head

head

import "github.com/cognusion/prochydra/head"

• Overview
• Index

Overview

Index

• func ReadLogger(reader io.Reader, writer *log.Logger, errorChan chan<- error)
• type Head
  • func BashDashC(command string, errorChan chan error) *Head
  • func New(command string, args []string, errorChan chan error) *Head
  • func (r *Head) Autorestart(doit bool)
  • func (r *Head) Clone() *Head
  • func (r *Head) Errors() uint64
  • func (r *Head) Restarts() uint64
  • func (r *Head) RestartsPerMinute() uint64
  • func (r *Head) Run() string
  • func (r *Head) SetChildEnv(env []string)
  • func (r *Head) SetMgInterval(interval time.Duration)
  • func (r *Head) Stop()
  • func (r *Head) String() string
  • func (r *Head) Wait()
  • func (r *Head) Write(p []byte) (n int, err error)
• type Sbuffer
  • func (s *Sbuffer) String() string
  • func (s *Sbuffer) Write(p []byte) (n int, err error)

Package files

common.go head.go

func ReadLogger

func ReadLogger(reader io.Reader, writer *log.Logger, errorChan chan<- error)

ReadLogger continuously reads from an io.Reader, and blurts to the specified log.Logger

type Head

type Head struct {
    // ID is a generated ID based on the sequence
    ID string
    // RestartDelay specified the duration to wait between restarts
    RestartDelay time.Duration
    // MaxPSS specifies the maximum PSS size a process may have before being killed
    MaxPSS int64
    // DebugOut is a logger for debug information
    DebugOut *log.Logger
    // ErrOut is a logger for errors, generally, emitted by a Head
    ErrOut *log.Logger
    // StdErr is a logger for StdErr coming from a process
    StdErr *log.Logger
    // StdOut is a logger for StdOut coming from a process
    StdOut *log.Logger
    // UID is the uid to run as (leave unset for current user)
    UID uint32
    // GID is the gid to run as (leave unset for current group)
    GID uint32
    // Seq is a pointer to an initialized sequencer
    Seq *sequence.Seq
    // Values is a map for implementors to store key-value pairs. Never consulted by the Head library.
    Values sync.Map
    // Timeout is a duration after which the process running is stopped, subject to  Autorestart
    Timeout time.Duration
    // StdInNoNL is a boolean to describe if a NewLine should *not* be appended to lines written to StdIn.
    // This is advisory-only, and respected by hydra but not necessarily others.
    StdInNoNL bool
    // StdInShellEscapeInput is a boolean to describe if strings send to StdIn should be shell-escaped.
    // This is advisory-only, and respected by hydra but not necessarily others.
    StdInShellEscapeInput bool
    // contains filtered or unexported fields
}

Head is a struct to contain a process a run. You can Run() the same Head multiple times if you need clones.

func BashDashC

func BashDashC(command string, errorChan chan error) *Head

BashDashC creates a head that handles the command in its entirety running as a "bash -c command"

func New

func New(command string, args []string, errorChan chan error) *Head

New returns a Head struct, ready to Run() the command with the arguments specified. It would be wise to ensure the errorChan reader is ready before calling Run() to prevent goro plaque.

func (*Head) Autorestart

func (r *Head) Autorestart(doit bool)

Autorestart sets whether or not we will automatically restart Heads that "complete"

func (*Head) Clone

func (r *Head) Clone() *Head

Clone returns a new Head intialized the same as the current

func (*Head) Errors

func (r *Head) Errors() uint64

Errors returns the current number of errors sent to the error chan

func (*Head) Restarts

func (r *Head) Restarts() uint64

Restarts returns the current number of restarts for this Head instance

func (*Head) RestartsPerMinute

func (r *Head) RestartsPerMinute() uint64

RestartsPerMinute returns the number of restarts for this Head instance in the last minute

func (*Head) Run

func (r *Head) Run() string

Run executes a subprocess of the command and arguments specified, restarting it if applicable. The returned channel returns the name of the once it is running, or closes it without a value if it will not run.

func (*Head) SetChildEnv

func (r *Head) SetChildEnv(env []string)

SetChildEnv takes a list of key=value strings to pass to all spawned processes

func (*Head) SetMgInterval

func (r *Head) SetMgInterval(interval time.Duration)

SetMgInterval sets the interval at which the memory usage is checked, for use with MaxPSS. Default 30s.

func (*Head) Stop

func (r *Head) Stop()

Stop signals all of the running processes to die. May generate error output thereafter.

func (*Head) String

func (r *Head) String() string

String returns the original command and arguments in a line

func (*Head) Wait

func (r *Head) Wait()

Wait blocks until the Run() process has completed

func (*Head) Write

func (r *Head) Write(p []byte) (n int, err error)

Write implements io.Writer to ease writing to StdIn

type Sbuffer

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

Sbuffer is a goro-safe bytes.Buffer

func (*Sbuffer) String

func (s *Sbuffer) String() string

String returns the contents of the unread portion of the buffer as a string.

func (*Sbuffer) Write

func (s *Sbuffer) Write(p []byte) (n int, err error)

Write appends the contents of p to the buffer, growing the buffer as needed. It returns the number of bytes written or an error.

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