Files.Glob

import glob

print 'Named explicitly:'
for name in glob.glob('dir/subdir/*'):
    print '\t', name

print 'Named with wildcard:'
for name in glob.glob('dir/*/*'):
    print '\t', name

import glob
for name in glob.glob('dir/*[0-9].*'):
    print name

apiVersion: v1
kind: ConfigMap
metadata:
  name: conf
data:
{{ (.Files.Glob "foo/*").AsConfig | indent 2 }}
---
apiVersion: v1
kind: Secret
metadata:
  name: very-secret
type: Opaque
data:
{{ (.Files.Glob "bar/*").AsSecrets | indent 2 }}