利用Go语言快速实现一个极简任务调度系统

package main
​
import (
  "fmt"
  "github.com/gin-gonic/gin"
  "os"
)
​
func main() {
  // api engine
  app := gin.New()
​
  // api routes
  app.GET("/jobs", GetJobs)
  app.POST("/jobs", AddJob)
  app.DELETE("/jobs", DeleteJob)
​
  // run api on port 9092
  if err := app.Run(":9092"); err != nil {
    _, err = fmt.Fprintln(os.Stderr, err)
    os.Exit(1)
  }
}

package main
​
import "github.com/gin-gonic/gin"
​
func GetJobs(c *gin.Context) {
  // TODO: implementation here
}
​
func AddJob(c *gin.Context) {
  // TODO: implementation here
}
​
func DeleteJob(c *gin.Context) {
  // TODO: implementation here
}

package main
​
import "github.com/robfig/cron"
​
func init() {
  // start to run
  Cron.Run()
}
​
// Cron create a new cron.Cron instance
var Cron = cron.New()

package main
​
import (
  "github.com/gin-gonic/gin"
  "github.com/robfig/cron/v3"
  "net/http"
  "strconv"
)
​
func GetJobs(c *gin.Context) {
  // return a list of cron job entries
  var results []map[string]interface{}
  for _, e := range Cron.Entries() {
    results = append(results, map[string]interface{}{
      "id":   e.ID,
      "next": e.Next,
    })
  }
  c.JSON(http.StatusOK, Cron.Entries())
}
​
func AddJob(c *gin.Context) {
  // post JSON payload
  var payload struct {
    Cron string `json:"cron"`
    Exec string `json:"exec"`
  }
  if err := c.ShouldBindJSON(&payload); err != nil {
    c.AbortWithStatus(http.StatusBadRequest)
    return
  }
​
  // add cron job
  eid, err := Cron.AddFunc(payload.Cron, func() {
    // TODO: implementation here
  })
  if err != nil {
    c.AbortWithStatusJSON(http.StatusInternalServerError, map[string]interface{}{
      "error": err.Error(),
    })
    return
  }
​
  c.AbortWithStatusJSON(http.StatusOK, map[string]interface{}{
    "id": eid,
  })
}
​
func DeleteJob(c *gin.Context) {
  // cron job entry id
  id := c.Param("id")
  eid, err := strconv.Atoi(id)
  if err != nil {
    c.AbortWithStatus(http.StatusBadRequest)
    return
  }
​
  // remove cron job
  Cron.Remove(cron.EntryID(eid))
​
  c.AbortWithStatus(http.StatusOK)
}

package main
​
import (
  "fmt"
  "os"
  "os/exec"
  "strings"
)
​
func ExecuteTask(execCmd string) {
  // execute command string parts, delimited by space
  execParts := strings.Split(execCmd, " ")
​
  // executable name
  execName := execParts[0]
​
  // execute command parameters
  execParams := strings.Join(execParts[1:], " ")
​
  // execute command instance
  cmd := exec.Command(execName, execParams)
​
  // run execute command instance
  if err := cmd.Run(); err != nil {
    _, err = fmt.Fprintln(os.Stderr, err)
    fmt.Println(err.Error())
  }
}

...
  // add cron job
  eid, _ := Cron.AddFunc(payload.Cron, func() {
    ExecuteTask(payload.Exec)
  })
...

[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)
​
[GIN-debug] GET    /jobs                     --> main.GetJobs (1 handlers)
[GIN-debug] POST   /jobs                     --> main.AddJob (1 handlers)
[GIN-debug] DELETE /jobs/:id                 --> main.DeleteJob (1 handlers)
[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.
[GIN-debug] Listening and serving HTTP on :9092