mirror of https://github.com/k3s-io/k3s
99 lines
2.1 KiB
Markdown
99 lines
2.1 KiB
Markdown
|
# retry
|
||
|
|
|
||
|
|
[](https://travis-ci.org/Rican7/retry)
|
||
|
|
[](https://godoc.org/github.com/Rican7/retry)
|
||
|
|
[](http://goreportcard.com/report/Rican7/retry)
|
||
|
|
[](https://github.com/Rican7/retry/releases)
|
||
|
|
|
||
|
|
A simple, stateless, functional mechanism to perform actions repetitively until successful.
|
||
|
|
|
||
|
|
|
||
|
|
## Project Status
|
||
|
|
|
||
|
|
This project is currently in "pre-release". While the code is heavily tested, the API may change.
|
||
|
|
Vendor (commit or lock) this dependency if you plan on using it.
|
||
|
|
|
||
|
|
|
||
|
|
## Install
|
||
|
|
|
||
|
|
`go get github.com/Rican7/retry`
|
||
|
|
|
||
|
|
|
||
|
|
## Examples
|
||
|
|
|
||
|
|
### Basic
|
||
|
|
|
||
|
|
```go
|
||
|
|
Retry(func(attempt uint) error {
|
||
|
|
return nil // Do something that may or may not cause an error
|
||
|
|
})
|
||
|
|
```
|
||
|
|
|
||
|
|
### File Open
|
||
|
|
|
||
|
|
```go
|
||
|
|
const logFilePath = "/var/log/myapp.log"
|
||
|
|
|
||
|
|
var logFile *os.File
|
||
|
|
|
||
|
|
err := Retry(func(attempt uint) error {
|
||
|
|
var err error
|
||
|
|
|
||
|
|
logFile, err = os.Open(logFilePath)
|
||
|
|
|
||
|
|
return err
|
||
|
|
})
|
||
|
|
|
||
|
|
if nil != err {
|
||
|
|
log.Fatalf("Unable to open file %q with error %q", logFilePath, err)
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
### HTTP request with strategies and backoff
|
||
|
|
|
||
|
|
```go
|
||
|
|
var response *http.Response
|
||
|
|
|
||
|
|
action := func(attempt uint) error {
|
||
|
|
var err error
|
||
|
|
|
||
|
|
response, err = http.Get("https://api.github.com/repos/Rican7/retry")
|
||
|
|
|
||
|
|
if nil == err && nil != response && response.StatusCode > 200 {
|
||
|
|
err = fmt.Errorf("failed to fetch (attempt #%d) with status code: %d", attempt, response.StatusCode)
|
||
|
|
}
|
||
|
|
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
|
||
|
|
err := Retry(
|
||
|
|
action,
|
||
|
|
strategy.Limit(5),
|
||
|
|
strategy.Backoff(backoff.Fibonacci(10*time.Millisecond)),
|
||
|
|
)
|
||
|
|
|
||
|
|
if nil != err {
|
||
|
|
log.Fatalf("Failed to fetch repository with error %q", err)
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
### Retry with backoff jitter
|
||
|
|
|
||
|
|
```go
|
||
|
|
action := func(attempt uint) error {
|
||
|
|
return errors.New("something happened")
|
||
|
|
}
|
||
|
|
|
||
|
|
seed := time.Now().UnixNano()
|
||
|
|
random := rand.New(rand.NewSource(seed))
|
||
|
|
|
||
|
|
Retry(
|
||
|
|
action,
|
||
|
|
strategy.Limit(5),
|
||
|
|
strategy.BackoffWithJitter(
|
||
|
|
backoff.BinaryExponential(10*time.Millisecond),
|
||
|
|
jitter.Deviation(random, 0.5),
|
||
|
|
),
|
||
|
|
)
|
||
|
|
```
|