From 4d8f81a992e9da89961daca09cf0b020816d1bda Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Wed, 4 Aug 2021 15:23:18 -0700
Subject: [PATCH] remove replicate set fallback behavior (#12865)

replica set deployment style is an incorrect
style of distributed MinIO deployment, since
statefulsets have been around for many releases
in k8s now.
---
 cmd/common-main.go |  2 +-
 cmd/endpoint.go    | 70 ----------------------------------------------
 cmd/update.go      |  5 ----
 3 files changed, 1 insertion(+), 76 deletions(-)

diff --git a/cmd/common-main.go b/cmd/common-main.go
index ae1b07560..6cc931c4b 100644
--- a/cmd/common-main.go
+++ b/cmd/common-main.go
@@ -71,7 +71,7 @@ func init() {
 	logger.Init(GOPATH, GOROOT)
 	logger.RegisterError(config.FmtError)
 
-	if IsKubernetes() || IsDocker() || IsBOSH() || IsDCOS() || IsKubernetesReplicaSet() || IsPCFTile() {
+	if IsKubernetes() || IsDocker() || IsBOSH() || IsDCOS() || IsPCFTile() {
 		// 30 seconds matches the orchestrator DNS TTLs, have
 		// a 5 second timeout to lookup from DNS servers.
 		globalDNSCache = xhttp.NewDNSCache(30*time.Second, 5*time.Second, logger.LogOnceIf)
diff --git a/cmd/endpoint.go b/cmd/endpoint.go
index 9cc6262dc..8b3f87e7c 100644
--- a/cmd/endpoint.go
+++ b/cmd/endpoint.go
@@ -377,27 +377,6 @@ func (endpoints Endpoints) GetAllStrings() (all []string) {
 	return
 }
 
-func hostResolveToLocalhost(endpoint Endpoint) bool {
-	hostIPs, err := getHostIP(endpoint.Hostname())
-	if err != nil {
-		// Log the message to console about the host resolving
-		reqInfo := (&logger.ReqInfo{}).AppendTags(
-			"host",
-			endpoint.Hostname(),
-		)
-		ctx := logger.SetReqInfo(GlobalContext, reqInfo)
-		logger.LogIf(ctx, err, logger.Application)
-		return false
-	}
-	var loopback int
-	for _, hostIP := range hostIPs.ToSlice() {
-		if net.ParseIP(hostIP).IsLoopback() {
-			loopback++
-		}
-	}
-	return loopback == len(hostIPs)
-}
-
 func (endpoints Endpoints) atleastOneEndpointLocal() bool {
 	for _, endpoint := range endpoints {
 		if endpoint.IsLocal {
@@ -410,7 +389,6 @@ func (endpoints Endpoints) atleastOneEndpointLocal() bool {
 // UpdateIsLocal - resolves the host and discovers the local host.
 func (endpoints Endpoints) UpdateIsLocal(foundPrevLocal bool) error {
 	orchestrated := IsDocker() || IsKubernetes()
-	k8sReplicaSet := IsKubernetesReplicaSet()
 
 	var epsResolved int
 	var foundLocal bool
@@ -443,24 +421,6 @@ func (endpoints Endpoints) UpdateIsLocal(foundPrevLocal bool) error {
 					endpoints[i].Hostname(),
 				)
 
-				if k8sReplicaSet && hostResolveToLocalhost(endpoints[i]) {
-					err := fmt.Errorf("host %s resolves to 127.*, DNS incorrectly configured retrying",
-						endpoints[i])
-					// time elapsed
-					timeElapsed := time.Since(startTime)
-					// log error only if more than 1s elapsed
-					if timeElapsed > time.Second {
-						reqInfo.AppendTags("elapsedTime",
-							humanize.RelTime(startTime,
-								startTime.Add(timeElapsed),
-								"elapsed",
-								""))
-						ctx := logger.SetReqInfo(GlobalContext, reqInfo)
-						logger.LogIf(ctx, err, logger.Application)
-					}
-					continue
-				}
-
 				// return err if not Docker or Kubernetes
 				// We use IsDocker() to check for Docker environment
 				// We use IsKubernetes() to check for Kubernetes environment
@@ -489,36 +449,6 @@ func (endpoints Endpoints) UpdateIsLocal(foundPrevLocal bool) error {
 				} else {
 					resolvedList[i] = true
 					endpoints[i].IsLocal = isLocal
-					if k8sReplicaSet && !endpoints.atleastOneEndpointLocal() && !foundPrevLocal {
-						// In replicated set in k8s deployment, IPs might
-						// get resolved for older IPs, add this code
-						// to ensure that we wait for this server to
-						// participate atleast one disk and be local.
-						//
-						// In special cases for replica set with expanded
-						// pool setups we need to make sure to provide
-						// value of foundPrevLocal from pool1 if we already
-						// found a local setup. Only if we haven't found
-						// previous local we continue to wait to look for
-						// atleast one local.
-						resolvedList[i] = false
-						// time elapsed
-						err := fmt.Errorf("no endpoint is local to this host: %s", endpoints[i])
-						timeElapsed := time.Since(startTime)
-						// log error only if more than 1s elapsed
-						if timeElapsed > time.Second {
-							reqInfo.AppendTags("elapsedTime",
-								humanize.RelTime(startTime,
-									startTime.Add(timeElapsed),
-									"elapsed",
-									"",
-								))
-							ctx := logger.SetReqInfo(GlobalContext,
-								reqInfo)
-							logger.LogIf(ctx, err, logger.Application)
-						}
-						continue
-					}
 					epsResolved++
 					if !foundLocal {
 						foundLocal = isLocal
diff --git a/cmd/update.go b/cmd/update.go
index 354bfd738..dda344aca 100644
--- a/cmd/update.go
+++ b/cmd/update.go
@@ -150,11 +150,6 @@ func IsDCOS() bool {
 	return false
 }
 
-// IsKubernetesReplicaSet returns true if minio is running in kubernetes replica set.
-func IsKubernetesReplicaSet() bool {
-	return IsKubernetes() && (env.Get("KUBERNETES_REPLICA_SET", "") != "")
-}
-
 // IsKubernetes returns true if minio is running in kubernetes.
 func IsKubernetes() bool {
 	if env.Get("MINIO_CI_CD", "") == "" {