Fix remote_checksum with delegate_to and add tests for several ways that delegate_to works

lib/ansible/runner/__init__.py

@@ -1227,10 +1227,28 @@ class Runner(object):
 
     def _remote_checksum(self, conn, tmp, path, inject):
         ''' takes a remote checksum and returns 1 if no file '''
-        if 'delegate_to' in inject and inject['delegate_to'] and inject['delegate_to'] in inject['hostvars']:
-            python_interp = inject['hostvars'][inject['delegate_to']].get('ansible_python_interpreter', 'python')
+
+        # Lookup the python interp from the host or delegate
+
+        # host == inven_host when there is no delegate
+        host = inject['inventory_hostname']
+        if 'delegate_to' in inject:
+            delegate = inject['delegate_to']
+            if delegate:
+                # host == None when the delegate is not in inventory
+                host = None
+                # delegate set, check whether the delegate has inventory vars
+                delegate = template.template(self.basedir, delegate, inject)
+                if delegate in inject['hostvars']:
+                    # host == delegate if we need to lookup the
+                    # python_interpreter from the delegate's inventory vars
+                    host = delegate
+
+        if host:
+            python_interp = inject['hostvars'][host].get('ansible_python_interpreter', 'python')
         else:
-            python_interp = inject['hostvars'][inject['inventory_hostname']].get('ansible_python_interpreter', 'python')
+            python_interp = 'python'
+
         cmd = conn.shell.checksum(path, python_interp)
         data = self._low_level_exec_command(conn, cmd, tmp, sudoable=True)
         data2 = utils.last_non_blank_line(data['stdout'])

test/integration/Makefile

@@ -19,7 +19,7 @@ TMPDIR = $(shell mktemp -d 2>/dev/null || mktemp -d -t 'mytmpdir')
 
 VAULT_PASSWORD_FILE = vault-password
 
-all: parsing test_var_precedence unicode non_destructive destructive includes check_mode test_hash test_handlers test_group_by test_vault
+all: parsing test_var_precedence unicode non_destructive destructive includes check_mode test_hash test_handlers test_group_by test_vault test_delegate_to
 
 parsing:
 	ansible-playbook bad_parsing.yml -i $(INVENTORY) -e @$(VARS_FILE) $(CREDENTIALS_ARG) -vvv $(TEST_FLAGS) --tags prepare,common,scenario1; [ $$? -eq 3 ]
@@ -65,6 +65,9 @@ test_vault:
 	ansible-playbook test_vault.yml -i $(INVENTORY) $(CREDENTIALS_ARG) -v $(TEST_FLAGS) --vault-password-file $(VAULT_PASSWORD_FILE) --syntax-check
 	ansible-playbook test_vault.yml -i $(INVENTORY) $(CREDENTIALS_ARG) -v $(TEST_FLAGS) --vault-password-file $(VAULT_PASSWORD_FILE)
 
+test_delegate_to:
+	ansible-playbook test_delegate_to.yml -i $(INVENTORY) -e @$(VARS_FILE) $(CREDENTIALS_ARG) -v $(TEST_FLAGS)
+
 test_winrm:
 	ansible-playbook test_winrm.yml -i inventory.winrm -e @$(VARS_FILE) $(CREDENTIALS_ARG) -v $(TEST_FLAGS)
 

test/integration/inventory

 [local]
 testhost ansible_ssh_host=127.0.0.1 ansible_connection=local
 testhost2 ansible_ssh_host=127.0.0.1 ansible_connection=local
+# For testing delegate_to
+testhost3 ansible_ssh_host=127.0.0.3
+testhost4 ansible_ssh_host=127.0.0.4
 
 # the following inline declarations are accompanied
 # by (preferred) group_vars/ and host_vars/ variables

test/integration/test_delegate_to.yml

+- hosts: testhost3
+  roles:
+    - { role: prepare_tests }
+  vars:
+    - template_role: ./roles/test_template
+    - templated_var: foo
+  tasks:
+    - name: Test no delegate_to
+      setup:
+      register: setup_results
+
+    - assert:
+        that:
+          - '"127.0.0.3" in setup_results.ansible_facts.ansible_env["SSH_CONNECTION"]'
+
+    - name: Test delegate_to with host in inventory
+      setup:
+      register: setup_results
+      delegate_to: testhost4
+
+    - assert:
+        that:
+          - '"127.0.0.4" in setup_results.ansible_facts.ansible_env["SSH_CONNECTION"]'
+
+    - name: Test delegate_to with host not in inventory
+      setup:
+      register: setup_results
+      delegate_to: 127.0.0.254
+
+    - assert:
+        that:
+          - '"127.0.0.254" in setup_results.ansible_facts.ansible_env["SSH_CONNECTION"]'
+#
+# Smoketest some other modules do not error as a canary
+#
+    - name: Test file works with delegate_to and a host in inventory
+      file: path={{ output_dir }}/foo.txt mode=0644 state=touch
+      delegate_to: testhost4
+
+    - name: Test file works with delegate_to and a host not in inventory
+      file: path={{ output_dir }}/test_follow_link mode=0644 state=touch
+      delegate_to: 127.0.0.254
+
+    - name: Test template works with delegate_to and a host in inventory
+      template: src={{ template_role }}/templates/foo.j2 dest={{ output_dir }}/foo.txt
+      delegate_to: testhost4
+
+    - name: Test template works with delegate_to and a host not in inventory
+      template: src={{ template_role }}/templates/foo.j2 dest={{ output_dir }}/foo.txt
+      delegate_to: 127.0.0.254