feat: Add a simple wrp focused pubsub package.

go.mod

@@ -16,7 +16,7 @@ require (
 	github.com/xmidt-org/eventor v0.0.0-20230910205925-8ff168bd12ed
 	github.com/xmidt-org/retry v0.0.3
 	github.com/xmidt-org/sallust v0.2.2
-	github.com/xmidt-org/wrp-go/v3 v3.5.0
+	github.com/xmidt-org/wrp-go/v3 v3.5.1
 	go.uber.org/fx v1.21.0
 	go.uber.org/zap v1.27.0
 	gopkg.in/dealancer/validate.v2 v2.1.0

go.sum

@@ -65,8 +65,8 @@ github.com/xmidt-org/retry v0.0.3 h1:wvmBnEEn1OKwSZaQtr1RZ2Vey8JIvP72mGTgR+3wPiM
 github.com/xmidt-org/retry v0.0.3/go.mod h1:I7FO3VVrxPckNuotwGYZIxfBnmjMSyOTitTKNL0VkIA=
 github.com/xmidt-org/sallust v0.2.2 h1:MrINLEr7cMj6ENx/O76fvpfd5LNGYnk7OipZAGXPYA0=
 github.com/xmidt-org/sallust v0.2.2/go.mod h1:ytBoypcPw10OmjM6b92Jx3eoqWX4J5zVXOQozGwz4qs=
-github.com/xmidt-org/wrp-go/v3 v3.5.0 h1:2HzhdDticGvMVC8z+JWHBsp2si/aE/WQeZutY+erUr0=
-github.com/xmidt-org/wrp-go/v3 v3.5.0/go.mod h1:j1kLLoPJmKkMFz/vlwP238WBoFhJgbPyJDN9W2V1TxY=
+github.com/xmidt-org/wrp-go/v3 v3.5.1 h1:AYjdNDlck3M1rdsZugMxn8TcltySmT25HIuoqU105Fw=
+github.com/xmidt-org/wrp-go/v3 v3.5.1/go.mod h1:zruorkuO3UJQKD8okAFOr8PYIlrPBtRGBVQxsoKX8L8=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 go.uber.org/dig v1.17.1 h1:Tga8Lz8PcYNsWsyHMZ1Vm0OQOUaJNDyvPImgbAu9YSc=
 go.uber.org/dig v1.17.1/go.mod h1:Us0rSJiThwCv2GteUN0Q7OKvU7n5J4dxZ9JKUXozFdE=

