61 lines
1.2 KiB
Go
61 lines
1.2 KiB
Go
|
// Package don is a little helper if you need to check for the readiness of something.
|
||
|
|
// This could be a command to run (like ssh) or a `db.Ping()` for check of the readiness
|
||
|
|
// of a database container.
|
||
|
|
package don
|
||
|
|
|
||
|
|
import (
|
||
|
|
"errors"
|
||
|
|
"os"
|
||
|
|
"os/exec"
|
||
|
|
"time"
|
||
|
|
|
||
|
|
"github.com/rs/zerolog/log"
|
||
|
|
)
|
||
|
|
|
||
|
|
var errTimeout = errors.New("timeout")
|
||
|
|
|
||
|
|
// Cmd returns a `func() bool` for working with don.Check. It executes a command and
|
||
|
|
// returns a true if everything looks fine or a false if there was some kind of error.
|
||
|
|
func Cmd(c string) func() bool {
|
||
|
|
return func() bool {
|
||
|
|
cmd := exec.Command("sh", "-c", c)
|
||
|
|
cmd.Stdout = os.Stdout
|
||
|
|
cmd.Stderr = os.Stderr
|
||
|
|
|
||
|
|
if err := cmd.Run(); err != nil {
|
||
|
|
log.Warn().Err(err).Msg("cmd has error")
|
||
|
|
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
|
||
|
|
return true
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Check takes a function that executes something and returns a bool to indicate if
|
||
|
|
// something is ready or not. It returns an error if it timeouts.
|
||
|
|
func Check(f func() bool, timeout time.Duration, retry time.Duration) error {
|
||
|
|
chReady := make(chan struct{})
|
||
|
|
|
||
|
|
go func() {
|
||
|
|
for {
|
||
|
|
if f() {
|
||
|
|
chReady <- struct{}{}
|
||
|
|
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
<-time.After(retry)
|
||
|
|
log.Info().Msg("retrying")
|
||
|
|
}
|
||
|
|
}()
|
||
|
|
|
||
|
|
select {
|
||
|
|
case <-chReady:
|
||
|
|
return nil
|
||
|
|
|
||
|
|
case <-time.After(timeout):
|
||
|
|
return errTimeout
|
||
|
|
}
|
||
|
|
}
|