From 2c61b50b5f4d206ea714d7b6e99e10b51ca01aed Mon Sep 17 00:00:00 2001
From: Francis Lavoie <lavofr@gmail.com>
Date: Sat, 15 Apr 2023 08:44:12 -0400
Subject: [PATCH] Add `min_successes`

---
 modules/caddyhttp/reverseproxy/caddyfile.go    | 17 +++++++++++++++++
 modules/caddyhttp/reverseproxy/healthchecks.go |  8 ++++++++
 modules/caddyhttp/reverseproxy/reverseproxy.go |  4 ++++
 3 files changed, 29 insertions(+)

diff --git a/modules/caddyhttp/reverseproxy/caddyfile.go b/modules/caddyhttp/reverseproxy/caddyfile.go
index c12fb2ec0..119f433df 100644
--- a/modules/caddyhttp/reverseproxy/caddyfile.go
+++ b/modules/caddyhttp/reverseproxy/caddyfile.go
@@ -79,6 +79,7 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
 //	    max_fails         <num>
 //	    success_duration  <duration>
 //	    min_success_ratio <ratio>
+//	    min_success       <num>
 //	    unhealthy_status  <status>
 //	    unhealthy_latency <duration>
 //	    unhealthy_request_count <num>
@@ -456,6 +457,22 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 				}
 				h.HealthChecks.Passive.MinSuccessRatio = ratio
 
+			case "min_successes":
+				if !d.NextArg() {
+					return d.ArgErr()
+				}
+				if h.HealthChecks == nil {
+					h.HealthChecks = new(HealthChecks)
+				}
+				if h.HealthChecks.Passive == nil {
+					h.HealthChecks.Passive = new(PassiveHealthChecks)
+				}
+				count, err := strconv.Atoi(d.Val())
+				if err != nil {
+					return d.Errf("invalid minimum success count '%s': %v", d.Val(), err)
+				}
+				h.HealthChecks.Passive.MinSuccesses = count
+
 			case "fail_duration":
 				if !d.NextArg() {
 					return d.ArgErr()
diff --git a/modules/caddyhttp/reverseproxy/healthchecks.go b/modules/caddyhttp/reverseproxy/healthchecks.go
index 20ba0b9bf..14782e71b 100644
--- a/modules/caddyhttp/reverseproxy/healthchecks.go
+++ b/modules/caddyhttp/reverseproxy/healthchecks.go
@@ -127,6 +127,14 @@ type PassiveHealthChecks struct {
 	// must be configured for those stats to be counted. Default is 0 (no ratio).
 	MinSuccessRatio caddyhttp.Ratio `json:"min_success_ratio,omitempty"`
 
+	// The minimum number of successful requests before considering the
+	// minimum success ratio. Default is 5. Requires MinSuccessRatio >= 0.
+	//
+	// If there are less than this many successful requests, then the ratio is
+	// ignored, because of a lack of data. This ensures that the upstream isn't
+	// prematurely considered unhealthy because no requests have happened yet.
+	MinSuccesses int `json:"min_successes,omitempty"`
+
 	// Limits the number of simultaneous requests to a backend by
 	// marking the backend as "down" if it has this many concurrent
 	// requests or more.
diff --git a/modules/caddyhttp/reverseproxy/reverseproxy.go b/modules/caddyhttp/reverseproxy/reverseproxy.go
index ad0bcfcf0..6ba98da77 100644
--- a/modules/caddyhttp/reverseproxy/reverseproxy.go
+++ b/modules/caddyhttp/reverseproxy/reverseproxy.go
@@ -352,6 +352,10 @@ func (h *Handler) Provision(ctx caddy.Context) error {
 			if h.HealthChecks.Passive.FailDuration > 0 && h.HealthChecks.Passive.MaxFails == 0 {
 				h.HealthChecks.Passive.MaxFails = 1
 			}
+
+			if h.HealthChecks.Passive.MinSuccessRatio > 0 && h.HealthChecks.Passive.MinSuccesses == 0 {
+				h.HealthChecks.Passive.MinSuccesses = 5
+			}
 		}
 
 		// if active health checks are enabled, configure them and start a worker