Merge pull request #266 from srl-wim/doubled-links

Doubled links

clab/config.go

@@ -144,8 +144,8 @@ type Endpoint struct {
 	EndpointName string
 }
 
-// ParseIPInfo parses IP information
-func (c *CLab) parseIPInfo() error {
+// initMgmtNetwork sets management network config
+func (c *CLab) initMgmtNetwork() error {
 	if c.Config.Mgmt.Network == "" {
 		c.Config.Mgmt.Network = dockerNetName
 	}
@@ -168,8 +168,8 @@ func (c *CLab) parseIPInfo() error {
 func (c *CLab) ParseTopology() error {
 	log.Info("Parsing topology information ...")
 	log.Debugf("Lab name: %s", c.Config.Name)
-	// initialize DockerInfo
-	err := c.parseIPInfo()
+	// initialize Management network config
+	err := c.initMgmtNetwork()
 	if err != nil {
 		return err
 	}
@@ -679,8 +679,21 @@ func (c *CLab) NewEndpoint(e string) *Endpoint {
 	return endpoint
 }
 
+// CheckTopologyDefinition runs topology checks and returns any errors found
+func (c *CLab) CheckTopologyDefinition() error {
+	err := c.verifyBridgesExist()
+	if err != nil {
+		return err
+	}
+	err = c.verifyLinks()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 // VerifyBridgeExists verifies if every node of kind=bridge exists on the lab host
-func (c *CLab) VerifyBridgesExist() error {
+func (c *CLab) verifyBridgesExist() error {
 	for name, node := range c.Nodes {
 		if node.Kind == "bridge" {
 			if _, err := netlink.LinkByName(name); err != nil {
@@ -691,6 +704,23 @@ func (c *CLab) VerifyBridgesExist() error {
 	return nil
 }
 
+func (c *CLab) verifyLinks() error {
+	endpoints := map[string]struct{}{}
+	dups := []string{}
+	for _, lc := range c.Config.Topology.Links {
+		for _, e := range lc.Endpoints {
+			if _, ok := endpoints[e]; ok {
+				dups = append(dups, e)
+			}
+			endpoints[e] = struct{}{}
+		}
+	}
+	if len(dups) != 0 {
+		return fmt.Errorf("endpoints %q appeared more than once in the links section of the topology file", dups)
+	}
+	return nil
+}
+
 //resolvePath resolves a string path by expanding `~` to home dir or getting Abs path for the given path
 func resolvePath(p string) (string, error) {
 	if p == "" {

clab/config_test.go

@@ -261,3 +261,37 @@ func TestUserInit(t *testing.T) {
 		})
 	}
 }
+
+func TestVerifyLinks(t *testing.T) {
+	tests := map[string]struct {
+		got  string
+		want string
+	}{
+		"two_duplicated_links": {
+			got:  "test_data/topo6.yml",
+			want: "endpoints [\"lin1:eth1\" \"lin2:eth2\"] appeared more than once in the links section of the topology file",
+		},
+		"no_duplicated_links": {
+			got:  "test_data/topo1.yml",
+			want: "",
+		},
+	}
+
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			opts := []ClabOption{
+				WithTopoFile(tc.got),
+			}
+			c := NewContainerLab(opts...)
+
+			err := c.verifyLinks()
+			if err != nil && err.Error() != tc.want {
+				t.Fatalf("wanted %q got %q", tc.want, err.Error())
+			}
+			if err == nil && tc.want != "" {
+				t.Fatalf("wanted %q got %q", tc.want, err.Error())
+			}
+		})
+	}
+
+}

clab/test_data/topo6.yml

@@ -0,0 +1,15 @@
+name: 2l
+
+topology:
+  nodes:
+    lin1:
+      kind: linux
+      image: alpine:3
+    lin2:
+      kind: linux
+      image: alpine:3
+
+  links:
+    - endpoints: ["lin1:eth1", lin2:eth1]
+    - endpoints: ["lin1:eth1", lin2:eth2]
+    - endpoints: ["lin1:eth3", lin2:eth2]

cmd/deploy.go

@@ -54,6 +54,10 @@ var deployCmd = &cobra.Command{
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
 
+		if err = c.CheckTopologyDefinition(); err != nil {
+			return err
+		}
+
 		setFlags(c.Config)
 		log.Debugf("lab Conf: %+v", c.Config)
 		// Parse topology information
@@ -71,9 +75,6 @@ var deployCmd = &cobra.Command{
 			}
 
 		}
-		if err = c.VerifyBridgesExist(); err != nil {
-			return err
-		}
 
 		// create lab directory
 		log.Info("Creating lab directory: ", c.Dir.Lab)