Merge pull request #216 from fromanirh/warning-machinery

warning: support new option to override default

README.md

@@ -207,6 +207,26 @@ $ GHW_DISABLE_WARNINGS=1 ghwc memory
 memory (24GB physical, 24GB usable)
 ```
 
+You can disable warning programmatically using the `WithDisableWarnings` option:
+
+```go
+
+import (
+	"github.com/jaypipes/ghw"
+)
+
+mem, err := ghw.Memory(ghw.WithDisableWarnings())
+```
+
+`WithDisableWarnings` is a alias for the `WithNullAlerter` option, which in turn
+leverages the more general `Alerter` feature of ghw.
+
+You may supply a `Alerter` to ghw to redirect all the warnings there, like
+logger objects (see for example golang's stdlib `log.Logger`).
+`Alerter` is in fact the minimal logging interface `ghw needs.
+To learn more, please check the `option.Alerter` interface and the `ghw.WithAlerter()`
+function.
+
 ### Memory
 
 Information about the host computer's memory can be retrieved using the

alias.go

@@ -24,8 +24,12 @@ import (
 type WithOption = option.Option
 
 var (
-	WithChroot   = option.WithChroot
-	WithSnapshot = option.WithSnapshot
+	WithChroot       = option.WithChroot
+	WithSnapshot     = option.WithSnapshot
+	WithAlterter     = option.WithAlerter
+	WithNullAlterter = option.WithNullAlerter
+	// match the existing environ variable to minimize surprises
+	WithDisableWarnings = option.WithNullAlerter
 )
 
 type SnapshotOptions = option.SnapshotOptions

host.go

@@ -9,6 +9,8 @@ package ghw
 import (
 	"fmt"
 
+	"github.com/jaypipes/ghw/pkg/context"
+
 	"github.com/jaypipes/ghw/pkg/baseboard"
 	"github.com/jaypipes/ghw/pkg/bios"
 	"github.com/jaypipes/ghw/pkg/block"
@@ -26,6 +28,7 @@ import (
 // HostInfo is a wrapper struct containing information about the host system's
 // memory, block storage, CPU, etc
 type HostInfo struct {
+	ctx       *context.Context
 	Memory    *memory.Info    `json:"memory"`
 	Block     *block.Info     `json:"block"`
 	CPU       *cpu.Info       `json:"cpu"`
@@ -42,6 +45,8 @@ type HostInfo struct {
 // Host returns a pointer to a HostInfo struct that contains fields with
 // information about the host system's CPU, memory, network devices, etc
 func Host(opts ...*WithOption) (*HostInfo, error) {
+	ctx := context.New(opts...)
+
 	memInfo, err := memory.New(opts...)
 	if err != nil {
 		return nil, err
@@ -87,6 +92,7 @@ func Host(opts ...*WithOption) (*HostInfo, error) {
 		return nil, err
 	}
 	return &HostInfo{
+		ctx:       ctx,
 		CPU:       cpuInfo,
 		Memory:    memInfo,
 		Block:     blockInfo,
@@ -123,11 +129,11 @@ func (info *HostInfo) String() string {
 // YAMLString returns a string with the host information formatted as YAML
 // under a top-level "host:" key
 func (i *HostInfo) YAMLString() string {
-	return marshal.SafeYAML(i)
+	return marshal.SafeYAML(i.ctx, i)
 }
 
 // JSONString returns a string with the host information formatted as JSON
 // under a top-level "host:" key
 func (i *HostInfo) JSONString(indent bool) string {
-	return marshal.SafeJSON(i, indent)
+	return marshal.SafeJSON(i.ctx, i, indent)
 }

pkg/baseboard/baseboard.go

@@ -67,11 +67,11 @@ type baseboardPrinter struct {
 // YAMLString returns a string with the baseboard information formatted as YAML
 // under a top-level "dmi:" key
 func (info *Info) YAMLString() string {
-	return marshal.SafeYAML(baseboardPrinter{info})
+	return marshal.SafeYAML(info.ctx, baseboardPrinter{info})
 }
 
 // JSONString returns a string with the baseboard information formatted as JSON
 // under a top-level "baseboard:" key
 func (info *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(baseboardPrinter{info}, indent)
+	return marshal.SafeJSON(info.ctx, baseboardPrinter{info}, indent)
 }

pkg/bios/bios.go

@@ -67,11 +67,11 @@ type biosPrinter struct {
 // YAMLString returns a string with the BIOS information formatted as YAML
 // under a top-level "dmi:" key
 func (info *Info) YAMLString() string {
-	return marshal.SafeYAML(biosPrinter{info})
+	return marshal.SafeYAML(info.ctx, biosPrinter{info})
 }
 
 // JSONString returns a string with the BIOS information formatted as JSON
 // under a top-level "bios:" key
