runtime

Documentation

Overview

Package runtime contains code suitable for deployer implementers but not Service Weaver application developers.

Index

• Constants
• func CheckEnvelopeInfo(w *protos.EnvelopeInfo) error
• func ParseConfig(file string, input string, sectionValidator func(string, string) error) (*protos.AppConfig, error)
• func ParseConfigSection(key, shortKey string, sections map[string]string, dst any) error
• type Bootstrap
  • func GetBootstrap(ctx context.Context) (Bootstrap, error)
  • func (b Bootstrap) HasPipes() bool
  • func (b Bootstrap) MakePipes() (io.ReadCloser, io.WriteCloser, error)
• type BootstrapKey

Constants

const (
	// ToWeaveletKey is the environment variable under which the file descriptor
	// for messages sent from envelope to weavelet is stored. For internal use by
	// Service Weaver infrastructure.
	ToWeaveletKey = "ENVELOPE_TO_WEAVELET_FD"

	// ToEnvelopeKey is the environment variable under which the file descriptor
	// for messages sent from weavelet to envelope is stored. For internal use by
	// Service Weaver infrastructure.
	ToEnvelopeKey = "WEAVELET_TO_ENVELOPE_FD"
)

const (
	// The version of the deployer API---aka pipe API---in semantic version
	// format (Major.Minor.Patch).
	//
	// Every time we make a change to deployer API, we assign it a new version.
	// When an envelope spawns a weavelet, the weavelet reports this version to
	// the envelope. The envelope then errors out if it is not compatible with
	// the reported version.
	//
	// We could assign the deployer API versions v1, v2, v3, and so on.
	// However, this makes it hard to understand the relationship between the
	// deployer API version and the version of the Service Weaver module. (What
	// version of Service Weaver do I need to install to get version 7 of the
	// pipe?)
	//
	// Instead, we use Service Weaver module versions as deployer API versions.
	// For example, if we change the deployer API in v0.12.0 of Service Weaver,
	// then we update the deployer API version to v0.12.0. If we don't change
	// the deployer API in v0.13.0 of Service Weaver, then we leave the
	// deployer API at v0.12.0.
	//
	// TODO(mwhittaker): Write a doc explaining versioning in detail. Include
	// Srdjan's comments in PR #219.
	Major = 0
	Minor = 2
	Patch = 0
)

Functions

func CheckEnvelopeInfo

func CheckEnvelopeInfo(w *protos.EnvelopeInfo) error

CheckEnvelopeInfo checks that EnvelopeInfo is well-formed.

func ParseConfig

func ParseConfig(file string, input string, sectionValidator func(string, string) error) (*protos.AppConfig, error)

ParseConfig parses the specified configuration input, which should hold a set of sections in TOML format from the specified file. The section corresponding to the common Service Weaver application configuration is parsed and returned as a *AppConfig.

sectionValidator(key, val) is used to validate every section config entry.

func ParseConfigSection

func ParseConfigSection(key, shortKey string, sections map[string]string, dst any) error

ParseConfigSection parses the config section for key into dst. If shortKey is not empty, either key or shortKey is accepted. If the named section is not found, returns nil without changing dst.

Types

type Bootstrap

type Bootstrap struct {
	ToWeaveletFd   uintptr  // File descriptor on which to send to weavelet (0 if unset)
	ToEnvelopeFd   uintptr  // File descriptor from which to send to envelope (0 if unset)
	ToWeaveletFile *os.File // Pipe to send to weavelet (weavertest only).
	ToEnvelopeFile *os.File // Pipe to send to envelope (weavertest only).
	TestConfig     string   // Config file contents (weavertest only).
}

Bootstrap holds configuration information used to start a process execution.

func GetBootstrap

func GetBootstrap(ctx context.Context) (Bootstrap, error)

GetBootstrap returns information needed to configure process execution. For normal execution, this comes from the environment. For weavertest, it comes from a context value.

func (Bootstrap) HasPipes

func (b Bootstrap) HasPipes() bool

HasPipes returns true if pipe information has been supplied. This is true except in the case of singleprocess.

func (Bootstrap) MakePipes

func (b Bootstrap) MakePipes() (io.ReadCloser, io.WriteCloser, error)

MakePipes creates pipe reader and writer. It returns an error if pipes are not configured.

type BootstrapKey

type BootstrapKey struct{}

BootstrapKey is the Context key used by weavertest to pass Bootstrap to [weaver.Init].