Backport of watch: support -filter for consul watch: checks, services, nodes, service into release/1.16.x (#17965)

* backport to 1.16.x

---------

Co-authored-by: cskh <hui.kang@hashicorp.com>

.changelog/17780.txt

@@ -0,0 +1,3 @@
+```release-note:feature
+cli: `consul watch` command uses `-filter` expression to filter response from checks, services, nodes, and service.
+```

agent/consul/health_endpoint_test.go

@@ -1767,5 +1767,11 @@ func TestHealth_RPC_Filter(t *testing.T) {
 		out = new(structs.IndexedHealthChecks)
 		require.NoError(t, msgpackrpc.CallWithCodec(codec, "Health.ChecksInState", &args, out))
 		require.Len(t, out.HealthChecks, 1)
+
+		args.State = api.HealthAny
+		args.Filter = "connect in ServiceTags and v2 in ServiceTags"
+		out = new(structs.IndexedHealthChecks)
+		require.NoError(t, msgpackrpc.CallWithCodec(codec, "Health.ChecksInState", &args, out))
+		require.Len(t, out.HealthChecks, 1)
 	})
 }

api/watch/funcs.go

@@ -92,13 +92,20 @@ func keyPrefixWatch(params map[string]interface{}) (WatcherFunc, error) {
 // servicesWatch is used to watch the list of available services
 func servicesWatch(params map[string]interface{}) (WatcherFunc, error) {
 	stale := false
+	filter := ""
 	if err := assignValueBool(params, "stale", &stale); err != nil {
 		return nil, err
 	}
+	if err := assignValue(params, "filter", &filter); err != nil {
+		return nil, err
+	}
 
 	fn := func(p *Plan) (BlockingParamVal, interface{}, error) {
 		catalog := p.client.Catalog()
 		opts := makeQueryOptionsWithContext(p, stale)
+		if filter != "" {
+			opts.Filter = filter
+		}
 		defer p.cancelFunc()
 		services, meta, err := catalog.Services(&opts)
 		if err != nil {
@@ -112,13 +119,20 @@ func servicesWatch(params map[string]interface{}) (WatcherFunc, error) {
 // nodesWatch is used to watch the list of available nodes
 func nodesWatch(params map[string]interface{}) (WatcherFunc, error) {
 	stale := false
+	filter := ""
 	if err := assignValueBool(params, "stale", &stale); err != nil {
 		return nil, err
 	}
+	if err := assignValue(params, "filter", &filter); err != nil {
+		return nil, err
+	}
 
 	fn := func(p *Plan) (BlockingParamVal, interface{}, error) {
 		catalog := p.client.Catalog()
 		opts := makeQueryOptionsWithContext(p, stale)
+		if filter != "" {
+			opts.Filter = filter
+		}
 		defer p.cancelFunc()
 		nodes, meta, err := catalog.Nodes(&opts)
 		if err != nil {
@@ -132,9 +146,13 @@ func nodesWatch(params map[string]interface{}) (WatcherFunc, error) {
 // serviceWatch is used to watch a specific service for changes
 func serviceWatch(params map[string]interface{}) (WatcherFunc, error) {
 	stale := false
+	filter := ""
 	if err := assignValueBool(params, "stale", &stale); err != nil {
 		return nil, err
 	}
+	if err := assignValue(params, "filter", &filter); err != nil {
+		return nil, err
+	}
 
 	var (
 		service string
@@ -158,6 +176,9 @@ func serviceWatch(params map[string]interface{}) (WatcherFunc, error) {
 	fn := func(p *Plan) (BlockingParamVal, interface{}, error) {
 		health := p.client.Health()
 		opts := makeQueryOptionsWithContext(p, stale)
+		if filter != "" {
+			opts.Filter = filter
+		}
 		defer p.cancelFunc()
 		nodes, meta, err := health.ServiceMultipleTags(service, tags, passingOnly, &opts)
 		if err != nil {
@@ -175,13 +196,16 @@ func checksWatch(params map[string]interface{}) (WatcherFunc, error) {
 		return nil, err
 	}
 
