From 165c8d372d8e2fefd7c7f5d2617df79bc05f5023 Mon Sep 17 00:00:00 2001
From: Alex Aizman <alex.aizman@gmail.com>
Date: Fri, 20 Dec 2024 18:21:06 -0500
Subject: [PATCH] [API change] reload (updated) backend creds

* part three, prev. commit: 867157b84b6cc

Signed-off-by: Alex Aizman <alex.aizman@gmail.com>
---
 ais/prxclu.go | 13 +++++++++++++
 ais/target.go |  4 ++++
 ais/tgtcp.go  | 28 ++++++++++++++++++++++++++--
 cmn/err.go    |  8 ++++++++
 4 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/ais/prxclu.go b/ais/prxclu.go
index 6cdbdb2d2f..991213dc61 100644
--- a/ais/prxclu.go
+++ b/ais/prxclu.go
@@ -1053,6 +1053,19 @@ func (p *proxy) cluputMsg(w http.ResponseWriter, r *http.Request) {
 		p.xstop(w, r, msg)
 
 	case apc.ActReloadBackendCreds:
+		if msg.Name != "" {
+			normp := apc.NormalizeProvider(msg.Name)
+			if !apc.IsCloudProvider(normp) {
+				p.writeErrf(w, r, "cannot reload %q creds: not a Cloud provider", msg.Name)
+				return
+			}
+			config := cmn.GCO.Get()
+			if config.Backend.Get(normp) == nil {
+				p.writeErr(w, r, &cmn.ErrMissingBackend{Provider: msg.Name})
+				return
+			}
+			msg.Name = normp
+		}
 		p.reloadCreds(w, r, msg)
 
 	// internal
diff --git a/ais/target.go b/ais/target.go
index 362db00233..e77a3e1ede 100644
--- a/ais/target.go
+++ b/ais/target.go
@@ -154,6 +154,10 @@ func (t *target) initBuiltTagged(tstats *stats.Trunner, config *cmn.Config) erro
 		case err == nil && !configured:
 			disabled = append(disabled, provider)
 		case err != nil && configured:
+			if !cmn.IsErrInitMissingBackend(err) {
+				// as is
+				return fmt.Errorf("%s: failed to initialize [%s] backend, err: %v", t, provider, err)
+			}
 			notlinked = append(notlinked, provider)
 		case err != nil && !configured:
 			_, ok := err.(*cmn.ErrInitBackend) // error type to indicate a _mock_ backend
diff --git a/ais/tgtcp.go b/ais/tgtcp.go
index d2e47aec45..7307b5a137 100644
--- a/ais/tgtcp.go
+++ b/ais/tgtcp.go
@@ -183,10 +183,34 @@ func (t *target) daeputMsg(w http.ResponseWriter, r *http.Request) {
 		errorsOnly := msg.Value.(bool)
 		t.statsT.ResetStats(errorsOnly)
 	case apc.ActReloadBackendCreds:
-		debug.Assert(msg.Name == "", "reloading specific provider not yet supported")
-		if err := t.initBuiltTagged(t.statsT.(*stats.Trunner), cmn.GCO.Get()); err != nil {
+		var (
+			tstats   = t.statsT.(*stats.Trunner)
+			provider = msg.Name
+		)
+		if provider == "" { // all
+			if err := t.initBuiltTagged(t.statsT.(*stats.Trunner), cmn.GCO.Get()); err != nil {
+				t.writeErr(w, r, err)
+			}
+			return
+		}
+
+		// one
+		var add core.Backend
+		switch provider {
+		case apc.AWS:
+			add, err = backend.NewAWS(t, tstats)
+		case apc.GCP:
+			add, err = backend.NewGCP(t, tstats)
+		case apc.Azure:
+			add, err = backend.NewAzure(t, tstats)
+		case apc.OCI:
+			add, err = backend.NewOCI(t, tstats)
+		}
+		if err != nil {
 			t.writeErr(w, r, err)
+			return
 		}
+		t.backend[provider] = add
 	case apc.ActStartMaintenance:
 		if !t.ensureIntraControl(w, r, true /* from primary */) {
 			return
diff --git a/cmn/err.go b/cmn/err.go
index 9a2af6ce92..cc833b6c84 100644
--- a/cmn/err.go
+++ b/cmn/err.go
@@ -739,6 +739,14 @@ func (e *ErrMissingBackend) Error() string {
 	return apc.DisplayProvider(e.Provider) + " backend is missing in the cluster configuration"
 }
 
+func IsErrInitMissingBackend(err error) bool {
+	_, ok := err.(*ErrInitBackend)
+	if !ok {
+		_, ok = err.(*ErrMissingBackend)
+	}
+	return ok
+}
+
 // ErrETL
 
 func NewErrETL(ctx *ETLErrCtx, msg string) *ErrETL {