Keep the pid of the process, replace the executable file
example code
package main
import _ "embed"
import (
"fmt"
reload "github.com/cic-sap/go-hot-reload/v1"
"log"
"net/http"
"os"
"time"
)
import "github.com/gin-gonic/gin"
//go:embed ver.txt
var ver string
func main() {
log.Println("start")
log.SetFlags(log.Lshortfile | log.LstdFlags)
go reload.AutoReload()
// your app code ...
go func() {
for {
time.Sleep(time.Second)
log.Println("ver", ver, "pid", os.Getpid())
}
}()
r := gin.Default()
r.GET("/", func(c *gin.Context) {
c.String(http.StatusOK, fmt.Sprintf("hello ver:%s", ver))
})
r.Run("0.0.0.0:2345")
log.Println("end")
}
How to replace k8s pod process online
example
build-new:
date +"%H:%M:%S" > ver.txt
go build -o example.new .
http-hot_reload:build-new
curl http://127.0.0.1:8087/upload -F "file=@./example.new" -v
set -ex
export KUBECONFIG=~/.kube/kubeconfig--gcp01.yaml
(GOOS=linux go build -o myapp main.go ;mv myapp myapp.tmp;gzip -fv myapp.tmp) &
name=`kubectl get pods -n ns1 -l app=myapp -o=jsonpath='{.items[0].metadata.name}'`
wait
kubectl get pods -n ns1 -l app=myapp &
kubectl -n ns1 cp myapp.tmp.gz $name:/usr/local/bin/myapp.tmp.gz
kubectl -n ns1 exec $name -- sh -x -c 'cd /usr/local/bin/;pwd;ls -alh myapp*;gzip -f -d -v myapp.tmp.gz;mv -f -v myapp.tmp myapp;ls -alh myapp*;'