Java Maven source code deployment component

Principle document reading

Interpretation of Rainbond’s Principles of Building Java Maven Projects

Maven project identification strategy

When the pom.xml file exists in the source code root directory and there is no Dockerfile file, Rainbond will recognize the source code as a Java Maven project.

Maven multi-module project construction, please refer to Java Maven multi-module source code constructiondirectly.

Validation preparation

Before deploying the project to Rainbond, please follow the steps below for local verification. After the local build is successful, you can start trying to deploy the project on Rainbond.

• The source code is hosted on a Git or SVN server.

• Check the local build environment and runtime environment to determine the Maven version, JDK version, and whether OracleJDK is used.

mvn -v
java -version

• Clear the local build cache. In general, the local localRepository is located at ${HOME}/.m2/repository. Please change the path of this folder temporarily after confirmation.

mv ${HOME}/.m2/repository ${HOME}/.m2/repository.bak

• Execute the following build command, which is also the default command：for Rainbond Java Maven project builds

mvn -DskipTests clean dependency:list install

pom.xml specification

• The SpringBoot project packaging method is recommended to use the jar package method.
• It is recommended to use the war package for the packaging method of non-SpringBoot projects.

Compile and run environment configuration

In the environment preparation stage, the Rainbond build and run environment needs to be as unified as possible with the commonly used local build and run environment.Such as JDK version, Maven version, etc.

Graphical settings

Rainbond supports the graphical definition of the compilation and runtime environment, and the configuration is located on the build source page of the service component.Modifications to these configurations need to take effect through build!

• Disable caching, this switch should always be on until the first successful build is done, off by default.

• Select the JDK (OpenJDK provided by default) and MAVEN version used to compile and run,must use the version verified when preparing for verification.

• Select the custom JDK download address, you need to provide the path to which the Rainbond server can be downloaded to download the JDK (which can be OracleJDK) installation package in tar.gz format.

• When the build product is war file, version selection of Tomcat and Jetty is also provided.

• Disable Maven Mirror. This switch determines whether to proxy through rbd-repo (the default proxy is to Alibaba Cloud maven warehouse). Once the switch is turned, the MAVEN MIRROR OF configuration and MAVEN MIRROR URL configuration defined below**will all be invalid. The repository address will only depend on the definitions in the pom.xml files (if there is no repositories definition in the file, the dependencies will be pulled from the Maven central repository).

• The MAVEN MIRROR OF configuration, used in conjunction with the MAVEN MIRROR URL configuration, can define the behavior of pulling dependencies from the mirror private server during the build process.The default configuration is centralIf it is set to *, all dependent packages will be pulled from the mirror warehouse address defined in the MAVEN MIRROR URL configuration.

• The MAVEN MIRROR URL configuration defines the warehouse private server address used in the build process.Rainbond does not support local installation and deployment of jar packages. Please upload all required third-party jar packages to the warehouse private server.The default maven.goodrain.me is the intranet resolution domain name of the rbd-repo component, which represents the Alibaba Cloud maven warehouse.

• MAVEN build parameters and build commands are two options, which constitute the command executed by compilation. The default build command is mvn -DskipTests clean dependency:list install.

• The MAVEN build java parameter configuration is mainly used to specify the stack memory allocated during the build process.This configuration only affects the maven build process. The stack memory specified when the built component is run is specified by ${JAVA_OPTS} variable.

• The startup command specifies how Rainbond starts the current service component after the build process is completed. For details, see chapter Startup Command Configuration below.

Set via code (recommended)

Rainbond supports defining all of the above configurations in code.The advantage of this is：by adding several configuration files to the source code repository, the definition of the compilation and running environment is completed, and automatic CI is completed without any manual configuration.

system.properties

Add system.properties file in the root directory of the source code, you can define the Maven version, JDK version,Be sure to use the version verified when preparing for verification：

java.runtime.version=1.8
maven.version=3.3.1

The selection range of the two versions is as follows:：

settings.xml (recommended)

Add the settings.xml file available to the user’s local build in the source code root directory to completely simulate the user’s local build settings, including warehouse private server settings.This file is usually located in the ${M2_HOME}/conf or ${HOME}/.m2 directory of the user environment, and the configuration used by the user’s local build can be defined in it.

In the upcoming Rainbond v5.2.2 version, the settings of settings.xml will be added to the graphical settings.

mvnw

If your code root directory defines mvnw, this script will be used to start the Maven process.If a Maven version is specified,mvnwis ignored.Build with default commands.

rainbondfile

Adding rainbondfile to the root directory of the source code can define environment variables for the service component, and more configurations during the build process can be defined by means of environment variables.