-	var service, state string
+	var service, state, filter string
 	if err := assignValue(params, "service", &service); err != nil {
 		return nil, err
 	}
 	if err := assignValue(params, "state", &state); err != nil {
 		return nil, err
 	}
+	if err := assignValue(params, "filter", &filter); err != nil {
+		return nil, err
+	}
 	if service != "" && state != "" {
 		return nil, fmt.Errorf("Cannot specify service and state")
 	}
@@ -196,6 +220,9 @@ func checksWatch(params map[string]interface{}) (WatcherFunc, error) {
 		var checks []*consulapi.HealthCheck
 		var meta *consulapi.QueryMeta
 		var err error
+		if filter != "" {
+			opts.Filter = filter
+		}
 		if state != "" {
 			checks, meta, err = health.State(state, &opts)
 		} else {

api/watch/funcs_test.go

@@ -378,6 +378,82 @@ func TestServicesWatch(t *testing.T) {
 
 }
 
+func TestServicesWatch_Filter(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	s.WaitForSerfCheck(t)
+
+	var (
+		wakeups  []map[string][]string
+		notifyCh = make(chan struct{})
+	)
+
+	plan := mustParse(t, `{"type":"services", "filter":"b in ServiceTags and a in ServiceTags"}`)
+	plan.Handler = func(idx uint64, raw interface{}) {
+		if raw == nil {
+			return // ignore
+		}
+		v, ok := raw.(map[string][]string)
+		if !ok {
+			return // ignore
+		}
+		wakeups = append(wakeups, v)
+		notifyCh <- struct{}{}
+	}
+
+	// Register some services
+	{
+		agent := c.Agent()
+
+		// we don't want to find this
+		reg := &api.AgentServiceRegistration{
+			ID:   "foo",
+			Name: "foo",
+			Tags: []string{"b"},
+		}
+		if err := agent.ServiceRegister(reg); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// // we want to find this
+		reg = &api.AgentServiceRegistration{
+			ID:   "bar",
+			Name: "bar",
+			Tags: []string{"a", "b"},
+		}
+		if err := agent.ServiceRegister(reg); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if err := plan.Run(s.HTTPAddr); err != nil {
+			t.Errorf("err: %v", err)
+		}
+	}()
+	defer plan.Stop()
+
+	// Wait for second wakeup.
+	<-notifyCh
+
+	plan.Stop()
+	wg.Wait()
+
+	require.Len(t, wakeups, 1)
+
+	{
+		v := wakeups[0]
+		require.Len(t, v, 1)
+		_, ok := v["bar"]
+		require.True(t, ok)
+	}
+}
+
 func TestNodesWatch(t *testing.T) {
 	t.Parallel()
 	c, s := makeClient(t)
@@ -453,6 +529,82 @@ func TestNodesWatch(t *testing.T) {
 	}
 }
 
+func TestNodesWatch_Filter(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	s.WaitForSerfCheck(t) // wait for AE to sync
+
+	var (
+		wakeups  [][]*api.Node
+		notifyCh = make(chan struct{})
+	)
+
+	plan := mustParse(t, `{"type":"nodes", "filter":"Node == foo"}`)
+	plan.Handler = func(idx uint64, raw interface{}) {
+		if raw == nil {
+			return // ignore
+		}
+		v, ok := raw.([]*api.Node)
+		if !ok {
+			return // ignore
+		}
+		wakeups = append(wakeups, v)
+		notifyCh <- struct{}{}
+	}
+
+	// Register 2 nodes
+	{
+		catalog := c.Catalog()
+
+		// we want to find this node
+		reg := &api.CatalogRegistration{
+			Node:       "foo",
+			Address:    "1.1.1.1",
+			Datacenter: "dc1",
+		}
+		if _, err := catalog.Register(reg, nil); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// we don't want to find this node
+		reg = &api.CatalogRegistration{
+			Node:       "bar",
+			Address:    "2.2.2.2",
+			Datacenter: "dc1",
+		}
+		if _, err := catalog.Register(reg, nil); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	// Start the watch nodes plan
+	go func() {
+		defer wg.Done()
+		if err := plan.Run(s.HTTPAddr); err != nil {
+			t.Errorf("err: %v", err)
+		}
+	}()
+	defer plan.Stop()
+
+	// Wait for first wakeup.
+	<-notifyCh
+
+	plan.Stop()
+	wg.Wait()
+
+	require.Len(t, wakeups, 1)
+
+	{
+		v := wakeups[0]
+		require.Len(t, v, 1)
+		require.Equal(t, "foo", v[0].Node)
+	}
+}
+
 func TestServiceWatch(t *testing.T) {
 	t.Parallel()
 	c, s := makeClient(t)
@@ -616,6 +768,94 @@ func TestServiceMultipleTagsWatch(t *testing.T) {
 	}
 }
 
