Documentation
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Overview ¶
Package trigger provides tools for remotely controlling service lifecycle
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ErrRateLimitExceeded = errors.New("Rate limit exceeded for trigger")
ErrRateLimitExceeded indicates that the trigger has been called more than the allowed number of times within the specified duration, and so the guarded trigger will not be called.
Functions ¶
func LoadPlugin ¶
func LoadPlugin()
LoadPlugin being called forces the package to be loaded in order to ensure that the resource types are registered during the package's Init.
Types ¶
type CompoundTrigger ¶
type CompoundTrigger struct {
Triggers []Triggerrer
}
CompoundTrigger is a Triggerrer that allows more than one trigger to be fired off at a time. It any trigger returns an error, it isn't guaranteed that all triggers will fire.
func (*CompoundTrigger) Trigger ¶
func (c *CompoundTrigger) Trigger() error
Trigger executes all the child triggers, exiting immediately after a single failure.
func (*CompoundTrigger) UnmarshalJSON ¶
func (c *CompoundTrigger) UnmarshalJSON(input []byte) error
UnmarshalJSON implements encoding/json.Unmarshaler.
type DelayTrigger ¶
type DelayTrigger struct {
DelayedTrigger Triggerrer
Delay time.Duration
// contains filtered or unexported fields
}
DelayTrigger is a Triggerrer that delays the execution of another trigger for at least a minimum amount of time after the most recent request. The obvious analogy would be a screen saver, which will start after a certain period has elapsed, but the timer is reset quite often.
func NewDelayTrigger ¶
func NewDelayTrigger( delayedTrigger Triggerrer, delay time.Duration, ) *DelayTrigger
NewDelayTrigger initializes a DelayTrigger. It might not be strictly necessary anymore.
func (*DelayTrigger) Trigger ¶
func (d *DelayTrigger) Trigger() error
Trigger sets or resets the delay after which it will execute the child trigger. The child trigger will be executed no sooner than the delay time after any particular call, but subsequent calls may extend that time out further (possibly indefinitely).
func (*DelayTrigger) UnmarshalJSON ¶
func (d *DelayTrigger) UnmarshalJSON(input []byte) error
UnmarshalJSON implements encoding/json.Unmarshaler.
type RateLimitTrigger ¶
type RateLimitTrigger struct {
GuardedTrigger Triggerrer
MaxAllowed uint
Period time.Duration
// contains filtered or unexported fields
}
RateLimitTrigger is a Triggerrer that will prevent a guarded trigger from being called more than a specified number of times over a specified duration.
func NewRateLimitTrigger ¶
func NewRateLimitTrigger( guardedTrigger Triggerrer, maxAllowed uint, period time.Duration, ) *RateLimitTrigger
NewRateLimitTrigger initializes a RateLimitTrigger. It may no longer be strictly necessary.
func (*RateLimitTrigger) Trigger ¶
func (r *RateLimitTrigger) Trigger() error
Trigger executes its guarded trigger if and only if it has not be called more than the allowed number of times within the specified rolling window of time. If the rate limit is exceeded, ErrRateLimitExceeded will be returned, and the guarded trigger will not be called.
func (*RateLimitTrigger) UnmarshalJSON ¶
func (r *RateLimitTrigger) UnmarshalJSON(input []byte) error
UnmarshalJSON implements encoding/json.Unmarshaler.
type ShellTriggerrer ¶
ShellTriggerrer is a basic Triggerrer that calls a stored shell command (along with arguments) when triggered.
The message given to TriggerString will be passed to the command via stdin.
func NewShellTriggerrer ¶
func NewShellTriggerrer( command string, args []string, ) *ShellTriggerrer
NewShellTriggerrer constructs a new ShellTriggerrer given the command (and arguments) to be run each time TriggerString is called. Entire shell scripts could potentially be stored in the arguments, though the trigger could just as easily call an external shell script. As a result, a wide variety of actions could be taken based on the message passed in via stdin.
func (*ShellTriggerrer) Trigger ¶
func (s *ShellTriggerrer) Trigger() (err error)
Trigger will execute the given command with the given args using the system shell.
func (*ShellTriggerrer) UnmarshalJSON ¶
func (s *ShellTriggerrer) UnmarshalJSON(input []byte) error
UnmarshalJSON implements encoding/json.Unmarshaler.
type SqsTriggerrer ¶
type SqsTriggerrer struct {
// contains filtered or unexported fields
}
SqsTriggerrer is a work-in-progress that is intended to eventually send SQS messages as the result of a triggering event.
func NewSqsTriggerrer ¶
func NewSqsTriggerrer(url string) *SqsTriggerrer
NewSqsTriggerrer initializes a SqsTriggerrer. It may no longer be strictly necessary.
func (*SqsTriggerrer) Trigger ¶
func (handler *SqsTriggerrer) Trigger(message string) (err error)
Trigger implemented Triggerrer and actually performs the encapsulated behavior.
type Triggerrer ¶
type Triggerrer interface {
Trigger() (err error)
}
Triggerrer is an abstract interface describing a system which provides triggers that can be called based on certain events (like a service being detected as down, an amount of time passing without a service being accessed, etc.).
Source Files