Allow list_unreleased_changes to format results at json & yaml formats

Rewrite list_unreleased_changes as python format and add new features.

By default it will behave as the previous version of this command (the
shell script).

Few new feature have been added in these changes to allow us to more
easily handle outputs in scripts.

Features added:
- allow user to retrieve results in json format
- allow user to retrieve results in yaml format
- allow user to ignore project not yet released

The shell script entry-point (tools) is still there but it will call
the python command in a venv instead of directly implement features.

Also the python version allow us to more surround this tools with unit tests.

Change-Id: Iaf86ecb1589c40102acb621b23ea12d71ed453bb

tools/list_unreleased_changes.sh

@@ -17,46 +17,20 @@
 if [[ $# -lt 2 ]]; then
     echo "Usage: $(basename $0) <branch> <repo> [<repo>...]"
     echo "repo should be e.g. openstack/glance"
+    echo
+    echo "Example: $(basename $0) victoria oslo.rootwrap"
+    echo "Example: $(basename $0) independent reno bugfix"
+    echo
+    echo "For further details about how to use the command:"
+    echo "tox -e venv -- list-unreleased-changes --help"
     exit 1
 fi
 
-branch="$1"
-shift
-repos="$@"
-
-TOOLSDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-BASEDIR=$(dirname $TOOLSDIR)
-source $TOOLSDIR/functions
-
-# Make sure no pager is configured so the output is not blocked
-export PAGER=
-
-setup_temp_space 'list-unreleased'
-
-function list_changes {
-    title "Unreleased changes in $repo ($branch)"
-    clone_repo $repo $branch
-    if [[ $? -ne 0 ]]; then
-        return 1
+if [[ -z "$VIRTUAL_ENV" ]]; then
+    if [[ ! -d .tox/venv ]]; then
+        tox -e venv --notest
     fi
-    cd $repo
-    prev_tag=$(get_last_tag)
-    if [ -z "$prev_tag" ]; then
-        echo "$repo has not yet been released"
-    else
-        echo
-        end_sha=$(git log -n 1 --pretty=tformat:%h)
-        echo "Changes between $prev_tag and $end_sha"
-        echo
-        git log --no-color --no-merges --format='%h %ci %s' \
-            --graph ${prev_tag}..${end_sha}
-        echo
-    fi
-}
+    source ./.tox/venv/bin/activate
+fi
 
-# Show the unreleased changes for each repository.
-for repo in $repos; do
-    cd $MYTMPDIR
-    echo
-    list_changes "$repo"
-done
+list-unreleased-changes $@