health

Documentation

Overview

Package health provides health check implementations for Docker services.

Index

• func Poll(ctx context.Context, timeout, interval time.Duration, fn func() error) error
• func ScanForPattern(r io.Reader, pattern string) (bool, error)
• type Checker
• type DockerChecker
  • func NewDockerChecker(cli *dockerclient.Client, containerID string, timeout, interval time.Duration) *DockerChecker
  • func (c *DockerChecker) Check(ctx context.Context) error
• type HTTPChecker
  • func NewHTTPChecker(url string, timeout, interval time.Duration) *HTTPChecker
  • func (c *HTTPChecker) Check(ctx context.Context) error
• type LogChecker
  • func NewLogChecker(cli *dockerclient.Client, service, pattern string, ...) *LogChecker
  • func (c *LogChecker) Check(ctx context.Context) error
• type Named
• type TCPChecker
  • func NewTCPChecker(host, port string, timeout, interval time.Duration) *TCPChecker
  • func (c *TCPChecker) Check(ctx context.Context) error

Functions

func Poll

func Poll(ctx context.Context, timeout, interval time.Duration, fn func() error) error

Poll retries fn until it returns nil or the timeout is exceeded. Between attempts it waits for interval, respecting context cancellation.

func ScanForPattern

func ScanForPattern(r io.Reader, pattern string) (bool, error)

ScanForPattern reads lines from r looking for a line containing pattern.

Types

type Checker

type Checker interface {
	Check(ctx context.Context) error
}

Checker polls a service until it is healthy or the timeout is exceeded.

type DockerChecker

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

DockerChecker polls the Docker API for a container's built-in HEALTHCHECK status.

func NewDockerChecker

func NewDockerChecker(cli *dockerclient.Client, containerID string, timeout, interval time.Duration) *DockerChecker

NewDockerChecker creates a health checker that inspects the container's health state.

func (*DockerChecker) Check

func (c *DockerChecker) Check(ctx context.Context) error

Check polls Docker until the container reports healthy or timeout.

type HTTPChecker

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

HTTPChecker polls an HTTP endpoint until it returns a 2xx status code.

func NewHTTPChecker

func NewHTTPChecker(url string, timeout, interval time.Duration) *HTTPChecker

NewHTTPChecker creates a health checker that GETs the given URL.

func (*HTTPChecker) Check

func (c *HTTPChecker) Check(ctx context.Context) error

Check polls the HTTP endpoint until healthy or timeout.

type LogChecker

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

LogChecker watches container logs for a specific pattern string.

func NewLogChecker

func NewLogChecker(cli *dockerclient.Client, service, pattern string, timeout, interval time.Duration) *LogChecker

NewLogChecker creates a health checker that scans container stdout/stderr for pattern.

func (*LogChecker) Check

func (c *LogChecker) Check(ctx context.Context) error

type Named

type Named struct {
	Checker Checker
	Label   string
}

Named pairs a Checker with a human-readable label for terminal output.

type TCPChecker

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

TCPChecker polls a TCP endpoint until a connection can be established.

func NewTCPChecker

func NewTCPChecker(host, port string, timeout, interval time.Duration) *TCPChecker

NewTCPChecker creates a health checker that dials the given host:port.

func (*TCPChecker) Check

func (c *TCPChecker) Check(ctx context.Context) error

Check polls the TCP endpoint until connectable or timeout.