E2E Integration Test for NETCONF/TLS Configuration in SDNC.

[integration/csit.git] / scripts / sdnc / netconf-pnp-simulator / netconf-config / subscriber.py

diff --git a/scripts/sdnc/netconf-pnp-simulator/netconf-config/subscriber.py b/scripts/sdnc/netconf-pnp-simulator/netconf-config/subscriber.py
new file mode 100755 (executable)
index 0000000..6127296
--- /dev/null
+++ b/scripts/sdnc/netconf-pnp-simulator/netconf-config/subscriber.py
@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+
+__author__ = "Mislav Novakovic <mislav.novakovic@sartura.hr>"
+__copyright__ = "Copyright 2018, Deutsche Telekom AG"
+__license__ = "Apache 2.0"
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This sample application demonstrates use of Python programming language bindings for sysrepo library.
+# Original c application was rewritten in Python to show similarities and differences
+# between the two.
+#
+# Most notable difference is in the very different nature of languages, c is weakly statically typed language
+# while Python is strongly dynamically typed. Python code is much easier to read and logic easier to comprehend
+# for smaller scripts. Memory safety is not an issue but lower performance can be expected.
+#
+# The original c implementation is also available in the source, so one can refer to it to evaluate trade-offs.
+
+import sysrepo as sr
+import sys
+
+
+# Helper function for printing changes given operation, old and new value.
+def print_change(op, old_val, new_val):
+    if op == sr.SR_OP_CREATED:
+        print(f"CREATED: {new_val.to_string()}")
+    elif op == sr.SR_OP_DELETED:
+        print(f"DELETED: {old_val.to_string()}")
+    elif op == sr.SR_OP_MODIFIED:
+        print(f"MODIFIED: {old_val.to_string()} to {new_val.to_string()}")
+    elif op == sr.SR_OP_MOVED:
+        print(f"MOVED: {new_val.xpath()} after {old_val.xpath()}")
+
+
+# Helper function for printing events.
+def ev_to_str(ev):
+    if ev == sr.SR_EV_VERIFY:
+        return "verify"
+    elif ev == sr.SR_EV_APPLY:
+        return "apply"
+    elif ev == sr.SR_EV_ABORT:
+        return "abort"
+    else:
+        return "unknown"
+
+
+# Function to print current configuration state.
+# It does so by loading all the items of a session and printing them out.
+def print_current_config(session, module_name):
+    select_xpath = f"/{module_name}:*//*"
+
+    values = session.get_items(select_xpath)
+
+    if values is not None:
+        print("========== BEGIN CONFIG ==========")
+        for i in range(values.val_cnt()):
+            print(values.val(i).to_string(), end='')
+        print("=========== END CONFIG ===========")
+
+
+# Function to be called for subscribed client of given session whenever configuration changes.
+def module_change_cb(sess, module_name, event, private_ctx):
+    try:
+        print("========== Notification " + ev_to_str(event) + " =============================================")
+        if event == sr.SR_EV_APPLY:
+            print_current_config(sess, module_name)
+
+        print("========== CHANGES: =============================================")
+
+        change_path = f"/{module_name}:*"
+
+        it = sess.get_changes_iter(change_path)
+
+        while True:
+            change = sess.get_change_next(it)
+            if change is None:
+                break
+            print_change(change.oper(), change.old_val(), change.new_val())
+
+        print("========== END OF CHANGES =======================================")
+    except Exception as e:
+        print(e)
+
+    return sr.SR_ERR_OK
+
+
+def main():
+    # Notable difference between c implementation is using exception mechanism for open handling unexpected events.
+    # Here it is useful because `Connection`, `Session` and `Subscribe` could throw an exception.
+    try:
+        module_name = "ietf-interfaces"
+        if len(sys.argv) > 1:
+            module_name = sys.argv[1]
+        else:
+            print("\nYou can pass the module name to be subscribed as the first argument")
+
+        print(f"Application will watch for changes in {module_name}")
+
+        # connect to sysrepo
+        conn = sr.Connection(module_name)
+
+        # start session
+        sess = sr.Session(conn)
+
+        # subscribe for changes in running config */
+        subscribe = sr.Subscribe(sess)
+
+        subscribe.module_change_subscribe(module_name, module_change_cb)
+
+        try:
+            print_current_config(sess, module_name)
+        except Exception as e:
+            print(e)
+
+        print("========== STARTUP CONFIG APPLIED AS RUNNING ==========")
+
+        sr.global_loop()
+
+        print("Application exit requested, exiting.")
+
+    except Exception as e:
+        print(e)
+
+
+if __name__ == '__main__':
+    main()