T353: add the Python library for reading VyOS config to the new package.

2 files changed, 134 insertions, 0 deletions

diff --git a/python/vyos/__init__.py b/python/vyos/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/python/vyos/__init__.py
diff --git a/python/vyos/config.py b/python/vyos/config.py
new file mode 100644
index 000000000..a142d31cb
--- /dev/null
+++ b/python/vyos/config.py
@@ -0,0 +1,134 @@
+# Copyright (c) 2017 VyOS maintainers and contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the Software
+# is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included 
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+# OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+#  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+import subprocess
+import re
+
+
+class VyOSError(Exception):
+    pass
+
+
+class Config(object):
+    def __init__(self):
+        self._cli_shell_api = "/bin/cli-shell-api"
+        self._level = ""
+
+    def _make_command(self, op, path):
+        args = path.split()
+        cmd = [self._cli_shell_api, op] + args
+        return cmd
+
+    def _run(self, cmd):
+        p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+        out = p.stdout.read()
+        p.wait()
+        if p.returncode != 0:
+            raise VyOSError()
+        else:
+            return out
+
+    def set_level(self, path):
+        # Make sure there's always a space between default path (level)
+        # and path supplied as method argument
+        # XXX: for small strings in-place concatenation is not a problem
+        self._level = path + " "
+
+    def get_level(self):
+        return(self._level.strip())
+
+    def exists(self, path):
+        try:
+            self._run(self._make_command('exists', self._level + path))
+            return True
+        except VyOSError:
+            return False
+
+    def session_changed(self):
+        try:
+            self._run(self._make_command('sessionChanged', ''))
+            return True
+        except VyOSError:
+            return False
+
+    def in_session(self):
+        try:
+            self._run(self._make_command('inSession', ''))
+            return True
+        except VyOSError:
+            return False
+
+    def is_multi(self, path):
+        try:
+            self._run(self._make_command('isMulti', self._level + path))
+            return True
+        except VyOSError:
+            return False
+
+    def is_tag(self, path):
+        try:
+            self._run(self._make_command('isTag', self._level + path))
+            return True
+        except VyOSError:
+            return False
+
+    def is_leaf(self, path):
+        try:
+            self._run(self._make_command('isLeaf', self._level + path))
+            return True
+        except VyOSError:
+            return False
+
+    def return_value(self, path):
+        full_path = self._level + path
+        if self.is_multi(path):
+            raise VyOSError("Cannot use return_value on multi node: {0}".format(full_path))
+        elif not self.is_leaf(path):
+            raise VyOSError("Cannot use return_value on non-leaf node: {0}".format(full_path))
+        else:
+            try:
+                out = self._run(self._make_command('returnValue', full_path))
+                return out
+            except VyOSError:
+                raise VyOSError("Path doesn't exist: {0}".format(full_path))
+
+    def return_values(self, path):
+        full_path = self._level + path
+        if not self.is_multi(path):
+            raise VyOSError("Cannot use return_values on non-multi node: {0}".format(full_path))
+        elif not self.is_leaf(path):
+            raise VyOSError("Cannot use return_values on non-leaf node: {0}".format(full_path))
+        else:
+            try:
+                out = self._run(self._make_command('returnValues', full_path))
+                return out
+            except VyOSError:
+                raise VyOSError("Path doesn't exist: {0}".format(full_path))
+
+    def list_nodes(self, path):
+        full_path = self._level + path
+        if self.is_tag(path):
+            try:
+                out = self._run(self._make_command('listNodes', full_path))
+                values = out.split()
+                return list(map(lambda x: re.sub(r'^\'(.*)\'$', r'\1',x), values))
+            except VyOSError:
+                raise VyOSError("Path doesn't exist: {0}".format(full_path)) 
+        else:
+            raise VyOSError("Cannot use list_nodes on a non-tag node: {0}".format(full_path))