SLF4J VS config

A few years ago, my team moved from Java to Go. Working on Go projects, we encountered a wide variety of logging frameworks with different APIs, configuration, and formatting. We soon found ourselves longing for a logging abstraction layer like Java’s slf4j, which had proven invaluable for use in reusable libraries or configuring and debugging production systems. So, not long after moving to Go, we began working toward replacing what we had lost in slf4j.

I'm not familiar with Serilog as I code mostly in Java, use slf4j (logs to stdout) and our apps send logs to Cloudwatch using the task definition's awslogs configuration. I prefer it this way because I can customize the log configurations in my task definitions. Also the default stream name has this format prefix-name/container-name/ecs-task-id so I can easily identify the logs of the task I want to look at. I haven't experienced any downsides with this approach and our apps publish a shit ton of logs. Cloudwatch approach looks like you can customize the stream name?

slf4j is open source. You can look at the code.

Java -> Logback, Log4j2, JDK (Java Util Logging), Slf4j, e.t.c.

slf4j para padronização dos logs;

SLF4J

> My God. Logging in protobuf?

Yes, or any other data format and/or transport protocol.

I'm surprised this is up for debate.

> Logging is the lowest of all debugging utilities - its the first thing you ever do writing software - “hello world”. And, while I admire structural logging, the truth is printing strings remains (truly) the lowest common denominator across software developers.

This sort of comment is terribly miopic. You can have a logging API, and then configure your logging to transport the events anywhere, any way. This is a terribly basic feature and requirement, and one that comes out of the box with some systems. Check how SLF4J[1] is pervasive in Java, and how any SLF4J implementation offers logging to stdout or a local file as a very specific and basic usecase.

It turns out that nowadays most developers write software that runs on many computers that aren't stashed over or under their desks, and thus they need efficient and convenient ways to check what's happening either in a node or in all deployments.

[1] https://www.slf4j.org/

I don‘t understand why HOCON (https://github.com/lightbend/config/blob/main/HOCON.md) isn‘t used more often (at least for configuration use cases). It‘s a superset of JSON, has comments, multiline strings, optional quotes, replacement syntax. We use it at many places, and it‘s as nice at it can get.

HOCON is a great human-readable alternative to JSON. It's a superset of JSON with lots of cool features that make it both more readable and easier to use.

Here's a rundown of HOCON's main features: https://github.com/lightbend/config#features-of-hocon

"Typesafe Config" is the library generally used to read configuration files in HOCON format, which this library introduced. It's commonly used in essentially OOP/imperative Scala contexts, including Akka and its ecosystem.

Interesting!

For my own servers I use an internal tool that integrates apps with systemd. You point it at the output of your build system and a config file, and it produces a deb that contains systemd unit files and which registers/starts the server on install/reboot/upgrade, as a regular debian package would. Then it uploads it to the server via sftp and installs it using apt, so dependencies are resolved. As part of the build process it can download and bundle language runtimes (I use it with a JVM), it scans native binaries to find packages that the app should depend on, and you can define your config including package metadata like dependencies and systemd units using the HOCON language [1].

Upshot is you can go from a Gradle or Maven build to a running server with a few lines of config. Oh and it can build debs from any OS, so you can push from macOS and Windows too. If your server needs to depend on e.g. Postgres, you just add that dependency in your config and it'll be up and running after the push.

It also has features to turn on DynamicUser and other sandboxing features. I think I'll experiment with socket activation next, and then bundled BorgBackup.

Net/net it's pretty nice. I haven't tried with containers because many language ecosystems don't seem to really need them for many use cases. If your build tool knows how to download your language runtime and bundle it sans container by just setting up paths correctly, then going without means you can rely on your Linux distribution to keep things up to date with security patches in the background, it means networking works as you'd expect (no accidentally opened firewall ports!) and so on. SystemD knows how to configure resource isolation/cgroups and kernel sandboxing, so if you need those you can just write that into your build config and it's done. Or not, as you wish.

With a deployment tool to automate builds/pushes, systemd to supervise processes and a big beefy dedicated machine to let you scale up, I wonder how much value the container part is really still providing if you don't need the full functionality of Kubernetes.

[1] https://github.com/lightbend/config/blob/main/HOCON.md

Other similar standards: TOML, HOCON

I've also used HOCON pretty extensively for config, and it is better than both YAML and JSON for config with moderate to high complexity.