chore: initial commit

Signed-off-by: Alan Brault <alan.brault@visus.io>

src/main/kotlin/io/visus/demos/kotlinapi/KotlinApiApplication.kt

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+package io.visus.demos.kotlinapi
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class KotlinApiApplication
+
+fun main(args: Array<String>) {
+    runApplication<KotlinApiApplication>(*args)
+}

src/main/kotlin/io/visus/demos/kotlinapi/api/dto/HealthResponse.kt

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+package io.visus.demos.kotlinapi.api.dto
+
+import io.swagger.v3.oas.annotations.media.Schema
+import io.visus.demos.kotlinapi.domain.model.ComponentHealth
+import io.visus.demos.kotlinapi.domain.model.HealthStatus
+
+@Schema(description = "Health check response")
+data class HealthResponse(
+    @Schema(description = "Current status of the API", example = "UP")
+    val status: String,
+    @Schema(description = "Timestamp of the health check", example = "2024-01-01T12:00:00Z")
+    val timestamp: String,
+    @Schema(description = "Status of individual components")
+    val components: Map<String, ComponentHealthDto>? = null,
+) {
+    companion object {
+        fun from(healthStatus: HealthStatus): HealthResponse =
+            HealthResponse(
+                status = healthStatus.status.name,
+                timestamp = healthStatus.timestamp.toString(),
+                components =
+                    if (healthStatus.components.isNotEmpty()) {
+                        healthStatus.components.mapValues { ComponentHealthDto.from(it.value) }
+                    } else {
+                        null
+                    },
+            )
+    }
+}
+
+@Schema(description = "Health status of an individual component")
+data class ComponentHealthDto(
+    @Schema(description = "Component status", example = "UP")
+    val status: String,
+    @Schema(description = "Optional message with additional details", example = "MongoDB connection is active")
+    val message: String? = null,
+) {
+    companion object {
+        fun from(componentHealth: ComponentHealth): ComponentHealthDto =
+            ComponentHealthDto(
+                status = componentHealth.status.name,
+                message = componentHealth.message,
+            )
+    }
+}

src/main/kotlin/io/visus/demos/kotlinapi/config/MongoConfig.kt

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+package io.visus.demos.kotlinapi.config
+
+import com.mongodb.ConnectionString
+import com.mongodb.MongoClientSettings
+import com.mongodb.client.MongoClient
+import com.mongodb.client.MongoClients
+import org.springframework.beans.factory.annotation.Value
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import java.util.concurrent.TimeUnit
+
+@Configuration
+class MongoConfig {
+    @Bean
+    fun mongoClient(
+        @Value("\${spring.mongodb.uri}") uri: String,
+    ): MongoClient {
+        val connectionString = ConnectionString(uri)
+
+        val settings =
+            MongoClientSettings
+                .builder()
+                .applyConnectionString(connectionString)
+                .applyToSocketSettings { builder ->
+                    builder
+                        .connectTimeout(2, TimeUnit.SECONDS)
+                        .readTimeout(2, TimeUnit.SECONDS)
+                }.applyToClusterSettings { builder ->
+                    builder.serverSelectionTimeout(2, TimeUnit.SECONDS)
+                }.build()
+
+        return MongoClients.create(settings)
+    }
+}

src/main/kotlin/io/visus/demos/kotlinapi/config/OpenApiConfig.kt

@@ -0,0 +1,19 @@
+package io.visus.demos.kotlinapi.config
+
+import io.swagger.v3.oas.models.OpenAPI
+import io.swagger.v3.oas.models.info.Info
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+
+@Configuration
+class OpenApiConfig {
+    @Bean
+    fun customOpenAPI(): OpenAPI =
+        OpenAPI()
+            .info(
+                Info()
+                    .title("Kotlin API")
+                    .version("0.0.1-SNAPSHOT")
+                    .description("API documentation for Kotlin Spring Boot application"),
+            )
+}

src/main/kotlin/io/visus/demos/kotlinapi/config/SecurityConfig.kt

@@ -0,0 +1,27 @@
+package io.visus.demos.kotlinapi.config
+
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.security.config.annotation.web.builders.HttpSecurity
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity
+import org.springframework.security.web.SecurityFilterChain
+
+@Configuration
+@EnableWebSecurity
+class SecurityConfig {
+    @Bean
+    fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
+        http
+            .authorizeHttpRequests { authorize ->
+                authorize
+                    .requestMatchers("/health")
+                    .permitAll()
+                    .requestMatchers("/swagger-ui/**", "/v3/api-docs/**")
+                    .permitAll()
+                    .anyRequest()
+                    .authenticated()
+            }
+
+        return http.build()
+    }
+}

