From d23f460ad372e25c9fc63121b2fce0e3be5e1456 Mon Sep 17 00:00:00 2001
From: Kevin Klues <kklues@nvidia.com>
Date: Thu, 11 Aug 2022 13:27:57 +0000
Subject: [PATCH] Move the nvinfo package into pkg/nvlib/info

Also build an interface around the API so that it can more easily be mocked.

Signed-off-by: Kevin Klues <kklues@nvidia.com>
---
 pkg/{nvinfo => nvlib/info}/info.go | 25 ++++++++++++++-----
 pkg/nvlib/info/options.go          | 39 ++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 6 deletions(-)
 rename pkg/{nvinfo => nvlib/info}/info.go (76%)
 create mode 100644 pkg/nvlib/info/options.go

diff --git a/pkg/nvinfo/info.go b/pkg/nvlib/info/info.go
similarity index 76%
rename from pkg/nvinfo/info.go
rename to pkg/nvlib/info/info.go
index e7319bb..a901d54 100644
--- a/pkg/nvinfo/info.go
+++ b/pkg/nvlib/info/info.go
@@ -14,18 +14,31 @@
 # limitations under the License.
 **/
 
-package nvinfo
+package info
 
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/NVIDIA/go-nvml/pkg/dl"
 )
 
-// HasNVML returns true if NVML is detected on the system
-func HasNVML() (bool, string) {
+// Interface provides the API to the info package
+type Interface interface {
+	HasNvml() (bool, string)
+	IsTegraSystem() (bool, string)
+}
+
+type infolib struct {
+	root string
+}
+
+var _ Interface = &infolib{}
+
+// HasNvml returns true if NVML is detected on the system
+func (i *infolib) HasNvml() (bool, string) {
 	const (
 		nvmlLibraryName      = "libnvidia-ml.so.1"
 		nvmlLibraryLoadFlags = dl.RTLD_LAZY
@@ -40,9 +53,9 @@ func HasNVML() (bool, string) {
 }
 
 // IsTegraSystem returns true if the system is detected as a Tegra-based system
-func IsTegraSystem() (bool, string) {
-	const tegraReleaseFile = "/etc/nv_tegra_release"
-	const tegraFamilyFile = "/sys/devices/soc0/family"
+func (i *infolib) IsTegraSystem() (bool, string) {
+	tegraReleaseFile := filepath.Join(i.root, "/etc/nv_tegra_release")
+	tegraFamilyFile := filepath.Join(i.root, "/sys/devices/soc0/family")
 
 	if info, err := os.Stat(tegraReleaseFile); err == nil && !info.IsDir() {
 		return true, fmt.Sprintf("%v found", tegraReleaseFile)
diff --git a/pkg/nvlib/info/options.go b/pkg/nvlib/info/options.go
new file mode 100644
index 0000000..314efa6
--- /dev/null
+++ b/pkg/nvlib/info/options.go
@@ -0,0 +1,39 @@
+/**
+# Copyright (c) 2022, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package info
+
+// Option defines a function for passing options to the New() call
+type Option func(*infolib)
+
+// New creates a new instance of the 'info' interface
+func New(opts ...Option) Interface {
+	i := &infolib{}
+	for _, opt := range opts {
+		opt(i)
+	}
+	if i.root == "" {
+		i.root = "/"
+	}
+	return i
+}
+
+// WithRoot provides a Option to set the root of the 'info' interface
+func WithRoot(root string) Option {
+	return func(i *infolib) {
+		i.root = root
+	}
+}