Add StartBackgroundServices as a new interface method for ExperimentR…

…unner

engines/experiment/examples/plugins/hardcoded/go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/caraml-dev/turing/engines/experiment v1.0.0
 	github.com/hashicorp/go-hclog v0.16.0
 	github.com/stretchr/testify v1.8.0
+	golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced
 )
 
 replace github.com/caraml-dev/turing/engines/experiment => ../../../

engines/experiment/examples/plugins/hardcoded/runner.go

@@ -9,6 +9,7 @@ import (
 	"github.com/caraml-dev/turing/engines/experiment/examples/plugins/hardcoded/utils"
 	"github.com/caraml-dev/turing/engines/experiment/pkg/request"
 	"github.com/caraml-dev/turing/engines/experiment/runner"
+	"golang.org/x/net/context"
 )
 
 type ExperimentRunner struct {
@@ -74,3 +75,9 @@ func (e *ExperimentRunner) GetTreatmentForRequest(
 
 	return nil, errors.New("no experiment configured for the unit")
 }
+
+func (e *ExperimentRunner) StartBackgroundServices(
+	chan error,
+) context.CancelFunc {
+	return nil
+}

engines/experiment/examples/plugins/nop/runner.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/caraml-dev/turing/engines/experiment/runner"
+	"golang.org/x/net/context"
 )
 
 type ExperimentRunner struct{}
@@ -23,3 +24,9 @@ func (r *ExperimentRunner) GetTreatmentForRequest(
 		Config: json.RawMessage(`{"config-1": "value-a"}`),
 	}, nil
 }
+
+func (r *ExperimentRunner) StartBackgroundServices(
+	chan error,
+) context.CancelFunc {
+	return nil
+}

engines/experiment/go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/stretchr/testify v1.7.0
 	github.com/zaffka/zap-to-hclog v0.10.5
 	go.uber.org/zap v1.21.0
+	golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced
 	google.golang.org/grpc v1.48.0
 )
 
@@ -35,7 +36,6 @@ require (
 	github.com/stretchr/objx v0.1.0 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	golang.org/x/net v0.0.0-20220809184613-07c6da5e1ced // indirect
 	golang.org/x/sys v0.0.0-20220728004956-3c1f35247d10 // indirect
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/genproto v0.0.0-20220810155839-1856144b1d9c // indirect

engines/experiment/plugin/inproc/runner/runner_test.go

@@ -9,6 +9,7 @@ import (
 	runnerPlugin "github.com/caraml-dev/turing/engines/experiment/plugin/inproc/runner"
 	"github.com/caraml-dev/turing/engines/experiment/runner"
 	"github.com/caraml-dev/turing/engines/experiment/runner/mocks"
+	"golang.org/x/net/context"
 )
 
 type fakeRunner struct {
@@ -25,6 +26,12 @@ func (runner fakeRunner) GetTreatmentForRequest(
 	return nil, nil
 }
 
+func (runner fakeRunner) StartBackgroundServices(
+	chan error,
+) context.CancelFunc {
+	return nil
+}
+
 func TestRegisterAndGet(t *testing.T) {
 	tests := []struct {
 		name            string

engines/experiment/plugin/rpc/runner/rpc.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/caraml-dev/turing/engines/experiment/plugin/rpc/shared"
 	"github.com/caraml-dev/turing/engines/experiment/runner"
+	"golang.org/x/net/context"
 )
 
 // rpcClient implements ConfigurableExperimentRunner interface
@@ -37,6 +38,17 @@ func (c *rpcClient) GetTreatmentForRequest(
 	return &resp, nil
 }
 
+func (c *rpcClient) StartBackgroundServices(
+	errChannel chan error,
+) context.CancelFunc {
+	var cancelBackgroundServices context.CancelFunc
+	err := c.Call("Plugin.StartBackgroundServices", &errChannel, cancelBackgroundServices)
+	if err != nil {
+		errChannel <- err
+	}
+	return cancelBackgroundServices
+}
+
 // rpcServer serves the implementation of a ConfigurableExperimentRunner
 type rpcServer struct {
 	Impl ConfigurableExperimentRunner
@@ -55,3 +67,10 @@ func (s *rpcServer) GetTreatmentForRequest(req *GetTreatmentRequest, resp *runne
 	*resp = *treatment
 	return nil
 }
+
+func (s *rpcServer) StartBackgroundServices(errChannel *chan error, resp *context.CancelFunc) error {
+	cancelBackgroundServices := s.Impl.StartBackgroundServices(*errChannel)
+
+	*resp = cancelBackgroundServices
+	return nil
+}

engines/experiment/runner/nop/experiment_runner.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"github.com/caraml-dev/turing/engines/experiment/runner"
+	"golang.org/x/net/context"
 )
 
 var nopTreatment = &runner.Treatment{}
@@ -21,6 +22,13 @@ func (ExperimentRunner) GetTreatmentForRequest(
 	return nopTreatment, nil
 }
 
+// StartBackgroundServices returns a dummy context cancellation function
+func (r *ExperimentRunner) StartBackgroundServices(
+	chan error,
+) context.CancelFunc {
+	return nil
+}
+
 // NewExperimentRunner is a creator for the experiment runners
 func NewExperimentRunner(json.RawMessage) (runner.ExperimentRunner, error) {
 	return &ExperimentRunner{}, nil

engines/experiment/runner/runner.go

@@ -3,6 +3,8 @@ package runner
 import (
 	"encoding/json"
 	"net/http"
+
+	"golang.org/x/net/context"
 )
 
 type GetTreatmentOptions struct {
@@ -23,4 +25,7 @@ type ExperimentRunner interface {
 		payload []byte,
 		options GetTreatmentOptions,
 	) (*Treatment, error)
+	StartBackgroundServices(
+		errChannel chan error,
+	) context.CancelFunc
 }

engines/router/missionctl/fiberapi/internal/testutils/mocks.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/caraml-dev/turing/engines/experiment/runner"
+	"golang.org/x/net/context"
 )
 
 // MockExperimentRunner is a mock implementation for the Planner interface
@@ -36,5 +37,11 @@ func (mp MockExperimentRunner) GetTreatmentForRequest(
 		return nil, errors.New("failed to retrieve experiment treatment")
 	}
 	return mp.Treatment, nil
+}
 
+// StartBackgroundServices returns a dummy context cancellation function
+func (mp MockExperimentRunner) StartBackgroundServices(
+	chan error,
+) context.CancelFunc {
+	return nil
 }