Move debian package building into its own package. 

As more package options are added, it's confusing that the
debian package is generated in scripts/package/BUILD, but
scripts/package/debian/ contains the related files (and isn't
itself a Bazel package). This change makes the file locations
more predictable, and also makes it easier to see what
is happening in scripts/packages.

--
Change-Id: Id8c445fc164a1a4aa09c52559a5143578cfdea88
Reviewed-on: https://cr.bazel.build/8510
PiperOrigin-RevId: 146003934
MOS_MIGRATED_REVID=146003934
diff --git a/scripts/packages/debian/convert_changelog.py b/scripts/packages/debian/convert_changelog.py
new file mode 100644
index 0000000..a4fb78e
--- /dev/null
+++ b/scripts/packages/debian/convert_changelog.py
@@ -0,0 +1,89 @@
+# pylint: disable=g-bad-file-header
+# Copyright 2015 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""This tool convert Bazel's changelog file to debian changelog format."""
+
+from datetime import datetime
+import sys
+
+
+def main(input_file, changelog_file, output_file):
+  changelog_out = open(output_file, "w")
+  changelog = None
+  version = None
+  with open(input_file, "r") as status_file:
+    for line in status_file:
+      line = line.strip()
+
+      if line.startswith("RELEASE_NOTES"):
+        changelog = line[14:].strip().replace("\f", "\n")
+      elif line.startswith("RELEASE_NAME"):
+        version = line[13:].strip()
+
+  if changelog:
+    time_stamp = None
+    lines = changelog.split("\n")
+    header = lines[0]
+    lines = lines[4:]  # Skip the header
+    if lines[0] == "Cherry picks:":
+      # Skip cherry picks list
+      i = 1
+      while lines[i].strip():
+        i += 1
+      lines = lines[i + 1:]
+
+    # Process header
+    parts = header.split(" ")
+    time_stamp = datetime.strptime(
+        parts[2], "(%Y-%m-%d)").strftime("%a, %d %b %Y %H:%M:%S +0100")
+    changelog_out.write("bazel (%s) unstable; urgency=low\n" % version)
+
+    for line in lines:
+      if line.startswith("+") or line.startswith("-"):
+        parts = line.split(" ")
+        line = "*" + line[1:]
+        changelog_out.write("  %s\n" % line)
+
+      elif line.endswith(":"):
+        changelog_out.write("\n  %s\n" % line)
+
+      elif line:
+        changelog_out.write("    %s\n" % line)
+
+    if time_stamp:
+      changelog_out.write(
+          "\n -- The Bazel Authors <bazel-dev@googlegroups.com>  %s\n\n" %
+          time_stamp)
+  else:
+    # Develeopment version, generate a changelog from the change log file
+    with open(changelog_file, "r") as changelog_in:
+      for line in changelog_in:
+        line = line.strip()
+        if line.startswith("## Release"):
+          parts = line.split(" ")
+          version = parts[2]
+          time_stamp = datetime.strptime(
+              parts[3], "(%Y-%m-%d)").strftime("%a, %d %b %Y %H:%M:%S +0100")
+          changelog_out.write("bazel (%s~HEAD) unstable; urgency=low\n" %
+                              version)
+          changelog_out.write("    Development version\n")
+          changelog_out.write(
+              "\n -- The Bazel Authors <bazel-dev@googlegroups.com>  %s\n\n" %
+              time_stamp)
+          # Stop after parsing latest release
+          return
+
+
+if __name__ == "__main__":
+  main(sys.argv[1], sys.argv[2], sys.argv[3])