replace dict.update by a dict merge in zuul_return

This fixes an issue when using zuul_return several times.

zuul_return module takes a dictionary as a parameter with one root key: 'zuul'
Using dict.update with two identical keys will cause dict key overriding

When using zuul_return in child and parent playbooks, the parent zuul_return
value overwrites the child zuul_return value

Change-Id: I6308020d2af0670eb5c598a3daf0ef51066651f6

tests/fixtures/config/data-return/git/common-config/playbooks/several-zuul-return-child.yaml

@@ -0,0 +1,6 @@
+- hosts: localhost
+  tasks:
+    - zuul_return:
+        data:
+          zuul:
+            child_jobs: []

tests/fixtures/config/data-return/git/common-config/playbooks/several-zuul-return-parent-post.yaml

@@ -0,0 +1,6 @@
+- hosts: localhost
+  tasks:
+    - zuul_return:
+        data:
+          zuul:
+            log_url: http://example.com/test/log/url/

tests/fixtures/config/data-return/git/common-config/zuul.yaml

@@ -41,6 +41,15 @@
     name: child
     run: playbooks/child.yaml
 
+- job:
+    name: several-zuul-return-parent
+    post-run: playbooks/several-zuul-return-parent-post.yaml
+
+- job:
+    name: several-zuul-return-child
+    parent: several-zuul-return-parent
+    run: playbooks/several-zuul-return-child.yaml
+
 - project:
     name: org/project
     check:
@@ -84,3 +93,12 @@
         - child:
             dependencies:
               - data-return-skip-all
+
+- project:
+    name: org/project4
+    check:
+      jobs:
+        - several-zuul-return-child
+        - data-return:
+            dependencies:
+              - several-zuul-return-child

tests/fixtures/config/data-return/git/org_project4/README

@@ -0,0 +1 @@
+test

tests/fixtures/config/data-return/main.yaml

@@ -9,3 +9,4 @@
           - org/project1
           - org/project2
           - org/project3
+          - org/project4

tests/unit/test_v3.py

@@ -3084,6 +3084,20 @@ class TestDataReturn(AnsibleZuulTestCase):
         self.assertIn('data-return : SKIPPED', A.messages[-1])
         self.assertIn('Build succeeded', A.messages[-1])
 
+    def test_several_zuul_return(self):
+        A = self.fake_gerrit.addFakeChange('org/project4', 'master', 'A')
+        self.fake_gerrit.addEvent(A.getPatchsetCreatedEvent(1))
+        self.waitUntilSettled()
+        self.assertHistory([
+            dict(name='several-zuul-return-child', result='SUCCESS',
+                 changes='1,1'),
+        ])
+        self.assertIn(
+            '- several-zuul-return-child http://example.com/test/log/url/',
+            A.messages[-1])
+        self.assertIn('data-return : SKIPPED', A.messages[-1])
+        self.assertIn('Build succeeded', A.messages[-1])
+
 
 class TestDiskAccounting(AnsibleZuulTestCase):
     config_file = 'zuul-disk-accounting.conf'

zuul/ansible/library/zuul_return.py

@@ -20,6 +20,22 @@ import json
 import tempfile
 
 
+def merge_dict(dict_a, dict_b):
+    """
+    Add dict_a into dict_b
+    Merge values if possible else dict_a value replace dict_b value
+    """
+    for key in dict_a:
+        if key in dict_b:
+            if isinstance(dict_a[key], dict) and isinstance(dict_b[key], dict):
+                merge_dict(dict_a[key], dict_b[key])
+            else:
+                dict_b[key] = dict_a[key]
+        else:
+            dict_b[key] = dict_a[key]
+    return dict_b
+
+
 def set_value(path, new_data, new_file):
     workdir = os.path.dirname(path)
     data = None
@@ -33,9 +49,9 @@ def set_value(path, new_data, new_file):
 
     if new_file:
         with open(new_file, 'r') as f:
-            data.update(json.load(f))
+            merge_dict(json.load(f), data)
     if new_data:
-        data.update(new_data)
+        merge_dict(new_data, data)
 
     (f, tmp_path) = tempfile.mkstemp(dir=workdir)
     try: