Collecting client information when an error occurs in a web application

This goal

If an error occurs in the web application (Spring this time), use Sentry to collect information on the client OS and browser.

What is Sentry?

OSS that collects error information in various languages such as Java, JavaScript, Ruby, and C #. It is convenient because you can pick up the browser and OS of the operated client. In addition, you can easily browse and check errors on a GUI-based (Slack-like screen). You can also notify Slack and register as an issue in Jira.

Sentry setting procedure

Create an account on Sentry's official page

https://www.getsentry.com/signup/

Sentry team and project creation

Select Java from the screen below and create a project

Get the project DSN

Select Client Keys in the project settings and copy the following DSN URL

Web application "Java (Spring)" settings

Package installation on Maven

Sentry-logback is a library that sends the contents of log output to Sentry

pom.xml

		<dependency>
			<groupId>io.sentry</groupId>
			<artifactId>sentry-spring</artifactId>
			<version>1.7.4</version>
		</dependency>
		<dependency>
			<groupId>io.sentry</groupId>
			<artifactId>sentry-logback</artifactId>
			<version>1.2.0</version>
		</dependency>

Describe Sentry settings in Java and add Bean

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletContextInitializer;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.HandlerExceptionResolver;

import io.sentry.Sentry;

@SpringBootApplication
public class SentryApplication {
	public static void main(String[] args) {
		SpringApplication.run(SentryApplication.class, args);
		Sentry.init("https://[email protected]/1202285");
	}
	@Bean
	public HandlerExceptionResolver sentryExceptionResolver() {
		return new io.sentry.spring.SentryExceptionResolver();
	}
	@Bean
	public ServletContextInitializer sentryServletContextInitializer() {
		return new io.sentry.spring.SentryServletContextInitializer();
	}
}

Added Sentry to LogBack

Install the following files under resource

logback.xml

<configuration>

  <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>

  <appender name="Sentry" class="io.sentry.logback.SentryAppender">
    <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
      <level>WARN</level>
    </filter>
  </appender>

  <root level="DEBUG">
    <appender-ref ref="Console" />
    <appender-ref ref="Sentry"/>
  </root>

</configuration>

Log output described in Controller class

The contents at the time of logger.error are sent to Sentry

	@RequestMapping("/")
	public String list(Model model) {
		logger.error("sentry error");
		return "Greetings from Spring Boot!";
	}

result

Send an error email to the email address registered by Sentry. Also, errors accumulate in Sentry projects

[Supplement]: Sentry and Slack integration

It is possible to link with Slack from the setting screen of Sentry. Works with many other apps.