Add peer provider plugin registration

common/config/config.go

@@ -43,6 +43,8 @@ type (
 	Config struct {
 		// Ringpop is the ringpop related configuration
 		Ringpop ringpopprovider.Config `yaml:"ringpop"`
+		// Membership is used to configure peer provider plugin
+		Membership Membership `yaml:"membership"`
 		// Persistence contains the configuration for cadence datastores
 		Persistence Persistence `yaml:"persistence"`
 		// Log is the logging config
@@ -84,6 +86,14 @@ type (
 		AsyncWorkflowQueues map[string]AsyncWorkflowQueueProvider `yaml:"asyncWorkflowQueues"`
 	}
 
+	// Membership holds peer provider configuration.
+	Membership struct {
+		Provider PeerProvider `yaml:"provider"`
+	}
+
+	// PeerProvider is provider config. Contents depends on plugin in use
+	PeerProvider map[string]*YamlNode
+
 	HeaderRule struct {
 		Add   bool // if false, matching headers are removed if previously matched.
 		Match *regexp.Regexp

common/peerprovider/plugin.go

@@ -0,0 +1,87 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2017-2020 Uber Technologies Inc.
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package peerprovider
+
+import (
+	"fmt"
+
+	"go.uber.org/yarpc/transport/tchannel"
+
+	"github.com/uber/cadence/common/config"
+	"github.com/uber/cadence/common/log"
+	"github.com/uber/cadence/common/membership"
+	"github.com/uber/cadence/common/syncmap"
+)
+
+// Container is passed to peer provider plugin
+type Container struct {
+	Service string
+	// Channel is required by ringpop
+	Channel tchannel.Channel
+	Logger  log.Logger
+	Portmap membership.PortMap
+}
+
+type constructorFn func(cfg *config.YamlNode, container Container) (membership.PeerProvider, error)
+
+var plugins = syncmap.New[string, plugin]()
+
+type plugin struct {
+	fn        constructorFn
+	configKey string
+}
+
+type Provider struct {
+	config    config.PeerProvider
+	container Container
+}
+
+func New(config config.PeerProvider, container Container) *Provider {
+	return &Provider{
+		config:    config,
+		container: container,
+	}
+}
+
+func Register(configKey string, constructor constructorFn) error {
+	inserted := plugins.Put(configKey, plugin{
+		fn:        constructor,
+		configKey: configKey,
+	})
+
+	if !inserted {
+		return fmt.Errorf("peer provider %q is already registered", configKey)
+	}
+
+	return nil
+}
+
+func (p *Provider) Provider() (membership.PeerProvider, error) {
+	for configKey, cfg := range p.config {
+		if plugin, found := plugins.Get(configKey); found {
+			return plugin.fn(cfg, p.container)
+		}
+	}
+
+	return nil, fmt.Errorf("no configured peer providers found")
+}

common/peerprovider/plugin_test.go

@@ -0,0 +1,63 @@
+// The MIT License (MIT)
+
+// Copyright (c) 2017-2020 Uber Technologies Inc.
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package peerprovider
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/uber/cadence/common/config"
+	"github.com/uber/cadence/common/membership"
+)
+
+func TestRegisterAllowsPluginOnlyOnce(t *testing.T) {
+	assert.NoError(t, Register("testConfig", func(cfg *config.YamlNode, container Container) (membership.PeerProvider, error) { return nil, nil }))
+	assert.Error(t, Register("testConfig",
+		func(cfg *config.YamlNode, container Container) (membership.PeerProvider, error) { return nil, nil }),
+		"plugin can be registered only once",
+	)
+
+}
+func TestProviderRetrunsErrorWhenNoProviderRegistered(t *testing.T) {
+	a := Provider{
+		config:    nil,
+		container: Container{},
+	}
+	p, err := a.Provider()
+	assert.Nil(t, p)
+	assert.EqualError(t, err, "no configured peer providers found")
+}
+
+func TestProviderRetrunsErrorWhenNoConfigFound(t *testing.T) {
+	err := Register("providerName", func(cfg *config.YamlNode, container Container) (membership.PeerProvider, error) {
+		return nil, nil
+	})
+	assert.NoError(t, err)
+	ppConfig := config.PeerProvider{
+		"configKey": &config.YamlNode{},
+	}
+	p, err := New(ppConfig, Container{}).Provider()
+	assert.Nil(t, p)
+	assert.Error(t, err)
+}