CloudFunction

Description

The CloudFunction class allows you to create an Abstract Google Function that acts as a container to instantiate and run components and expose them via an external entry point.

Importan points

• When handling calls, the “cmd” parameter determines the action that shall be called, while the other parameters are passed to the action itself.

• The container configuration for this Google Function is stored in "./config/config.yml" file. But this path can be overriden by CONFIG_PATH environment variable.

References

• *:logger:*:*:1.0: (optional) ILogger components to pass log messages
• *:counters:*:*:1.0: (optional) ICounters components to pass collected measurements
• *:service:gcp-function:*:1.0: (optional) ICloudFunctionService services to handle action requests.
• *:service:commandable-gcp-function:*:1.0: (optional) ICloudFunctionService services to handle action requests.

Constructors

NewCloudFunctionWithParams

Creates a new instance of this Google Function.

NewCloudFunctionWithParams(name string, description string) *CloudFunction

• name: string - (optional) container’s name (accessible via ContextInfo)
• description: string - (optional) container’s description (accessible via ContextInfo)

NewCloudFunction

Creates a new instance of this Google Function function.

NewCloudFunction() *CloudFunction

InheritCloudFunction

InheritCloudFunction creates new instance of CloudFunction

InheritCloudFunction(overrides ICloudFunctionOverrides) *CloudFunction

• overrides: ICloudFunctionOverrides - instance with override methods.

InheritCloudFunctionWithParams

InheritCloudFunction creates new instance of CloudFunction

InheritCloudFunctionWithParams(overrides ICloudFunctionOverrides, name string, description string) *CloudFunction

• name: string - (optional) container’s name (accessible via ContextInfo)
• description: string - (optional) container’s description (accessible via ContextInfo)

Fields

Instance methods

Execute

Executes this Google Function and returns the result. This method can be overloaded in child classes if they need to change the default behavior

(c *CloudFunction) Execute(res http.ResponseWriter, req *http.Request)

• req: http.ResponseWriter - the request object (with function arguments)
• res: *http.Request - the result of the function execution.

GetCommand

Returns command from Google Function request. This method can be overloaded in child classes

(c *CloudFunction) GetCommand(r *http.Request) (string, error)

• r: *http.Request - Google Function request
• returns: (string, error) - Returns command from req

GetCorrelationId

Returns correlationId from Googel Function request. This method can be overloaded in child classes

(c *CloudFunction) GetCorrelationId(r *http.Request) string

• r: *http.Request - Google Function request
• returns: string - Returns correlationId from req

GetHandler

Return plugin function

(c *CloudFunction) GetHandler() http.HandlerFunc

• returns: http.HandlerFunc - request handler function.

Instrument

Adds instrumentation to log calls and measures call time. It returns a Timing object that is used to end the time measurement.

(c *CloudFunction) Instrument(ctx context.Context, correlationId string, name string) *InstrumentTiming

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• name: string - method’s name.
• returns: *InstrumentTiming - Timing object to end the time measurement.

Open

Opens the component.

(c *CloudFunction) Open(ctx context.Context, correlationId string) error

• ctx: context.Context - operation context.
• correlationId: string - (optional) transaction id used to trace execution through the call chain.
• returns: error - open error.

RegisterAction

Registers an action in this Google Function.

Note: This method has been deprecated. Use CloudFunctionService instead.

(c *CloudFunction) RegisterAction(cmd string, schema *Schema, action http.HandlerFunc)

• cmd: str - a action/command name.
• schema: *Schema - a validation schema to validate received parameters.
• action: http.HandlerFunc - an action function that is called when action is invoked.

Register

Registers all actions in this Googel Function.

Note: Overloading of this method has been deprecated. Use GoogelFunctionService instead.

Register()

RegisterServices

Registers all Google Function services in the container.

(c *CloudFunction) RegisterServices()

Run

Runs this Google Function, loads container configuration, instantiate components and manage their lifecycle, makes this function ready to access action calls.

(c *CloudFunction) Run(ctx context.Context)

• ctx: context.Context - operation context.

SetReferences

Sets references to dependent components.

(c *CloudFunction) SetReferences(ctx context.Context, references IReferences)

• ctx: context.Context - operation context.
• references: IReferences - references to locate the component’s dependencies.

Examples

type MyCloudFunction struct {
	*containers.CloudFunction
}

func NewMyCloudFunction() *MyCloudFunction {
	c := MyCloudFunction{}
	c.CloudFunction = containers.NewCloudFunctionWithParams("mygroup", "MyGroup Google Function")

	return &c
}

...

cloudFunction := NewMyCloudFunction()
cloudFunction.Run(ctx)
fmt.Println("MyCloudFunction is started")