nvsandboxutils: Add usage of GetGpuResource and GetFileContent APIs

This change adds a new discoverer for Sandboxutils to report the file
system paths and associated symbolic links using GetGpuResource and
GetFileContent APIs. Both GPU and MIG devices are supported. If the
Sandboxutils discoverer fails, the NVML discoverer is used to report
the file system information.

Signed-off-by: Evan Lezar <elezar@nvidia.com>
Signed-off-by: Huy Nguyen <huyn@nvidia.com>
Signed-off-by: Sananya Majumder <sananyam@nvidia.com>

internal/discover/first-valid.go

@@ -0,0 +1,72 @@
+/**
+# Copyright 2024 NVIDIA CORPORATION
+#
+# 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 discover
+
+import "errors"
+
+type firstOf []Discover
+
+// FirstValid returns a discoverer that returns the first non-error result from a list of discoverers.
+func FirstValid(discoverers ...Discover) Discover {
+	var f firstOf
+	for _, d := range discoverers {
+		if d == nil {
+			continue
+		}
+		f = append(f, d)
+	}
+	return f
+}
+
+func (f firstOf) Devices() ([]Device, error) {
+	var errs error
+	for _, d := range f {
+		devices, err := d.Devices()
+		if err != nil {
+			errs = errors.Join(errs, err)
+			continue
+		}
+		return devices, nil
+	}
+	return nil, errs
+}
+
+func (f firstOf) Hooks() ([]Hook, error) {
+	var errs error
+	for _, d := range f {
+		hooks, err := d.Hooks()
+		if err != nil {
+			errs = errors.Join(errs, err)
+			continue
+		}
+		return hooks, nil
+	}
+	return nil, errs
+}
+
+func (f firstOf) Mounts() ([]Mount, error) {
+	var errs error
+	for _, d := range f {
+		mounts, err := d.Mounts()
+		if err != nil {
+			errs = errors.Join(errs, err)
+			continue
+		}
+		return mounts, nil
+	}
+	return nil, nil
+}