пятница, 13 декабря 2013 г.

Notes about build version

What Makes Version Information Useful?

Here are the things we wanted from version information:

  • Determine if two builds come from the same source (even if built on different machines, at different times).
  • Easily find the code associated with a particular build.
  • Easily determine approximately how old a build is; compare age of versions.
  • Provide an easy mechanism for the user to tell different versions of builds apart.

A Decent Solution

After a bit of messing around with our build system and our source control tools, we ended up using these 4 values as our “version” information:


  • Commit Hash – Makes it trivial to figure out the source that the build is derived from. If you were using a SVN or something, you could use your repo path and revision instead.
  • Most Recent Tag – Not necessary, but nice for applying traceable easily-human-readable version numbers. Any code built from a commit after the tag would have this.
  • A Local Changes Flag – Indicates if there are uncommitted changes that are not reflected in the commit hash, which would also indicate that this is unsafe for production use.
  • Change Date – If local changes is false, this is the date-time of the commit, otherwise it is the date-time at the start of the build.

среда, 11 декабря 2013 г.

Setting up your application server with maven


In many cases there is no way to deploy an application without the need to setup your application before. In JBoss AS 7.x you may want to configure for example your database connection. Or you have to configure a security realm. Maybe you also want to adjust the SLSB pool… In any of these cases all developers in the team have to share a common or at least a similar configuration.

Often this information can be found in sporadically sent emails or on some wiki page. But what happens sometime after a release, when you have to check out a branch to fix some bug or to add a new feature? You will have to reconstruct the configuration that was valid for this branch. So why not add the configuration files to your version control system and together with the mere configuration files, a maven configuration that sets up the whole application server?

Let’s try to keep it simple and use only public available and commonly used plugins. First of all let’s add all versions that we will need in the following to the properties part of the pom.xml:

<properties>
  <jboss.install.dir>${project.build.directory}/jboss</jboss.install.dir>
  <jboss.version>7.2.0.Final</jboss.version>
  <app.version>${project.version}</app.version>
  <ojdbc.version>11.2.0.1.0</ojdbc.version>
</properties>

We also define here the installation directory of the JBoss AS. This way we can change it, if we want, using the command line option -D. Now we add a new profile, such that we have to explicitly switch the setup procedure on and that it is not part of the normal build:

<profile>
  <id>setupAs</id>
  <build>
    <plugins>
    ...
    </plugins
  </build>
</profile>

If we have the current JBoss version as a maven artifact deployed in our maven repository, we can use the maven-dependency-plugin to download and unpack the JBoss to the installation directory given above:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-dependency-plugin</artifactId>
  <version>2.8</version>
  <executions>
    <execution>
      <id>unpack-jboss</id>
      <phase>package</phase>
      <goals>
        <goal>unpack</goal>
      </goals>
      <configuration>
        <artifactItems>
          <artifactItem>
            <groupId>org.jboss</groupId>
            <artifactId>jboss-as</artifactId>
            <version>${jboss.version}</version>
            <type>zip</type>
            <outputDirectory>${project.build.directory}/jboss</outputDirectory>
          </artifactItem>
        </artifactItems>
      </configuration>
    </execution>

Now that the application server is unpacked, we have to add the JDBC driver as well as our application (or anything else you need). We set this up by adding another execution block to the maven dependency plugin:

<execution>
  <id>copy</id>
  <phase>package</phase>
  <goals>
    <goal>copy</goal>
  </goals>
  <configuration>
    <artifactItems>
      <artifactItem>
        <groupId>our-company</groupId>
        <artifactId>our-application-ear</artifactId>
        <version>${app.version}</version>
        <type>ear</type>
        <outputDirectory>${jboss.install.dir}/jboss-as-${jboss.version}/standalone/deployments</outputDirectory>
      </artifactItem>
      <artifactItem>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc6</artifactId>
        <version>${ojdbc.version}</version>
        <outputDirectory>${jboss.install.dir}/jboss-as-${jboss.version}/standalone/deployments</outputDirectory>
        <destFileName>ojdbc6.jar</destFileName>
      </artifactItem>
    </artifactItems>
  </configuration>
</execution>

Last but not least, we also want to adjust the standard configuration files to our needs. We can use the maven-resources-plugin to substitute variable values within each file. Therefore we add templates for these files to the resources folder of our JBoss module and call the goal copy-resources:

<plugin>
  <artifactId>maven-resources-plugin</artifactId>
  <version>2.6</version>
  <executions>
    <execution>
      <id>copy-jboss-configuration</id>
      <phase>package</phase>
      <goals>
        <goal>copy-resources</goal>
      </goals>
      <configuration>
        <outputDirectory>${jboss.install.dir}/jboss-as-${jboss.version}/standalone/configuration</outputDirectory>
        <resources>
          <resource>
            <directory>src/main/resources/jboss/standalone/configuration</directory>
            <filtering>true</filtering>
          </resource>
        </resources>
      </configuration>
    </execution>
    <execution>
      <id>copy-jboss-bin</id>
      <phase>package</phase>
      <goals>
        <goal>copy-resources</goal>
      </goals>
      <configuration>
        <outputDirectory>${jboss.install.dir}/jboss-as-${jboss.version}/bin</outputDirectory>
        <resources>
          <resource>
            <directory>src/main/resources/jboss/bin</directory>
            <filtering>true</filtering>
          </resource>
        </resources>
      </configuration>
    </execution>
  </executions>
</plugin>

The values for the filtering can be given on the command line with the -D option. If the team has more than a few members, it is also possible to create for each user a properties file that contains his/her specific configuration values. If we use the OS user as filename, we can easily choose the file by the name of the currently logged in user. This way each team member can easily setup its own completely configured application server instance by simply running:

mvn clean install -PsetupAs

In order to prevent that the newly configured server is deleted with the next clean invocation, we disable the maven clean plugin for the normal build:

<plugin>
  <artifactId>maven-clean-plugin</artifactId>
  <version>2.5</version>
  <configuration>
    <skip>false</skip>
  </configuration>
</plugin>

Within the setupAs profile created above, we have to enable it of course, such that we can delete the whole installation just by calling “mvn clean -PsetupAs”. Now switching to an older branch is easy as we don’t lose any time searching for the right configuration…