build: handle template syntax errors better

Before:

(venv-for-kolla) 15:35 (s) hrw@puchatek:kolla$ ./tools/build.py --template-only
INFO:kolla.common.utils:Found the docker image folder at /home/hrw/devel/linaro/kolla/docker
Traceback (most recent call last):

[.. here goes 100 lines of Jinja2 traceback ..]

jinja2.exceptions.TemplateSyntaxError: unexpected '}', expected ']'

After:

(venv-for-kolla) 15:44 (s) hrw@puchatek:kolla$ ./tools/build.py --template-only
INFO:kolla.common.utils:Found the docker image folder at /home/hrw/devel/linaro/kolla/docker
ERROR:kolla.common.utils:Syntax error in template: ironic-inspector/Dockerfile.j2
ERROR:kolla.common.utils:unexpected '}', expected ']'
INFO:kolla.common.utils:Dockerfiles are generated in /tmp/kolla-2019-03-13_15-44-28_0ovk4xu_/docker

Change-Id: Iaa899f0b81f6698aa86b15977c39af3269d31e9a

1 files changed, 13 insertions, 7 deletions

diff --git a/kolla/cmd/build.py b/kolla/cmd/build.py
index 25facd19d..e912a6d12 100755
--- a/kolla/cmd/build.py
+++ b/kolla/cmd/build.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import jinja2
 import os
 import sys
 
@@ -28,13 +29,18 @@ from kolla.image import build  # noqa
 
 
 def main():
-    statuses = build.run_build()
-    if statuses:
-        (bad_results, good_results, unmatched_results,
-         skipped_results) = statuses
-        if bad_results:
-            return 1
-    return 0
+    try:
+        statuses = build.run_build()
+        if statuses:
+            (bad_results, good_results, unmatched_results,
+             skipped_results) = statuses
+            if bad_results:
+                return 1
+        return 0
+    except jinja2.exceptions.TemplateSyntaxError as e:
+        build.LOG.error("Syntax error in template: %s" % e.name)
+        build.LOG.error(e.message)
+        return 1
 
 
 if __name__ == '__main__':