enhance version management

When making an official release of scapy, one must:

* Modify the hardcoded version in setup.py and scapy/config.py
* Create a commit with this change
* Create a git tag with the same version
* Run ./setup.py sdist register upload
* Modify the hardcoded version in setup.py and scapy/config.py again to
  append '-dev'.
* Create another commit with the modified version.
* Push the 3 commits and the tag.

Not only this is tedious but it is also error prone.

Add utility functions in scapy/__init__.py to determine current version.

If git is available (thus running from a git clone), use "git describe" to
get the current version. Write the version for future reference to a
text file (scapy/VERSION).

If git is not available (running from an installed scapy package) read
the version from the scapy/VERSION file.

This changes the release process as follows:

* Create a git tag on the commit where you want to release
* Run ./setup.py sdist register upload
* Push the tag

This allows to have a single place where the version is managed: git.

Note: change the development versions to X.Y.Z.devN where N is the
number of commits after the last tag. This complies to PEP 440
https://www.python.org/dev/peps/pep-0440/#developmental-releases



Signed-off-by: Robin Jarry <robin.jarry@6wind.com>

.gitignore

 *.pyc
 *.pyo
+dist/
+build/
+MANIFEST
+*.egg-info/
+scapy/VERSION

MANIFEST.in

@@ -3,3 +3,4 @@ include run_scapy
 recursive-include bin *
 recursive-include doc *
 recursive-include test *
+include scapy/VERSION

README

+README.md
\ No newline at end of file

scapy/__init__.py

@@ -3,6 +3,8 @@
 ## Copyright (C) Philippe Biondi <phil@secdev.org>
 ## This program is published under a GPLv2 license
 
+from __future__ import with_statement
+
 """
 Scapy: create, send, sniff, dissect and manipulate network packets.
 
@@ -10,6 +12,71 @@ Usable either from an interactive console or as a Python library.
 http://www.secdev.org/projects/scapy
 """
 
+import os
+import re
+import subprocess
+
+
+_SCAPY_PKG_DIR = os.path.dirname(__file__)
+
+def _version_from_git_describe():
+    """
+    Read the version from ``git describe``. It returns the latest tag with an
+    optional suffix if the current directory is not exactly on the tag.
+
+    Example::
+
+        $ git describe --always
+        v2.3.2-346-g164a52c075c8
+
+    The tag prefix (``v``) and the git commit sha1 (``-g164a52c075c8``) are
+    removed if present.
+
+    If the current directory is not exactly on the tag, a ``.devN`` suffix is
+    appended where N is the number of commits made after the last tag.
+
+    Example::
+
+        >>> _version_from_git_describe()
+        '2.3.2.dev346'
+    """
+    p = subprocess.Popen(['git', 'describe', '--always'], cwd=_SCAPY_PKG_DIR,
+                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+    out, err = p.communicate()
+
+    if p.returncode == 0:
+        tag = out.strip()
+        match = re.match(r'^v?(.+?)-(\d+)-g[a-f0-9]+$', tag)
+        if match:
+            # remove the 'v' prefix and add a '.devN' suffix
+            return '%s.dev%s' % (match.group(1), match.group(2))
+        else:
+            # just remove the 'v' prefix
+            return re.sub(r'^v', '', tag)
+    else:
+        raise subprocess.CalledProcessError(p.returncode, err)
+
+def _version():
+    version_file = os.path.join(_SCAPY_PKG_DIR, 'VERSION')
+    try:
+        tag = _version_from_git_describe()
+        # successfully read the tag from git, write it in VERSION for
+        # installation and/or archive generation.
+        with open(version_file, 'w') as f:
+            f.write(tag)
+        return tag
+    except:
+        # failed to read the tag from git, try to read it from a VERSION file
+        try:
+            with open(version_file, 'r') as f:
+                tag = f.read()
+            return tag
+        except:
+            return 'unknown.version'
+
+VERSION = _version()
+
 if __name__ == "__main__":
     from scapy.main import interact
     interact()

scapy/config.py

@@ -9,6 +9,7 @@ Implementation for of the configuration object.
 
 import os,time,socket,sys
 
+from scapy import VERSION
 from scapy.data import *
 from scapy import base_classes
 from scapy import themes
@@ -319,7 +320,7 @@ noenum    : holds list of enum fields for which conversion to string should NOT
 AS_resolver: choose the AS resolver class to use
 extensions_paths: path or list of paths where extensions are to be looked for
 """
-    version = "2.3.2-dev"
+    version = VERSION
     session = ""
     interactive = False
     interactive_shell = ""

setup.cfg

 [metadata]
 description-file = README.md
+
+[sdist]
+formats=gztar
+owner=root
+group=root

setup.py

@@ -47,7 +47,7 @@ if os.name == "nt":
 
 setup(
     name='scapy',
-    version='2.3.2-dev',
+    version=__import__('scapy').VERSION,
     packages=[
         'scapy',
         'scapy/arch',
@@ -62,6 +62,9 @@ setup(
     ],
     scripts=SCRIPTS,
     data_files=[('share/man/man1', ["doc/scapy.1.gz"])],
+    package_data={
+        'scapy': ['VERSION'],
+    },
 
     # Metadata
     author='Philippe BIONDI',