From 498f32bab96ba00e1a7d04c6bc8b367c97d8a335 Mon Sep 17 00:00:00 2001 From: Cory Cooper Date: Wed, 5 Oct 2022 21:34:49 -0700 Subject: caddyconfig: Implement retries into HTTPLoader (#5077) * httploader: Add max_retries * caddyconfig: dependency-free http config loading retries * caddyconfig: support `retry_delay` in http loader * httploader: Implement retries * Apply suggestions from code review Co-authored-by: Matt Holt Co-authored-by: Matt Holt --- caddyconfig/httploader.go | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'caddyconfig') diff --git a/caddyconfig/httploader.go b/caddyconfig/httploader.go index 80eab44..f199219 100644 --- a/caddyconfig/httploader.go +++ b/caddyconfig/httploader.go @@ -94,7 +94,7 @@ func (hl HTTPLoader) LoadConfig(ctx caddy.Context) ([]byte, error) { } } - resp, err := client.Do(req) + resp, err := doHttpCallWithRetries(ctx, client, req) if err != nil { return nil, err } @@ -119,6 +119,37 @@ func (hl HTTPLoader) LoadConfig(ctx caddy.Context) ([]byte, error) { return result, nil } +func attemptHttpCall(client *http.Client, request *http.Request) (*http.Response, error) { + resp, err := client.Do(request) + if err != nil { + return nil, fmt.Errorf("problem calling http loader url: %v", err) + } else if resp.StatusCode < 200 || resp.StatusCode > 499 { + return nil, fmt.Errorf("bad response status code from http loader url: %v", resp.StatusCode) + } + return resp, nil +} + +func doHttpCallWithRetries(ctx caddy.Context, client *http.Client, request *http.Request) (*http.Response, error) { + var resp *http.Response + var err error + const maxAttempts = 10 + + // attempt up to 10 times + for i := 0; i < maxAttempts; i++ { + resp, err = attemptHttpCall(client, request) + if err != nil && i < maxAttempts-1 { + // wait 500ms before reattempting, or until context is done + select { + case <-time.After(time.Millisecond * 500): + case <-ctx.Done(): + return resp, ctx.Err() + } + } + } + + return resp, err +} + func (hl HTTPLoader) makeClient(ctx caddy.Context) (*http.Client, error) { client := &http.Client{ Timeout: time.Duration(hl.Timeout), -- cgit v1.2.3