e2e: add limit and sort to generator (#6998)

I observed a couple of problems with the generator in some recent tests: 

- there were a couple of hybrid test cases which did not have any
  legacy nodes (randomness and all.) I change the probability to
  produce more reliable results.

- added options to the generation to be able to add a max (to
  compliment the earlier min) number of nodes for local testing. 

- added an option to support reversing the sort order so "more
  complex" networks were first, as well as tweaked some of the point
  values. 

- this refactored the generators cli parsing to be a bit more clear.

test/e2e/generator/generate.go

@@ -90,6 +90,10 @@ func Generate(r *rand.Rand, opts Options) ([]e2e.Manifest, error) {
 			}
 		}
 
+		if opts.MaxNetworkSize > 0 && len(manifest.Nodes) >= opts.MaxNetworkSize {
+			continue
+		}
+
 		manifests = append(manifests, manifest)
 	}
 
@@ -98,9 +102,11 @@ func Generate(r *rand.Rand, opts Options) ([]e2e.Manifest, error) {
 
 type Options struct {
 	MinNetworkSize int
+	MaxNetworkSize int
 	NumGroups      int
 	Directory      string
 	P2P            P2PMode
+	Reverse        bool
 }
 
 type P2PMode string
@@ -159,7 +165,7 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 		case LegacyP2PMode:
 			node.UseLegacyP2P = true
 		case HybridP2PMode:
-			node.UseLegacyP2P = r.Intn(2) == 1
+			node.UseLegacyP2P = r.Intn(5) < 2
 		}
 
 		manifest.Nodes[fmt.Sprintf("seed%02d", i)] = node
@@ -184,7 +190,7 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 		case LegacyP2PMode:
 			node.UseLegacyP2P = true
 		case HybridP2PMode:
-			node.UseLegacyP2P = r.Intn(2) == 1
+			node.UseLegacyP2P = r.Intn(5) < 2
 		}
 
 		manifest.Nodes[name] = node
@@ -221,7 +227,7 @@ func generateTestnet(r *rand.Rand, opt map[string]interface{}) (e2e.Manifest, er
 		case LegacyP2PMode:
 			node.UseLegacyP2P = true
 		case HybridP2PMode:
-			node.UseLegacyP2P = r.Intn(2) == 1
+			node.UseLegacyP2P = r.Intn(5) < 2
 		}
 
 		manifest.Nodes[fmt.Sprintf("full%02d", i)] = node

test/e2e/generator/main.go

@@ -41,25 +41,11 @@ func NewCLI() *CLI {
 			var opts Options
 			var err error
 
-			cli.opts.Directory, err = cmd.Flags().GetString("dir")
-			if err != nil {
-				return err
-			}
-
-			cli.opts.NumGroups, err = cmd.Flags().GetInt("groups")
-			if err != nil {
-				return err
-			}
-
-			cli.opts.MinNetworkSize, err = cmd.Flags().GetInt("min-size")
-			if err != nil {
-				return err
-			}
-
 			p2pMode, err := cmd.Flags().GetString("p2p")
 			if err != nil {
 				return err
 			}
+
 			switch mode := P2PMode(p2pMode); mode {
 			case NewP2PMode, LegacyP2PMode, HybridP2PMode, MixedP2PMode:
 				opts.P2P = mode
@@ -71,12 +57,16 @@ func NewCLI() *CLI {
 		},
 	}
 
-	cli.root.PersistentFlags().StringP("dir", "d", "", "Output directory for manifests")
+	cli.root.PersistentFlags().StringVarP(&cli.opts.Directory, "dir", "d", "", "Output directory for manifests")
 	_ = cli.root.MarkPersistentFlagRequired("dir")
-	cli.root.PersistentFlags().IntP("groups", "g", 0, "Number of groups")
+	cli.root.Flags().BoolVarP(&cli.opts.Reverse, "reverse", "r", false, "Reverse sort order")
+	cli.root.PersistentFlags().IntVarP(&cli.opts.NumGroups, "groups", "g", 0, "Number of groups")
 	cli.root.PersistentFlags().StringP("p2p", "p", string(MixedP2PMode),
 		"P2P typology to be generated [\"new\", \"legacy\", \"hybrid\" or \"mixed\" ]")
-	cli.root.PersistentFlags().IntP("min-size", "m", 1, "Minimum Network Size")
+	cli.root.PersistentFlags().IntVarP(&cli.opts.MinNetworkSize, "min-size", "", 1,
+		"Minimum network size (nodes)")
+	cli.root.PersistentFlags().IntVarP(&cli.opts.MaxNetworkSize, "max-size", "", 0,
+		"Maxmum network size (nodes), 0 is unlimited")
 
 	return cli
 }
@@ -95,7 +85,7 @@ func (cli *CLI) generate() error {
 
 	switch {
 	case cli.opts.NumGroups <= 0:
-		e2e.SortManifests(manifests)
+		e2e.SortManifests(manifests, cli.opts.Reverse)
 
 		if err := e2e.WriteManifests(filepath.Join(cli.opts.Directory, "gen"), manifests); err != nil {
 			return err
@@ -104,7 +94,7 @@ func (cli *CLI) generate() error {
 		groupManifests := e2e.SplitGroups(cli.opts.NumGroups, manifests)
 
 		for idx, gm := range groupManifests {
-			e2e.SortManifests(gm)
+			e2e.SortManifests(gm, cli.opts.Reverse)
 
 			prefix := filepath.Join(cli.opts.Directory, fmt.Sprintf("gen-group%02d", idx))
 			if err := e2e.WriteManifests(prefix, gm); err != nil {