Documentation
¶
Overview ¶
Package httpmw provides outbound HTTP-client middleware: composable http.RoundTripper wrappers for resilient calls to upstream services.
RetryTransport retries throttled/unavailable responses (429 and 503 by default) using the shared worker.Backoff policy, honoring a server-supplied Retry-After header (RFC 7231 §7.1.3) when present. It rewinds the request body between attempts (buffering in memory when the body is not otherwise replayable) and aborts as soon as the request context is cancelled. Wrap it around any http.RoundTripper (or http.DefaultTransport when nil) and install it on an http.Client.
Usage ¶
client := &http.Client{
Transport: httpmw.NewRetryTransport(nil, httpmw.RetryConfig{
Backoff: worker.Backoff{
Base: 200 * time.Millisecond, Max: 5 * time.Second,
MaxAttempts: 4, Jitter: 0.2,
},
}),
}
resp, err := client.Get("https://upstream/api")
Config ¶
RetryConfig fields:
- Backoff (worker.Backoff): inter-attempt delay and the total-attempt budget via MaxAttempts. MaxAttempts <= 1 disables retries (a single try).
- Statuses ([]int): status codes that trigger a retry. Empty defaults to {429 Too Many Requests, 503 Service Unavailable}.
- DisableRetryAfter (bool): when false (default), a retryable response's Retry-After value (delta-seconds or HTTP-date) is preferred over the backoff delay, clamped to Backoff.Max when Max > 0.
- Rand (func() float64): source of backoff jitter in [0,1); defaults to math/rand/v2. Override for deterministic tests.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type RetryConfig ¶
type RetryConfig struct {
// Backoff drives the delay between attempts and the total-attempt budget via
// its MaxAttempts field. MaxAttempts <= 1 disables retries (a single try).
Backoff worker.Backoff
// Statuses are the response status codes that trigger a retry. When empty it
// defaults to {429 Too Many Requests, 503 Service Unavailable}.
Statuses []int
// DisableRetryAfter turns off honoring the server's Retry-After header. By
// default (false) a Retry-After value (delta-seconds or HTTP-date) on a
// retryable response is used in preference to the backoff delay, clamped to
// Backoff.Max when Max > 0.
DisableRetryAfter bool
// Rand returns a pseudo-random value in [0,1) used for backoff jitter. It
// defaults to math/rand/v2; override it in tests for determinism.
Rand func() float64
}
RetryConfig configures a RetryTransport.
type RetryTransport ¶
type RetryTransport struct {
// contains filtered or unexported fields
}
RetryTransport is an http.RoundTripper that retries retryable responses according to its RetryConfig. The zero value is not usable; build it with NewRetryTransport.
func NewRetryTransport ¶
func NewRetryTransport(next http.RoundTripper, cfg RetryConfig) *RetryTransport
NewRetryTransport wraps next (or http.DefaultTransport when nil) with retry behavior. The result is safe for concurrent use if next is.
Source Files