fix(servicegroup): use logx for shutdown message

[AlexLast]

Currently when stopping a service in a ServiceGroup the standard logger is used, this changes the log line to use the logx package and ensure all log lines are of the same format.

[kevwan]

Here, we cannot guarantee that logx is still available, it might be closed already.

[codecov]

Codecov Report

Merging #3719 (8017c1f) into master (4003864) will decrease coverage by 0.03%.
The diff coverage is 100.00%.

Additional details and impacted files

Files	Coverage Δ
core/service/servicegroup.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

[AlexLast]

Here, we cannot guarantee that logx is still available, it might be closed already.

@kevwan Thanks for the feedback, what's the expected behaviour when logx is closed? With the default logx.LogConf I don't encounter any issues with this code. Does this only cause issues when writing to file?

I also can't seem to force an issue by manually closing logx, for example, the below still outputs logs:

logx.Close()
logx.Info("Foo")

Ideally I'd like my service logs to all be the same format (json) to keep parsing/shipping easier. Let me know what you think?

[kevwan]

Here, we cannot guarantee that logx is still available, it might be closed already.

@kevwan Thanks for the feedback, what's the expected behaviour when logx is closed? With the default logx.LogConf I don't encounter any issues with this code. Does this only cause issues when writing to file?

I also can't seem to force an issue by manually closing logx, for example, the below still outputs logs:

logx.Close()
logx.Info("Foo")

Ideally I'd like my service logs to all be the same format (json) to keep parsing/shipping easier. Let me know what you think?

If logx is closed already, logs are printed to console.

You can try it with the following code.

package main

import (
	"time"

	"github.com/zeromicro/go-zero/core/conf"
	"github.com/zeromicro/go-zero/core/logx"
)

func main() {
	var c logx.LogConf
	if err := conf.FillDefault(&c); err != nil {
		panic(err)
	}
	c.Mode = "file"
	logx.MustSetup(c)
	logx.Info("hello")
	logx.Close()

	time.Sleep(time.Second)
	logx.Info("world")
}

[kevwan]

LGTM.