 func (info *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(biosPrinter{info}, indent)
+	return marshal.SafeJSON(info.ctx, biosPrinter{info}, indent)
 }

pkg/block/block.go

@@ -240,11 +240,11 @@ type blockPrinter struct {
 // YAMLString returns a string with the block information formatted as YAML
 // under a top-level "block:" key
 func (i *Info) YAMLString() string {
-	return marshal.SafeYAML(blockPrinter{i})
+	return marshal.SafeYAML(i.ctx, blockPrinter{i})
 }
 
 // JSONString returns a string with the block information formatted as JSON
 // under a top-level "block:" key
 func (i *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(blockPrinter{i}, indent)
+	return marshal.SafeJSON(i.ctx, blockPrinter{i}, indent)
 }

pkg/block/block_linux.go

@@ -15,6 +15,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/jaypipes/ghw/pkg/context"
 	"github.com/jaypipes/ghw/pkg/linuxpath"
 	"github.com/jaypipes/ghw/pkg/util"
 )
@@ -25,7 +26,7 @@ const (
 
 func (i *Info) load() error {
 	paths := linuxpath.New(i.ctx)
-	i.Disks = disks(paths)
+	i.Disks = disks(i.ctx, paths)
 	var tpb uint64
 	for _, d := range i.Disks {
 		tpb += d.SizeBytes
@@ -179,12 +180,12 @@ func diskWWN(paths *linuxpath.Paths, disk string) string {
 // but just the name. In other words, "sda", not "/dev/sda" and "nvme0n1" not
 // "/dev/nvme0n1") and returns a slice of pointers to Partition structs
 // representing the partitions in that disk
-func diskPartitions(paths *linuxpath.Paths, disk string) []*Partition {
+func diskPartitions(ctx *context.Context, paths *linuxpath.Paths, disk string) []*Partition {
 	out := make([]*Partition, 0)
 	path := filepath.Join(paths.SysBlock, disk)
 	files, err := ioutil.ReadDir(path)
 	if err != nil {
-		util.Warn("failed to read disk partitions: %s\n", err)
+		ctx.Warn("failed to read disk partitions: %s\n", err)
 		return out
 	}
 	for _, file := range files {
@@ -194,7 +195,7 @@ func diskPartitions(paths *linuxpath.Paths, disk string) []*Partition {
 		}
 		size := partitionSizeBytes(paths, disk, fname)
 		mp, pt, ro := partitionInfo(paths, fname)
-		du := diskPartUUID(fname)
+		du := diskPartUUID(ctx, fname)
 		p := &Partition{
 			Name:       fname,
 			SizeBytes:  size,
@@ -208,7 +209,7 @@ func diskPartitions(paths *linuxpath.Paths, disk string) []*Partition {
 	return out
 }
 
-func diskPartUUID(part string) string {
+func diskPartUUID(ctx *context.Context, part string) string {
 	if !strings.HasPrefix(part, "/dev") {
 		part = "/dev/" + part
 	}
@@ -220,7 +221,7 @@ func diskPartUUID(part string) string {
 	}
 	out, err := exec.Command(args[0], args[1:]...).Output()
 	if err != nil {
-		util.Warn("failed to read disk partuuid of %s : %s\n", part, err.Error())
+		ctx.Warn("failed to read disk partuuid of %s : %s\n", part, err.Error())
 		return ""
 	}
 
@@ -230,7 +231,7 @@ func diskPartUUID(part string) string {
 
 	parts := strings.Split(string(out), "PARTUUID=")
 	if len(parts) != 2 {
-		util.Warn("failed to parse the partuuid of %s\n", part)
+		ctx.Warn("failed to parse the partuuid of %s\n", part)
 		return ""
 	}
 
@@ -250,7 +251,7 @@ func diskIsRemovable(paths *linuxpath.Paths, disk string) bool {
 	return false
 }
 
-func disks(paths *linuxpath.Paths) []*Disk {
+func disks(ctx *context.Context, paths *linuxpath.Paths) []*Disk {
 	// In Linux, we could use the fdisk, lshw or blockdev commands to list disk
 	// information, however all of these utilities require root privileges to
 	// run. We can get all of this information by examining the /sys/block
@@ -269,7 +270,7 @@ func disks(paths *linuxpath.Paths) []*Disk {
 		driveType, storageController := diskTypes(dname)
 		// TODO(jaypipes): Move this into diskTypes() once abstracting
 		// diskIsRotational for ease of unit testing
-		if !diskIsRotational(paths, dname) {
+		if !diskIsRotational(ctx, paths, dname) {
 			driveType = DRIVE_TYPE_SSD
 		}
 		size := diskSizeBytes(paths, dname)
@@ -297,7 +298,7 @@ func disks(paths *linuxpath.Paths) []*Disk {
 			WWN:                    wwn,
 		}
 
-		parts := diskPartitions(paths, dname)
+		parts := diskPartitions(ctx, paths, dname)
 		// Map this Disk object into the Partition...
