Add health check

persistance/src/main/kotlin/HealthCheck.kt

@@ -0,0 +1,28 @@
+package be.simplenotes.persistance
+
+import be.simplenotes.persistance.utils.DbType
+import be.simplenotes.persistance.utils.type
+import be.simplenotes.shared.config.DataSourceConfig
+import me.liuwj.ktorm.database.Database
+import me.liuwj.ktorm.database.asIterable
+import java.sql.SQLTransientException
+
+interface DbHealthCheck {
+    fun isOk(): Boolean
+}
+
+internal class DbHealthCheckImpl(
+    private val db: Database,
+    private val dataSourceConfig: DataSourceConfig,
+) : DbHealthCheck {
+    override fun isOk() = if (dataSourceConfig.type() == DbType.H2) true
+    else try {
+        db.useConnection { connection ->
+            connection.prepareStatement("""SHOW DATABASES""").use {
+                it.executeQuery().asIterable().map { it.getString(1) }
+            }
+        }.any { it in dataSourceConfig.jdbcUrl }
+    } catch (e: SQLTransientException) {
+        false
+    }
+}

persistance/src/main/kotlin/Migrations.kt

@@ -1,18 +1,24 @@
 package be.simplenotes.persistance
 
+import be.simplenotes.persistance.utils.DbType
+import be.simplenotes.persistance.utils.type
 import be.simplenotes.shared.config.DataSourceConfig
 import org.flywaydb.core.Flyway
 import javax.sql.DataSource
 
+interface DbMigrations {
+    fun migrate()
+}
+
 internal class DbMigrationsImpl(
     private val dataSource: DataSource,
-    private val dataSourceConfig: DataSourceConfig
+    private val dataSourceConfig: DataSourceConfig,
 ) : DbMigrations {
     override fun migrate() {
 
-        val migrationDir = when {
-            dataSourceConfig.jdbcUrl.contains("mariadb") -> "db/migration/mariadb"
-            else -> "db/migration/other"
+        val migrationDir = when (dataSourceConfig.type()) {
+            DbType.H2 -> "db/migration/other"
+            DbType.MariaDb -> "db/migration/mariadb"
         }
 
         Flyway.configure()

persistance/src/main/kotlin/PersistanceModule.kt

@@ -13,10 +13,6 @@ import org.koin.dsl.module
 import org.koin.dsl.onClose
 import javax.sql.DataSource
 
-interface DbMigrations {
-    fun migrate()
-}
-
 private fun hikariDataSource(conf: DataSourceConfig): HikariDataSource {
     val hikariConfig = HikariConfig().also {
         it.jdbcUrl = conf.jdbcUrl
@@ -41,4 +37,5 @@ val persistanceModule = module {
         get<DbMigrations>().migrate()
         Database.connect(get<DataSource>())
     }
+    single<DbHealthCheck> { DbHealthCheckImpl(get(), get()) }
 }

persistance/src/main/kotlin/utils/DataSourceConfigUtils.kt

@@ -0,0 +1,8 @@
+package be.simplenotes.persistance.utils
+
+import be.simplenotes.shared.config.DataSourceConfig
+
+enum class DbType { H2, MariaDb }
+
+fun DataSourceConfig.type(): DbType = if (jdbcUrl.contains("mariadb")) DbType.MariaDb
+else DbType.H2