refactor: Derive path of a patch file in a common package

Author: dlipovetsky

pkg/common/constants.go

@@ -0,0 +1,26 @@
+// Copyright 2024 Nutanix. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package common
+
+import "path/filepath"
+
+const (
+	// PatchRootDirOnRemote is the directory on the machine where we write patches as files.
+	// These files are later applied by one or more commands that run on the machine.
+	PatchRootDirOnRemote = "/etc/caren"
+)
+
+// ContainerdPatchDirOnRemote is the directory where we write containerd patches as files.
+// It is a subdirectory of the root patches directory.
+var ContainerdPatchDirOnRemote = filepath.Join(PatchRootDirOnRemote, "containerd")
+
+// PatchPathOnRemote returns the absolute path of a patch on the machine.
+func PatchPathOnRemote(relativePath string) string {
+	return filepath.Join(PatchRootDirOnRemote, relativePath)
+}
+
+// ContainerdPatchPathOnRemote returns the absolute path of a containerd patch on the machine.
+func ContainerdPatchPathOnRemote(relativePath string) string {
+	return (filepath.Join(ContainerdPatchDirOnRemote, relativePath))
+}

pkg/handlers/generic/mutation/containerdmetrics/metrics.go

@@ -4,23 +4,16 @@ package containerdmetrics
 
 import (
 	_ "embed"
-	"path"
 
 	cabpkv1 "sigs.k8s.io/cluster-api/bootstrap/kubeadm/api/v1beta1"
-)
 
-const (
-	// TODO Factor out this constant to a common package.
-	containerdPatchesDirOnRemote = "/etc/caren/containerd"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/common"
 )
 
 var (
 	//go:embed files/metrics-config.toml
 	metricsConfigDropIn             []byte
-	metricsConfigDropInFileOnRemote = path.Join(
-		containerdPatchesDirOnRemote,
-		"metrics-config.toml",
-	)
+	metricsConfigDropInFileOnRemote = common.ContainerdPatchPathOnRemote("metrics-config.toml")
 )
 
 func generateMetricsConfigDropIn() cabpkv1.File {

pkg/handlers/generic/mutation/imageregistries/credentials/credential_provider_install_files.go

@@ -10,14 +10,18 @@ import (
 	"text/template"
 
 	cabpkv1 "sigs.k8s.io/cluster-api/bootstrap/kubeadm/api/v1beta1"
+
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/common"
 )
 
-const (
-	//nolint:gosec // Does not contain hard coded credentials.
-	installKubeletCredentialProvidersScriptOnRemote = "/etc/caren/install-kubelet-credential-providers.sh"
+var (
+	installKubeletCredentialProvidersScriptOnRemote = common.PatchPathOnRemote(
+		"install-kubelet-credential-providers.sh")
 
 	installKubeletCredentialProvidersScriptOnRemoteCommand = "/bin/bash " + installKubeletCredentialProvidersScriptOnRemote
+)
 
+const (
 	//nolint:gosec // Does not contain hard coded credentials.
 	dynamicCredentialProviderImage = "ghcr.io/mesosphere/dynamic-credential-provider:v0.5.0"
 

pkg/handlers/generic/mutation/mirrors/mirror.go

@@ -17,6 +17,7 @@ import (
 	ctrlclient "sigs.k8s.io/controller-runtime/pkg/client"
 
 	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/api/v1alpha1"
+	"github.com/nutanix-cloud-native/cluster-api-runtime-extensions-nutanix/pkg/common"
 )
 
 const (
@@ -25,7 +26,6 @@ const (
 	secretKeyForMirrorCACert                = "ca.crt"
 
 	tomlMergeImage                              = "ghcr.io/mesosphere/toml-merge:v0.2.0"
-	containerdPatchesDirOnRemote                = "/etc/caren/containerd"
 	containerdApplyPatchesScriptOnRemote        = "/etc/containerd/apply-patches.sh"
 	containerdApplyPatchesScriptOnRemoteCommand = "/bin/bash " + containerdApplyPatchesScriptOnRemote
 )
@@ -40,8 +40,7 @@ var (
 
 	//go:embed templates/containerd-registry-config-drop-in.toml
 	containerdRegistryConfigDropIn             []byte
-	containerdRegistryConfigDropInFileOnRemote = path.Join(
-		containerdPatchesDirOnRemote,
+	containerdRegistryConfigDropInFileOnRemote = common.ContainerdPatchPathOnRemote(
 		"registry-config.toml",
 	)
 
@@ -203,7 +202,7 @@ func generateContainerdApplyPatchesScript() ([]cabpkv1.File, string, error) {
 		PatchDir       string
 	}{
 		TOMLMergeImage: tomlMergeImage,
-		PatchDir:       containerdPatchesDirOnRemote,
+		PatchDir:       common.ContainerdPatchDirOnRemote,
 	}
 
 	var b bytes.Buffer