Parent pom and microservices

Question

• We have several projects that are microservices, every project is independent (running on separate spring boot server, exposing rest services, using separate DB schema

Answer 1

The 'problem' with a multi-module parent pom is that, without complicated profiles, it locks the modules in the same release cycle (assuming you're using the Release Plugin, which you should be).

The way I work with Maven is to have a parent pom that declares:

• common dependencies (logging APIs, JUnit, etc).
• common plugins.
• all dependencies in the dependencyManagement section.
• all plugins in the pluginManagement section.

Each module delcares the parent pom as its parent but the parent knows nothing about the modules.

The benefit of this comes from the last to two bullets above, the 'management' sections. Anything contained in a 'management' section needs to be redeclared in a module that wants to use a particular dependency or plugin.

For example the parent might look like this:

  com.example
  parent
  1.0.00-SNAPSHOT

  ...

  

    
      org.slf4j
      slf4j-api
      1.7.7
    

    
      junit
      junit
      4.11
      test
                

  

  

    
      commons-lang
      commons-lang
      2.6
            

    
      commons-collections
      commons-collections
      2.1
    

  

  

    
      org.apache.maven.plugins
      maven-compiler-plugin
      3.1
      
        1.8
        1.8
      
    

  

  

    

      
        org.apache.maven.plugins
        maven-assembly-plugin
        2.4
        
          false
          
            src/main/assembly/assembly.xml
          
        
        
          
            make-assembly
            package
            
              single
            
          
        
      

    

  

And the module might look like this:

  
    com.example
    parent
    1.0.00-SNAPSHOT
  

  com.example
  module
  1.0.00-SNAPSHOT

  

    
      commons-lang
      commons-lang          
            

  

  

    
      org.apache.maven.plugins
      maven-assembly-plugin
    

  

The module would:

• have dependencies on org.slf4j:slf4j-api:1.7.7:compile, junit:junit:4.11:test and commons-lang:commons-lang:2.6:compile.
• has the plugin org.apache.maven.plugins:maven-assembly-plugin:2.4