GKE: cannot main class not found - spring

Question

I am trying to deploy a containerized Spring Boot application in GKE. The deployment is successful but the pod goes into CrashLoopBackOff. I find the error : Exception in thread "main" java.lang.ClassNotFoundException: com.xx.yy.api.Application
Application class is a valid SpringBoot Main class.
package com.xx.yy.api;
#SpringBootApplication(exclude = SecurityAutoConfiguration.class)
#EnableCaching
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
My pom.xml is:
<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.xx.yy.api</groupId>
<artifactId>my-api</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<name>My API</name>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.4.RELEASE</version>
<relativePath />
</parent>
<properties>
<start-class>com.xx.yy.api.Application</start-class>
<java.version>1.8</java.version>
<maven.compiler.target>${java.version}</maven.compiler.target>
<maven.compiler.source>${java.version}</maven.compiler.source>
<!-- Maven -->
<maven-surefire-plugin.version>3.0.0-M3</maven-surefire-plugin.version>
<maven-failsafe-plugin.version>3.0.0-M3</maven-failsafe-plugin.version>
<maven-compiler-plugin.version>3.6.1</maven-compiler-plugin.version>
<org.projectlombok.version>1.18.4</org.projectlombok.version>
<org.mapstruct.version>1.3.1.Final</org.mapstruct.version>
<!-- Junit & Jacoco -->
<jacoco.ut.execution.data.file>${project.build.directory}/coverage-reports/jacoco-ut.exec</jacoco.ut.execution.data.file>
<jacoco-plugin.version>0.8.4</jacoco-plugin.version>
<junit.jupiter.version>5.3.2</junit.jupiter.version>
<mockito.version>3.2.4</mockito.version>
<junit.platform.version>1.5.1</junit.platform.version>
<!-- Sonar -->
<sonar-maven-plugin.version>3.5.0.1254</sonar-maven-plugin.version>
<sonar.java.coveragePlugin>jacoco</sonar.java.coveragePlugin>
<sonar.dynamicAnalysis>reuseReports</sonar.dynamicAnalysis>
<sonar.jacoco.reportPaths>${jacoco.ut.execution.data.file}</sonar.jacoco.reportPaths>
<sonar.language>java</sonar.language>
<sonar.projectName>my-api</sonar.projectName>
<sonar.coverage.exclusions>
**/com/xx/yy/api/persistence/entity/**.*,
**/com/xx/yy/api/dto/**.*
</sonar.coverage.exclusions>
<!-- Encoding -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<exclusions>
<exclusion>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</exclusion>
</exclusions>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-testing</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.tngtech.archunit</groupId>
<artifactId>archunit-junit4</artifactId>
<version>0.9.3</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-test-autoconfigure</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<exclusions>
<exclusion>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct</artifactId>
<version>${org.mapstruct.version}</version>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
<version>1.0.1.Final</version>
</dependency>
<dependency>
<groupId>private.com</groupId>
<artifactId>logback-logging</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-oauth2-jose</artifactId>
</dependency>
<dependency>
<groupId>com.nimbusds</groupId>
<artifactId>nimbus-jose-jwt</artifactId>
<version>8.4</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
<version>20180813</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<dependency>
<groupId>org.glassfish.jaxb</groupId>
<artifactId>jaxb-runtime</artifactId>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-core</artifactId>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-apt</artifactId>
</dependency>
<dependency>
<groupId>com.querydsl</groupId>
<artifactId>querydsl-jpa</artifactId>
</dependency>
<!-- Only required to run tests in an IDE that bundles an older version -->
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-launcher</artifactId>
