Add tag task to internal fabfile.

fabfile.py

@@ -2,8 +2,11 @@
 Fabric's own fabfile.
 """
 
+from __future__ import with_statement
+
 from fabric.api import *
 from fabric.contrib import rsync_project
+import fabric.version
 
 
 def test():
@@ -24,5 +27,44 @@ def build_docs():
 
 @hosts('jforcier@fabfile.org')
 def push_docs():
+    """
+    Build and push the Sphinx docs to docs.fabfile.org
+    """
     build_docs()
     rsync_project('/var/www/docs.fabfile/', 'docs/_build/html/', delete=True)
+
+
+def tag():
+    """
+    Tag a new release of the software
+    """
+    with warnings_only():
+        # Get current version string
+        version = fabric.version.get_version()
+        # Does that tag already exist?
+        exists = local("git tag | grep %s" % version)
+        if exists:
+            # If no work has been done since, what's the point?
+            if not local("git log %s.." % version):
+                abort("No work done since last tag!")
+            # If work *has* been done since, we need to make a new tag. To the
+            # editor for version update!
+            raw_input("Work has been done since last tag, version update is needed. Hit Enter to load version info in your editor: ")
+            local("$EDITOR fabric/version.py", capture=False)
+            # Reload version module to get new version
+            reload(fabric.version)
+        # If the tag doesn't exist, the user has already updated version info
+        # and we can just move on.
+        else:
+            print("Version has already been updated, no need to edit...")
+        # Get version strings
+        verbose_version = fabric.version.get_version(verbose=True)
+        short_version = fabric.version.get_version()
+        # Commit the version update
+        local("git add fabric/version.py")
+        local("git commit -m \"Cut %s\"" % verbose_version)
+        # And tag it
+        local("git tag -m \"Fabric %s\" %s" % (
+            verbose_version,
+            short_version
+        ))