bugfix: consistent version string generation

different images have different ways to generate the version string,
leading to bugs and incorrect docker tags, etc:

$ docker run circleci/ruby:2.3 git version
git version 2.1.4
$ docker run circleci/golang:1.9.2 git version
git version 2.11.0

$ docker run circleci/golang:1.9.2 sh -c 'git clone
https://github.com/grafana/metrictank.git && cd metrictank && git
describe --always'
Cloning into 'metrictank'...
0.8.0-62-g4d1b958e

$ docker run circleci/ruby:2.3 sh -c 'cd /tmp && git clone
https://github.com/grafana/metrictank.git && cd metrictank && git
describe --always'
Cloning into 'metrictank'...
0.8.0-62-g4d1b958

With the new approach, we have consistency

scripts/build.sh

@@ -8,7 +8,7 @@ cd ${DIR}/..
 # and https://stackoverflow.com/questions/37531605/how-to-test-if-git-repository-is-shallow
 [ -f $(git rev-parse --git-dir)/shallow ] && git fetch --unshallow
 
-GITVERSION=`git describe --always`
+GITVERSION=`git describe --abbrev=7`
 BUILDDIR=$(pwd)/build
 
 # Make dir

scripts/build_docker.sh

@@ -5,7 +5,7 @@ set -x
 DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 cd ${DIR}
 
-VERSION=`git describe --always`
+VERSION=`git describe --abbrev=7`
 
 # regular image
 rm -rf build/*

scripts/build_packages.sh

@@ -11,7 +11,7 @@ mkdir $BUILD_PKG
 sudo apt-get install rpm # to be able to make rpms
 
 ARCH="$(uname -m)"
-VERSION=$(git describe --long --always)
+VERSION=$(git describe --long --abbrev=7)
 
 
 ## debian wheezy ##

scripts/build_tools.sh

@@ -3,7 +3,7 @@
 DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 cd ${DIR}/..
 
-GITVERSION=`git describe --always`
+GITVERSION=`git describe --abbrev=7`
 BUILDDIR=$(pwd)/build
 
 # Make dir

scripts/push/dockerhub.sh

@@ -3,7 +3,7 @@
 DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 cd ${DIR}/../..
 
-VERSION=`git describe --always`
+VERSION=`git describe --abbrev=7`
 
 echo docker push grafana/metrictank:$VERSION
 docker push grafana/metrictank:$VERSION || exit 2

scripts/push/extra-qa.sh

@@ -4,7 +4,7 @@ log () {
         echo "$(date +'%Y/%m/%d %H:%M:%S') $@"
 }
 
-VERSION=`git describe --always`
+VERSION=`git describe --abbrev=7`
 
 # try returns if did not succeed and is retryable
 # exits in all other cases

scripts/push/gcr.sh

@@ -3,7 +3,7 @@
 DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 cd ${DIR}/../..
 
-VERSION=`git describe --always`
+VERSION=`git describe --abbrev=7`
 
 docker login -u _json_key -p "$GOOGLE_AUTH" https://us.gcr.io
 echo docker push us.gcr.io/metrictank-gcr/metrictank:$VERSION