Can't build gradle application inside docker

Question

I am trying to build an application with gradle from within a docker container. This is my Dockerfile:

FROM openjdk:8-jdk
#install git
RUN apt-get install -y git
RUN git clone https://github.com/SFRJ/yurl.git
#install gradle
RUN wget https://downloads.gradle-dn.com/distributions/gradle-6.5-bin.zip
RUN unzip gradle-6.5-bin.zip
ENV GRADLE_HOME /gradle-6.5
ENV PATH $PATH:/gradle-6.5/bin
#compile and run app
RUN cd yurl
RUN gradle clean build --rerun-tasks --no-build-cache
ENTRYPOINT ["java", "-jar", "/yurlapp.jar"]

Everything goes well until the point where the build command is executed. It throws the following:

Step 9/10 : RUN gradle clean build --rerun-tasks --no-build-cache
 ---> Running in a25d344c3571

Welcome to Gradle 6.5!

Here are the highlights of this release:
 - Experimental file-system watching
 - Improved version ordering
 - New samples

For more details see https://docs.gradle.org/6.5/release-notes.html

Starting a Gradle Daemon (subsequent builds will be faster)

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project ''.
> The project name must not be empty. Set the 'rootProject.name' or adjust the 'include' statement (see https://docs.gradle.org/6.5/dsl/org.gradle.api.initialization.Settings.html#org.gradle.api.initialization.Settings:include(java.lang.String[]) for more details).

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 3s
ERROR: Service 'yurlapp' failed to build: The command '/bin/sh -c gradle clean build --rerun-tasks --no-build-cache' returned a non-zero code: 1

I just don't understand what it is. The app builds perfectly fine when I run the same command outside of docker but inside docker fails. This is not a multi module project not sure why it complains about rootProject.

I can confirm that I have a settings.gradle file and inside I have this

rootProject.name = 'yurl'

Also this is my build.gradle

buildscript {
    repositories {
        mavenLocal()
        mavenCentral()
    }
    dependencies {
        classpath "org.postgresql:postgresql:42.2.11"
    }
}

plugins {
    id 'org.springframework.boot' version '2.2.4.RELEASE'
    id 'io.spring.dependency-management' version '1.0.9.RELEASE'
    id 'java'
    id 'org.flywaydb.flyway' version '6.3.0'
    id 'nu.studer.jooq' version '4.1'
}

group 'com.javing.yurl'
version '1.0-SNAPSHOT'

sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {

    annotationProcessor 'org.projectlombok:lombok:1.18.8'

    implementation 'org.jooq:jooq'
    implementation 'org.jooq:jooq-codegen'
    jooqRuntime 'org.postgresql:postgresql:42.2.11'
    compile 'org.postgresql:postgresql:42.2.11'
    implementation 'org.projectlombok:lombok:1.18.8'
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-actuator'
    implementation 'org.springframework.boot:spring-boot-starter-jooq'
    implementation 'io.vavr:vavr:0.10.2'
    implementation 'com.konghq:unirest-java:3.7.00'

    testCompile group: 'junit', name: 'junit', version: '4.12'
    testCompile group: 'org.mockito', name: 'mockito-core', version: '2.1.0'
    testCompile group: 'org.assertj', name: 'assertj-core', version: '3.15.0'

}

jooq {
    sample(sourceSets.main) {
        jdbc {
            driver = 'org.postgresql.Driver'
            url = 'jdbc:postgresql://yurldb:5432/yurldb'
            user = 'postgres'
            password = 'somepassword'
        }
        generator {
            database() {
                name = 'org.jooq.meta.postgres.PostgresDatabase'
                inputSchema = 'public'
                includes = '.*'
            }
            target {
                packageName = 'com.javing.yurl'
                directory = 'build/generated/java'
            }
        }
    }
}

tasks.generateSampleJooqSchemaSource.with {
    def out = new ByteArrayOutputStream()
    javaExecSpec = { JavaExecSpec s ->
        s.standardOutput = out
        s.errorOutput = out
        s.ignoreExitValue = true
        s.jvmArgs '-Xmx512M'
    }
    execResultHandler = { ExecResult r ->
        if (r.exitValue != 0) {
            throw new RuntimeException('jOOQ source code generation failed:\n\n' + out.toString())
        }
    }
}

flyway {
    url = 'jdbc:postgresql://localhost:5432/yurldb'
    user = 'postgres'
    password = 'somepassword'
    schemas = ['public']
    locations = ["filesystem:$project.projectDir/src/main/resources/db/migration"]
}

I don't know how to fix this I tried multiple things but nothing worked. I need to build this app from within docker using gradle. I know gradle is installed correctly because if I add the version command (RUN gradle -v) in the Dockerfile, I can see this printed when docker is running:

------------------------------------------------------------
Gradle 6.5
------------------------------------------------------------

Build time:   2020-06-02 20:46:21 UTC
Revision:     a27f41e4ae5e8a41ab9b19f8dd6d86d7b384dad4

Kotlin:       1.3.72
Groovy:       2.5.11
Ant:          Apache Ant(TM) version 1.10.7 compiled on September 1 2019
JVM:          1.8.0_252 (Oracle Corporation 25.252-b09)
OS:           Linux 4.18.0-25-generic amd64

So my gradle and configuration of gradle seems ok. Also I know the installation of git and the clonning of the project is fine because if I add a RUN ls -s in my Dockerfile it will correctly print all the content of the project.

Something is wrong maybe in the build.gradle or settings.gradle file. Any idea what could be?

Answer 1

Can you try the below Dockerfile as have changed a little bit.

FROM openjdk:8-jdk
#install git
RUN apt-get install -y git
RUN git clone https://github.com/SFRJ/yurl.git
#install gradle
RUN wget https://downloads.gradle-dn.com/distributions/gradle-6.5-bin.zip
RUN unzip gradle-6.5-bin.zip
ENV GRADLE_HOME /gradle-6.5
ENV PATH $PATH:/gradle-6.5/bin
#compile and run app
WORKDIR yurl
RUN gradle clean build --rerun-tasks --no-build-cache
ENTRYPOINT ["java", "-jar", "/yurlapp.jar"]

The problem was, you mentioned a stageRUN cd yurl in which you are changing a directory, which is only valid for that particular stage not for the remaining stages. If you want to use that particular directory for the other stages as well. Use WORKDIR to run that operation which I did above.

P.S.:- If you want to use that directory only for 1 stage, then instead of WORKDIR use RUN cd DIR && ls -lart like command in 1 stage itself.