Add basic debugging capabilities

If debug is set to True, then custodia's own Exception handlers will
print a stack trace to standard output to aid debugging.

Signed-off-by: Simo Sorce <simo@redhat.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/custodia/log.py b/custodia/log.py
new file mode 100644
index 0000000..12a6ba7
--- /dev/null
+++ b/custodia/log.py
@@ -0,0 +1,31 @@
+# Copyright (C) 2015  Custodia Project Contributors - see LICENSE file
+
+import io
+import sys
+import traceback
+import time
+
+
+DEBUG = False
+
+
+def stacktrace():
+    with io.BytesIO() as f:
+        _, _, tb = sys.exc_info()
+        traceback.print_tb(tb, None, file=f)
+        del tb
+        return f.getvalue()
+
+
+def error(msg, head=None):
+    if head is not None:
+        t = time.gmtime(time.time())
+        head = '%04d/%02d/%02d %02d:%02d:%02d' % (
+            t[0], t[1], t[2], t[3], t[4], t[5])
+    sys.stderr.write('[%s] %s\n' % (head, msg))
+
+
+def debug(msg):
+    if DEBUG:
+        error(msg, 'DEBUG')
+        sys.stderr.write(stacktrace())