Ensure pgBackRest log directories are writable

The `install` command only sets permissions on the final directory.

internal/pgbackrest/config.go

@@ -7,6 +7,7 @@ package pgbackrest
 import (
 	"context"
 	"fmt"
+	"path"
 	"strconv"
 	"strings"
 	"time"
@@ -19,6 +20,7 @@ import (
 	"github.com/crunchydata/postgres-operator/internal/initialize"
 	"github.com/crunchydata/postgres-operator/internal/naming"
 	"github.com/crunchydata/postgres-operator/internal/postgres"
+	"github.com/crunchydata/postgres-operator/internal/shell"
 	"github.com/crunchydata/postgres-operator/pkg/apis/postgres-operator.crunchydata.com/v1beta1"
 )
 
@@ -152,7 +154,9 @@ func MakePGBackrestLogDir(template *corev1.PodTemplateSpec,
 	}
 
 	container := corev1.Container{
-		Command:         []string{"bash", "-c", "umask 000 && install -m 777 -d " + pgBackRestLogPath},
+		// TODO(log-rotation): The second argument here should be the path
+		// of the volume mount. Find a way to calculate that consistently.
+		Command:         []string{"bash", "-c", shell.MakeDirectories(0o775, path.Dir(pgBackRestLogPath), pgBackRestLogPath)},
 		Image:           config.PGBackRestContainerImage(cluster),
 		ImagePullPolicy: cluster.Spec.ImagePullPolicy,
 		Name:            naming.ContainerPGBackRestLogDirInit,

internal/pgbackrest/config_test.go

@@ -292,7 +292,7 @@ func TestMakePGBackrestLogDir(t *testing.T) {
 	for _, c := range podTemplate.Spec.InitContainers {
 		if c.Name == naming.ContainerPGBackRestLogDirInit {
 			// ignore "bash -c", should skip repo with no volume
-			assert.Equal(t, "umask 000 && install -m 777 -d /pgbackrest/repo2/log", c.Command[2])
+			assert.Equal(t, `mkdir -p '/pgbackrest/repo2/log' && chmod 0775 '/pgbackrest/repo2/log'`, c.Command[2])
 			assert.Equal(t, c.Image, "test-image")
 			assert.Equal(t, c.ImagePullPolicy, corev1.PullAlways)
 			assert.Assert(t, !cmp.DeepEqual(c.SecurityContext,