executor

Documentation

Overview

Copyright 2020 New Relic Corporation. All rights reserved. SPDX-License-Identifier: Apache-2.0

Copyright 2020 New Relic Corporation. All rights reserved. SPDX-License-Identifier: Apache-2.0 Package executor implements the executor module which is able to execute an individual command and forward the standard input, standard error, and go errors by a set of channels

Copyright 2020 New Relic Corporation. All rights reserved. SPDX-License-Identifier: Apache-2.0

Copyright 2020 New Relic Corporation. All rights reserved. SPDX-License-Identifier: Apache-2.0

Index

• func NewOutput() (OutputSend, OutputReceive)
• type Config
  • func (c *Config) BuildEnv() map[string]string
• type Executor
  • func FromCmdSlice(cmd []string, cfg *Config) Executor
  • func (r *Executor) DeepClone() Executor
  • func (r *Executor) Execute(ctx context.Context, pidChan, exitCodeCh chan<- int) OutputReceive
• type OutputReceive
• type OutputSend
  • func (t *OutputSend) Close()

Functions

func NewOutput

func NewOutput() (OutputSend, OutputReceive)

NewOutput creates a default OutputSend group as well as the read-only view.

Types

type Config

type Config struct {
	User            string
	Directory       string
	IntegrationName string
	// Manually specified variables
	Environment map[string]string
	// Global variables that need to be retrieved before the integration runs
	Passthrough []string
}

Config describes the context to execute a command: user, directory and environment variables.

func (*Config) BuildEnv

func (c *Config) BuildEnv() map[string]string

BuildEnv returns the environment configuration of an executable, merging the user-defined environment variables from the configuration files with the global passthrough_environment configuration. For backwards-compatibility reasons, the passthrough has higher precedence than the configured Environment

type Executor

type Executor struct {
	Cfg     *Config
	Command string
	Args    []string
}

Executor handles Executable commands asynchronously.

func FromCmdSlice

func FromCmdSlice(cmd []string, cfg *Config) Executor

FromCmdSlice builds a Executor instance from a string slices, being the first element the command path/name and the next, the command arguments

func (*Executor) DeepClone

func (r *Executor) DeepClone() Executor

DeepClone returns an exact copy of an Executor, without references to the same data structures. It will allow replacing ${config.path} variables by the agent in several executor instances.

func (*Executor) Execute

func (r *Executor) Execute(ctx context.Context, pidChan, exitCodeCh chan<- int) OutputReceive

Execute runs the command in background, sending by a channel the standard output and error, as well as any execution error may happen (task can't start, task is killed...). The executed process can be cancelled via the provided Context. When writable PID channel is provided, generated PID will be written, so process could be signaled by 3rd parties. When the process ends, all the channels are closed.

type OutputReceive

type OutputReceive struct {
	// Stdout is received line by line. It is closed when the task ends
	Stdout <-chan []byte
	// Stderr is received line by line. It is closed when the task ends
	Stderr <-chan []byte
	// Errors receives any execution error or error exit status. It is closed when the task ends
	Errors <-chan error
	// Done is a channel that is closed when the integration has finished
	Done <-chan struct{}
}

OutputReceive is a receive-only view of OutputSend, made for the sake of safety.

type OutputSend

type OutputSend struct {
	// Stdout is received line by line. It is closed when the task ends
	Stdout chan<- []byte
	// Stderr is received line by line. It is closed when the task ends
	Stderr chan<- []byte
	// Errors receives any execution error or error exit status. It is closed when the task ends
	Errors chan<- error
	// Done is a channel that is closed when the integration has finished
	Done chan<- struct{}
}

OutputSend holds information about a running task

func (*OutputSend) Close

func (t *OutputSend) Close()

Close closes all the channels of a task output