+func TestServiceWatch_Filter(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	s.WaitForSerfCheck(t)
+
+	var (
+		wakeups  [][]*api.ServiceEntry
+		notifyCh = make(chan struct{})
+	)
+
+	plan := mustParse(t, `{"type":"service", "service":"foo", "filter":"bar in Service.Tags and buzz in Service.Tags"}`)
+	plan.Handler = func(idx uint64, raw interface{}) {
+		if raw == nil {
+			return // ignore
+		}
+		v, ok := raw.([]*api.ServiceEntry)
+		if !ok {
+			return // ignore
+		}
+
+		wakeups = append(wakeups, v)
+		notifyCh <- struct{}{}
+	}
+
+	// register some services
+	{
+		agent := c.Agent()
+
+		// we do not want to find this one.
+		reg := &api.AgentServiceRegistration{
+			ID:   "foobarbiff",
+			Name: "foo",
+			Tags: []string{"bar", "biff"},
+		}
+		if err := agent.ServiceRegister(reg); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// we do not want to find this one.
+		reg = &api.AgentServiceRegistration{
+			ID:   "foobuzzbiff",
+			Name: "foo",
+			Tags: []string{"buzz", "biff"},
+		}
+		if err := agent.ServiceRegister(reg); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// we want to find this one
+		reg = &api.AgentServiceRegistration{
+			ID:   "foobarbuzzbiff",
+			Name: "foo",
+			Tags: []string{"bar", "buzz", "biff"},
+		}
+		if err := agent.ServiceRegister(reg); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if err := plan.Run(s.HTTPAddr); err != nil {
+			t.Errorf("err: %v", err)
+		}
+	}()
+	defer plan.Stop()
+
+	// Wait for second wakeup.
+	<-notifyCh
+
+	plan.Stop()
+	wg.Wait()
+
+	require.Len(t, wakeups, 1)
+
+	{
+		v := wakeups[0]
+		require.Len(t, v, 1)
+
+		require.Equal(t, "foobarbuzzbiff", v[0].Service.ID)
+		require.ElementsMatch(t, []string{"bar", "buzz", "biff"}, v[0].Service.Tags)
+	}
+}
+
 func TestChecksWatch_State(t *testing.T) {
 	t.Parallel()
 	c, s := makeClient(t)
@@ -772,6 +1012,190 @@ func TestChecksWatch_Service(t *testing.T) {
 	}
 }
 