<version>${junit.platform.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>${mockito.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<directory>target</directory>
<finalName>my-api</finalName>
<sourceDirectory>${basedir}/src/main/java</sourceDirectory>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.sonarsource.scanner.maven</groupId>
<artifactId>sonar-maven-plugin</artifactId>
<version>${sonar-maven-plugin.version}</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${maven-surefire-plugin.version}</version>
</plugin>
<!-- Runs integration tests -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>${maven-failsafe-plugin.version}</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<annotationProcessorPaths>
<path>
<groupId>org.mapstruct</groupId>
<artifactId>mapstruct-processor</artifactId>
<version>${org.mapstruct.version}</version>
</path>
<path>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${org.projectlombok.version}</version>
</path>
</annotationProcessorPaths>
<compilerArgs>
<compilerArg>-Amapstruct.suppressGeneratorTimestamp=true</compilerArg>
<compilerArg>-Amapstruct.suppressGeneratorVersionInfoComment=true</compilerArg>
<compilerArg>-Amapstruct.defaultComponentModel=spring</compilerArg>
</compilerArgs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<dependencies>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit.jupiter.version}</version>
</dependency>
</dependencies>
</plugin>
<!-- Jacoco : code coverage -->
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>${jacoco-plugin.version}</version>
<executions>
<execution>
<id>pre-unit-test</id>
<goals>
<goal>prepare-agent</goal>
</goals>
<configuration>
<destFile>${jacoco.ut.execution.data.file}</destFile>
</configuration>
</execution>
<execution>
<id>post-unit-test</id>
<phase>test</phase>
<goals>
<goal>report</goal>
</goals>
<configuration>
<dataFile>${jacoco.ut.execution.data.file}</dataFile>
<outputDirectory>${project.reporting.outputDirectory}/jacoco-ut</outputDirectory>
<excludes>
<exclude>**/com/xx/yy/api/persistence/entity/**.*</exclude>
<exclude>**/com/xx/yy/api/dto/**.*</exclude>
</excludes>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>${start-class}</mainClass>
</configuration>
</plugin>
<!-- JPA Query DSL -->
<plugin>
<groupId>com.mysema.maven</groupId>
<artifactId>apt-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>process</goal>
</goals>
<configuration>
<outputDirectory>target/generated-sources/java</outputDirectory>
<processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>artifactory</id>
<url>https://artifactory.dt.xx.com/artifactory/nexus-dt-proxy/</url>
</repository>
</repositories>
</project>
The docker file I am using:
FROM maven:3.5-jdk-8 as builder
ARG http_proxy
ARG HTTP_PROXY_HOST
ARG HTTP_PROXY_PORT
ARG MAVEN_SETTINGS_XML="settings_cicd.xml"
ARG TARGET="deploy"
ARG artifactory_username
ARG artifactory_apikey
WORKDIR /api/
COPY ./settings_cicd.xml /api/
COPY ./pom.xml /api/
COPY ./src /api/
RUN echo "MAVEN_SETTINGS_XML = $MAVEN_SETTINGS_XML"
RUN sed 's/PLACEHOLDER_ARTIFACTORY_USER/'"${artifactory_username}"'/' ${MAVEN_SETTINGS_XML} > tmp.settings.xml &&\
sed 's/PLACEHOLDER_ARTIFACTORY_APIKEY/'"${artifactory_apikey}"'/' tmp.settings.xml > ${MAVEN_SETTINGS_XML} &&\
mvn clean install -DskipTests -Dtarget=${TARGET} -e -q -s ${MAVEN_SETTINGS_XML}
FROM openjdk:8-jre-alpine
VOLUME /tmp
COPY --from=builder /api/target/my-api.jar /home/project/my-api.jar
ARG http_proxy
ARG https_proxy
ARG TAG_VERSION
ARG TAG_BUILD
ARG TAG_COMMIT
RUN apk update && apk --no-cache add curl bash
RUN ln -sf /bin/bash /bin/sh
RUN addgroup -g 1000 user \
&& adduser -u 1000 -G user -s /bin/bash -D user
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "/home/project/my-api.jar"]
Can't figure out what is going wrong. I have tested the Spring Boot jar separately it works. I am yet to test the container separately. Any leads will help.