 		for _, part := range parts {
 			part.Disk = d
@@ -348,9 +349,9 @@ func diskTypes(dname string) (
 	return driveType, storageController
 }
 
-func diskIsRotational(paths *linuxpath.Paths, devName string) bool {
+func diskIsRotational(ctx *context.Context, paths *linuxpath.Paths, devName string) bool {
 	path := filepath.Join(paths.SysBlock, devName, "queue", "rotational")
-	contents := util.SafeIntFromFile(path)
+	contents := util.SafeIntFromFile(ctx, path)
 	return contents == 1
 }
 

pkg/chassis/chassis.go

@@ -111,11 +111,11 @@ type chassisPrinter struct {
 // YAMLString returns a string with the chassis information formatted as YAML
 // under a top-level "dmi:" key
 func (info *Info) YAMLString() string {
-	return marshal.SafeYAML(chassisPrinter{info})
+	return marshal.SafeYAML(info.ctx, chassisPrinter{info})
 }
 
 // JSONString returns a string with the chassis information formatted as JSON
 // under a top-level "chassis:" key
 func (info *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(chassisPrinter{info}, indent)
+	return marshal.SafeJSON(info.ctx, chassisPrinter{info}, indent)
 }

pkg/context/context.go

@@ -18,12 +18,14 @@ type Context struct {
 	SnapshotPath      string
 	SnapshotRoot      string
 	SnapshotExclusive bool
+	alert             option.Alerter
 }
 
 // New returns a Context struct pointer that has had various options set on it
 func New(opts ...*option.Option) *Context {
 	merged := option.Merge(opts...)
 	ctx := &Context{
+		alert:  option.EnvOrDefaultAlerter(),
 		Chroot: *merged.Chroot,
 	}
 
@@ -35,6 +37,11 @@ func New(opts ...*option.Option) *Context {
 		}
 		ctx.SnapshotExclusive = merged.Snapshot.Exclusive
 	}
+
+	if merged.Alerter != nil {
+		ctx.alert = merged.Alerter
+	}
+
 	return ctx
 }
 
@@ -104,3 +111,7 @@ func (ctx *Context) Teardown() error {
 	}
 	return snapshot.Cleanup(ctx.SnapshotRoot)
 }
+
+func (ctx *Context) Warn(msg string, args ...interface{}) {
+	ctx.alert.Printf("WARNING: "+msg, args...)
