checks

Documentation

Index

• Constants
• Variables
• func ParseHost(host string) (string, string, string, error)
• type AliasNotifier
• type CheckAlias
  • func (c *CheckAlias) Start()
  • func (c *CheckAlias) Stop()
• type CheckDocker
  • func (c *CheckDocker) Start()
  • func (c *CheckDocker) Stop()
• type CheckGRPC
  • func (c *CheckGRPC) Start()
  • func (c *CheckGRPC) Stop()
• type CheckHTTP
  • func (c *CheckHTTP) Start()
  • func (c *CheckHTTP) Stop()
• type CheckMonitor
  • func (c *CheckMonitor) Start()
  • func (c *CheckMonitor) Stop()
• type CheckNotifier
• type CheckTCP
  • func (c *CheckTCP) Start()
  • func (c *CheckTCP) Stop()
• type CheckTTL
  • func (c *CheckTTL) SetStatus(status, output string)
  • func (c *CheckTTL) Start()
  • func (c *CheckTTL) Stop()
• type DockerClient
  • func NewDockerClient(host string, maxbuf int64) (*DockerClient, error)
  • func (c *DockerClient) Close() error
  • func (c *DockerClient) CreateExec(containerID string, cmd []string) (string, error)
  • func (c *DockerClient) Host() string
  • func (c *DockerClient) InspectExec(containerID, execID string) (int, error)
  • func (c *DockerClient) StartExec(containerID, execID string) (*circbuf.Buffer, error)
• type GrpcHealthProbe
  • func NewGrpcHealthProbe(target string, timeout time.Duration, tlsConfig *tls.Config) *GrpcHealthProbe
  • func (probe *GrpcHealthProbe) Check() error
• type RPC

Constants

const (
	// MinInterval is the minimal interval between
	// two checks. Do not allow for a interval below this value.
	// Otherwise we risk fork bombing a system.
	MinInterval = time.Second

	// BufSize is the maximum size of the captured
	// check output. Prevents an enormous buffer
	// from being captured
	BufSize = 4 * 1024 // 4KB

	// UserAgent is the value of the User-Agent header
	// for HTTP health checks.
	UserAgent = "Consul Health Check"
)

const DefaultDockerHost = "unix:///var/run/docker.sock"

Variables

var ErrGRPCUnhealthy = fmt.Errorf("gRPC application didn't report service healthy")

Functions

func ParseHost

func ParseHost(host string) (string, string, string, error)

ParseHost verifies that the given host strings is valid. copied from github.com/docker/docker/client.go

Types

type AliasNotifier

type AliasNotifier interface {
	CheckNotifier

	AddAliasCheck(types.CheckID, string, chan<- struct{}) error
	RemoveAliasCheck(types.CheckID, string)
	Checks() map[types.CheckID]*structs.HealthCheck
}

AliasNotifier is a CheckNotifier specifically for the Alias check. This requires additional methods that are satisfied by the agent local state.

type CheckAlias

type CheckAlias struct {
	Node      string // Node name of the service. If empty, assumed to be this node.
	ServiceID string // ID (not name) of the service to alias

	CheckID types.CheckID               // ID of this check
	RPC     RPC                         // Used to query remote server if necessary
	RPCReq  structs.NodeSpecificRequest // Base request
	Notify  AliasNotifier               // For updating the check state
	// contains filtered or unexported fields
}

CheckAlias is a check type that aliases the health of another service instance or node. If the service aliased has any critical health checks, then this check is critical. If the service has no critical but warnings, then this check is warning, and if a service has only passing checks, then this check is passing.

func (*CheckAlias) Start

func (c *CheckAlias) Start()

Start is used to start the check, runs until Stop() func (c *CheckAlias) Start() {

func (*CheckAlias) Stop

func (c *CheckAlias) Stop()

Stop is used to stop the check.

type CheckDocker

type CheckDocker struct {
	Notify            CheckNotifier
	CheckID           types.CheckID
	Script            string
	ScriptArgs        []string
	DockerContainerID string
	Shell             string
	Interval          time.Duration
	Logger            *log.Logger
	Client            *DockerClient
	// contains filtered or unexported fields
}

CheckDocker is used to periodically invoke a script to determine the health of an application running inside a Docker Container. We assume that the script is compatible with nagios plugins and expects the output in the same format.

func (*CheckDocker) Start

func (c *CheckDocker) Start()

func (*CheckDocker) Stop

func (c *CheckDocker) Stop()

type CheckGRPC

type CheckGRPC struct {
	Notify          CheckNotifier
	CheckID         types.CheckID
	GRPC            string
	Interval        time.Duration
	Timeout         time.Duration
	TLSClientConfig *tls.Config
	Logger          *log.Logger
	// contains filtered or unexported fields
}

CheckGRPC is used to periodically send request to a gRPC server application that implements gRPC health-checking protocol. The check is passing if returned status is SERVING. The check is critical if connection fails or returned status is not SERVING.

