Make sure we have tripleo-heat-templates at tuskar startup

If we don't then tuskar startup cannot proceed, with an appropriate
error message. A conf var is added: CONF.tht_local_dir that points
to the local path in which the templates exist. A relevant note
was added to INSTALL.rst

Implements: blueprint retrieve-ooo-templates
Change-Id: I7cb1151f35aef00f416a7d06be6229553fbe9d22

.gitignore

@@ -31,3 +31,4 @@ AUTHORS
 ChangeLog
 etc/tuskar/tuskar.conf
 *.sqlite
+tuskar/api/templates/tripleo-heat-templates/

INSTALL.rst

@@ -56,6 +56,17 @@ Note: replace these values with credentials for our undercloud OpenStack. If
 you're using `Devstack <http://devstack.org/>`_, the username and password are
 printed out when `stack.sh` finishes its job.
 
+You will need a local checkout of the tripleo-heat-templates. A
+configuration entry is defined for this purpose: tht_local_dir should point
+to your local copy of the tripleo-heat-templates.
+
+    tht_local_dir = "/etc/tuskar/tripleo-heat-templates/"
+
+At tuskar startup, if the directory specified by tht_local_dir in your
+tuskar.conf doesn't exist startup will fail. You can clone the templates:
+
+    (sudo) git clone https://github.com/openstack/tripleo-heat-templates.git /etc/tuskar/tripleo-heat-templates/
+
 We need to initialise the database schema::
 
     # activate the virtualenv

etc/tuskar/tuskar.conf.sample

@@ -27,6 +27,7 @@
 # The port for the Tuskar API server (integer value)
 #tuskar_api_port=8585
 
+#tht_local_dir="/etc/tuskar/tripleo-heat-templates/"
 
 #
 # Options defined in tuskar.api.app

tuskar/api/__init__.py

@@ -31,6 +31,10 @@ API_SERVICE_OPTS = [
             default=8585,
             help='The port for the Tuskar API server',
             ),
+        cfg.StrOpt('tht_local_dir',
+            default='/etc/tuskar/tripleo-heat-templates/',
+            help='Local path holding tripleo-heat-templates',
+            )
         ]
 
 CONF = cfg.CONF

tuskar/cmd/api.py

@@ -21,6 +21,7 @@
 """The Tuskar Service API."""
 
 import logging
+import os
 import sys
 
 from oslo.config import cfg
@@ -48,6 +49,17 @@ def main():
     LOG.info("Serving on http://%s:%s" % (host, port))
     LOG.info("Configuration:")
     CONF.log_opt_values(LOG, logging.INFO)
+    # make sure we have tripleo-heat-templates:
+    heat_template_path = CONF.tht_local_dir
+    try:
+        templates = os.listdir(heat_template_path)
+    except OSError:
+        LOG.info("Can't find local tripleo-heat-template files at %s"
+                  % (heat_template_path))
+        LOG.info("Cannot proceed - missing tripleo heat templates " +
+                  "See INSTALL documentation for more info")
+        raise
+    LOG.info("Using tripleo-heat-templates at %s" % (heat_template_path))
 
     try:
         wsgi.serve_forever()