Add health check

Dockerfile

@@ -32,6 +32,8 @@ RUN strip -p --strip-unneeded /myjdk/lib/server/libjvm.so
 
 FROM alpine
 
+RUN apk add --no-cache curl
+
 ENV APPLICATION_USER simplenotes
 RUN adduser -D -g '' $APPLICATION_USER
 

app/src/main/kotlin/controllers/HealthCheckController.kt

@@ -0,0 +1,12 @@
+package be.simplenotes.app.controllers
+
+import be.simplenotes.persistance.DbHealthCheck
+import org.http4k.core.Request
+import org.http4k.core.Response
+import org.http4k.core.Status.Companion.OK
+import org.http4k.core.Status.Companion.SERVICE_UNAVAILABLE
+
+class HealthCheckController(private val dbHealthCheck: DbHealthCheck) {
+    fun healthCheck(request: Request) =
+        if (dbHealthCheck.isOk()) Response(OK) else Response(SERVICE_UNAVAILABLE)
+}

app/src/main/kotlin/modules/CoreModules.kt

@@ -1,9 +1,6 @@
 package be.simplenotes.app.modules
 
-import be.simplenotes.app.controllers.BaseController
-import be.simplenotes.app.controllers.NoteController
-import be.simplenotes.app.controllers.SettingsController
-import be.simplenotes.app.controllers.UserController
+import be.simplenotes.app.controllers.*
 import be.simplenotes.app.views.BaseView
 import be.simplenotes.app.views.NoteView
 import be.simplenotes.app.views.SettingView
@@ -16,6 +13,7 @@ val userModule = module {
 }
 
 val baseModule = module {
+    single { HealthCheckController(get()) }
     single { BaseController(get()) }
     single { BaseView(get()) }
 }

app/src/main/kotlin/modules/ServerModule.kt

@@ -45,6 +45,7 @@ val serverModule = module {
             get(),
             get(),
             get(),
+            get(),
             requiredAuth = get(AuthType.Required.qualifier),
             optionalAuth = get(AuthType.Optional.qualifier),
             apiAuth = get(named("apiAuthFilter")),

app/src/main/kotlin/routes/Router.kt

@@ -2,10 +2,7 @@ package be.simplenotes.app.routes
 
 import be.simplenotes.app.api.ApiNoteController
 import be.simplenotes.app.api.ApiUserController
-import be.simplenotes.app.controllers.BaseController
-import be.simplenotes.app.controllers.NoteController
-import be.simplenotes.app.controllers.SettingsController
-import be.simplenotes.app.controllers.UserController
+import be.simplenotes.app.controllers.*
 import be.simplenotes.app.filters.*
 import be.simplenotes.domain.security.JwtPayload
 import org.http4k.core.*
@@ -22,6 +19,7 @@ class Router(
     private val settingsController: SettingsController,
     private val apiUserController: ApiUserController,
     private val apiNoteController: ApiNoteController,
+    private val healthCheckController: HealthCheckController,
     private val requiredAuth: Filter,
     private val optionalAuth: Filter,
     private val apiAuth: Filter,
@@ -31,7 +29,11 @@ class Router(
 ) {
     operator fun invoke(): RoutingHttpHandler {
 
-        val basicRoutes = ImmutableFilter.then(static(Classpath("/static"), "woff2" to ContentType("font/woff2")))
+        val basicRoutes =
+            routes(
+                "/health" bind GET to healthCheckController::healthCheck,
+                ImmutableFilter.then(static(Classpath("/static"), "woff2" to ContentType("font/woff2")))
+            )
 
         val publicRoutes = routes(
             "/" bind GET public baseController::index,

caddy/Caddyfile

@@ -11,7 +11,11 @@ simplenotes.be {
     import strict-transport
     header -Server
 
-    reverse_proxy http://localhost:8080
+    reverse_proxy http://localhost:8080 {
+       health_path /health
+       health_interval 5s
+       health_timeout 200ms
+   }
 }
 
 dev.simplenotes.be {

docker-compose.yml

@@ -19,8 +19,10 @@ services:
         volumes:
             - notes-db-volume:/var/lib/mysql
         healthcheck:
-            test: ["CMD", "mysqladmin" ,"ping", "-h", "localhost"]
-            timeout: 10s
+            test: "mysql --protocol=tcp -u simplenotes -p$MYSQL_PASSWORD -e 'show databases'"
+            interval: 5s
+            timeout: 1s
+            start_period: 2s
             retries: 10
 
     simplenotes:
@@ -39,6 +41,12 @@ services:
             # - PASSWORD
         ports:
             - 127.0.0.1:8080:8080
+        healthcheck:
+            test: "curl --fail -s http://localhost:8080/health"
+            interval: 5s
+            timeout: 1s
+            start_period: 2s
+            retries: 3
         depends_on:
             db:
                 condition: service_healthy

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