Exit early when diff is empty

README.md

@@ -2,7 +2,7 @@
 
 Ansible Collection to manage Nokia SR Linux devices. Documentation is provided at <https://learn.srlinux.dev/ansible/collection/>
 
-## Dev setup
+## Quick start for developers
 
 Start with cloning the repo:
 
@@ -17,7 +17,7 @@ Deploy the lab to support the tests:
 ./run.sh deploy-lab
 ```
 
-Run the automated suite of tests to make sure nothing is missing. This will also prepare a dev environment
+Run the automated suite of tests to make sure nothing is missing. This will also prepare a dev environment (you have to make sure the venv with ansible is activated or ansible-playbook is in your path):
 
 ```bash
 ./run.sh test
@@ -28,3 +28,19 @@ To validate that the code passes Ansible's sanity check, run:
 ```bash
 ./run.sh sanity-test
 ```
+
+Note, that the lab uses IXR-6 chassis, which only runs for 5 minutes without a license. This is enough to finish the test suite, but if you want to play with the lab for a longer period, remove the type or provide a license.
+
+### Running individual tests
+
+To run an individual test, first make sure that the local code base is used by ansible. This can be done by running:
+
+```bash
+./run.sh prepare-dev-env
+```
+
+Then either run one of the provided test playbooks (defined in [run.sh](run.sh)) or run your own:
+
+```bash
+./run.sh test-set-leaves
+```

plugins/modules/config.py

@@ -212,6 +212,11 @@ def main():
             msg = diff_resp.get("error", {}).get("message", "No diff response")
             module.fail_json(msg=msg, method="diff", id=diff_resp["jsonrpc_req_id"])
 
+        # if diff response is empty, the operation is a noop and we can exit the module
+        if not [x for x in diff_resp.get("result") if x.strip() != ""]:
+            json_output["jsonrpc_req_id"] = diff_resp["jsonrpc_req_id"]
+            module.exit_json(**json_output)
+
     # if diff response is not empty, we have a diff
     # we need to set the changed flag to True
     # and save the diff response result in the json_output

run.sh

@@ -190,6 +190,15 @@ function test-set-leaves {
   ansible-playbook playbooks/set-leaves.yml "$@"
 }
 
+# test that subsequent config changes are idempotent
+# and does not lead to commit being recorded since
+# the diff is empty
+function test-set-leaves-twice {
+  _cdTests
+  revert-to-checkpoint
+  ansible-playbook playbooks/set-leaves-twice.yml "$@"
+}
+
 function test-set-interface {
   _cdTests
   revert-to-checkpoint
@@ -269,6 +278,7 @@ function _run-tests {
   test-tls-skip "$@"
   test-set-check-mode "$@"
   test-set-leaves "$@"
+  test-set-leaves-twice "$@"
   test-set-wrong-value "$@"
   test-set-multiple-paths "$@"
   test-set-interface "$@"

scripts/topo.clab.yml

@@ -7,8 +7,8 @@ name: ansible
 topology:
   nodes:
     srl:
-      kind: srl
-      image: ghcr.io/nokia/srlinux:${SRLINUX_VERSION:=23.7.2}
+      kind: nokia_srlinux
+      image: ghcr.io/nokia/srlinux:${SRLINUX_VERSION:=23.10.1}
       # type and startup config are used to test Openconfig modules
       type: ixr6
       startup-config: oc.cfg

tests/playbooks/set-leaves-twice.yml

@@ -0,0 +1,79 @@
+# Copyright 2023 Nokia
+# Licensed under the BSD 3-Clause License.
+# SPDX-License-Identifier: BSD-3-Clause
+
+- name: Set leaves
+  hosts: clab
+  gather_facts: false
+  tasks:
+    - name: Set system information with values
+      nokia.srlinux.config:
+        update:
+          - path: /system/information
+            value:
+              location: some location
+      register: set_response
+
+    - debug:
+        var: set_response
+
+    - name: Ensure changes were made to the device
+      nokia.srlinux.get:
+        paths:
+          - path: /system/information
+            datastore: state
+      register: get_response
+      failed_when: (get_response.result[0].location != "some location")
+
+    - debug:
+        var: get_response
+
+    - name: get commits
+      nokia.srlinux.get:
+        paths:
+          - path: /system/configuration/commit
+      register: commits
+
+    - debug:
+        var: commits
+
+    - name: Count the number of commits registered after the first set
+      set_fact:
+        first_commit_count: "{{ commits.result[0].commit | length }}"
+
+    - name: Set information with the same value again
+      nokia.srlinux.config:
+        update:
+          - path: /system/information
+            value:
+              location: some location
+      register: set_response
+
+    - debug:
+        var: set_response
+
+    - name: check that no change has been recorded by the module
+      assert:
+        that:
+          - set_response.changed is false
+
+    - name: get commits again
+      nokia.srlinux.get:
+        paths:
+          - path: /system/configuration/commit
+      register: commits
+
+    - debug:
+        var: commits
+
+    - name: Count the number of commits registered after the second set
+      set_fact:
+        second_commit_count: "{{ commits.result[0].commit | length }}"
+
+    - debug:
+        msg: "1st commit count is: {{ first_commit_count }}, 2nd commit count is: {{ second_commit_count }}"
+
+    - name: check that no new commits have been recorded
+      assert:
+        that:
+          - first_commit_count == second_commit_count