PMM-3336 Filter by service_id

handlers/inventory_agents.go

@@ -31,9 +31,9 @@ type AgentsServer struct {
 	Agents *inventory.AgentsService
 }
 
-// ListAgents returns a list of all Agents.
+// ListAgents returns a list of Agents for a given filters.
 func (s *AgentsServer) ListAgents(ctx context.Context, req *api.ListAgentsRequest) (*api.ListAgentsResponse, error) {
-	agents, err := s.Agents.List(ctx)
+	agents, err := s.Agents.List(ctx, req.ServiceId)
 	if err != nil {
 		return nil, err
 	}

models/agent.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/go-sql-driver/mysql"
+	"github.com/pkg/errors"
 	"gopkg.in/reform.v1"
 )
 
@@ -211,3 +212,40 @@ func (q *QanAgent) DSN(service *MySQLService) string {
 	// TODO Other parameters?
 	return cfg.FormatDSN()
 }
+
+// AgentFilters represents filters for agents list.
+type AgentFilters struct {
+	ServiceID *string
+}
+
+// AgentsByFilters returns agents providing insights for a given filters.
+func AgentsByFilters(q *reform.Querier, filters AgentFilters) ([]*AgentRow, error) {
+	var agentIDs []interface{}
+	var structs []reform.Struct
+	var err error
+	if filters.ServiceID != nil {
+		agentServices, err := q.SelectAllFrom(AgentServiceView, "WHERE service_id = ? ORDER BY ID", *filters.ServiceID)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+		for _, str := range agentServices {
+			agentIDs = append(agentIDs, str.(*AgentService).AgentID)
+		}
+
+		if len(agentIDs) == 0 {
+			return []*AgentRow{}, nil
+		}
+
+		structs, err = q.FindAllFrom(AgentRowTable, "id", agentIDs...)
+	} else {
+		structs, err = q.SelectAllFrom(AgentRowTable, "ORDER BY ID")
+	}
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	agents := make([]*AgentRow, len(structs))
+	for i, str := range structs {
+		agents[i] = str.(*AgentRow)
+	}
+	return agents, nil
+}

services/inventory/agents.go

@@ -114,17 +114,20 @@ func (as *AgentsService) get(ctx context.Context, id string) (*models.AgentRow,
 	}
 }
 
-// List selects all Agents in a stable order.
-func (as *AgentsService) List(ctx context.Context) ([]inventory.Agent, error) {
-	structs, err := as.q.SelectAllFrom(models.AgentRowTable, "ORDER BY id")
+// List selects all Agents in a stable order for a given service.
+func (as *AgentsService) List(ctx context.Context, serviceID string) ([]inventory.Agent, error) {
+	filters := models.AgentFilters{}
+	if serviceID != "" {
+		filters.ServiceID = &serviceID
+	}
+	agentRows, err := models.AgentsByFilters(as.q, filters)
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
 
-	// TODO That loop makes len(structs) SELECTs, that can be slow. Optimize when needed.
-	res := make([]inventory.Agent, len(structs))
-	for i, str := range structs {
-		row := str.(*models.AgentRow)
+	// TODO That loop makes len(agentRows) SELECTs, that can be slow. Optimize when needed.
+	res := make([]inventory.Agent, len(agentRows))
+	for i, row := range agentRows {
 		agent, err := as.makeAgent(ctx, row)
 		if err != nil {
 			return nil, err

services/inventory/inventory_test.go

@@ -354,7 +354,7 @@ func TestAgents(t *testing.T) {
 		ss, as, teardown := setup(t)
 		defer teardown(t)
 
-		actualAgents, err := as.List(ctx)
+		actualAgents, err := as.List(ctx, "")
 		require.NoError(t, err)
 		require.Len(t, actualAgents, 0)
 
@@ -407,12 +407,17 @@ func TestAgents(t *testing.T) {
 		require.NoError(t, err)
 		assert.Equal(t, expectedMySQLdExporterAgent, actualAgent)
 
-		actualAgents, err = as.List(ctx)
+		actualAgents, err = as.List(ctx, "")
 		require.NoError(t, err)
 		require.Len(t, actualAgents, 2)
 		assert.Equal(t, expectedNodeExporterAgent, actualAgents[0])
 		assert.Equal(t, expectedMySQLdExporterAgent, actualAgents[1])
 
+		actualAgents, err = as.List(ctx, "gen:00000000-0000-4000-8000-000000000002")
+		require.NoError(t, err)
+		require.Len(t, actualAgents, 1)
+		assert.Equal(t, expectedMySQLdExporterAgent, actualAgents[0])
+
 		err = as.Remove(ctx, "gen:00000000-0000-4000-8000-000000000001")
 		require.NoError(t, err)
 		actualAgent, err = as.Get(ctx, "gen:00000000-0000-4000-8000-000000000001")
@@ -425,7 +430,7 @@ func TestAgents(t *testing.T) {
 		tests.AssertGRPCError(t, status.New(codes.NotFound, `Agent with ID "gen:00000000-0000-4000-8000-000000000003" not found.`), err)
 		assert.Nil(t, actualAgent)
 
-		actualAgents, err = as.List(ctx)
+		actualAgents, err = as.List(ctx, "")
 		require.NoError(t, err)
 		require.Len(t, actualAgents, 0)
 	})