Add a local logging interface for nvpci

Signed-off-by: Christopher Desiniotis <cdesiniotis@nvidia.com>

pkg/nvpci/logger.go

@@ -0,0 +1,29 @@
+/**
+# Copyright (c) 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 nvpci
+
+import "log"
+
+type logger interface {
+	Warningf(string, ...interface{})
+}
+
+type simpleLogger struct{}
+
+func (l simpleLogger) Warningf(format string, v ...interface{}) {
+	log.Printf("WARNING: "+format, v)
+}

pkg/nvpci/nvpci.go

@@ -68,6 +68,7 @@ type ResourceInterface interface {
 }
 
 type nvpci struct {
+	logger         logger
 	pciDevicesRoot string
 	pcidbPath      string
 }
@@ -134,6 +135,9 @@ func New(opts ...Option) Interface {
 	for _, opt := range opts {
 		opt(n)
 	}
+	if n.logger == nil {
+		n.logger = &simpleLogger{}
+	}
 	if n.pciDevicesRoot == "" {
 		n.pciDevicesRoot = PCIDevicesRoot
 	}
@@ -143,6 +147,13 @@ func New(opts ...Option) Interface {
 // Option defines a function for passing options to the New() call
 type Option func(*nvpci)
 
+// WithLogger provides an Option to set the logger for the library
+func WithLogger(logger logger) Option {
+	return func(n *nvpci) {
+		n.logger = logger
+	}
+}
+
 // WithPCIDevicesRoot provides an Option to set the root path
 // for PCI devices on the system.
 func WithPCIDevicesRoot(root string) Option {
@@ -308,12 +319,12 @@ func (p *nvpci) GetGPUByPciBusID(address string) (*NvidiaPCIDevice, error) {
 
 	deviceName, err := pciDB.GetDeviceName(uint16(vendorID), uint16(deviceID))
 	if err != nil {
-		fmt.Printf("WARNING: unable to get device name: %v\n", err)
+		p.logger.Warningf("unable to get device name: %v\n", err)
 		deviceName = UnknownDeviceString
 	}
 	className, err := pciDB.GetClassName(uint32(classID))
 	if err != nil {
-		fmt.Printf("WARNING: unable to get class name for device: %v\n", err)
+		p.logger.Warningf("unable to get class name for device: %v\n", err)
 		className = UnknownClassString
 	}