fix(topo): return error message for get status

Close #1018

Signed-off-by: Jiyong Huang <huangjy@emqx.io>

internal/server/ruleManager.go

@@ -19,6 +19,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"github.com/lf-edge/ekuiper/internal/conf"
 	"github.com/lf-edge/ekuiper/internal/topo"
 	"github.com/lf-edge/ekuiper/internal/topo/planner"
 	"github.com/lf-edge/ekuiper/pkg/api"
@@ -47,7 +48,7 @@ func (rs *RuleState) GetTopoGraph() *topo.PrintableTopo {
 	}
 }
 
-// Assume rule has started and the topo has instantiated
+// Stop Assume rule has started and the topo has instantiated
 func (rs *RuleState) Stop() {
 	rs.Triggered = false
 	rs.Topology.Cancel()
@@ -73,7 +74,7 @@ func (rr *RuleRegistry) Load(key string) (value *RuleState, ok bool) {
 	return result, ok
 }
 
-// Atomic get and delete
+// Delete Atomic get and delete
 func (rr *RuleRegistry) Delete(key string) (*RuleState, bool) {
 	rr.Lock()
 	result, ok := rr.internal[key]
@@ -100,7 +101,10 @@ func createRuleState(rule *api.Rule) (*RuleState, error) {
 
 // Assume rs is started with topo instantiated
 func doStartRule(rs *RuleState) error {
-	ruleProcessor.ExecReplaceRuleState(rs.Name, true)
+	err := ruleProcessor.ExecReplaceRuleState(rs.Name, true)
+	if err != nil {
+		return err
+	}
 	go func() {
 		tp := rs.Topology
 		select {
@@ -149,25 +153,25 @@ func getRuleState(name string) (string, error) {
 
 func doGetRuleState(rs *RuleState) (string, error) {
 	result := ""
-	if !rs.Triggered {
+	if rs.Topology == nil {
 		result = "Stopped: canceled manually or by error."
-		return result, nil
-	}
-	c := (*rs.Topology).GetContext()
-	if c != nil {
-		err := c.Err()
-		switch err {
-		case nil:
-			result = "Running"
-		case context.Canceled:
-			result = "Stopped: canceled by error."
-		case context.DeadlineExceeded:
-			result = "Stopped: deadline exceed."
-		default:
-			result = fmt.Sprintf("Stopped: %v.", err)
-		}
 	} else {
-		result = "Stopped: no context found."
+		c := (*rs.Topology).GetContext()
+		if c != nil {
+			err := c.Err()
+			switch err {
+			case nil:
+				result = "Running"
+			case context.Canceled:
+				result = "Stopped: canceled by error."
+			case context.DeadlineExceeded:
+				result = "Stopped: deadline exceed."
+			default:
+				result = fmt.Sprintf("Stopped: %v.", err)
+			}
+		} else {
+			result = "Stopped: no context found."
+		}
 	}
 	return result, nil
 }
@@ -206,15 +210,15 @@ func getRuleStatus(name string) (string, error) {
 
 func getRuleTopo(name string) (string, error) {
 	if rs, ok := registry.Load(name); ok {
-		topo := rs.GetTopoGraph()
-		if topo == nil {
+		graph := rs.GetTopoGraph()
+		if graph == nil {
 			return "", errorx.New(fmt.Sprintf("Fail to get rule %s's topo, make sure the rule has been started before", name))
 		}
-		bytes, err := json.Marshal(topo)
+		bs, err := json.Marshal(graph)
 		if err != nil {
 			return "", errorx.New(fmt.Sprintf("Fail to encode rule %s's topo", name))
 		} else {
-			return string(bytes), nil
+			return string(bs), nil
 		}
 	} else {
 		return "", errorx.NewWithCode(errorx.NOT_FOUND, fmt.Sprintf("Rule %s is not found", name))
@@ -244,7 +248,10 @@ func startRule(name string) error {
 func stopRule(name string) (result string) {
 	if rs, ok := registry.Load(name); ok && rs.Triggered {
 		rs.Stop()
-		ruleProcessor.ExecReplaceRuleState(name, false)
+		err := ruleProcessor.ExecReplaceRuleState(name, false)
+		if err != nil {
+			conf.Log.Warnf("stop rule found error: %s", err.Error())
+		}
 		result = fmt.Sprintf("Rule %s was stopped.", name)
 	} else {
 		result = fmt.Sprintf("Rule %s was not found.", name)