Releasing Apache Twill

This guide describes the steps to building and releasing Apache Twill artifacts.

Environment Setup

Generate GPG keypair

Generate a GPG keypair for signing artifacts, if you don’t already have one. See GPG key generation on how to do so. Make sure the public key is published to a public key server, as well as added to the Twill KEYS file.

Generate an encrypted password for maven deploy

Generate an encrypted password for your apache id using maven (see Maven Encryption Guide) and add the following section to your Maven settings (~/.m2/settings.xml):


Release procedure

Create a new release branch from master

git checkout -b branch-${RELEASE_VERSION}

The ${RELEASE_VERSION} is something such as 0.5.0.

Update the version to the non-snapshot version

mvn versions:set -DgenerateBackupPoms=false -DnewVersion=${RELEASE_VERSION}
git commit . -m "Prepare for releasing ${RELEASE_VERSION}"

Create a new signed tag for the release

git tag -s v${RELEASE_VERSION} -m 'Releasing ${RELEASE_VERSION}'

Push both the new branch and the tag

git push origin branch-${RELEASE_VERSION}
git push origin v${RELEASE_VERSION}

Start gpg-agent

  • Run gpg-agent to save the number of times that you have to type in your GPG password when building release artifacts.
  • You can run gpg -ab to confirm the the agent is running and it has cached your password correctly.
  • Alternatively, if you don’t want to run GPG agent, you can specify your GPG password through -Dgpg.passphrase=[GPG_PASSWORD] when running Maven.

Build the source tarball and publish artifacts to the staging repo

mvn clean prepare-package -DskipTests -Dremoteresources.skip=true -P hadoop-2.0 &&
mvn prepare-package -DskipTests -Dremoteresources.skip=true -P hadoop-2.3 &&
mvn deploy -DskipTests -Dremoteresources.skip=true -P hadoop-2.3 -P apache-release

The source tarball can be found in target/apache-twill-${RELEASE_VERSION}-source-release.tar.gz after the above command has successfully completed.

Compute the MD5 and SHA512 of the source release tarball

cd target
md5 -q apache-twill-${RELEASE_VERSION}-source-release.tar.gz > apache-twill-${RELEASE_VERSION}-source-release.tar.gz.md5
shasum -a 512 apache-twill-${RELEASE_VERSION}-source-release.tar.gz > apache-twill-${RELEASE_VERSION}-source-release.tar.gz.sha512

Prepare release artifacts

  1. Checkin the source release tarball, together with the signature, md5 and sha512 files to${RELEASE_VERSION}-rc1/src/
  2. Create a CHANGES.txt file to describe the changes in the release and checkin the file to${RELEASE_VERSION}-rc1/CHANGES.txt
  3. Go to and close the staging repository.

Increase the version in master

git checkout master
git merge --no-ff branch-${RELEASE_VERSION}
mvn versions:set -DgenerateBackupPoms=false -DnewVersion=${NEXT_RELEASE_VERSION}-SNAPSHOT
git commit . -m "Bump version to ${NEXT_RELEASE_VERSION}-SNAPSHOT"
git push origin master

Vote for release in dev mailing list

Create a vote in the dev@twill mailing list and wait for 72 hours for the vote result. Here is a template for the email:

Subject: [VOTE] Release of Apache Twill-${RELEASE_VERSION} [rc1]

Hi all,

This is a call for a vote on releasing Apache Twill ${RELEASE_VERSION}, release candidate 1. This
is the [Nth] release of Twill.

The source tarball, including signatures, digests, etc. can be found at:${RELEASE_VERSION}-rc1/src

The tag to be voted upon is v${RELEASE_VERSION}:;a=shortlog;h=refs/tags/v${RELEASE_VERSION}

The release hash is [REF]:;a=commit;h=[REF]

The Nexus Staging URL:[STAGE_ID]

Release artifacts are signed with the following key:

KEYS file available:

For information about the contents of this release, see:${RELEASE_VERSION}-rc1/CHANGES.txt

Please vote on releasing this package as Apache Twill ${RELEASE_VERSION}

The vote will be open for 72 hours.

[ ] +1 Release this package as Apache Twill ${RELEASE_VERSION}
[ ] +0 no opinion
[ ] -1 Do not release this package because ...


Consolidate vote result

After the vote is up for 72 hours and having at least three +1 binding votes and no -1 votes, close the vote by replying to the voting thread. Here is a template for the reply email:

Subject: [RESULT][VOTE] Release of Apache Twill-${RELEASE_VERSION} [rc1]

Hi all,

After being opened for over 72 hours, the vote for releasing Apache Twill
${RELEASE_VERSION} passed with n binding +1s and no 0 or -1.

Binding +1s:

Non-binding +1s

This release vote has passed. Thanks everyone for voting.


Finalize the release

  1. Copy the release artifacts and CHANGES.txt from the dev to release directory at${RELEASE_VERSION}
  2. Go to and release the staging repository.
  3. Send out an announcement of the release to dev@twill and announce@ mailing lists.

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