gradle build script: increment build number (1.0.0-build23), commit and tag repo

build.sh

#! /bin/sh -e
#
# Build Gradle distribution tarball.  Crank version and tag repo if code has changed since last build.
#
# Abort if uncommitted changes.
# Maintain build number (in build.log file) and increment if code has changed since last build.
# When build number changes, update version in build.gradle and tag repo.
# Version number pattern in build.gradle: version = "1.0.0-build31"
#
# Usage: ./build.sh
#

#
#               Define which file stores the build number log.
#               Log contains three tab-delimited columns: (build_num, build_node_sha1, build_date)
#

BUILDLOG=build.log


#
#               Prefix used on commmit messages; e.g, "buildbot: build new release 1.0.0-build31"
#

BOTNAME=buildbot



#
#               If 'Y' crank build number, tag, etc.
#

NEW_TAG_NEEDED='N'


#
#               Abort if uncommitted changes.  Annoying as hell but the guarantee is nice.
#
#               Ignore .iml files.
#               IntelliJ updates those with the new build num. some time after build.gradle changes.
#

N=$(git status -s|grep -v '\.iml'|wc -l)
[ $N -ne 0 ] && echo "$(basename $0): uncommitted changes or untracked files" && exit 1


#
#               We need a new tag if SHA1 in build log doesn't match HEAD~1.
#
#
#                   (D)      <---- buildbot: add 1.0.0-build37 to build log.
#                    |                * Tag as build/1.0.0-build37
#                    |                * Note: The SHA1 (C) is written to build.log
#                    |
#                   (C)      <---- buildbot: release 1.0.0-build37
#                    |                * build.gradle with new version
#                    |
#                   (B)      <---- commit a new feature
#                    |
#                    |
#                   (A)      <---- buildbot: add 1.0.0-build36 to build log.
#                                     * Tag as build/1.0.0-build36
#
#
#               All this so running ./build.sh after a clone will not create a new tag.
#

if [ ! -f $BUILDLOG ]
then
        NEW_TAG_NEEDED='Y'
        BUILDNUM=0
else
        LASTLINE=$(tail -1 $BUILDLOG)
        BUILDNUM=$(echo "$LASTLINE" | cut -f 1)
        SHA1=$(echo "$LASTLINE" | cut -f 2)
        BUILDDATE=$(echo "$LASTLINE" | cut -f 3)

        X=$(git rev-parse HEAD~1)
        [ "x$X" != "x$SHA1" ] && NEW_TAG_NEEDED='Y'
fi
if [ "x$NEW_TAG_NEEDED" = "xY" ]
then
        #       Crank build number in build.gradle and commit.
        X=$(grep ^version build.gradle)
        OLD=$(echo $X | cut -d = -f 2 |tr -d "'"|tr -d '"'|sed 's/-build.*//'|tr -d ' ')
        BUILDNUM=$((BUILDNUM + 1))
        NEW="$OLD-build$BUILDNUM"
        cat build.gradle | sed "s/^version.*/version = \"$NEW\"/" > t
        mv t build.gradle
        git commit -a -m "$BOTNAME: release $NEW"
        #       Write line to build log and commit.
        printf "%s\t%s\t%s\n" $BUILDNUM $(git rev-parse HEAD) $(date +"%FT%T-%Z") >> build.log
        git add build.log
        git commit -a -m "$BOTNAME: update build.log with $NEW"
        #       Tag builds/X.Y.Z-buildN
        git tag -a -m "$BOTNAME" builds/$NEW
fi



#
#               Build Gradle distribution tarball.
#

./gradlew clean
./gradlew distTar
echo "built tarball $(find ./build/distributions -type f)"