option

Documentation

Index

• Constants
• Variables
• func EnvOrDefaultChroot() string
• func EnvOrDefaultSnapshotExclusive() bool
• func EnvOrDefaultSnapshotPath() string
• func EnvOrDefaultSnapshotPreserve() bool
• func EnvOrDefaultSnapshotRoot() string
• func EnvOrDefaultTools() bool
• type Alerter
  • func EnvOrDefaultAlerter() Alerter
• type Option
  • func Merge(opts ...*Option) *Option
  • func WithAlerter(alerter Alerter) *Option
  • func WithChroot(dir string) *Option
  • func WithDisableTools() *Option
  • func WithNullAlerter() *Option
  • func WithPathOverrides(overrides PathOverrides) *Option
  • func WithSnapshot(opts SnapshotOptions) *Option
• type PathOverrides
• type SnapshotOptions

Constants

const (
	DefaultChroot = "/"
)

Variables

var (
	NullAlerter = log.New(io.Discard, "", 0)
)

Functions

func EnvOrDefaultChroot

func EnvOrDefaultChroot() string

EnvOrDefaultChroot returns the value of the GHW_CHROOT environs variable or the default value of "/" if not set

func EnvOrDefaultSnapshotExclusive

func EnvOrDefaultSnapshotExclusive() bool

EnvOrDefaultSnapshotExclusive returns the value of the GHW_SNAPSHOT_EXCLUSIVE environs variable or the default value of false if not set

func EnvOrDefaultSnapshotPath

func EnvOrDefaultSnapshotPath() string

EnvOrDefaultSnapshotPath returns the value of the GHW_SNAPSHOT_PATH environs variable or the default value of "" (disable snapshot consumption) if not set

func EnvOrDefaultSnapshotPreserve

func EnvOrDefaultSnapshotPreserve() bool

EnvOrDefaultSnapshotPreserve returns the value of the GHW_SNAPSHOT_PRESERVE environs variable or the default value of false if not set

func EnvOrDefaultSnapshotRoot

func EnvOrDefaultSnapshotRoot() string

EnvOrDefaultSnapshotRoot returns the value of the the GHW_SNAPSHOT_ROOT environs variable or the default value of "" (self-manage the snapshot unpack directory, if relevant) if not set

func EnvOrDefaultTools

func EnvOrDefaultTools() bool

EnvOrDefaultTools return true if ghw should use external tools to augment the data collected from sysfs. Most users want to do this most of time, so this is enabled by default. Users consuming snapshots may want to opt out, thus they can set the GHW_DISABLE_TOOLS environs variable to any value to make ghw skip calling external tools even if they are available.

Types

type Alerter

type Alerter interface {
	Printf(format string, v ...interface{})
}

Alerter emits warnings about undesirable but recoverable errors. We use a subset of a logger interface only to emit warnings, and `Warninger` sounded ugly.

func EnvOrDefaultAlerter

func EnvOrDefaultAlerter() Alerter

EnvOrDefaultAlerter returns the default instance ghw will use to emit its warnings. ghw will emit warnings to stderr by default unless the environs variable GHW_DISABLE_WARNINGS is specified; in the latter case all warning will be suppressed.

type Option

type Option struct {
	// To facilitate querying of sysfs filesystems that are bind-mounted to a
	// non-default root mountpoint, we allow users to set the GHW_CHROOT environ
	// variable to an alternate mountpoint. For instance, assume that the user of
	// ghw is a Golang binary being executed from an application container that has
	// certain host filesystems bind-mounted into the container at /host. The user
	// would ensure the GHW_CHROOT environ variable is set to "/host" and ghw will
	// build its paths from that location instead of /
	Chroot *string

	// Snapshot contains options for handling ghw snapshots
	Snapshot *SnapshotOptions

	// Alerter contains the target for ghw warnings
	Alerter Alerter

	// EnableTools optionally request ghw to not call any external program to learn
	// about the hardware. The default is to use such tools if available.
	EnableTools *bool

	// PathOverrides optionally allows to override the default paths ghw uses internally
	// to learn about the system resources.
	PathOverrides PathOverrides

	// Context may contain a pointer to a `Context` struct that is constructed
	// during a call to the `context.WithContext` function. Only used internally.
	// This is an interface to get around recursive package import issues.
	Context interface{}
}

Option is used to represent optionally-configured settings. Each field is a pointer to some concrete value so that we can tell when something has been set or left unset.

func Merge

func Merge(opts ...*Option) *Option

Merge accepts one or more Options and merges them together, returning the merged Option

func WithAlerter

func WithAlerter(alerter Alerter) *Option

WithAlerter sets alerting options for ghw

func WithChroot

func WithChroot(dir string) *Option

WithChroot allows to override the root directory ghw uses.

func WithDisableTools

func WithDisableTools() *Option

WithDisableTools sets enables or prohibts ghw to call external tools to discover hardware capabilities.

func WithNullAlerter

func WithNullAlerter() *Option

WithNullAlerter sets No-op alerting options for ghw

func WithPathOverrides

func WithPathOverrides(overrides PathOverrides) *Option

WithPathOverrides supplies path-specific overrides for the context

func WithSnapshot

func WithSnapshot(opts SnapshotOptions) *Option

WithSnapshot sets snapshot-processing options for a ghw run

type PathOverrides

type PathOverrides map[string]string

PathOverrides is a map, keyed by the string name of a mount path, of override paths

type SnapshotOptions

type SnapshotOptions struct {
	// Path allows users to specify a snapshot (captured using ghw-snapshot) to be
	// automatically consumed. Users need to supply the path of the snapshot, and
	// ghw will take care of unpacking it on a temporary directory.
	// Set the environment variable "GHW_SNAPSHOT_PRESERVE" to make ghw skip the cleanup
	// stage and keep the unpacked snapshot in the temporary directory.
	Path string
	// Root is the directory on which the snapshot must be unpacked. This allows
	// the users to manage their snapshot directory instead of ghw doing that on
	// their behalf. Relevant only if SnapshotPath is given.
	Root *string
	// Exclusive tells ghw if the given directory should be considered of exclusive
	// usage of ghw or not If the user provides a Root. If the flag is set, ghw will
	// unpack the snapshot in the given SnapshotRoot iff the directory is empty; otherwise
	// any existing content will be left untouched and the unpack stage will exit silently.
	// As additional side effect, give both this option and SnapshotRoot to make each
	// context try to unpack the snapshot only once.
	Exclusive bool
}

SnapshotOptions contains options for handling of ghw snapshots