https://github.com/bryanmikaelian/clj-polylith-slf4j-logback-example
A small demo with Clojure and Polylith showing how to configure SLF4J + Logback
https://github.com/bryanmikaelian/clj-polylith-slf4j-logback-example
clojure logback pedestal polylith sl4fj slf4j-api
Last synced: 2 months ago
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A small demo with Clojure and Polylith showing how to configure SLF4J + Logback
- Host: GitHub
- URL: https://github.com/bryanmikaelian/clj-polylith-slf4j-logback-example
- Owner: bryanmikaelian
- License: mit
- Created: 2024-08-07T12:48:44.000Z (10 months ago)
- Default Branch: main
- Last Pushed: 2024-08-07T13:25:20.000Z (10 months ago)
- Last Synced: 2025-01-19T13:25:30.581Z (4 months ago)
- Topics: clojure, logback, pedestal, polylith, sl4fj, slf4j-api
- Language: Clojure
- Homepage:
- Size: 19.5 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# clj-polylith-slf4j-logback-example
A small demo with Clojure and Polylith showing how to configure SLF4J + Logback
## Background
This polylith workspace has one base: `server`. This base has logging configured with the following libraries:
- `io.pedestal/pedestal.log`
- `org.slf4j/slf4j-api`
- `ch.qos.logback/logback-classic`
It also configures a `development` project and `server` project that generates a `jar` artifact.
In the development project, logback will use `resources/logback-test.xml` but in the jar file, we will use `bases/server/resources/logback.xml`
The most important take away from all this:
**logback.xml must at the top of the resources folder. It cannot be nested under something like `bases/server/resources/server/logback.xml`**
## Requirements
- Clojure 1.11
- Java 21 (although it probably works with other LTS versions)
- A working REPL (this project used nrepl + conjure)
## Demo
### JAR File
Using `clojure.tools.build`, we can generate a `jar` file like so
```
clj -T:build uberjar :project server
```
You should see the following output:
```
Compiling com.example.server.core...
Building uberjar target/server.jar...
Uberjar is built.
```
Run the jar like so and note how the `l/debug` statement is not printed based [on our configuration](https://github.com/bryanmikaelian/clj-polylith-slf4j-logback-example/blob/main/bases/server/resources/logback.xml#L9)
```
java -jar projects/server/target/server.jar
````
```
INFO com.example.server.core - {:msg "hello. I show up in production.", :line 10}
ERROR com.example.server.core - {:msg "hello. I show up in production.", :line 11}
WARN com.example.server.core - {:msg "hello. I show up in production.", :line 12}
```
### REPL
Start a repl
```
clj -A:dev
```
You should see the following log output immediately. Note the `DEBUG` statement because our [development configuration allows for debug logs](https://github.com/bryanmikaelian/clj-polylith-slf4j-logback-example/blob/main/development/resources/logback-test.xml)
```
INFO com.example.server.core - {:msg "hello. I show up in production.", :line 10}
ERROR com.example.server.core - {:msg "hello. I show up in production.", :line 11}
WARN com.example.server.core - {:msg "hello. I show up in production.", :line 12}
DEBUG com.example.server.core - {:msg "hello. I show up in development.", :line 13}
```