Expose config values for database connection pool

config/config.example.yml

@@ -15,6 +15,29 @@ db:
   port: 5432
   dbname: invidious
 
+  ##
+  ## Granular pooling behavior controls
+  ## The following is entirely optional.
+  ##
+
+  ## Initial amount of connections in the pool 
+  #initial_pool_size:
+
+  ## Maximum amount of connections in the pool. 0 is unlimited.
+  #max_pool_size: 0
+
+  ## Amount of connections when idle
+  #max_idle_pool_size: 1 
+
+  ## Amount of seconds to wait if the connection pool is full, and a connection is unavailable. 
+  #checkout_timeout: 5 
+
+  ## Amount of retries when a connection is either lost or can't be established.
+  #retry_attempts: 1
+
+  ## Amount of seconds between each retry
+  #retry_delay: 1
+
 ##
 ## Database configuration using a single URI. This is an
 ## alternative to the 'db' parameter above. If both forms

src/invidious/helpers/helpers.cr

@@ -188,6 +188,16 @@ class Config
           host: db.host,
           port: db.port,
           path: db.dbname,
+
+          # Pooling config
+          query: URI::Params.build do |pool_controls|
+            pool_controls.add "initial_pool_size", db.initial_pool_size.to_s
+            pool_controls.add "max_pool_size", db.max_pool_size.to_s
+            pool_controls.add "max_idle_pool_size", db.max_idle_pool_size.to_s
+            pool_controls.add "checkout_timeout", db.checkout_timeout.to_s
+            pool_controls.add "retry_attempts", db.retry_attempts.to_s
+            pool_controls.add "retry_delay", db.retry_delay.to_s
+          end
         )
       else
         puts "Config : Either database_url or db.* is required"
@@ -207,6 +217,14 @@ struct DBConfig
   property host : String
   property port : Int32
   property dbname : String
+
+  # https://crystal-lang.org/reference/database/connection_pool.html#configuration
+  property initial_pool_size : Int32 = 1
+  property max_pool_size : Int32 = 0
+  property max_idle_pool_size : Int32 = 1
+  property checkout_timeout : Int32 = 5
+  property retry_attempts : Int32 = 1
+  property retry_delay : Int32 = 1
 end
 
 def login_req(f_req)