test: cover NewFromCluster replica-source derivation

Add config-package tests exercising the parse path the pg_basebackup replica
fix lives in: NewFromCluster must derive ReplicaSourceBarmanObjectName from the
external cluster plugin (while leaving the backup and recovery object stores
empty) and Validate must accept it. Also assert that a replica source backed by
a different plugin is ignored.

Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>

internal/cnpgi/operator/config/config_test.go

@@ -20,8 +20,13 @@ SPDX-License-Identifier: Apache-2.0
 package config
 
 import (
+	cnpgv1 "github.com/cloudnative-pg/cloudnative-pg/api/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+
+	"github.com/cloudnative-pg/plugin-barman-cloud/internal/cnpgi/metadata"
 )
 
 var _ = Describe("PluginConfiguration.Validate", func() {
@@ -45,3 +50,77 @@ var _ = Describe("PluginConfiguration.Validate", func() {
 		Expect(cfg.Validate()).To(Succeed())
 	})
 })
+
+var _ = Describe("NewFromCluster", func() {
+	enabled := true
+
+	It("derives the replica source object store for a pg_basebackup replica cluster", func() {
+		cluster := &cnpgv1.Cluster{
+			ObjectMeta: metav1.ObjectMeta{Name: "cluster-replica", Namespace: "test-ns"},
+			Spec: cnpgv1.ClusterSpec{
+				Bootstrap: &cnpgv1.BootstrapConfiguration{
+					PgBaseBackup: &cnpgv1.BootstrapPgBaseBackup{Source: "source"},
+				},
+				ReplicaCluster: &cnpgv1.ReplicaClusterConfiguration{
+					Enabled: &enabled,
+					Source:  "source",
+				},
+				ExternalClusters: []cnpgv1.ExternalCluster{
+					{
+						Name: "source",
+						PluginConfiguration: &cnpgv1.PluginConfiguration{
+							Name: metadata.PluginName,
+							Parameters: map[string]string{
+								"barmanObjectName": "minio-store",
+								"serverName":       "cluster-example",
+							},
+						},
+					},
+				},
+			},
+		}
+
+		cfg := NewFromCluster(cluster)
+
+		// The replica source object store is derived from the external cluster plugin,
+		// while the backup/archive and recovery object stores remain empty: this is the
+		// distinguishing trait of a pg_basebackup replica cluster (a recovery-bootstrapped
+		// replica would also populate RecoveryBarmanObjectName).
+		Expect(cfg.ReplicaSourceBarmanObjectName).To(Equal("minio-store"))
+		Expect(cfg.ReplicaSourceServerName).To(Equal("cluster-example"))
+		Expect(cfg.BarmanObjectName).To(BeEmpty())
+		Expect(cfg.RecoveryBarmanObjectName).To(BeEmpty())
+
+		// Validate must accept it, otherwise the lifecycle hook skips sidecar injection.
+		Expect(cfg.Validate()).To(Succeed())
+	})
+
+	It("ignores a replica source backed by a different plugin", func() {
+		cluster := &cnpgv1.Cluster{
+			ObjectMeta: metav1.ObjectMeta{Name: "cluster-replica", Namespace: "test-ns"},
+			Spec: cnpgv1.ClusterSpec{
+				Bootstrap: &cnpgv1.BootstrapConfiguration{
+					PgBaseBackup: &cnpgv1.BootstrapPgBaseBackup{Source: "source"},
+				},
+				ReplicaCluster: &cnpgv1.ReplicaClusterConfiguration{
+					Enabled: &enabled,
+					Source:  "source",
+				},
+				ExternalClusters: []cnpgv1.ExternalCluster{
+					{
+						Name: "source",
+						PluginConfiguration: &cnpgv1.PluginConfiguration{
+							Name:       "some-other-plugin.cloudnative-pg.io",
+							Parameters: map[string]string{"barmanObjectName": "minio-store"},
+						},
+					},
+				},
+			},
+		}
+
+		cfg := NewFromCluster(cluster)
+
+		Expect(cfg.ReplicaSourceBarmanObjectName).To(BeEmpty())
+		Expect(cfg.Validate()).NotTo(Succeed())
+	})
+})