+}

pkg/cpu/cpu.go

@@ -159,11 +159,11 @@ type cpuPrinter struct {
 // YAMLString returns a string with the cpu information formatted as YAML
 // under a top-level "cpu:" key
 func (i *Info) YAMLString() string {
-	return marshal.SafeYAML(cpuPrinter{i})
+	return marshal.SafeYAML(i.ctx, cpuPrinter{i})
 }
 
 // JSONString returns a string with the cpu information formatted as JSON
 // under a top-level "cpu:" key
 func (i *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(cpuPrinter{i}, indent)
+	return marshal.SafeJSON(i.ctx, cpuPrinter{i}, indent)
 }

pkg/cpu/cpu_linux.go

@@ -204,7 +204,7 @@ func CoresForNode(ctx *context.Context, nodeID int) ([]*ProcessorCore, error) {
 			continue
 		}
 		coreIDPath := filepath.Join(cpuPath, "topology", "core_id")
-		coreID := util.SafeIntFromFile(coreIDPath)
+		coreID := util.SafeIntFromFile(ctx, coreIDPath)
 		core := findCoreByID(coreID)
 		core.LogicalProcessors = append(
 			core.LogicalProcessors,

pkg/gpu/gpu.go

@@ -85,11 +85,11 @@ type gpuPrinter struct {
 // YAMLString returns a string with the gpu information formatted as YAML
 // under a top-level "gpu:" key
 func (i *Info) YAMLString() string {
-	return marshal.SafeYAML(gpuPrinter{i})
+	return marshal.SafeYAML(i.ctx, gpuPrinter{i})
 }
 
 // JSONString returns a string with the gpu information formatted as JSON
 // under a top-level "gpu:" key
 func (i *Info) JSONString(indent bool) string {
-	return marshal.SafeJSON(gpuPrinter{i}, indent)
+	return marshal.SafeJSON(i.ctx, gpuPrinter{i}, indent)
 }

pkg/gpu/gpu_linux.go

@@ -57,7 +57,7 @@ func (i *Info) load() error {
 	paths := linuxpath.New(i.ctx)
 	links, err := ioutil.ReadDir(paths.SysClassDRM)
 	if err != nil {
-		util.Warn(_WARN_NO_SYS_CLASS_DRM)
+		i.ctx.Warn(_WARN_NO_SYS_CLASS_DRM)
 		return nil
 	}
 	cards := make([]*GraphicsCard, 0)
@@ -139,7 +139,7 @@ func gpuFillNUMANodes(ctx *context.Context, cards []*GraphicsCard) {
 			"device",
 			"numa_node",
 		)
-		nodeIdx := util.SafeIntFromFile(fpath)
+		nodeIdx := util.SafeIntFromFile(ctx, fpath)
 		if nodeIdx == -1 {
 			continue
 		}

pkg/linuxdmi/dmi_linux.go

@@ -21,7 +21,7 @@ func Item(ctx *context.Context, value string) string {
 
 	b, err := ioutil.ReadFile(path)
 	if err != nil {
-		util.Warn("Unable to read %s: %s\n", value, err)
+		ctx.Warn("Unable to read %s: %s\n", value, err)
 		return util.UNKNOWN
 	}
 

pkg/marshal/marshal.go

@@ -10,19 +10,19 @@ import (
 	"encoding/json"
 
 	"github.com/ghodss/yaml"
-	"github.com/jaypipes/ghw/pkg/util"
+	"github.com/jaypipes/ghw/pkg/context"
 )
 
 // safeYAML returns a string after marshalling the supplied parameter into YAML
-func SafeYAML(p interface{}) string {
+func SafeYAML(ctx *context.Context, p interface{}) string {
 	b, err := json.Marshal(p)
 	if err != nil {
-		util.Warn("error marshalling JSON: %s", err)
+		ctx.Warn("error marshalling JSON: %s", err)
 		return ""
 	}
 	yb, err := yaml.JSONToYAML(b)
 	if err != nil {
-		util.Warn("error converting JSON to YAML: %s", err)
+		ctx.Warn("error converting JSON to YAML: %s", err)
 		return ""
 	}
 	return string(yb)
@@ -31,7 +31,7 @@ func SafeYAML(p interface{}) string {
 // safeJSON returns a string after marshalling the supplied parameter into
 // JSON. Accepts an optional argument to trigger pretty/indented formatting of
 // the JSON string
-func SafeJSON(p interface{}, indent bool) string {
+func SafeJSON(ctx *context.Context, p interface{}, indent bool) string {
 	var b []byte
 	var err error
 	if !indent {
@@ -40,7 +40,7 @@ func SafeJSON(p interface{}, indent bool) string {
 		b, err = json.MarshalIndent(&p, "", "  ")
 	}
 	if err != nil {
-		util.Warn("error marshalling JSON: %s", err)
+		ctx.Warn("error marshalling JSON: %s", err)
 		return ""
 	}
 	return string(b)