pkg/logger

[applejag]

Logging! It's finally here!

Took heavy inspiration from https://github.com/rs/zerolog in the architecture and pretty console output.
The code base may seem bloated, but I think it's more readable than zerolog's source code.

Dont be afraid of bashing it even though it has all those pretty comments in it.

Motive

The requested feature set was this:

• LogLevel
• Multiple writers/sinks (ex: JSON for Kibana & pretty for console)
• Scope per-module configs (ex: warn for Gin, info for API audits)
• Easy integration with Gin-Gonic
• Easy integration with GORM
• Easy integration with io.Writer's, ex gin.DefaultWriter & gin.DefaultErrorWriter
• Fields (WithString, WithInt...)

When coding this I tried to find an existing logger with similar features, and then wrap it inside some abstraction. I then noticed that the concrete implementation is so small so I chose to not depend on any external logging library.

Preview

Sample output of the different pre-packaged Sink types.

pkg/logger/consolepretty

pkg/logger/consolejson

{"level":"debug","date":"2021-06-18T15:01:29+02:00","caller":"wharf-core/main.go","line":20,"scope":"TEST","message":"Sample","hello":"world"}
{"level":"info","date":"2021-06-18T15:01:29+02:00","caller":"wharf-core/main.go","line":21,"scope":"TEST","message":"Sample","hello":"world","error":"EOF"}
{"level":"warn","date":"2021-06-18T15:01:29+02:00","caller":"wharf-core/main.go","line":22,"scope":"TEST","message":"Sample","hello":"world","someSpan":1000000000}
{"level":"error","date":"2021-06-18T15:01:29+02:00","caller":"wharf-core/main.go","line":23,"scope":"TEST","message":"Sample","hello":"world"}
{"level":"debug","date":"2021-06-18T15:01:29+02:00","caller":"gorm@v1.21.11/callbacks.go","line":133,"scope":"GORM","rows":0,"elapsed":120476,"sql":"SELECT * FROM \"users\" WHERE \"users\".\"id\" = 125 AND \"users\".\"deleted_at\" IS NULL"}
{"level":"warn","date":"2021-06-18T15:01:29+02:00","caller":"fmt/print.go","line":205,"scope":"GIN-debug","message":"Running in \"debug\" mode. Switch to \"release\" mode in production.\n - using env:\texport GIN_MODE=release\n - using code:\tgin.SetMode(gin.ReleaseMode)"}
{"level":"debug","date":"2021-06-18T15:01:29+02:00","caller":"fmt/print.go","line":205,"scope":"GIN-debug","message":"Environment variable PORT is undefined. Using port :8080 by default"}
{"level":"debug","date":"2021-06-18T15:01:29+02:00","caller":"fmt/print.go","line":205,"scope":"GIN-debug","message":"Listening and serving HTTP on :8080"}
{"level":"debug","date":"2021-06-18T15:01:37+02:00","caller":"gin@v1.7.1/logger.go","line":268,"scope":"GIN","clientIp":"::1","method":"GET","path":"/","status":404,"latency":311}
{"level":"debug","date":"2021-06-18T15:01:38+02:00","caller":"gin@v1.7.1/logger.go","line":268,"scope":"GIN","clientIp":"::1","method":"GET","path":"/favicon.ico","status":404,"latency":391}

[Pikabanga]

Before I review this, I have an important question.

Is this flog compatible? :D

[applejag]

Before I review this, I have an important question.

Is this flog compatible? :D

Hehe the JSON variant is, but will add support for our custom syntax

[fredx30]

For 2000+ lines of new functionality we could have an rfc.
The description is good in the aspect that it describes what it is. It need a description of why this. Why not any other exsisting plug and play log library?

[applejag]

@fredx30
For 2000+ lines of new functionality we could have an rfc.
The description is good in the aspect that it describes what it is. It need a description of why this. Why not any other exsisting plug and play log library?

Have updated the description with this:

The requested feature set was this:

• LogLevel
• Multiple writers/sinks (ex: JSON for Kibana & pretty for console)
• Scope per-module configs (ex: warn for Gin, info for API audits)
• Easy integration with Gin-Gonic
• Easy integration with GORM
• Easy integration with io.Writer's, ex gin.DefaultWriter & gin.DefaultErrorWriter
• Fields (WithString, WithInt...)

When coding this I tried to find an existing logger with similar features, and then wrap it inside some abstraction. I then noticed that the concrete implementation is so small so I chose to not depend on any external logging library.

Hopefully that answers your wonder.

It was quite difficult to split this one up into smaller PRs.

An RFC would've been suitable here, yes.

[Alexamakans]

Mostly nits and typo corrections from me.

[Alexamakans]

LGTM 👍🏻

[Alexamakans]

Oops, forgot these. Sorry.

[Alexamakans]

LGTM 👍🏻
For real this time!