tailer

README

Tailer

This plugin can tail multiple files and generate events via the events SPI so that the client can follow log files remotely.

You can use infrakit plugin start to start the plugin. Without a configuration JSON for defining rules on starting up plugins, you can do:

# Assuming at the top of the project directory

# Run a file logger
pkg/plugin/event/tailer/test1.sh &  # will generate a file called test1.log in the same diretory

INFRAKIT_EVENT_TAILER_PATH=${PWD}/pkg/plugin/event/tailer/test1.log infrakit plugin start tailer:mylogfile

This is the simplest case of using the tailer. Using the infrakit CLI, you will see

$ infrakit


infrakit command line interface

Usage:
  infrakit [command]

Available Commands:
  event       Access event exposed by infrakit plugins
  manager     Access the manager
  metadata    Access metadata exposed by infrakit plugins
  mylogfile   Access plugin mylogfile which implements Event/0.1.0,Metadata/0.1.0  <----- This is new
  playbook    Manage playbooks
  plugin      Manage plugins
  remote      Manage remotes

Now you can see the topics:

$ infrakit mylogfile event ls -al
total 1:
Users/.../pkg/plugin/event/tailer/test1.log

And you can tail the file

$ infrakit mylogfile event tail Users/.../pkg/plugin/event/tailer/test1.log
INFO[0000] Connecting to broker url= unix://mylogfile topic= Users/davidchung/project3/src/github.com/docker/infrakit/pkg/plugin/event/tailer/test1.log opts= {/Users/davidchung/.infrakit/plugins /events}
Mon Aug 14 01:16:42 PDT 2017 -- 16675
Mon Aug 14 01:16:43 PDT 2017 -- 18597
Mon Aug 14 01:16:44 PDT 2017 -- 21251

For more complex configuration, you can use a config JSON file (see plugins.json). In this example there are two keys applogs and syslogs, and each rule uses the tailer kind to tail at least one file. To start both you can simply

infrakit --log 5 plugin start --config-url file://${PWD}/pkg/plugin/event/tailer/plugins.json syslogs applogs

Note the args syslogs and applogs are keys in the plugins.json file. Once this starts, you can see there are two event plugins visible. One with the name applogs and the other, syslogs.

Documentation

Index

• type Options
• type Rule
• type Tailer
  • func NewPlugin(options Options) (*Tailer, error)
  • func (t *Tailer) Data() map[string]interface{}
  • func (t *Tailer) List(topic types.Path) ([]string, error)
  • func (t *Tailer) PublishOn(c chan<- *event.Event)
  • func (t *Tailer) Stop()

Types

type Options

type Options []Rule

Options contains configuration parameters for the tailer

type Rule

type Rule struct {
	Path      string
	ReOpen    bool // Reopen recreated files (tail -F)
	MustExist bool // Fail early if the file does not exist
	Pipe      bool // Is a named pipe (mkfifo)
	// contains filtered or unexported fields
}

Rule contains configuration parameters for a single file

type Tailer

type Tailer struct {
	// contains filtered or unexported fields
}

Tailer is a tailer of multiple files. It is an event source that with topics that match the file paths

func NewPlugin

func NewPlugin(options Options) (*Tailer, error)

NewPlugin creates a tailer plugin

func (*Tailer) Data

func (t *Tailer) Data() map[string]interface{}

Data returns the metadata data (current line of each file)

func (*Tailer) List

func (t *Tailer) List(topic types.Path) ([]string, error)

List returns the nodes under the given topic

func (*Tailer) PublishOn

func (t *Tailer) PublishOn(c chan<- *event.Event)

PublishOn sets the channel to publish on

func (*Tailer) Stop

func (t *Tailer) Stop()

Stop stops the tailer