A simple and configurable retry library for go, with exponential backoff, and constant delay support out of the box. Inspired by backoff.
Check test files to see example of usage again_test.go.
There two main concepts:
- Retry: Given an operation and a ticks calculator keeps retrying until either permanent error or timeout happen
- TicksCalculator: Provide delay for retryer to wait between retries
package main
import (
"context"
"errors"
"fmt"
"net/http"
"github.com/jdvr/go-again"
)
func main() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
err := again.Retry(ctx, func(ctx context.Context) error {
fmt.Println("Running Operation")
resp, err := http.DefaultClient.Get("https://sameflaky.api/path")
if err != nil {
// operation will be retried
return err
}
if resp.StatusCode == http.StatusForbidden {
// no more retries
return again.NewPermanentError(errors.New("no retry, permanent error"))
}
if resp.StatusCode > 400 {
return errors.New("this will be retry")
}
// do whatever you need with a valid response ...
return nil // no retry
})
if err != nil {
panic(err)
}
fmt.Println("Finished")
}package main
import (
"context"
"database/sql"
"errors"
"fmt"
"time"
"github.com/jdvr/go-again"
)
type dbOperation struct {
repo Repo
}
func(db dbOperation) Run(ctx context.Context) error {
fmt.Println("Running Operation")
resp, err := db.repo.GetAll()
if err != nil {
if errors.Is(err, sql.ErrConnDone) {
return again.NewPermanentError(fmt.Errorf("no retry, permanent error: %w", err))
}
// operation will be retried
return err
}
// do whatever you need with a valid response ...
return nil // no retry
}
func main() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
constantRetryer := again.WithConstantDelay(15 * time.Millisecond, 30 * time.Second)
err := constantRetryer.Retry(ctx, dbOperation{})
if err != nil {
panic(err)
}
fmt.Println("Finished")
}make test
- Get rid of manual mocks
- Improve flaky testing (depends on system clock)
- Configure the linter