Ensure that reference/projects.yaml is sorted

Add to docs tox target a check that reference/projects.yaml is sorted
alphabetically and display entries that are not sorted.

Change-Id: Ia86b50622e2fac5fdf791d57c884d2d8a9ec6c44

tools/check_projects_yaml_alphabetized.sh

@@ -0,0 +1,24 @@
+#!/bin/bash -xe
+
+# Checks that reference/projects.yaml alphabetized and prints list of
+# projects that should be sorted.
+
+export TMPDIR=`/bin/mktemp -d`
+trap "rm -rf $TMPDIR" EXIT
+
+pushd $TMPDIR
+PROJECTS_LIST=$OLDPWD/reference/projects.yaml
+
+grep '^[a-zA-Z0-9]' $PROJECTS_LIST > projects_list
+
+LC_ALL=C sort --ignore-case projects_list -o projects_list.sorted
+
+if ! diff projects_list projects_list.sorted > projects_list.diff; then
+    echo "The following projects should be alphabetized: "
+    cat projects_list.diff | grep -e '> '
+    exit 1
+else
+    echo "Projects alphabetized."
+fi
+
+popd

tox.ini

@@ -14,3 +14,4 @@ commands = {posargs}
 
 [testenv:docs]
 commands = python setup.py build_sphinx
+            {toxinidir}/tools/check_projects_yaml_alphabetized.sh