Deprecate min_pool_size option

min_pool_size option is not used，see:

https://review.opendev.org/#/c/565090/

Change-Id: Ia6d09856e71e42bfa12b91a49735798bfed9818f
Closes-Bug: #1868511

manifests/db.pp

@@ -12,10 +12,6 @@
 #   Timeout when db connections should be reaped.
 #   (Optional) Defaults to $::os_service_default
 #
-# [*database_min_pool_size*]
-#   Minimum number of SQL connections to keep open in a pool.
-#   (Optional) Defaults to $::os_service_default
-#
 # [*database_max_pool_size*]
 #   Maximum number of SQL connections to keep open in a pool.
 #   (Optional) Defaults to $::os_service_default
@@ -42,25 +38,35 @@
 #   before error is raised. Set to -1 to specify an infinite retry count.
 #   Defaults to $::os_service_default
 #
+# DEPRECATED PARAMETERS
+#
+# [*database_min_pool_size*]
+#   Minimum number of SQL connections to keep open in a pool.
+#   (Optional) Defaults to undef
+#
 class mistral::db (
   $database_connection              = 'sqlite:////var/lib/mistral/mistral.sqlite',
   $database_connection_recycle_time = $::os_service_default,
-  $database_min_pool_size           = $::os_service_default,
   $database_max_pool_size           = $::os_service_default,
   $database_max_retries             = $::os_service_default,
   $database_retry_interval          = $::os_service_default,
   $database_max_overflow            = $::os_service_default,
   $database_pool_timeout            = $::os_service_default,
   $database_db_max_retries          = $::os_service_default,
+  # DEPRECATED PARAMETERS
+  $database_min_pool_size           = undef,
 ) {
 
   include mistral::deps
 
+  if $database_min_pool_size {
+    warning('The database_min_pool_size parameter is deprecated, and will be removed in a future release.')
+  }
+
   # NOTE(spredzy): In order to keep backward compatibility we rely on the pick function
   # to use mistral::<myparam> if mistral::db::<myparam> isn't specified.
   $database_connection_real              = pick($::mistral::database_connection,$database_connection)
   $database_connection_recycle_time_real = pick($::mistral::database_idle_timeout, $database_connection_recycle_time)
-  $database_min_pool_size_real           = pick($::mistral::database_min_pool_size,$database_min_pool_size)
   $database_max_pool_size_real           = pick($::mistral::database_max_pool_size,$database_max_pool_size)
   $database_max_retries_real             = pick($::mistral::database_max_retries,$database_max_retries)
   $database_retry_interval_real          = pick($::mistral::database_retry_interval,$database_retry_interval)
@@ -72,7 +78,6 @@ class mistral::db (
   oslo::db { 'mistral_config':
     connection              => $database_connection_real,
     connection_recycle_time => $database_connection_recycle_time_real,
-    min_pool_size           => $database_min_pool_size_real,
     max_pool_size           => $database_max_pool_size_real,
     max_retries             => $database_max_retries_real,
     retry_interval          => $database_retry_interval_real,

manifests/init.pp

@@ -21,10 +21,6 @@
 #   Timeout when db connections should be reaped.
 #   (Optional) Defaults to undef.
 #
-# [*database_min_pool_size*]
-#   Minimum number of SQL connections to keep open in a pool.
-#   (Optional) Defaults to undef.
-#
 # [*database_max_pool_size*]
 #   Maximum number of SQL connections to keep open in a pool.
 #   (Optional) Defaults to undef.

releasenotes/notes/deprecate_database_min_pool_size-option-848a4c6b7de5dea7.yaml

@@ -0,0 +1,4 @@
+---
+deprecations:
+  - database_min_pool_size option is now deprecated for removal, the
+    parameter has no effect.

spec/classes/mistral_db_spec.rb

@@ -9,7 +9,6 @@ describe 'mistral::db' do
         :db_max_retries          => '<SERVICE DEFAULT>',
         :connection              => 'sqlite:////var/lib/mistral/mistral.sqlite',
         :connection_recycle_time => '<SERVICE DEFAULT>',
-        :min_pool_size           => '<SERVICE DEFAULT>',
         :max_pool_size           => '<SERVICE DEFAULT>',
         :max_retries             => '<SERVICE DEFAULT>',
         :retry_interval          => '<SERVICE DEFAULT>',
@@ -23,7 +22,6 @@ describe 'mistral::db' do
         {
           :database_connection              => 'mysql+pymysql://mistral:mistral@localhost/mistral',
           :database_connection_recycle_time => '3601',
-          :database_min_pool_size           => '2',
           :database_max_pool_size           => '11',
           :database_max_retries             => '11',
           :database_retry_interval          => '11',
@@ -39,7 +37,6 @@ describe 'mistral::db' do
         :db_max_retries          => '-1',
         :connection              => 'mysql+pymysql://mistral:mistral@localhost/mistral',
         :connection_recycle_time => '3601',
-        :min_pool_size           => '2',
         :max_pool_size           => '11',
         :max_retries             => '11',
         :retry_interval          => '11',