Magic releasey thing

#!/bin/bash
set -e
echo "Started running at: $(date '+%Y-%m-%d %H:%M:%S %:z')"

if [[ ! `bundle show puppet | grep "puppet-5"` ]]; then
    export PUPPET_VERSION=5.3.3
fi

source ~/.github

## Use rbenv to install gems
export PATH=${HOME}/rbenv/shims:${HOME}/rbenv/bin:/usr/local/bin:/usr/local/sbin:$PATH
export RBENV_ROOT=${HOME}/rbenv
export RBENV_SHELL=bash

## Use rbenv to install gems
rbenv versions
rbenv local 2.3.1

if [ -n "${PUPPET_VERSION}" ]; then
    bundle update puppet
    bundle show puppet
fi

bundle install --binstubs --path ~/.gem

## Purge any librarian config file that might have been created:
if [ -f spec/fixtures/.librarian/puppet/config ]; then
    rm -fv spec/fixtures/.librarian/puppet/config
fi

# Here we only attempt to cut the release if a release file is present
if [ -f *.release ] && [ $(ls -1 *.release | wc -l) -eq 1 ]; then
    echo "INFO: Release file found - Cutting release"

    #first check that we have exactly one *.release file
    if [ -f *.release ] && [ $(ls -1 *.release | wc -l) -gt 1 ];then
      echo "ERROR: There needs to be exactly 1 *.release file present";exit 1
    else
      #set release filename, and extract the required version increment
      relfile=$(ls -1 *.release);incr=$(echo $relfile | awk -F '.' '{print $(NF-1)}')
    fi

    # Check that tests had passed on pre-merge commit
    source ~/.github
    gitrepo=$(echo $(git config --get remote.origin.url) | sed 's@.*/@@' | sed 's/.git//')
    prcommit=$(git show-ref -s $(git log --merges -n 1 --pretty=format:"%s" | awk -F 'ITV/' '{print $2}'))
    tests=$(${HOME}/scripts/git/get_pullrequest_status.rb -a ${oauth} -r ${gitrepo} -c 'Running puppet test jobs' -h ${prcommit} 2> /dev/null)
    if [ ! -z $tests ] && [ $tests == 'success' ]; then
        echo "OK: Tests are green, proceeding"
    else
        echo "ERROR: Tests were not green on merged PR - not releasing"; exit 1
    fi

    #allow either cAsE for increment
    lincr=$(echo $incr | tr '[A-Z]' '[a-z]')
    #extract current version from itv.yaml
    cver=$(cat itv.yaml | awk -F "'" '/^[[:blank:]]*version/ {print $2; exit}')
    if [[ ! "$cver" =~ ^[0-9]+(\.[0-9]+)+(\.[0-9]+)?$ ]];then
        echo "ERROR: unable to extract current version";exit 1
    fi
    #handle version increment logic here
    v=( ${cver//./ } )
    set +e
    if [ $lincr == "major" ];then ((v[0]++)); v[1]=0;  v[2]=0
    elif [ $lincr == "minor" ];then ((v[1]++)); v[2]=0
    elif [ $lincr == "patch" ];then ((v[2]++))
    else
        echo "ERROR: incorrect version increment '$incr'"
        echo "       format of release filename must be: '\$branchname.(major|minor|patch).release'";exit 1
    fi
    set -e
    #iterate version
    nver=( ${v[0]}.${v[1]}.${v[2]} )
    echo "Release has $lincr increment. Old version: $cver. New version $nver"
    #apply version change to itv.yaml (via stage)
    cat itv.yaml | sed s/^"version: '$cver'"/"version: '$nver'"/ > tmp.yaml
    #verify that only 1 version has changed
    if [ $(diff itv.yaml tmp.yaml | grep -c '>\|<') -ne 2 ];then
        echo "ERROR: error updating itv.yaml version";exit 1
    else
        mv tmp.yaml itv.yaml
    fi

    ## Update metadata.json
    bundle exec rake update_module

    # Prepare new Changelog entry (using commit time of merge) and release description file
    echo "v$nver" > /var/tmp/$relfile
    echo "" >> /var/tmp/$relfile
    echo "## $(git log -1 --format=%cd --date=short) - Release $nver" | tee -a tmp.md /var/tmp/$relfile
    printf '\n' >> tmp.md; cat $relfile >> tmp.md
    printf '\n' >> tmp.md; cat CHANGELOG.md >> tmp.md
    mv tmp.md CHANGELOG.md
    cat $relfile >> /var/tmp/$relfile;rm -f $relfile
    #add link to PR on release notes
    echo "" >> /var/tmp/$relfile
    commithash=$(git log --pretty=tformat:"%H" -1);
    if [ -z "$commithash" ]; then echo "ERROR: Unable to get commit hash"; exit 1; fi
    echo "- [Link to Pull Request Changes](https://github.com/ITV/${gitrepo}/commit/${commithash})" >> /var/tmp/$relfile

    # add, commit and push changes
    echo "Pushing version changes to remote (and removing .release file)"
    echo "git add CHANGELOG.md itv.yaml metadata.json $relfile; git commit -m \"Preparing changelog for release $nver\"; git push origin master"
    git add --all CHANGELOG.md itv.yaml metadata.json $relfile; git commit -m "Preparing changelog for release $nver"; git push origin HEAD:master
    if [ $? != 0 ]; then
        echo "ERROR: Unable to push changes to remote";exit 1
    fi
    # use jenkins' commit hash for release tag
    jenkinscommithash=$(git log -1 | awk '/^commit / {print $2}')
    if [ -z "$jenkinscommithash" ]; then echo "ERROR: Unable to get commit hash"; exit 1; fi

    # finally, create the release
    echo "Creating github release with the following tag/description"
    echo "tag: v$nver"
    echo "description:"
    cat /var/tmp/$relfile
    echo "hub release create -F /var/tmp/$relfile v$nver -t $jenkinscommithash"
    /opt/cp-tools/bin/hub release create -F /var/tmp/$relfile v$nver -t $jenkinscommithash
    if [ $? != 0 ]; then
        echo "ERROR: Unable to create github release";exit 1
    fi

    # clean up temp release file
    rm -f /var/tmp/$relfile

else
    echo "WARN: No release file present - Running Spec tests and danger only"

    ## Run test suite, ensuring we honour the Puppetfile.lock
    LIBRARIAN_lock=true bundle exec rake test

    if [ -f "Dangerfile" ]; then
        if [ -n "ghprbGhRepository" ]; then
            bundle exec danger
        fi
    fi
fi

echo "Finished running at: $(date '+%Y-%m-%d %H:%M:%S %:z')"

Definitely needs improvement... and ridding of clever or magic...