unit

Documentation

Overview

Package unit provides utilities for parsing, serializing, and manipulating systemd unit files. It supports both reading unit file content into Go data structures and writing Go data structures back to unit file format.

The package provides functionality to:

• Parse systemd unit files into UnitOption and UnitSection structures
• Serialize Go structures back into unit file format
• Escape and unescape unit names according to systemd conventions

Unit files are configuration files that describe how systemd should manage services, sockets, devices, and other system resources.

Index

• Constants
• Variables
• func AllMatch(u1 []*UnitOption, u2 []*UnitOption) bool
• func Serialize(opts []*UnitOption) io.Reader
• func SerializeSections(sections []*UnitSection) io.Reader
• func UnitNameEscape(unescaped string) string
• func UnitNamePathEscape(unescaped string) string
• func UnitNamePathUnescape(escaped string) string
• func UnitNameUnescape(escaped string) string
• type UnitEntry
  • func (u *UnitEntry) String() string
• type UnitOption
  • func Deserialize(f io.Reader) (opts []*UnitOption, err error)
  • func DeserializeOptions(f io.Reader) (opts []*UnitOption, err error)
  • func NewUnitOption(section, name, value string) *UnitOption
  • func (uo *UnitOption) Match(other *UnitOption) bool
  • func (uo *UnitOption) String() string
• type UnitSection
  • func DeserializeSections(f io.Reader) ([]*UnitSection, error)
  • func (s *UnitSection) String() string

Constants

const (
	// SYSTEMD_LINE_MAX mimics the maximum line length that systemd can use.
	// On typical systemd platforms (i.e. modern Linux), this will most
	// commonly be 2048, so let's use that as a sanity check.
	// Technically, we should probably pull this at runtime:
	//    SYSTEMD_LINE_MAX = int(C.sysconf(C.__SC_LINE_MAX))
	// but this would introduce an (unfortunate) dependency on cgo
	SYSTEMD_LINE_MAX = 2048

	// SYSTEMD_NEWLINE defines characters that systemd considers indicators
	// for a newline.
	SYSTEMD_NEWLINE = "\r\n"
)

Variables

var ErrLineTooLong = fmt.Errorf("line too long (max %d bytes)", SYSTEMD_LINE_MAX)

ErrLineTooLong gets returned when a line is too long for systemd to handle.

Functions

func AllMatch

func AllMatch(u1 []*UnitOption, u2 []*UnitOption) bool

AllMatch compares two slices of UnitOptions and returns true if they are identical.

func Serialize

func Serialize(opts []*UnitOption) io.Reader

Serialize encodes all of the given UnitOption objects into a unit file. When serialized the options are sorted in their supplied order but grouped by section.

func SerializeSections

func SerializeSections(sections []*UnitSection) io.Reader

SerializeSections will serializes the unit file from the given UnitSections.

func UnitNameEscape

func UnitNameEscape(unescaped string) string

UnitNameEscape escapes a string as `systemd-escape` would

func UnitNamePathEscape

func UnitNamePathEscape(unescaped string) string

UnitNamePathEscape escapes a string as `systemd-escape --path` would

func UnitNamePathUnescape

func UnitNamePathUnescape(escaped string) string

UnitNamePathUnescape unescapes a string as `systemd-escape --path --unescape` would

func UnitNameUnescape

func UnitNameUnescape(escaped string) string

UnitNameUnescape unescapes a string as `systemd-escape --unescape` would

Types

type UnitEntry

type UnitEntry struct {
	Name  string
	Value string
}

UnitEntry is a single line entry in a Unit file.

func (*UnitEntry) String

func (u *UnitEntry) String() string

String implements the stringify interface for UnitEntry

type UnitOption

type UnitOption struct {
	Section string
	Name    string
	Value   string
}

UnitOption represents an option in a systemd unit file.

func Deserialize

func Deserialize(f io.Reader) (opts []*UnitOption, err error)

Deserialize parses a systemd unit file into a list of UnitOptions. Note: this function is deprecated in favor of DeserializeOptions and will be removed at a future date.

func DeserializeOptions

func DeserializeOptions(f io.Reader) (opts []*UnitOption, err error)

DeserializeOptions parses a systemd unit file into a list of UnitOptions

func NewUnitOption

func NewUnitOption(section, name, value string) *UnitOption

NewUnitOption returns a new UnitOption instance with pre-set values.

func (*UnitOption) Match

func (uo *UnitOption) Match(other *UnitOption) bool

Match compares two UnitOptions and returns true if they are identical.

func (*UnitOption) String

func (uo *UnitOption) String() string

type UnitSection

type UnitSection struct {
	Section string
	Entries []*UnitEntry
}

UnitSection is a section in a Unit file. The section name and a list of entries in that section.

func DeserializeSections

func DeserializeSections(f io.Reader) ([]*UnitSection, error)

DeserializeSections deserializes into a list of UnitSections.

func (*UnitSection) String

func (s *UnitSection) String() string

String implements the stringify interface for UnitSection