1 files changed, 17 insertions, 0 deletions
diff --git a/yamljsonlib/__init__.py b/yamljsonlib/__init__.py
new file mode 100644
index 0000000..4b12525
--- /dev/null
+++ b/yamljsonlib/__init__.py
@@ -0,0 +1,17 @@
+import os
+import string
+
+
+def template_replace(template):
+    placeholders = map(lambda match: match.group('named', 'braced'),
+                       string.Template.pattern.finditer(template.template))
+    placeholders = set(filter(None, itertools.chain(*placeholders)))
+
+    # Pretend that missing environment variables are set to empty strings.
+    # It would be better to throw an error on missing environment variables,
+    # but this doesn't play nicely with Jenkins. When Jenkins adds parameters to
+    # a triggered job via a properties file, any parameters explicitly set to
+    # the empty string will be unset in the environment of the downstream job.
+    substitutions = {x: os.environ.get(x) or '' for x in placeholders}
+    lava_template = template.safe_substitute(substitutions)
+    return lava_template