databroker: implement leases (#2172)

* databroker: implement leases

* return error

* handle gRPC errors

pkg/grpc/databroker/mock_databroker/leaser.go

@@ -0,0 +1,64 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: leaser.go
+
+// Package mock_databroker is a generated GoMock package.
+package mock_databroker
+
+import (
+	context "context"
+	reflect "reflect"
+
+	gomock "github.com/golang/mock/gomock"
+	databroker "github.com/pomerium/pomerium/pkg/grpc/databroker"
+)
+
+// MockLeaserHandler is a mock of LeaserHandler interface.
+type MockLeaserHandler struct {
+	ctrl     *gomock.Controller
+	recorder *MockLeaserHandlerMockRecorder
+}
+
+// MockLeaserHandlerMockRecorder is the mock recorder for MockLeaserHandler.
+type MockLeaserHandlerMockRecorder struct {
+	mock *MockLeaserHandler
+}
+
+// NewMockLeaserHandler creates a new mock instance.
+func NewMockLeaserHandler(ctrl *gomock.Controller) *MockLeaserHandler {
+	mock := &MockLeaserHandler{ctrl: ctrl}
+	mock.recorder = &MockLeaserHandlerMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use.
+func (m *MockLeaserHandler) EXPECT() *MockLeaserHandlerMockRecorder {
+	return m.recorder
+}
+
+// GetDataBrokerServiceClient mocks base method.
+func (m *MockLeaserHandler) GetDataBrokerServiceClient() databroker.DataBrokerServiceClient {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "GetDataBrokerServiceClient")
+	ret0, _ := ret[0].(databroker.DataBrokerServiceClient)
+	return ret0
+}
+
+// GetDataBrokerServiceClient indicates an expected call of GetDataBrokerServiceClient.
+func (mr *MockLeaserHandlerMockRecorder) GetDataBrokerServiceClient() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "GetDataBrokerServiceClient", reflect.TypeOf((*MockLeaserHandler)(nil).GetDataBrokerServiceClient))
+}
+
+// RunLeased mocks base method.
+func (m *MockLeaserHandler) RunLeased(ctx context.Context) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "RunLeased", ctx)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// RunLeased indicates an expected call of RunLeased.
+func (mr *MockLeaserHandlerMockRecorder) RunLeased(ctx interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "RunLeased", reflect.TypeOf((*MockLeaserHandler)(nil).RunLeased), ctx)
+}