src/main/kotlin/io/visus/demos/kotlinapi/controller/HealthController.kt

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+package io.visus.demos.kotlinapi.controller
+
+import io.swagger.v3.oas.annotations.Operation
+import io.swagger.v3.oas.annotations.media.Content
+import io.swagger.v3.oas.annotations.media.Schema
+import io.swagger.v3.oas.annotations.responses.ApiResponse
+import io.swagger.v3.oas.annotations.tags.Tag
+import io.visus.demos.kotlinapi.api.dto.HealthResponse
+import io.visus.demos.kotlinapi.domain.model.HealthStatus
+import io.visus.demos.kotlinapi.domain.model.Status
+import io.visus.demos.kotlinapi.domain.service.HealthService
+import org.springframework.http.HttpStatus
+import org.springframework.http.MediaType
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@Tag(name = "Health", description = "Health check endpoints")
+class HealthController(
+    private val healthCheckServices: List<HealthService>,
+) {
+    @GetMapping("/health", produces = [MediaType.APPLICATION_JSON_VALUE])
+    @Operation(
+        summary = "Health check",
+        description = "Returns the health status of the API",
+        responses = [
+            ApiResponse(
+                responseCode = "200",
+                description = "API is healthy",
+                content = [
+                    Content(
+                        mediaType = MediaType.APPLICATION_JSON_VALUE,
+                        schema = Schema(implementation = HealthResponse::class),
+                    ),
+                ],
+            ),
+            ApiResponse(
+                responseCode = "503",
+                description = "API is down or degraded",
+                content = [
+                    Content(
+                        mediaType = MediaType.APPLICATION_JSON_VALUE,
+                        schema = Schema(implementation = HealthResponse::class),
+                    ),
+                ],
+            ),
+        ],
+    )
+    fun health(): ResponseEntity<HealthResponse> {
+        val componentHealths = healthCheckServices.map { it.check() }
+        val healthStatus = HealthStatus.fromComponents(componentHealths)
+        val response = HealthResponse.from(healthStatus)
+
+        val httpStatus =
+            when (healthStatus.status) {
+                Status.UP -> HttpStatus.OK
+                Status.DOWN, Status.DEGRADED -> HttpStatus.SERVICE_UNAVAILABLE
+            }
+
+        return ResponseEntity.status(httpStatus).body(response)
+    }
+}

src/main/kotlin/io/visus/demos/kotlinapi/domain/model/ComponentHealth.kt

@@ -0,0 +1,7 @@
+package io.visus.demos.kotlinapi.domain.model
+
+data class ComponentHealth(
+    val name: String,
+    val status: ComponentStatus,
+    val message: String? = null,
+)

src/main/kotlin/io/visus/demos/kotlinapi/domain/model/ComponentStatus.kt

@@ -0,0 +1,6 @@
+package io.visus.demos.kotlinapi.domain.model
+
+enum class ComponentStatus {
+    UP,
+    DOWN,
+}

src/main/kotlin/io/visus/demos/kotlinapi/domain/model/HealthStatus.kt

@@ -0,0 +1,27 @@
+package io.visus.demos.kotlinapi.domain.model
+
+import java.time.Instant
+
+data class HealthStatus(
+    val status: Status,
+    val timestamp: Instant,
+    val components: Map<String, ComponentHealth> = emptyMap(),
+) {
+    companion object {
+        fun fromComponents(components: List<ComponentHealth>): HealthStatus {
+            val componentMap = components.associateBy { it.name }
+            val status =
+                when {
+                    components.all { it.status == ComponentStatus.UP } -> Status.UP
+                    components.all { it.status == ComponentStatus.DOWN } -> Status.DOWN
+                    else -> Status.DEGRADED
+                }
+
+            return HealthStatus(
+                status = status,
+                timestamp = Instant.now(),
+                components = componentMap,
+            )
+        }
+    }
+}

src/main/kotlin/io/visus/demos/kotlinapi/domain/model/Status.kt

@@ -0,0 +1,7 @@
+package io.visus.demos.kotlinapi.domain.model
+
+enum class Status {
+    UP,
+    DOWN,
+    DEGRADED,
+}

src/main/kotlin/io/visus/demos/kotlinapi/domain/service/HealthService.kt

@@ -0,0 +1,7 @@
+package io.visus.demos.kotlinapi.domain.service
+
+import io.visus.demos.kotlinapi.domain.model.ComponentHealth
+
+interface HealthService {
+    fun check(): ComponentHealth
+}

src/main/kotlin/io/visus/demos/kotlinapi/infrastructure/health/MongoHealthService.kt

@@ -0,0 +1,31 @@
+package io.visus.demos.kotlinapi.infrastructure.health
+
+import com.mongodb.client.MongoClient
+import io.visus.demos.kotlinapi.domain.model.ComponentHealth
+import io.visus.demos.kotlinapi.domain.model.ComponentStatus
+import io.visus.demos.kotlinapi.domain.service.HealthService
+import org.bson.Document
+import org.springframework.stereotype.Service
+
+@Service
+class MongoHealthService(
+    private val mongoClient: MongoClient,
+) : HealthService {
+    override fun check(): ComponentHealth =
+        try {
+            val command = Document("ping", 1)
+            mongoClient.getDatabase("admin").runCommand(command)
+
+            ComponentHealth(
+                name = "mongodb",
+                status = ComponentStatus.UP,
+                message = "MongoDB connection is active",
+            )
+        } catch (e: Exception) {
+            ComponentHealth(
+                name = "mongodb",
+                status = ComponentStatus.DOWN,
+                message = "MongoDB connection failed: ${e.message}",
+            )
+        }
+}