internal/pubsub/end2end_test.go

@@ -0,0 +1,229 @@
+// SPDX-FileCopyrightText: 2024 Comcast Cable Communications Management, LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package pubsub_test
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/xmidt-org/wrp-go/v3"
+	"github.com/xmidt-org/xmidt-agent/internal/pubsub"
+)
+
+type msgWithExpectations struct {
+	msg       wrp.Message
+	expectErr error
+}
+
+var messages = []msgWithExpectations{
+	{
+		msg: wrp.Message{
+			Type:        wrp.SimpleEventMessageType,
+			Source:      "self:/service/ignored",
+			Destination: "event:event_1/ignored",
+		},
+	}, {
+		msg: wrp.Message{
+			Type:        wrp.SimpleEventMessageType,
+			Source:      "self:/service/ignored",
+			Destination: "event:event_2/ignored",
+		},
+	}, {
+		msg: wrp.Message{
+			Type:        wrp.SimpleRequestResponseMessageType,
+			Source:      "dns:tr1d1um.example.com/service/ignored",
+			Destination: "mac:112233445566/service/ignored",
+		},
+	}, {
+		msg: wrp.Message{
+			Type:        wrp.SimpleRequestResponseMessageType,
+			Source:      "mac:112233445566/service/ignored",
+			Destination: "dns:tr1d1um.example.com/service/ignored",
+		},
+	}, {
+		// invalid message - no src
+		msg: wrp.Message{
+			Type:        wrp.SimpleRequestResponseMessageType,
+			Destination: "dns:tr1d1um.example.com/service/ignored",
+		},
+		expectErr: wrp.ErrorInvalidLocator,
+	}, {
+		// invalid message - no dest
+		msg: wrp.Message{
+			Type:   wrp.SimpleRequestResponseMessageType,
+			Source: "mac:112233445566/service/ignored",
+		},
+		expectErr: wrp.ErrorInvalidLocator,
+	}, {
+		// invalid message - invalid msg type (empty)
+		msg: wrp.Message{
+			Source:      "mac:112233445566/service/ignored",
+			Destination: "dns:tr1d1um.example.com/service/ignored",
+		},
+		expectErr: wrp.ErrInvalidMessageType,
+	}, {
+		// invalid message - a string field is not valid UTF-8
+		msg: wrp.Message{
+			Type:        wrp.SimpleRequestResponseMessageType,
+			Source:      "self:/service/ignored",
+			Destination: "dns:tr1d1um.example.com/service/ignored",
+			PartnerIDs:  []string{string([]byte{0xbf})},
+			ContentType: string([]byte{0xbf}),
+		},
+		expectErr: wrp.ErrNotUTF8,
+	},
+}
+
+type mockHandler struct {
+	lock   sync.Mutex
+	wg     *sync.WaitGroup
+	name   string
+	calls  int
+	dests  []wrp.Locator
+	expect []wrp.Locator
+}
+
+func (h *mockHandler) WG(wg *sync.WaitGroup) {
+	h.wg = wg
+	h.wg.Add(len(h.expect))
+	//fmt.Printf("%s adding %d to the wait group\n", h.name, len(h.expect))
+}
+
+func (h *mockHandler) HandleWrp(msg wrp.Message) {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	h.calls++
+	dest, _ := wrp.ParseLocator(msg.Destination)
+	h.dests = append(h.dests, dest)
+	h.wg.Done()
+	//fmt.Printf("%s done\n", h.name)
+}
+
+func (h *mockHandler) assert(a *assert.Assertions) {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	if !a.Equal(len(h.expect), h.calls, "handler %s calls mismatch", h.name) {
+		return
+	}
+
+	for _, expected := range h.expect {
+		var found bool
+		for j, d := range h.dests {
+			if expected.Scheme == d.Scheme &&
+				expected.Authority == d.Authority &&
+				expected.Service == d.Service &&
+				expected.Ignored == d.Ignored {
+				found = true
+				h.dests[j].Scheme = ""
+				break
+			}
+		}
+		if !found {
+			a.Fail("dest not found", "handler: %s expected: %s", h.name, expected.String())
+		}
+	}
+}
+
+func TestEndToEnd(t *testing.T) {
+	id := wrp.DeviceID("mac:112233445566")
+
+	var wg sync.WaitGroup
+
+	allEventListener := &mockHandler{
+		name: "allEventListener",
+		expect: []wrp.Locator{
+			{Scheme: "event", Authority: "event_1", Ignored: "/ignored"},
+			{Scheme: "event", Authority: "event_2", Ignored: "/ignored"},
+		},
+	}
+	allEventListener.WG(&wg)
+
+	singleEventListener := &mockHandler{
+		name: "singleEventListener",
+		expect: []wrp.Locator{
+			{Scheme: "event", Authority: "event_2", Ignored: "/ignored"},
+		},
+	}
+	singleEventListener.WG(&wg)
+
+	singleServiceListener := &mockHandler{
+		name: "singleServiceListener",
+		expect: []wrp.Locator{
+			{Scheme: "mac", Authority: "112233445566", Service: "service", Ignored: "/ignored"},
+		},
+	}
+	singleServiceListener.WG(&wg)
+
+	egressListener := &mockHandler{
+		name: "egressListener",
+		expect: []wrp.Locator{
+			{Scheme: "event", Authority: "event_1", Ignored: "/ignored"},
+			{Scheme: "event", Authority: "event_2", Ignored: "/ignored"},
+			{Scheme: "dns", Authority: "tr1d1um.example.com", Service: "service", Ignored: "/ignored"},
+		},
+	}
+	egressListener.WG(&wg)
+
+	assert := assert.New(t)
+	require := require.New(t)
+
+	transIdValidator := pubsub.HandlerFunc(
+		func(msg wrp.Message) {
+			if msg.TransactionUUID == "" {
+				assert.Fail("transaction UUID is empty")
+			}
+		})
+
+	noTransIdValidator := pubsub.HandlerFunc(
+		func(msg wrp.Message) {
+			if msg.TransactionUUID != "" {
+				assert.Fail("transaction UUID is not empty")
+			}
+		})
+
+	var allCancel, singleCancel, serviceCancel, egressCancel pubsub.CancelFunc
+	ps, err := pubsub.New(id,
+		pubsub.WithEgressHandler(egressListener, &egressCancel),
+		pubsub.WithEventHandler("*", allEventListener, &allCancel),
+		pubsub.WithEventHandler("event_2", singleEventListener, &singleCancel),
+		pubsub.WithServiceHandler("service", singleServiceListener, &serviceCancel),
+
+		pubsub.WithEgressHandler(transIdValidator),
+		pubsub.WithServiceHandler("*", noTransIdValidator),
+		pubsub.Normify(
+			wrp.ValidateMessageType(),
+			wrp.EnsureTransactionUUID(),
+			wrp.ValidateOnlyUTF8Strings(),
+		),
+	)
+
+	require.NoError(err)
+	require.NotNil(ps)
+	require.NotNil(allCancel)
+	require.NotNil(singleCancel)
+	require.NotNil(serviceCancel)
+	require.NotNil(egressCancel)
+
+	for _, m := range messages {
+		msg := m.msg
+		err := ps.Publish(&msg)
+
+		if m.expectErr != nil {
+			assert.ErrorIs(err, m.expectErr)
+		} else {
+			assert.NoError(err)
+		}
+	}
+
+	wg.Wait()
+
+	allEventListener.assert(assert)
+	singleEventListener.assert(assert)
+	singleServiceListener.assert(assert)
+	egressListener.assert(assert)
+}

