Release Datahike

SNAPSHOT

To create a snapshot of Datahike and upload it to Clojars the version in project.clj needs to end on -SNAPSHOT. Snapshots can and will be overwritten if a snapshot with the current version is already present. There is no easy way to recognize that there is a new snapshot available on Clojars.

A snapshot in Datahike is created by committing/merging on and pushing to the development branch. Then the snapshot gets validated. This means the version string from project.clj is extracted and it needs to end on -SNAPSHOT and the current branch needs to be development. Only then a snapshot gets released to Clojars.

Release

To create a release of Datahike and upload it to Clojars the version in project.clj needs to be incremented at the respective position. Then you can commit and push the current version to GitHub. CircleCI will then unittest, integrationtest and build this version of Datahike. When this succeeds it releases the new version to Clojars only if the version string does not end on -SNAPSHOT and the current branch is master.

The deploy to Clojars will fail if this version is already present on Clojars. It is not possible to overwrite a release, only snapshots can be overwritten.

CircleCI

On CircleCI there will be run unittests, integrationtests, Datahike will be compiled and released. The official CircleCI jdk-8 image is used and the secret key to release to Clojars needs to be stored as an environment variable on CircleCI. There needs to be a variable LEIN_USERNAME set to your Clojars username and a variable LEIN_PASSWORD set to the password that permits to deploy on clojars.

Git tags

It is nice to have git tags for releases, especially for non-snapshot releases. Therefor you can use following small hook that must be copied into the folder .git/hooks/ as post-commit and a duplicate as post-merge. It creates annotated tags when committing on or merging into master.

Snapshots should not be tagged because it might be necessary to publish multiple snapshots and then you would have to force-push them.

#!/bin/bash

BRANCH=$(git rev-parse --abbrev-ref HEAD)
REMOTE=$(git config --get remote.origin.url)
TAG=$(head -n 1 project.clj | awk '{print $3}' | tr -d \")

# tag current release
if [[ ${BRANCH} == master ]] \
    && [[ ${REMOTE} =~ "replikativ/datahike.git" ]] \
    && [[ ! ${TAG} =~ "-SNAPSHOT" ]]; then
    echo "tagging release ${TAG}"
    git tag -a -m "${TAG}" ${TAG}
fi

For this to work you need to set following option at the appropriate level:

git config push.followTags true

Only then the tag will be pushed without a second push with the --tags option.