Renamed utils/distro.py

The file utils/distro.py is renamed to utils/distro_utils.py
because we need import the distro file to update some calls.

The file is used in IMAP.py, I need change the import.

offlineimap/utils/distro_utils.py

@@ -0,0 +1,97 @@
+# Copyright 2006-2018 Eygene A. Ryabinkin & contributors.
+#
+# Module that supports distribution-specific functions.
+
+import platform
+import os
+
+# Each dictionary value is either string or some iterable.
+#
+# For the former we will just return the value, for an iterable
+# we will walk through the values and will return the first
+# one that corresponds to the existing file.
+__DEF_OS_LOCATIONS = {
+    'freebsd': '/usr/local/share/certs/ca-root-nss.crt',
+    'openbsd': '/etc/ssl/cert.pem',
+    'dragonfly': '/etc/ssl/cert.pem',
+    'darwin': [
+        # MacPorts, port curl-ca-bundle
+        '/opt/local/share/curl/curl-ca-bundle.crt',
+        # homebrew, package openssl
+        '/usr/local/etc/openssl/cert.pem',
+    ],
+    'linux-ubuntu': '/etc/ssl/certs/ca-certificates.crt',
+    'linux-debian': '/etc/ssl/certs/ca-certificates.crt',
+    'linux-gentoo': '/etc/ssl/certs/ca-certificates.crt',
+    'linux-fedora': '/etc/pki/tls/certs/ca-bundle.crt',
+    'linux-redhat': '/etc/pki/tls/certs/ca-bundle.crt',
+    'linux-suse': '/etc/ssl/ca-bundle.pem',
+    'linux-opensuse': '/etc/ssl/ca-bundle.pem',
+    'linux-arch': '/etc/ssl/certs/ca-certificates.crt',
+}
+
+
+def get_os_name():
+    """
+    Finds out OS name.  For non-Linux system it will be just a plain
+    OS name (like FreeBSD), for Linux it will be "linux-<distro>",
+    where <distro> is the name of the distribution, as returned by
+    the first component of platform.linux_distribution.
+
+    Return value will be all-lowercase to avoid confusion about
+    proper name capitalisation.
+
+    """
+    os_name = platform.system().lower()
+
+    if os_name.startswith('linux'):
+        distro_name = platform.linux_distribution()[0]
+        if distro_name:
+            os_name = os_name + "-%s" % distro_name.split()[0].lower()
+        if os.path.exists('/etc/arch-release'):
+            os_name = "linux-arch"
+
+    return os_name
+
+
+def get_os_sslcertfile_searchpath():
+    """Returns search path for CA bundle for the current OS.
+
+    We will return an iterable even if configuration has just
+    a single value: it is easier for our callers to be sure
+    that they can iterate over result.
+
+    Returned value of None means that there is no search path
+    at all.
+    """
+
+    OS = get_os_name()
+
+    l = None
+    if OS in __DEF_OS_LOCATIONS:
+        l = __DEF_OS_LOCATIONS[OS]
+        if not hasattr(l, '__iter__'):
+            l = (l,)
+    return l
+
+
+def get_os_sslcertfile():
+    """
+    Finds out the location for the distribution-specific
+    CA certificate file bundle.
+
+    Returns the location of the file or None if there is
+    no known CA certificate file or all known locations
+    correspond to non-existing filesystem objects.
+    """
+
+    l = get_os_sslcertfile_searchpath()
+    if l is None:
+        return None
+
+    for f in l:
+        assert (type(f) == type(""))
+        if os.path.exists(f) and (os.path.isfile(f) or os.path.islink(f)):
+            return f
+
+    return None