Using the maven-scm-plugin with git without storing a password in plaintext

Question

I need to use the maven-scm-plugin to export/checkout (the default branch of) a repository on github. I can get this working if I hard-code the username/password somewhere, but I can't get it to use ssh keys or the local filesystem password manager.

On the command prompt, I can do "git clone git@github.com:org/repo" or "git clone https://github.com/org/repo", and it will complete without my having to manually re-enter username/password details.

In my plugin, I can have the connectionUrl be scm:git:https://github.com/org/repo" and I can pass "-Dusername=foo -Dpassword=bar". But, then somewhere I have to have the username/password (foo/bar) in plain text somewhere.

I've seen advice for putting it in setting.xml, passing them as args, and having them in the pom file themselves. And I find evidence that ssh connections are supported. But, I can't find actual use of an ssh connection, or an https connection where you don't have the password in plain text somewhere. Any advice?

I got the following to work (if I pass -Dusername= -Dpassword=):

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-scm-plugin</artifactId>
<version>1.9.4</version>
<executions>
    <execution>
        <phase>generate-resources</phase>
        <goals>
            <goal>checkout</goal>
        </goals>
        <id>perform-export</id>
        <configuration>
            <!-- Would be happy to get rid of provider -->
            <providerImplementations> 
                <git>jgit</git>
            </providerImplementations>
            <!-- 
                 Want to use ssh, but cannot 
                 <connectionUrl>scm:git:ssh://github.com/org/repo</connectionUrl>
            -->
            <connectionUrl>scm:git:https://github.com/org/repo</connectionUrl>
            <exportDirectory>target</exportDirectory>
        </configuration>
    </execution>
</executions>
<dependencies>
    <dependency>
        <groupId>org.apache.maven.scm</groupId>
        <artifactId>maven-scm-provider-jgit</artifactId>
        <version>1.9.4</version>
    </dependency>
</dependencies>

Answer 1

You can put the password on your ~/.netrc file:

machine github.com login john.smith password mypass