Demo of context-aware logging capabilities in ZIO environment
sbt example/run
curl -XPOST -H 'access-token: 1234' -H 'x-correlation-id: id22234' -H 'content-type: application/json; charset=utf-8' 'http://127.0.0.1:9090/whisk.console.recipe.v1.RecipeAPI/GetRecipe' -d '{
"id": "dsfdsf"
}'
Info
com.whisk.util.logging.LoggingContext - view to underlying context. Likely only need to be used directly when constructing program on top level. It is ZIO-independent, we can implement similar for Monix
com.whisk.util.logging.Logging - Type for constructing Loggers and accessing/modifying underlying context
com.whisk.util.logging.ZIOLoggingContext - ZIO implementation of LoggingContext, which is using FiberRef
whisk.console.logging.GrpcLoggingContext - extracts correlationId from grpc request context and puts it into LoggingContext
Usage
Example of effectful creation of Logger. The returned type is log4cats.StructuredLogger
class RecipeDao[F[_]: Monad: Logging] {
def get(id: String): F[Option[RecipeDetails]] = {
for {
logger <- Logging[F].fromName(getClass.getName)
_ <- logger.info(Map("extraParam" -> "0"))("requesting with id=" + id)
} yield {
Some(RecipeDetails(id))
}
}
}
Example with 'unsafe' creation of Logger within class
class RecipeDao2[F[_]: Monad: Logging] {
private val logger = Logging[F].getLoggerFromClass(getClass)
def get(id: String): F[Option[RecipeDetails]] = {
logger.info(Map("extraParam" -> "0"))("requesting with id=" + id) *>
Applicative[F].pure(Some(RecipeDetails(id)))
}
}Injecting more powerful MDCLogging[F[_]] construct when needed the access to underlying context
class Live(recipeDao: RecipeDao[Task], recipeDao2: RecipeDao2[Task])(implicit logging: MDCLogging[Task])
extends Service {
override def getRecipe(request: GetRecipeRequest): ZIO[Has[User], Status, GetRecipeResponse] = {
(for {
user <- ZIO.service[User]
logger <- logging.fromName(getClass.getName)
_ <- logger.info("logging request: " + user)
_ <- logging.withLocal(Map("localValue" -> "123")) {
logger.info("local message")
}
details <- recipeDao.get(request.id)
_ <- recipeDao2.get(request.id)
} yield {
GetRecipeResponse(details)
}).mapError(Status.fromThrowable)
}
}