JarCastingLogZ
Simple lightweight logging library
- Composable
- Modular
- Open to extension
- And it can help you to save some money with Log Buffer .
Getting Started
Add the following dependencies to you build.sbt
"com.github.jeffersonzapata" %% "logz-core" % "0.0.1" // core lightweight abstractions
"com.github.jeffersonzapata" %% "logz-test-instances" % "0.0.1" // test instances
"com.github.jeffersonzapata" %% "logz-slf4j" % "0.0.1" // slf4j instances
"com.github.jeffersonzapata" %% "logz-context-provider" % "0.0.1"
Core Module
let your functions/libraries be part of the application history without committing to a specific implementation (it doesn't depends on any external dependencies).
import logz.Logger
def addTwoNumbers(a: Int, b: Int)(implicit logger: Logger[IO]): IO[Int] = {
for {
_ <- Logger.debug[IO](s"I'm adding $a plus $b")
c <- IO(a + b)
_ <- Logger.info[IO](s"The result is $c!")
} yield c
}
Logz Instances
Choose how the history should be written. logz-slf4j, logz-test-instances and logz-context-provider provide useful implementations
logz-slf4j
SLF4JLogger provides a SLF4J basic implementation
import logz.Logger
import logz.instances.slf4j.SLF4JLogger
val slf4jLogger = org.slf4j.LoggerFactory.getLogger("LogzExample")
implicit val logger: Logger[IO] = SLF4JLogger[IO](slf4jLogger)
addTwoNumbers(4, 6)
//[main] DEBUG LogzExample - I'm adding 4 plus 6
//[main] INFO LogzExample - the result is 10!
Add context to your logs with LoggerContext
// Context will marks you logs with a identifier
import logz.instances.slf4j.SLF4JLoggerMarkerContext // recommended
import logz.instances.slf4j.SLF4JLoggerMDCContext // not recommend for multi-thread applications
val slf4jLogger = org.slf4j.LoggerFactory.getLogger("LogzExample")
implicit val loggerContext: LoggerContext[IO] = SLF4JLoggerMarkerContext[IO](slf4jLogger)
val ctx: Context = Context()
for {
result <- addTwoNumbers(4, 6)
_ <- LoggerContext.info[IO](ctx)(s"I got the result $result!")
} yield result
//[main] DEBUG LogzExample - I'm adding 4 plus 6 // you can add a `context_id` to these logs without modifying
//[main] INFO LogzExample - the result is 10! // the `addTwoNumbers` function by using `LoggerCtxProvided`
//[main] INFO LogzExample {context_id=e7ebce44-b7b0-4993-acdc-530d9e3d2bcc} - I got the result 10!
logz-context-provider
LoggerCtxProvided makes your life easier
import logz.instances.slf4j.SLF4JLoggerMarkerContext
import logz.syntax.context._
val slf4jLogger = org.slf4j.LoggerFactory.getLogger("LogzExample")
val loggerContext: LoggerContext[IO] = SLF4JLoggerMarkerContext[IO](slf4jLogger)
implicit val loggerCtxProvided: LoggerCtxProvided[IO] = Context().toLoggerCtxProvided(loggerContext)
for {
result <- addTwoNumbers(4, 6)
_ <- LoggerCtxProvided.info[IO](s"I got the result $result!") // yep, no need to pass `context1`
_ <- LoggerCtxProvided.debug[IO](s"We got a context_id for free!")
} yield result
//[main] DEBUG LogzExample {context_id=a5a741a8-a0b6-4406-82f4-4cef0d883a8e} - I'm adding 4 plus 6
//[main] INFO LogzExample {context_id=a5a741a8-a0b6-4406-82f4-4cef0d883a8e} - the result is 10!
//[main] INFO LogzExample {context_id=a5a741a8-a0b6-4406-82f4-4cef0d883a8e} - I got the result 10!
//[main] DEBUG LogzExample {context_id=a5a741a8-a0b6-4406-82f4-4cef0d883a8e} - We got a context_id for free
LoggerCtxProvidedBuffer takes care of your disk space and your time looking for errors by writing the complete log's history only when a Warning or an Error is being logged
import logz.instances.slf4j.SLF4JLoggerMarkerContext
import logz.syntax.context._
val slf4jLogger = org.slf4j.LoggerFactory.getLogger("LogzExample")
val loggerContext: LoggerContext[IO] = SLF4JLoggerMarkerContext[IO](slf4jLogger)
Context().toLoggerCtxProvidedBuffer[IO, Int](loggerContext)(implicit logger =>
for {
result <- addTwoNumbers(4, 6)
_ <- Logger.info[IO](s"I got the result $result!")
_ <- LoggerCtxProvidedBuffer.debugB[IO](s"This will only be written if there is a Warning or an Error log")
_ <- LoggerCtxProvidedBuffer.warnB[IO](s"I will write the previous logs")
_ <- LoggerCtxProvidedBuffer.infoB[IO](s"I won't show up, you don't need me")
} yield result
)
//[main] DEBUG LogzExample {context_id=95000a64-2d7b-4152-b1b6-869cef907eda} - I'm adding 4 plus 6
//[main] INFO LogzExample {context_id=95000a64-2d7b-4152-b1b6-869cef907eda} - the result is 10!
//[main] INFO LogzExample {context_id=95000a64-2d7b-4152-b1b6-869cef907eda} - I got the result 10!
//[main] DEBUG LogzExample {context_id=95000a64-2d7b-4152-b1b6-869cef907eda} - This will only be written if there is a Warning or an Error log
//[main] WARN LogzExample {context_id=95000a64-2d7b-4152-b1b6-869cef907eda} - I will write the previous log
logz-test-instances
Provides your tests with an in memory logger
import logz.instances.TestLogger
import logz.instances.TestLoggerContext
// Example
val slf4j: org.slf4j.Logger = TestLoggerFactory.getTestLogger("TestSLF4JLoggerMarkerContextSpec").pure[IO]
implicit val logger: LoggerContext[IO] = SLF4JLoggerMarkerContext[IO](slf4j)
myGreatLibrary[IO]()