Disable restart for hot reload (#118)

Author: dokshina

CHANGELOG.md

@@ -11,6 +11,10 @@ README.md and examples/getting-started-app/README.md
 to use the newest tag with new release
 -->
 
+### Added
+
+- `restarted: false` to disable instance restart
+
 ## [1.4.0] - 2020-07-15
 
 ### Added

README.md

@@ -88,6 +88,7 @@ all:
         advertise_uri: '172.19.0.2:3302'
         http_port: 8082
       restarted: true  # force instance restart
+      # restarted: false  # disable instance restart
 
     storage-1:
       config:
@@ -172,7 +173,9 @@ Configuration format is described in detail in the
   indicates if the Tarantool repository should be enabled (for packages with
   open-source Tarantool dependency);
 * `config` (`dict`, required): [instance configuration](#instances);
-* `restarted` (`boolean`, optional, default: `false`): indicates that instance must be forcedly restarted;
+* `restarted` (`boolean`, optional): flag indicates if instance should be
+  restarted or not (if this flag isn't specified, instance will be restarted if
+  it's needed to apply configuration changes);
 * `expelled` (`boolean`, optional, default: `false`): boolean flag that indicates if instance must be expelled from topology;
 * `stateboard` (`boolean`, optional, default: `false`): boolean flag that indicates
    that the instance is a [stateboard](#stateboard-instance);
@@ -181,7 +184,7 @@ Configuration format is described in detail in the
 * `failover_priority` (`list-of-string`): failover priority;
 * `roles` (`list-of-strings`, required if `replicaset_alias` specified): roles to be enabled on the replicaset;
 * `all_rw` (`boolean`, optional): indicates that that all servers in the replicaset should be read-write;
-* `weight` (`number`, optional): vshard replicaset weight (matters only if `vshard-storage` role is enabled.
+* `weight` (`number`, optional): vshard replicaset weight (matters only if `vshard-storage` role is enabled);
 * [DEPRECATED] `cartridge_failover` (`boolean`, optional): boolean flag that
   indicates if eventual failover should be enabled or disabled;
 

defaults/main.yml

@@ -1,7 +1,7 @@
 ---
 cartridge_defaults: {}
 cartridge_enable_tarantool_repo: true
-restarted: false
+restarted: null
 expelled: false
 stateboard: false
 instance_start_timeout: 60

library/cartridge_needs_restart.py

@@ -8,7 +8,7 @@
 
 
 argument_spec = {
-    'restart_forced': {'required': True, 'type': 'bool'},
+    'restarted': {'required': False, 'type': 'bool'},
     'control_sock': {'required': True, 'type': 'str'},
     'appname': {'required': True, 'type': 'str'},
     'instance_conf_file': {'required': True, 'type': 'str'},
@@ -77,10 +77,13 @@ def get_memtx_memory(control_console):
 
 
 def needs_restart(params):
-    restart_forced = params['restart_forced']
-    if restart_forced:
+    restarted = params['restarted']
+    if restarted is True:
         return ModuleRes(success=True, changed=True)
 
+    if restarted is False:
+        return ModuleRes(success=True, changed=False)
+
     stateboard = params['stateboard']
 
     control_sock = params['control_sock']

tasks/start_instance.yml

@@ -11,7 +11,7 @@
 
 - name: Check if instance restart is forced or required to apply changes
   cartridge_needs_restart:
-    restart_forced: '{{ restarted }}'
+    restarted: '{{ restarted }}'
     control_sock: '{{ instance_control_sock }}'
     appname: '{{ cartridge_app_name }}'
     instance_conf_file: '{{ instance_conf_file }}'

unit/test_needs_restart.py

@@ -15,7 +15,7 @@
 
 
 def call_needs_restart(control_sock,
-                       restart_forced=False,
+                       restarted=None,
                        appname=Instance.APPNAME,
                        instance_conf_file=Instance.INSTANCE_CONF_PATH,
                        conf_section_name=Instance.CONF_SECTION,
@@ -24,7 +24,7 @@ def call_needs_restart(control_sock,
                        cartridge_defaults={},
                        stateboard=False):
     return needs_restart({
-        'restart_forced': restart_forced,
+        'restarted': restarted,
         'control_sock': control_sock,
         'appname': appname,
         'instance_conf_file': instance_conf_file,
@@ -47,11 +47,19 @@ def setUp(self):
     def test_restart_forced(self):
         res = call_needs_restart(
             control_sock=self.console_sock,
-            restart_forced=True
+            restarted=True
         )
         self.assertTrue(res.success, msg=res.msg)
         self.assertTrue(res.changed)
 
+    def test_restart_disabled(self):
+        res = call_needs_restart(
+            control_sock=self.console_sock,
+            restarted=False
+        )
+        self.assertTrue(res.success, msg=res.msg)
+        self.assertFalse(res.changed)
+
     def test_instance_not_started(self):
         # console sock doesn't exists
         self.instance.remove_file(self.console_sock)