I want to execute shell commands from Maven's pom.xml

Question

Here's what's been working for me:

<plugin>
  <artifactId>exec-maven-plugin</artifactId>
  <groupId>org.codehaus.mojo</groupId>
  <executions>
    <execution><!-- Run our version calculation script -->
      <id>Version Calculation</id>
      <phase>generate-sources</phase>
      <goals>
        <goal>exec</goal>
      </goals>
      <configuration>
        <executable>${basedir}/scripts/calculate-version.sh</executable>
      </configuration>
    </execution>
  </executions>
</plugin>

The problem here is that I don't know what is expected. With your current setup, invoking the plugin on the command line would just work:

$ mvn exec:exec
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Q3491937
[INFO]    task-segment: [exec:exec]
[INFO] ------------------------------------------------------------------------
[INFO] [exec:exec {execution: default-cli}]
[INFO] laptop
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
...

The global configuration is used, the hostname command is executed (laptop is my hostname). In other words, the plugin works as expected.

Now, if you want a plugin to get executed as part of the build, you have to bind a goal on a specific phase. For example, to bind it on compile:

  <plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.1.1</version>
    <executions>
      <execution>
        <id>some-execution</id>
        <phase>compile</phase>
        <goals>
          <goal>exec</goal>
        </goals>
      </execution>
    </executions>
    <configuration>
      <executable>hostname</executable>
    </configuration>
  </plugin>

And then:

$ mvn compile
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Q3491937
[INFO]    task-segment: [compile]
[INFO] ------------------------------------------------------------------------
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/pascal/Projects/Q3491937/src/main/resources
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Nothing to compile - all classes are up to date
[INFO] [exec:exec {execution: some-execution}]
[INFO] laptop
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
...

Note that you can specify a configuration inside an execution.

Solved. The problem is, executable is working in a different way in Linux. If you want to run an .sh file, you should add the exec-maven-plugin to the <plugins> section of your pom.xml file.

<plugin>
  <artifactId>exec-maven-plugin</artifactId>
  <version>3.0.0</version>
  <groupId>org.codehaus.mojo</groupId>
  <executions>
    <execution>
      <!-- Run our version calculation script -->
      <id>Renaming build artifacts</id>
      <phase>package</phase>
      <goals>
        <goal>exec</goal>
      </goals>
      <configuration>
        <executable>bash</executable>
        <commandlineArgs>handleResultJars.sh</commandlineArgs>
      </configuration>
    </execution>
  </executions>
</plugin>

2 Options:

1. You want to exec a command from maven without binding to any phase, you just type the command and maven runs it, you just want to maven to run something, you don't care if we are in compile/package/... Let's say I want to run npm start with maven, you can achieve it with the below:

mvn exec:exec -Pstart-node

For that you need the below maven section

  <profiles>
    <profile>
      <id>start-node</id>
      <build>
        <plugins>
          <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.3.2</version>
            <executions>
              <execution>
                <goals>
                  <goal>exec</goal>
                </goals>
              </execution>
            </executions>
            <configuration>
              <executable>npm</executable>
              <arguments><argument>start</argument></arguments>
            </configuration>
          </plugin>
        </plugins>
      </build>
    </profile>

  </profiles>

2. You want to run an arbitrary command from maven while you are at a specific phase, for example when I'm at install phase I want to run npm install you can do that with:

mvn install

And for that to work you would need the below section:

  <plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>1.3.2</version>
    <executions>

      <execution>
        <id>npm install (initialize)</id>
        <goals>
          <goal>exec</goal>
        </goals>
        <phase>initialize</phase>
        <configuration>
          <executable>npm</executable>
          <arguments>
            <argument>install</argument>
          </arguments>
        </configuration>
      </execution>

Thanks! Tomer Ben David. it helped me. as I am doing pip install in demo folder as you mentioned npm install

<groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.3.2</version>
            <executions>
              <execution>
                <goals>
                  <goal>exec</goal>
                </goals>
              </execution>
            </executions>
            <configuration>
              <executable>pip</executable>
              <arguments><argument>install</argument></arguments>                            
             <workingDirectory>${project.build.directory}/Demo</workingDirectory>
            </configuration>