Check for pending migrations on app startup. Includes index change migration

src/invidious.cr

@@ -135,6 +135,9 @@ end
 OUTPUT = CONFIG.output.upcase == "STDOUT" ? STDOUT : File.open(CONFIG.output, mode: "a")
 LOGGER = Invidious::LogHandler.new(OUTPUT, CONFIG.log_level)
 
+# Check pending migrations
+Invidious::Database::Migrator.new(PG_DB).check_pending_migrations
+
 # Check table integrity
 Invidious::Database.check_integrity(CONFIG)
 

src/invidious/database/migration.cr

@@ -4,11 +4,16 @@ abstract class Invidious::Database::Migration
   end
 
   @@version : Int64?
+  @@required : Bool = false
 
   def self.version(version : Int32 | Int64)
     @@version = version.to_i64
   end
 
+  def self.required(required : Bool)
+    @@required = required
+  end
+
   getter? completed = false
 
   def initialize(@db : DB::Database)
@@ -32,6 +37,10 @@ abstract class Invidious::Database::Migration
     @@version.not_nil!
   end
 
+  def required? : Bool
+    @@required
+  end
+
   private def track(conn : DB::Connection)
     conn.exec("INSERT INTO #{Migrator::MIGRATIONS_TABLE} (version) VALUES ($1)", version)
   end

src/invidious/database/migrations/0011_limit_channel_videos_index.cr

@@ -0,0 +1,18 @@
+module Invidious::Database::Migrations
+  class LimitChannelVideosIndex < Migration
+    version 11
+
+    def up(conn : DB::Connection)
+      conn.exec <<-SQL
+        CREATE INDEX IF NOT EXISTS channel_videos_ucid_published_idx
+            ON public.channel_videos
+            USING btree
+            (ucid COLLATE pg_catalog."default", published);
+      SQL
+
+      conn.exec <<-SQL
+        DROP INDEX IF EXISTS channel_videos_ucid_idx;
+      SQL
+    end
+  end
+end

src/invidious/database/migrator.cr

@@ -1,5 +1,6 @@
 class Invidious::Database::Migrator
   MIGRATIONS_TABLE = "public.invidious_migrations"
+  MIGRATE_INSTRUCTION = "Run `invidious --migrate` to apply the migration(s)."
 
   class_getter migrations = [] of Invidious::Database::Migration.class
 
@@ -22,11 +23,20 @@ class Invidious::Database::Migrator
     puts "No migrations to run." unless ran_migration
   end
 
-  def pending_migrations? : Bool
+  def check_pending_migrations
     versions = load_versions
 
-    load_migrations.sort_by(&.version)
-      .any? { |migration| !versions.includes?(migration.version) }
+    pending_migrations = load_migrations.sort_by(&.version)
+      .select { |migration| !versions.includes?(migration.version) }
+
+    return if pending_migrations.empty?
+
+    if pending_migrations.any?(&.required?)
+      LOGGER.error("There are pending migrations and the application is unable to continue. #{MIGRATE_INSTRUCTION}")
+      exit 1
+    else
+      LOGGER.warn("There are pending migrations. #{MIGRATE_INSTRUCTION}")
+    end
   end
 
   private def load_migrations : Array(Invidious::Database::Migration)