spring boot mvc docker Whitelabel Error - docker

Question

I have a spring boot mvc app running on docker container. Container is running perfectly fine but when I try to access app on the browser I get Whitelabel Error Page saying it cannot find /WEB-INF/views/***.jsp. Below is my pom.xml
<?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>com.jay.webapp</groupId>
<artifactId>LoginModel</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>LoginModel</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-dbcp2</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Below is my Dockerfile
FROM openjdk:8-jdk-alpine
MAINTAINER "***"
COPY LoginModel-0.0.1-SNAPSHOT.jar app.jar
CMD ["java","-Djava.security.egd=file:/dev/./urandom","-jar","app.jar"]
When I did "java -jar target/LoginModel-0.0.1-SNAPSHOT.jar" locally and tried to see it on browser the it worked perfectly without any errors. I only get the error when i tried to run the app on docker container. Where exactly is the mistake?

Answer 1

It seems you're using JSPs, but your app is packaged as a JAR. You should package your application as a WAR. Documentation also mentions that
Creating a custom error.jsp page won’t override the default view for error handling, custom error pages should be used instead.
Look at the JSP limitations section in the reference documentation for more on this.

Answer 2

You need your project to be a war and a Dockerfile like this
FROM tomcat:8.5-alpine
VOLUME /tmp
ARG WAR_FILE
ADD ${WAR_FILE} /usr/local/tomcat/webapps/app.war
RUN sh -c 'touch /usr/local/tomcat/webapps/app.war'
ENTRYPOINT [ "sh", "-c", "java -Djava.security.egd=file:/dev/./urandom -jar /usr/local/tomcat/webapps/app.war" ]
and a pom plugin like this
<plugin>
<groupId>com.spotify</groupId>
<artifactId>dockerfile-maven-plugin</artifactId>
<version>1.3.6</version>
<configuration>
<repository>${docker.image.prefix}/${project.artifactId}</repository>
<buildArgs>
<WAR_FILE>target/${project.build.finalName}.war</WAR_FILE>
</buildArgs>
</configuration>
</plugin>
As Brian Clozel said you also need to read the restrictions on deploying with JSPs
Also be aware of the dependency changes when deploying as a war
This example project demonstrates the solution (Spring Boot / Docker / JSP / Spring Security)

Answer 3

I faced the similar condition while I tried to run simple springboot web application in docker-container. I have packaged my application and .jar so the contents of JSP page was not displayed on the browser. I changed the packaging to .war and ran the process again and got the contents displayed in the browser.