+func TestChecksWatch_Service_Filter(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	s.WaitForSerfCheck(t)
+
+	var (
+		wakeups  [][]*api.HealthCheck
+		notifyCh = make(chan struct{})
+	)
+
+	plan := mustParse(t, `{"type":"checks", "filter":"b in ServiceTags and a in ServiceTags"}`)
+	plan.Handler = func(idx uint64, raw interface{}) {
+		if raw == nil {
+			return // ignore
+		}
+		v, ok := raw.([]*api.HealthCheck)
+		if !ok {
+			return // ignore
+		}
+		wakeups = append(wakeups, v)
+		notifyCh <- struct{}{}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if err := plan.Run(s.HTTPAddr); err != nil {
+			t.Errorf("err: %v", err)
+		}
+	}()
+	defer plan.Stop()
+
+	// Wait for first wakeup.
+	<-notifyCh
+	{
+		catalog := c.Catalog()
+		reg := &api.CatalogRegistration{
+			Node:       "foobar",
+			Address:    "1.1.1.1",
+			Datacenter: "dc1",
+			Service: &api.AgentService{
+				ID:      "foobar",
+				Service: "foobar",
+				Tags:    []string{"a", "b"},
+			},
+			Check: &api.AgentCheck{
+				Node:      "foobar",
+				CheckID:   "foobar",
+				Name:      "foobar",
+				Status:    api.HealthPassing,
+				ServiceID: "foobar",
+			},
+		}
+		if _, err := catalog.Register(reg, nil); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	// Wait for second wakeup.
+	<-notifyCh
+
+	plan.Stop()
+	wg.Wait()
+
+	require.Len(t, wakeups, 2)
+
+	{
+		v := wakeups[0]
+		require.Len(t, v, 0)
+	}
+	{
+		v := wakeups[1]
+		require.Len(t, v, 1)
+		require.Equal(t, "foobar", v[0].CheckID)
+	}
+}
+
+func TestChecksWatch_Filter(t *testing.T) {
+	t.Parallel()
+	c, s := makeClient(t)
+	defer s.Stop()
+
+	s.WaitForSerfCheck(t)
+
+	var (
+		wakeups  [][]*api.HealthCheck
+		notifyCh = make(chan struct{})
+	)
+
+	plan := mustParse(t, `{"type":"checks", "filter":"b in ServiceTags and a in ServiceTags"}`)
+	plan.Handler = func(idx uint64, raw interface{}) {
+		if raw == nil {
+			return // ignore
+		}
+		v, ok := raw.([]*api.HealthCheck)
+		if !ok {
+			return // ignore
+		}
+		wakeups = append(wakeups, v)
+		notifyCh <- struct{}{}
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if err := plan.Run(s.HTTPAddr); err != nil {
+			t.Errorf("err: %v", err)
+		}
+	}()
+	defer plan.Stop()
+
+	// Wait for first wakeup.
+	<-notifyCh
+	{
+		catalog := c.Catalog()
+
+		// we don't want to find this one
+		reg := &api.CatalogRegistration{
+			Node:       "foo",
+			Address:    "1.1.1.1",
+			Datacenter: "dc1",
+			Service: &api.AgentService{
+				ID:      "foo",
+				Service: "foo",
+				Tags:    []string{"a"},
+			},
+			Check: &api.AgentCheck{
+				Node:      "foo",
+				CheckID:   "foo",
+				Name:      "foo",
+				Status:    api.HealthPassing,
+				ServiceID: "foo",
+			},
+		}
+		if _, err := catalog.Register(reg, nil); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		// we want to find this one
+		reg = &api.CatalogRegistration{
+			Node:       "bar",
+			Address:    "2.2.2.2",
+			Datacenter: "dc1",
+			Service: &api.AgentService{
+				ID:      "bar",
+				Service: "bar",
+				Tags:    []string{"a", "b"},
+			},
+			Check: &api.AgentCheck{
+				Node:      "bar",
+				CheckID:   "bar",
+				Name:      "bar",
+				Status:    api.HealthPassing,
+				ServiceID: "bar",
+			},
+		}
+		if _, err := catalog.Register(reg, nil); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+	}
+
+	// Wait for second wakeup.
+	<-notifyCh
+
+	plan.Stop()
+	wg.Wait()
+
+	require.Len(t, wakeups, 2)
+
+	{
+		v := wakeups[0]
+		require.Len(t, v, 0)
+	}
+	{
+		v := wakeups[1]
+		require.Len(t, v, 1)
+		require.Equal(t, "bar", v[0].CheckID)
+	}
+}
+
 func TestEventWatch(t *testing.T) {
 	t.Parallel()
 	c, s := makeClient(t)

command/watch/watch.go

@@ -45,6 +45,7 @@ type cmd struct {
 	state       string
 	name        string
 	shell       bool
+	filter      string
 }
 
 func (c *cmd) init() {
@@ -71,6 +72,7 @@ func (c *cmd) init() {
 		"Specifies the states to watch. Optional for 'checks' type.")
 	c.flags.StringVar(&c.name, "name", "",
 		"Specifies an event name to watch. Only for 'event' type.")
+	c.flags.StringVar(&c.filter, "filter", "", "Filter to use with the request")
 
 	c.http = &flags.HTTPFlags{}
 	flags.Merge(c.flags, c.http.ClientFlags())
@@ -128,6 +130,9 @@ func (c *cmd) Run(args []string) int {
 	if c.service != "" {
 		params["service"] = c.service
 	}
+	if c.filter != "" {
+		params["filter"] = c.filter
+	}
 	if len(c.tag) > 0 {
 		params["tag"] = c.tag
 	}