During the Rainbond source code building process, the variables defined for service components starting with BUILD_ can be passed into the build environment for use.Some commonly used environment variables are as follows:

Start command configuration

After the Java Maven source code construction process is completed, Rainbond will automatically run the service component, which requires us to specify the start command of the service component in advance.

Procfile specification

Rainbond defines the project startup command through the Procfile file in the source code root directory, and theProcfile file definition specification is detailed in Procfile.

The startup command can be entered graphically on the service component building source page. The format of the command entered here is the same as Procfile , and the priority is higher than Procfile in the source code root directory.After the input is complete, it will take effect the next time the current service component is built.

If the project does not define a Procfile, the platform will generate a default Procfile based on the identified project type by default.

• The packaging method is war package, and the platform uses webapp-runner.jar to run the packaged war package.Example

web: java $JAVA_OPTS -jar ./webapp-runner.jar --port $PORT target/*.war

• The packaging method is jar package, example

web: java -Dserver.port=$PORT $JAVA_OPTS -jar target/*.jar

The above is the default Procfile , if you need to expand more startup parameters, you can customize Procfile.

• web: there is a space betweenandjava
• End of file cannot contain special characters
• If it is a multi-module project, pay attention to the path of the jar package or war package after compilation. The path is<submodule name>/targets/*.jaror<submodule name>/targets/*.war
• $JAVA_OPTS: The platform will automatically set the values of Xmx and Xms according to the memory size of the application
• $PORT: Listen according to the port set by the user on the platform, the default listening port is 5000

When the web server support is adjusted, packaged into War needs to adjust the startup command：

• When choosing a different version of tomcat web: java $JAVA_OPTS -jar ./webapp-runner.jar --port $PORT ./*.war
• When choosing a different version of jetty web: java $JAVA_OPTS -jar ./jetty-runner.jar --port $PORT ./*.war
• Need to configure context path, you can specify webapp-runner parameter pathby custom Procfile
  • Example web: java $JAVA_OPTS -jar ./webapp-runner.jar --path <path路径,示例: /r6d> --port $PORT ./*.war

Web service support

If the Maven project is packaged as a war package, Web service support needs to be configured.

Run the war package through web service (tomcat or jetty), that is, through java -jar ./webapp-runner.jar ./*.war or java -jar ./jetty-runner.jar ./*.war ways to operate.

Currently you can set the web service version through the build source or define webserver file in the source root directory

1. Console build source configuration supports versions tomcat7, tomcat8, tomcat85, tomcat9, jetty7, jetty9
2. Define the webserver version in the source root directory
   • webapp-runner-7.0.91.0.jar
   • webapp-runner-8.0.52.0.jar,webapp-runner-8.5.38.0.jar
   • webapp-runner-9.0.16.0.jar
   • jetty-runner-7.5.4.v20111024.jar,jetty-runner-9.4.0.v20161208.jar

The specific correspondence is as follows:

Selecting the tomcat7 version requires attention to ensure that the local can be run through java -jar ./webapp-runner-7.0.91.0.jar ./*.war. For detailed configuration of webapp-runner, please refer to webapp-runner Instructions for Use

other instructions

If it is compiled into a war package, the war file will be decompressed to the /app/target/ directory by default at runtime. It is not supported to add a configuration file to the war decompression path, otherwise the application will not be able to start normally.

Sample demo program

Example Spring Boot project: https://github.com/goodrain/java-maven-demo

FAQ

• The project is more complex and cannot be compiled using the above method

  At this time, it is recommended that you define your own Dockerfile file for compilation and running environment control.

• How to deal with compilation failure

  Check the build log to get the reason for the compilation failure from the log.If your project needs to download the dependency package from the public network, there is a high possibility that the dependency package download fails. If the network is unlimited, try again.

• The project dependency package has changed, but it is found that it does not take effect after compilation

  If your dependency package has been correctly updated to the private server, it is considered that the local cache dependency package has not been updated.You can manually disable the cache and rebuild.

• The project compiles successfully, but runs abnormally after startup

  Reason 1：The running command mentioned above is set incorrectly, causing the container to fail to start.The solution is to set the startup command correctly.

  Reason 2：Exit after the code runs in error. Refer to the component operation log to determine the cause from the log content.

  Reason 3：The memory allocation is too small, and the component cannot be started normally.The log phenomenon for this factor is that components are starting up and then suddenly exiting.At this time, consider more OOM caused by insufficient memory settings.

• After entering the container environment through the WEB terminal, directly execute java -version version 1.7.

  The java command used to run the service component is located at /app/.jdk/bin/java this path is not in $PATH.

Recommended reading

• Java-Jar source code building application
• Java-War source code building application
• Java-Gradle source build application
• Tomcat configures Redis to implement Session sharing
• webapp-runner instructions