feat: make the entrypoint of pgBackRest image configurable

config/crd/bases/postgres-operator.crunchydata.com_postgresclusters.yaml

@@ -43,6 +43,12 @@ spec:
                   pgbackrest:
                     description: pgBackRest archive configuration
                     properties:
+                      command:
+                        description: The command for pgBackRest containers. The default
+                          is "/opt/crunchy/bin/pgbackrest".
+                        items:
+                          type: string
+                        type: array
                       configuration:
                         description: 'Projected volumes containing custom pgBackRest
                           configuration.  These files are mounted under "/etc/pgbackrest/conf.d"

internal/controller/postgrescluster/pgbackrest.go

@@ -679,7 +679,6 @@ func generateBackupJobSpecIntent(postgresCluster *v1beta1.PostgresCluster,
 	cmdOpts = append(cmdOpts, opts...)
 
 	container := corev1.Container{
-		Command: []string{"/opt/crunchy/bin/pgbackrest"},
 		Env: []corev1.EnvVar{
 			{Name: "COMMAND", Value: "backup"},
 			{Name: "COMMAND_OPTS", Value: strings.Join(cmdOpts, " ")},
@@ -694,6 +693,12 @@ func generateBackupJobSpecIntent(postgresCluster *v1beta1.PostgresCluster,
 		SecurityContext: initialize.RestrictedSecurityContext(),
 	}
 
+	if postgresCluster.Spec.Backups.PGBackRest.Command != nil {
+		container.Command = postgresCluster.Spec.Backups.PGBackRest.Command
+	} else {
+		container.Command = []string{"/opt/crunchy/bin/pgbackrest"}
+	}
+
 	if postgresCluster.Spec.Backups.PGBackRest.Jobs != nil {
 		container.Resources = postgresCluster.Spec.Backups.PGBackRest.Jobs.Resources
 	}

internal/controller/postgrescluster/pgbackrest_test.go

@@ -2715,6 +2715,19 @@ volumes:
 			}
 		})
 	})
+
+	t.Run("Command", func(t *testing.T) {
+		cmd := []string{"cmd", "blah"}
+		cluster := &v1beta1.PostgresCluster{}
+		cluster.Spec.Backups.PGBackRest.Command = cmd
+		job, err := generateBackupJobSpecIntent(
+			cluster, v1beta1.PGBackRestRepo{},
+			"",
+			nil, nil,
+		)
+		assert.NilError(t, err)
+		assert.DeepEqual(t, job.Template.Spec.Containers[0].Command, cmd)
+	})
 }
 
 func TestGenerateRepoHostIntent(t *testing.T) {

pkg/apis/postgres-operator.crunchydata.com/v1beta1/pgbackrest_types.go

@@ -120,6 +120,10 @@ type PGBackRestArchive struct {
 	// +optional
 	Image string `json:"image,omitempty"`
 
+	// The command for pgBackRest containers. The default is "/opt/crunchy/bin/pgbackrest".
+	// +optional
+	Command []string `json:"command,omitempty"`
+
 	// Jobs field allows configuration for all backup jobs
 	// +optional
 	Jobs *BackupJobs `json:"jobs,omitempty"`