internal/pubsub/options.go

@@ -0,0 +1,79 @@
+// SPDX-FileCopyrightText: 2024 Comcast Cable Communications Management, LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package pubsub
+
+import (
+	"github.com/xmidt-org/wrp-go/v3"
+)
+
+type optionFunc func(*PubSub) error
+
+var _ Option = optionFunc(nil)
+
+func (f optionFunc) apply(ps *PubSub) error {
+	return f(ps)
+}
+
+// Normify is an option that sets the desired normalization options used to
+// normalize/validate the wrp message.
+//
+// As an example, if you want all messages to contain metadata about something
+// like the network interface used, this is the place to define it.
+func Normify(opts ...wrp.NormifierOption) Option {
+	return optionFunc(func(ps *PubSub) error {
+		ps.desiredOpts = append(ps.desiredOpts, opts...)
+		return nil
+	})
+}
+
+// WithEgressHandler is an option that adds a handler for egress messages.
+// If the optional cancel parameter is provided, it will be set to a function
+// that can be used to cancel the subscription.
+func WithEgressHandler(handler Handler, cancel ...*CancelFunc) Option {
+	return optionFunc(func(ps *PubSub) error {
+		c, err := ps.SubscribeEgress(handler)
+		if err != nil {
+			return err
+		}
+		if len(cancel) > 0 && cancel[0] != nil {
+			*cancel[0] = c
+		}
+
+		return nil
+	})
+}
+
+// WithServiceHandler is an option that adds a handler for service messages.
+// If the optional cancel parameter is provided, it will be set to a function
+// that can be used to cancel the subscription.
+func WithServiceHandler(service string, handler Handler, cancel ...*CancelFunc) Option {
+	return optionFunc(func(ps *PubSub) error {
+		c, err := ps.SubscribeService(service, handler)
+		if err != nil {
+			return err
+		}
+		if len(cancel) > 0 && cancel[0] != nil {
+			*cancel[0] = c
+		}
+
+		return nil
+	})
+}
+
+// WithEventHandler is an option that adds a handler for event messages.
+// If the optional cancel parameter is provided, it will be set to a function
+// that can be used to cancel the subscription.
+func WithEventHandler(event string, handler Handler, cancel ...*CancelFunc) Option {
+	return optionFunc(func(ps *PubSub) error {
+		c, err := ps.SubscribeEvent(event, handler)
+		if err != nil {
+			return err
+		}
+		if len(cancel) > 0 && cancel[0] != nil {
+			*cancel[0] = c
+		}
+
+		return nil
+	})
+}