f-50: lab: topologie et calcul du plan #50

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

internal/lab/topology/topology.go

@@ -0,0 +1,151 @@
+package topology
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+
+	"go.yaml.in/yaml/v3"
+)
+
+const (
+	RoleSwitch     = "switch"
+	RoleRR         = "rr"
+	RoleHypervisor = "hypervisor"
+
+	DefaultMTU = 9000
+)
+
+type Topology struct {
+	Name     string
+	Images   []Image
+	Segments []Segment
+	Nodes    []Node
+}
+
+type Image struct {
+	Name string
+	URL  string
+	Sums string
+}
+
+type Segment struct {
+	Name   string
+	Switch string
+	CIDR   string
+	MTU    int
+}
+
+type Node struct {
+	Name      string
+	Role      string
+	Image     string
+	CPUs      int
+	Memory    int
+	Segments  []string
+	Addresses map[string]string
+}
+
+type fileImage struct {
+	URL  string `yaml:"url"`
+	Sums string `yaml:"sums"`
+}
+
+type fileSegment struct {
+	Switch string `yaml:"switch"`
+	CIDR   string `yaml:"cidr"`
+	MTU    int    `yaml:"mtu"`
+}
+
+type fileNode struct {
+	Role      string            `yaml:"role"`
+	Image     string            `yaml:"image"`
+	CPUs      int               `yaml:"cpus"`
+	Memory    int               `yaml:"memory"`
+	Segments  []string          `yaml:"segments"`
+	Addresses map[string]string `yaml:"addresses"`
+}
+
+type file struct {
+	Name     string                 `yaml:"name"`
+	Images   map[string]fileImage   `yaml:"images"`
+	Segments map[string]fileSegment `yaml:"segments"`
+	Nodes    map[string]fileNode    `yaml:"nodes"`
+}
+
+func Load(path string) (*Topology, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	t, err := Parse(data)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", path, err)
+	}
+	return t, nil
+}
+
+func Parse(data []byte) (*Topology, error) {
+	var f file
+	dec := yaml.NewDecoder(bytes.NewReader(data))
+	dec.KnownFields(true)
+	if err := dec.Decode(&f); err != nil {
+		return nil, fmt.Errorf("yaml: %w", err)
+	}
+
+	var root yaml.Node
+	if err := yaml.Unmarshal(data, &root); err != nil {
+		return nil, fmt.Errorf("yaml: %w", err)
+	}
+	order, err := keyOrder(&root)
+	if err != nil {
+		return nil, err
+	}
+
+	t := &Topology{Name: f.Name}
+	for _, name := range order["images"] {
+		i := f.Images[name]
+		t.Images = append(t.Images, Image{Name: name, URL: i.URL, Sums: i.Sums})
+	}
+	for _, name := range order["segments"] {
+		s := f.Segments[name]
+		mtu := s.MTU
+		if mtu == 0 {
+			mtu = DefaultMTU
+		}
+		t.Segments = append(t.Segments, Segment{Name: name, Switch: s.Switch, CIDR: s.CIDR, MTU: mtu})
+	}
+	for _, name := range order["nodes"] {
+		n := f.Nodes[name]
+		t.Nodes = append(t.Nodes, Node{
+			Name:      name,
+			Role:      n.Role,
+			Image:     n.Image,
+			CPUs:      n.CPUs,
+			Memory:    n.Memory,
+			Segments:  n.Segments,
+			Addresses: n.Addresses,
+		})
+	}
+	return t, nil
+}
+
+func keyOrder(root *yaml.Node) (map[string][]string, error) {
+	order := map[string][]string{}
+	if root.Kind != yaml.DocumentNode || len(root.Content) != 1 || root.Content[0].Kind != yaml.MappingNode {
+		return nil, errors.New("yaml: the document must be a mapping")
+	}
+	top := root.Content[0]
+	for i := 0; i+1 < len(top.Content); i += 2 {
+		section := top.Content[i].Value
+		value := top.Content[i+1]
+		if value.Kind != yaml.MappingNode {
+			continue
+		}
+		for j := 0; j+1 < len(value.Content); j += 2 {
+			order[section] = append(order[section], value.Content[j].Value)
+		}
+	}
+	return order, nil
+}