func (*CheckGRPC) Start

func (c *CheckGRPC) Start()

func (*CheckGRPC) Stop

func (c *CheckGRPC) Stop()

type CheckHTTP

type CheckHTTP struct {
	Notify          CheckNotifier
	CheckID         types.CheckID
	HTTP            string
	Header          map[string][]string
	Method          string
	Interval        time.Duration
	Timeout         time.Duration
	Logger          *log.Logger
	TLSClientConfig *tls.Config
	// contains filtered or unexported fields
}

CheckHTTP is used to periodically make an HTTP request to determine the health of a given check. The check is passing if the response code is 2XX. The check is warning if the response code is 429. The check is critical if the response code is anything else or if the request returns an error

func (*CheckHTTP) Start

func (c *CheckHTTP) Start()

Start is used to start an HTTP check. The check runs until stop is called

func (*CheckHTTP) Stop

func (c *CheckHTTP) Stop()

Stop is used to stop an HTTP check.

type CheckMonitor

type CheckMonitor struct {
	Notify     CheckNotifier
	CheckID    types.CheckID
	Script     string
	ScriptArgs []string
	Interval   time.Duration
	Timeout    time.Duration
	Logger     *log.Logger
	// contains filtered or unexported fields
}

CheckMonitor is used to periodically invoke a script to determine the health of a given check. It is compatible with nagios plugins and expects the output in the same format.

func (*CheckMonitor) Start

func (c *CheckMonitor) Start()

Start is used to start a check monitor. Monitor runs until stop is called

func (*CheckMonitor) Stop

func (c *CheckMonitor) Stop()

Stop is used to stop a check monitor.

type CheckNotifier

type CheckNotifier interface {
	UpdateCheck(checkID types.CheckID, status, output string)
}

CheckNotifier interface is used by the CheckMonitor to notify when a check has a status update. The update should take care to be idempotent.

type CheckTCP

type CheckTCP struct {
	Notify   CheckNotifier
	CheckID  types.CheckID
	TCP      string
	Interval time.Duration
	Timeout  time.Duration
	Logger   *log.Logger
	// contains filtered or unexported fields
}

CheckTCP is used to periodically make an TCP/UDP connection to determine the health of a given check. The check is passing if the connection succeeds The check is critical if the connection returns an error

func (*CheckTCP) Start

func (c *CheckTCP) Start()

Start is used to start a TCP check. The check runs until stop is called

func (*CheckTCP) Stop

func (c *CheckTCP) Stop()

Stop is used to stop a TCP check.

type CheckTTL

type CheckTTL struct {
	Notify  CheckNotifier
	CheckID types.CheckID
	TTL     time.Duration
	Logger  *log.Logger
	// contains filtered or unexported fields
}

CheckTTL is used to apply a TTL to check status, and enables clients to set the status of a check but upon the TTL expiring, the check status is automatically set to critical.

func (*CheckTTL) SetStatus

func (c *CheckTTL) SetStatus(status, output string)

SetStatus is used to update the status of the check, and to renew the TTL. If expired, TTL is restarted.

func (*CheckTTL) Start

func (c *CheckTTL) Start()

Start is used to start a check ttl, runs until Stop()

func (*CheckTTL) Stop

func (c *CheckTTL) Stop()

Stop is used to stop a check ttl.

type DockerClient

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

DockerClient is a simplified client for the Docker Engine API to execute the health checks and avoid significant dependencies. It also consumes all data returned from the Docker API through a ring buffer with a fixed limit to avoid excessive resource consumption.

func NewDockerClient

func NewDockerClient(host string, maxbuf int64) (*DockerClient, error)

func (*DockerClient) Close

func (c *DockerClient) Close() error

func (*DockerClient) CreateExec

func (c *DockerClient) CreateExec(containerID string, cmd []string) (string, error)

func (*DockerClient) Host

func (c *DockerClient) Host() string

func (*DockerClient) InspectExec

func (c *DockerClient) InspectExec(containerID, execID string) (int, error)

func (*DockerClient) StartExec

func (c *DockerClient) StartExec(containerID, execID string) (*circbuf.Buffer, error)

type GrpcHealthProbe

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

GrpcHealthProbe connects to gRPC application and queries health service for application/service status.

func NewGrpcHealthProbe

func NewGrpcHealthProbe(target string, timeout time.Duration, tlsConfig *tls.Config) *GrpcHealthProbe

NewGrpcHealthProbe constructs GrpcHealthProbe from target string in format server[/service] If service is omitted, health of the entire application is probed

func (*GrpcHealthProbe) Check

func (probe *GrpcHealthProbe) Check() error

Check if the target of this GrpcHealthProbe is healthy If nil is returned, target is healthy, otherwise target is not healthy

type RPC

type RPC interface {
	RPC(method string, args interface{}, reply interface{}) error
}

RPC is an interface that an RPC client must implement. This is a helper interface that is implemented by the agent delegate for checks that need to make RPC calls.