1 files changed, 83 insertions, 0 deletions
diff --git a/src/leap/mx/runner.py b/src/leap/mx/runner.py
new file mode 100644
index 0000000..daf956e
--- /dev/null
+++ b/src/leap/mx/runner.py
@@ -0,0 +1,83 @@
+#-*- coding: utf-8 -*-
+"""
+runner
+------
+A module containing application and daemon process utilities.
+
+@author Isis Agora Lovecruft <isis@leap.se>, 0x2cdb8b35
+@version 0.0.1
+
+"""
+
+from os import path as ospath
+
+import re
+
+
+class CheckRequirements(ImportError):
+    """
+    Raised when we're missing something from requirements.pip.
+    """
+    def __init__(self, package_name, pipfile, message=None):
+        """
+        Display an error message with instructions for obtaining missing
+        dependencies.
+
+        @param message: A string describing the error.
+        @param missing: A string indicating which dependency is missing.
+        @param pipfile: The path and filename of the pip requirements file,
+            relative to the top-level repository directory.
+        """
+        if message:
+            self.message = message
+            return self
+
+        self.package_name = package_name
+        self.pipfile      = pipfile
+        self.dependencies = self.__read_pip_requirements__()
+        self.missing      = []
+
+        for package, version in self.dependencies:
+            pkg = package.lower() if package == "Twisted" else package
+            try:
+                __import__(pkg)
+            except ImportError:
+                self.missing.append(package)
+
+        if len(self.missing) > 0:
+            self.message = self.package_name + " requires "
+        elif len(self.missing) <= 0:
+            return None
+
+        if len(self.missing) >= 1:
+            for missed in self.missing[:-1]:
+                self.message += missed + ", "
+            self.message += "and "
+
+        if len(self.missing) == 1:
+            self.message += self.missing[0] + "."
+            self.message += "\nPlease see %s for ".format(self.pipfile)
+            self.message += "instruction on installing dependencies."
+            raise self(self.message)
+
+    def __read_pip_requirements__(self, file=None):
+        """
+        Check the pip requirements file to determine our dependencies.
+
+        @param file: The full path of the pip requirements.txt file.
+        @returns: A list of tuple(package_name, package_version).
+        """
+        if not file:
+            file = self.pipfile
+
+        requirement  = re.compile('[^0-9=><]+')
+        dependencies = []
+
+        with open(file) as pipfile:
+            for line in pipfile.readlines():
+                shortened       = line.strip()
+                matched         = requirement.match(shortened)
+                package_name    = matched.group()
+                package_version = shortened.split(package_name, 1)[1]
+                dependencies.append((package_name, package_version))
+        return dependencies