https://spring.io/guides/gs/spring-boot/
[2] – https://docs.spring.io/spring-boot/docs/current/reference/html/getting-started-installing-spring-boot.html
[3] – https://en.wikipedia.org/wiki/Systemd
