更改容器运行时的日志级别

Question

im using logrus for logging for out applications which run on K8S we have env variable which we can set the log-level and change it when we restart out application our applications is running with docker containers on k8s Now we want to change the log-level on runtime, i.e. don’t restart the container and change it when it’s running and with this we can change it from error to debug, I think this is legitimic request but didn’t find any reference or any open source which doing this, any idea?

package logs

import (
    "fmt"
    "os"

    "github.com/sirupsen/logrus"
)

const (
    AppLogLevel = “APP_LOG_LEVEL"
    DefLvl = "info"
)


var Logger *logrus.Logger


func NewLogger() *logrus.Logger {

    var level logrus.Level
    lvl := getLogLevel()
    // In case level doesn't set will not print any message
    level = logLevel(lvl)
    logger := &logrus.Logger{
        Out:   os.Stdout,
        Level: level,
    }
    Logger = logger
    return Logger
}

// use from env
func getLogLevel() string {
    lvl, _ := os.LookupEnv(AppLogLevel)
    if lvl != "" {
        return lvl
    }
    return DefLvl
}

func logLevel(lvl string) logrus.Level {

    switch lvl {
    case "debug":
        // Used for tracing
        return logrus.DebugLevel
    case "info":
        return logrus.InfoLevel
    case "error":
        return logrus.ErrorLevel
    case "fatal":
        return logrus.FatalLevel
    default:
        panic(fmt.Sprintf("the specified %s log level is not supported", lvl))
    }
}

I know how to change the log level but I need a way to infuance the logger to change the level

Answer 1

You can run the command kubectl exec -it <container_name> bash and use the command line inside the container to change the environment variable . You can do it by running the command export LOG_LEVEL=debug or export LOG_LEVEL=error inside the container.