Explore automating maven releases

Right now, releases to maven are done manually, and it would be nice to do this within a script triggered by Travis. This may be a bit tricky because deploying requires signing the bits.

This would be super cool. You are also right, it might be tricky and there's a bit of a lack of information on how to do it. If I remember correctly we should add a <profile> element in settings.xml to tell the gpg maven plugin where to look for the gpg keys:

<properties>
  <gpg.homedir>${TRAVIS_BUILD_DIR}/target/travis</gpg.homedir>
  <gpg.keyname>KEYNAME</gpg.keyname>
  <gpg.passphrase>PASSPHRASE</gpg.passphrase>
</properties>

The pgp keys must then be signed (using either travis file-encrypt or openssl directly) and put in the repository (travis branch), lets call them secring.gpg.enc and pubring.gpg.enc. We must then add the decryption commands to the before_install phase in .travis.yml. If we use travis file-encrypt to encrypt the files the command should also output the code to decrypt them. We must only change the path to the encrypted files (as they will be in /target/travis), something like:

before-install:
- openssl aes-256-cbc -K $encrypted_0a6446eb3ae3_key -iv $encrypted_0a6446eb3ae3_key -in secring.gpg.enc -out local.secring.gpg -d
- openssl aes-256-cbc -K $encrypted_0z6656gf43dc_key -iv $encrypted_0z6656gf43dc_key -in pubring.gpg.enc -out local.pubring.gpg -d

Once this is set up mvn clean deploy should do the job.
We could then trigger mvn clean deploy when tags are pushed (TRAVIS_TAG variable would be set with the tag name).