add Redis cache and some clean up

- update and cleanup in README.md
- update getIdentity to throw response exception with 401 in JwtService
- update http files to use identity from env
- add cacheable to getIdentityFromDevice in DeviceRegistryService
- add RedisCacheConfiguration
- add CacheProperty
- set up cache property
- set up data redis cache

src/main/kotlin/ltd/hlaeja/Application.kt

@@ -1,5 +1,6 @@
 package ltd.hlaeja
 
+import ltd.hlaeja.property.CacheProperty
 import ltd.hlaeja.property.DeviceConfigurationProperty
 import ltd.hlaeja.property.DeviceDataProperty
 import ltd.hlaeja.property.DeviceRegistryProperty
@@ -7,8 +8,11 @@ import ltd.hlaeja.property.JwtProperty
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.context.properties.EnableConfigurationProperties
 import org.springframework.boot.runApplication
+import org.springframework.cache.annotation.EnableCaching
 
+@EnableCaching
 @EnableConfigurationProperties(
+    CacheProperty::class,
     DeviceConfigurationProperty::class,
     DeviceDataProperty::class,
     DeviceRegistryProperty::class,

src/main/kotlin/ltd/hlaeja/configuration/RedisCacheConfiguration.kt

@@ -0,0 +1,26 @@
+package ltd.hlaeja.configuration
+
+import java.time.Duration
+import ltd.hlaeja.exception.CacheException
+import ltd.hlaeja.property.CacheProperty
+import org.springframework.context.annotation.Bean
+import org.springframework.context.annotation.Configuration
+import org.springframework.data.redis.cache.RedisCacheConfiguration
+import org.springframework.data.redis.cache.RedisCacheManager
+import org.springframework.data.redis.core.RedisTemplate
+
+@Configuration
+class RedisCacheConfiguration(
+    private val cacheProperty: CacheProperty,
+) {
+
+    @Bean
+    fun cacheManager(
+        redisTemplate: RedisTemplate<String, String>,
+    ): RedisCacheManager = redisTemplate.connectionFactory
+        ?.let { RedisCacheManager.builder(it).cacheDefaults(getRedisCacheConfiguration()).build() }
+        ?: throw CacheException("Redis connection factory is not set")
+
+    private fun getRedisCacheConfiguration(): RedisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
+        .entryTtl(Duration.ofMinutes(cacheProperty.timeToLive))
+}

src/main/kotlin/ltd/hlaeja/exception/CacheException.kt

@@ -0,0 +1,23 @@
+package ltd.hlaeja.exception
+
+@Suppress("unused")
+class CacheException : Exception {
+
+    constructor() : super()
+
+    constructor(message: String) : super(message)
+
+    constructor(cause: Throwable) : super(cause)
+
+    constructor(
+        message: String,
+        cause: Throwable,
+    ) : super(message, cause)
+
+    constructor(
+        message: String,
+        cause: Throwable,
+        enableSuppression: Boolean,
+        writableStackTrace: Boolean,
+    ) : super(message, cause, enableSuppression, writableStackTrace)
+}

src/main/kotlin/ltd/hlaeja/property/CacheProperty.kt

@@ -0,0 +1,8 @@
+package ltd.hlaeja.property
+
+import org.springframework.boot.context.properties.ConfigurationProperties
+
+@ConfigurationProperties(prefix = "cache")
+data class CacheProperty(
+    val timeToLive: Long,
+)

src/main/kotlin/ltd/hlaeja/service/DeviceRegistryService.kt

@@ -7,6 +7,7 @@ import java.util.UUID
 import ltd.hlaeja.library.deviceRegistry.Identity
 import ltd.hlaeja.property.DeviceRegistryProperty
 import ltd.hlaeja.util.deviceRegistryIdentityDevice
+import org.springframework.cache.annotation.Cacheable
 import org.springframework.http.HttpStatus.SERVICE_UNAVAILABLE
 import org.springframework.stereotype.Service
 import org.springframework.web.ErrorResponseException
@@ -31,6 +32,7 @@ class DeviceRegistryService(
         .description("Number of failed device identity calls")
         .register(meterRegistry)
 
+    @Cacheable(value = ["identity"], key = "#device")
     suspend fun getIdentityFromDevice(
         device: UUID,
     ): Identity.Response = try {

src/main/kotlin/ltd/hlaeja/service/JwtService.kt

@@ -1,13 +1,16 @@
 package ltd.hlaeja.service
 
 import io.github.oshai.kotlinlogging.KotlinLogging
+import io.jsonwebtoken.JwtException
 import io.jsonwebtoken.JwtParser
 import io.jsonwebtoken.Jwts
 import java.util.UUID
 import ltd.hlaeja.library.deviceRegistry.Identity
 import ltd.hlaeja.property.JwtProperty
 import ltd.hlaeja.util.PublicKeyProvider
+import org.springframework.http.HttpStatus
 import org.springframework.stereotype.Service
+import org.springframework.web.server.ResponseStatusException
 
 private val log = KotlinLogging.logger {}
 
@@ -23,8 +26,13 @@ class JwtService(
 
     suspend fun getIdentity(
         identityToken: String,
-    ): Identity.Response = readIdentity(identityToken)
-        .let { deviceRegistry.getIdentityFromDevice(it) }
+    ): Identity.Response = try {
+        readIdentity(identityToken)
+            .let { deviceRegistry.getIdentityFromDevice(it) }
+    } catch (e: JwtException) {
+        log.warn { e.localizedMessage }
+        throw ResponseStatusException(HttpStatus.UNAUTHORIZED)
+    }
 
     private suspend fun readIdentity(
         identity: String,