feat: fetch held deb packages' version (#618)

* propagate return value from @Deploy decorator

e.g. this allows writing code like:

  @Deploy
  def ripgrep(**kwargs):
      return apt.packages('ripgrep', **kwargs)

  res = ripgrep()
  if res.changed:
       # do something else

* feat: support held deb packages

It would be useful to fetch the version number of held deb packages to have scripts that manually unhold them to be able to upgrade if the need be.

Co-authored-by: Dima Gerasimov <karlicoss@gmail.com>

Author: 2 people

pyinfra/facts/deb.py

@@ -25,7 +25,7 @@ class DebPackages(FactBase):
 
     default = dict
 
-    regex = r'^ii\s+([a-zA-Z0-9\+\-\.]+):?[a-zA-Z0-9]*\s+([a-zA-Z0-9:~\.\-\+]+).+$'
+    regex = r'^[i|h]i\s+([a-zA-Z0-9\+\-\.]+):?[a-zA-Z0-9]*\s+([a-zA-Z0-9:~\.\-\+]+).+$'
 
     def process(self, output):
         return parse_packages(self.regex, output)

tests/facts/deb.DebPackages/hold_packages.json

@@ -0,0 +1,13 @@
+{
+    "command": "dpkg -l",
+    "output": [
+        "hi  matrix-synapse-py3 1.37.1+bionic1 amd64 Open federated Instant Messaging and VoIP server",
+        "hi  miniflux 2.0.31 amd64 Minimalist Feed Reader",
+        "hi  wireguard 1.0.20200513-1~18.04.2 all fast, modern, secure kernel VPN tunnel (metapackage)"
+    ],
+    "fact": {
+        "matrix-synapse-py3": ["1.37.1+bionic1"],
+        "miniflux": ["2.0.31"],
+        "wireguard": ["1.0.20200513-1~18.04.2"]
+    }
+}