primary role: add 'is-secondary' environment; precedence

* add 'is-secondary' environment * use it at proxy startup (bootstrap) * from now on, (is-primary, is-secondary) environment always takes precedence - will override the primary recorded into local copy of the cluster map Signed-off-by: Alex Aizman <[email protected]>
NVIDIA · Mar 26, 2024 · b0538df · b0538df
1 parent 20d8ac7
commit b0538df
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Showing 2 changed files with 23 additions and 14 deletions.
diff --git a/ais/earlystart.go b/ais/earlystart.go
@@ -114,13 +114,18 @@ func (p *proxy) determineRole(loadedSmap *smapX) (pid string, primary bool) {
 	}
 	// parse env
 	envP := struct {
-		pid     string
-		primary bool
+		pid       string
+		primary   bool
+		secondary bool
 	}{
-		pid:     os.Getenv(env.AIS.PrimaryID),
-		primary: cos.IsParseBool(os.Getenv(env.AIS.IsPrimary)),
+		pid:       os.Getenv(env.AIS.PrimaryID),
+		primary:   cos.IsParseBool(os.Getenv(env.AIS.IsPrimary)),
+		secondary: cos.IsParseBool(os.Getenv(env.AIS.IsSecondary)),
 	}
 
+	if envP.primary && envP.secondary {
+		cos.ExitLogf("%s: both %s and %s cannot be true", p, env.AIS.IsPrimary, env.AIS.IsSecondary)
+	}
 	if envP.pid != "" && envP.primary && p.SID() != envP.pid {
 		cos.ExitLogf("%s: invalid combination of %s=true & %s=%s", p, env.AIS.IsPrimary, env.AIS.PrimaryID, envP.pid)
 	}
@@ -142,13 +147,15 @@ func (p *proxy) determineRole(loadedSmap *smapX) (pid string, primary bool) {
 			loadedSmap.Primary = primary
 		}
 	}
+
+	// NOTE: environment always takes precedence
 	if envP.pid != "" {
 		primary = envP.pid == p.SID()
 		pid = envP.pid
-	} else if loadedSmap != nil {
+	} else if envP.primary {
+		primary = true
+	} else if loadedSmap != nil && !envP.secondary {
 		primary = loadedSmap.isPrimary(p.si)
-	} else {
-		primary = envP.primary
 	}
 	return
 }

diff --git a/api/env/ais.go b/api/env/ais.go
@@ -15,10 +15,11 @@ package env
 
 var (
 	AIS = struct {
-		Endpoint  string
-		IsPrimary string
-		PrimaryID string
-		UseHTTPS  string
+		Endpoint    string
+		IsPrimary   string
+		IsSecondary string
+		PrimaryID   string
+		UseHTTPS    string
 		// TLS: client side
 		Certificate   string
 		CertKey       string
@@ -33,9 +34,10 @@ var (
 		K8sNamespace string
 	}{
 		// the way to designate primary when cluster's starting up
-		Endpoint:  "AIS_ENDPOINT",
-		IsPrimary: "AIS_IS_PRIMARY",
-		PrimaryID: "AIS_PRIMARY_ID",
+		Endpoint:    "AIS_ENDPOINT",
+		IsPrimary:   "AIS_IS_PRIMARY",
+		IsSecondary: "AIS_IS_SECONDARY",
+		PrimaryID:   "AIS_PRIMARY_ID",
 
 		// false: HTTP transport, with all the TLS config (below) ignored
 		// true:  HTTPS/TLS