chore: initial commit

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

.editorconfig

@@ -0,0 +1,50 @@
+# EditorConfig is awesome: https://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+# Kotlin files
+[*.{kt,kts}]
+indent_style = space
+indent_size = 4
+continuation_indent_size = 4
+max_line_length = 120
+ij_kotlin_allow_trailing_comma = true
+ij_kotlin_allow_trailing_comma_on_call_site = true
+
+# Gradle files
+[*.gradle.kts]
+indent_style = space
+indent_size = 4
+
+# YAML files (for application.yml, etc.)
+[*.{yml,yaml}]
+indent_style = space
+indent_size = 2
+
+# JSON files
+[*.json]
+indent_style = space
+indent_size = 2
+
+# XML files (for Maven, Spring configs, etc.)
+[*.xml]
+indent_style = space
+indent_size = 2
+
+# Markdown files
+[*.md]
+trim_trailing_whitespace = false
+max_line_length = off
+
+# Properties files
+[*.properties]
+indent_style = space
+indent_size = 4

.gitattributes

@@ -0,0 +1,3 @@
+/gradlew text eol=lf
+*.bat text eol=crlf
+*.jar binary

.gitignore

@@ -0,0 +1,40 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Kotlin ###
+.kotlin

build.gradle.kts

@@ -0,0 +1,82 @@
+plugins {
+    kotlin("jvm") version "2.2.21"
+    kotlin("plugin.spring") version "2.2.21"
+    id("org.springframework.boot") version "4.1.0-M2"
+    id("io.spring.dependency-management") version "1.1.7"
+    id("org.jlleitschuh.gradle.ktlint") version "12.1.0"
+}
+
+group = "io.visus.demos"
+version = "0.0.1-SNAPSHOT"
+description = "kotlin-api"
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+
+ktlint {
+    version.set("1.4.1")
+    android.set(false)
+    ignoreFailures.set(false)
+    reporters {
+        reporter(org.jlleitschuh.gradle.ktlint.reporter.ReporterType.PLAIN)
+    }
+    filter {
+        exclude("**/build/**")
+        exclude("**/generated/**")
+    }
+}
+
+dependencies {
+    implementation("tools.jackson.core:jackson-core:3.1.0")
+    implementation("tools.jackson.core:jackson-databind:3.1.0")
+    implementation("tools.jackson.module:jackson-module-kotlin:3.1.0")
+
+    implementation("org.springframework.boot:spring-boot-starter-mongodb")
+    implementation("org.springframework.boot:spring-boot-starter-restclient")
+    implementation("org.springframework.boot:spring-boot-starter-security")
+    implementation("org.springframework.boot:spring-boot-starter-webmvc")
+    implementation("org.jetbrains.kotlin:kotlin-reflect")
+    implementation("org.springdoc:springdoc-openapi-starter-webmvc-ui:2.8.4")
+    testImplementation("org.springframework.boot:spring-boot-starter-mongodb-test")
+    testImplementation("org.springframework.boot:spring-boot-starter-restclient-test")
+    testImplementation("org.springframework.boot:spring-boot-starter-security-test")
+    testImplementation("org.springframework.boot:spring-boot-starter-webmvc-test")
+    testImplementation("org.jetbrains.kotlin:kotlin-test-junit5")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+}
+
+configurations.all {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "tools.jackson.core") {
+            useVersion("3.1.0")
+        }
+        if (requested.group == "com.fasterxml.jackson.core") {
+            if (requested.name == "jackson-annotations") {
+                useVersion("2.21")
+            } else {
+                useVersion("2.21.1")
+            }
+        }
+    }
+}
+
+kotlin {
+    compilerOptions {
+        freeCompilerArgs.addAll("-Xjsr305=strict", "-Xannotation-default-target=param-property")
+    }
+}
+
+tasks.withType<Test> {
+    useJUnitPlatform()
+}
+
+tasks.named("check") {
+    dependsOn("ktlintCheck")
+}

gradle.properties

@@ -0,0 +1 @@
+org.gradle.configuration-cache=true

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,93 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle.kts

@@ -0,0 +1 @@
+rootProject.name = "kotlin-api"

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

@@ -0,0 +1,11 @@
+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

@@ -0,0 +1,45 @@
+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

@@ -0,0 +1,34 @@
+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

@@ -0,0 +1,63 @@
+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}",
+            )
+        }
+}

src/main/resources/application.yaml

@@ -0,0 +1,5 @@
+spring:
+  application:
+    name: kotlin-api
+  mongodb:
+    uri: ${MONGODB_URI:mongodb://localhost:27017/kotlin-api}

src/test/kotlin/io/visus/demos/kotlinapi/KotlinApiApplicationTests.kt

@@ -0,0 +1,11 @@
+package io.visus.demos.kotlinapi
+
+import org.junit.jupiter.api.Test
+import org.springframework.boot.test.context.SpringBootTest
+
+@SpringBootTest
+class KotlinApiApplicationTests {
+    @Test
+    fun contextLoads() {
+    }
+}