f-50: lab: arguments QEMU et seeds cloud-init des VM #50

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

internal/lab/render/seed.go

@@ -0,0 +1,192 @@
+package render
+
+import (
+	"fmt"
+	"strings"
+
+	"go.yaml.in/yaml/v3"
+
+	"git.g3e.fr/syonad/two/internal/lab/topology"
+)
+
+const (
+	SwitchScript = "/usr/local/sbin/lab-switch"
+	SwitchNFT    = "/etc/lab-switch.nft"
+	SwitchUnit   = "/etc/systemd/system/lab-switch.service"
+)
+
+type metaDoc struct {
+	InstanceID    string `yaml:"instance-id"`
+	LocalHostname string `yaml:"local-hostname"`
+}
+
+type writeFile struct {
+	Path        string `yaml:"path"`
+	Permissions string `yaml:"permissions"`
+	Content     string `yaml:"content"`
+}
+
+type cloudConfig struct {
+	Hostname          string      `yaml:"hostname"`
+	SSHPwauth         bool        `yaml:"ssh_pwauth"`
+	DisableRoot       bool        `yaml:"disable_root"`
+	SSHAuthorizedKeys []string    `yaml:"ssh_authorized_keys"`
+	Packages          []string    `yaml:"packages,omitempty"`
+	WriteFiles        []writeFile `yaml:"write_files,omitempty"`
+	Runcmd            [][]string  `yaml:"runcmd,omitempty"`
+}
+
+type match struct {
+	MACAddress string `yaml:"macaddress"`
+}
+
+type route struct {
+	To  string `yaml:"to"`
+	Via string `yaml:"via"`
+}
+
+type nameservers struct {
+	Addresses []string `yaml:"addresses"`
+}
+
+type ethernet struct {
+	Match       match        `yaml:"match"`
+	SetName     string       `yaml:"set-name"`
+	DHCP4       bool         `yaml:"dhcp4"`
+	MTU         int          `yaml:"mtu,omitempty"`
+	Addresses   []string     `yaml:"addresses,omitempty"`
+	Routes      []route      `yaml:"routes,omitempty"`
+	Nameservers *nameservers `yaml:"nameservers,omitempty"`
+}
+
+type networkDoc struct {
+	Version   int                 `yaml:"version"`
+	Ethernets map[string]ethernet `yaml:"ethernets"`
+}
+
+func metaData(p *topology.Plan, n topology.NodePlan) ([]byte, error) {
+	return yaml.Marshal(metaDoc{InstanceID: p.Name + "-" + n.Name, LocalHostname: n.Name})
+}
+
+func userData(p *topology.Plan, n topology.NodePlan, keys []string) ([]byte, error) {
+	cfg := cloudConfig{
+		Hostname:          n.Name,
+		SSHPwauth:         false,
+		DisableRoot:       true,
+		SSHAuthorizedKeys: keys,
+	}
+	if n.Role == topology.RoleSwitch {
+		cfg.Packages = []string{"nftables"}
+		cfg.WriteFiles = []writeFile{
+			{Path: SwitchScript, Permissions: "0755", Content: switchScript(p, n.Name)},
+			{Path: SwitchNFT, Permissions: "0644", Content: switchNFT(p, n.Name)},
+			{Path: SwitchUnit, Permissions: "0644", Content: switchUnit()},
+		}
+		cfg.Runcmd = [][]string{
+			{"systemctl", "daemon-reload"},
+			{"systemctl", "enable", "--now", "lab-switch.service"},
+		}
+	}
+	body, err := yaml.Marshal(cfg)
+	if err != nil {
+		return nil, err
+	}
+	return append([]byte("#cloud-config\n"), body...), nil
+}
+
+func networkConfig(p *topology.Plan, n topology.NodePlan, index int) ([]byte, error) {
+	doc := networkDoc{Version: 2, Ethernets: map[string]ethernet{}}
+	admin := ethernet{
+		Match:     match{MACAddress: adminMAC(index).String()},
+		SetName:   AdminInterface,
+		Addresses: []string{AdminAddress},
+	}
+	if n.Role == topology.RoleSwitch {
+		admin.Routes = []route{{To: "0.0.0.0/0", Via: AdminGateway}}
+		admin.Nameservers = &nameservers{Addresses: []string{AdminDNS}}
+		for _, c := range switchCables(p, n.Name) {
+			doc.Ethernets[c.SwitchInterface] = ethernet{
+				Match:   match{MACAddress: c.SwitchMAC.String()},
+				SetName: c.SwitchInterface,
+				MTU:     c.MTU,
+			}
+		}
+	}
+	doc.Ethernets[AdminInterface] = admin
+
+	for i, c := range nodeCables(p, n.Name) {
+		e := ethernet{
+			Match:     match{MACAddress: c.NodeMAC.String()},
+			SetName:   c.NodeInterface,
+			MTU:       c.MTU,
+			Addresses: []string{c.NodeAddress.String()},
+		}
+		if i == 0 {
+			e.Routes = []route{{To: "0.0.0.0/0", Via: gatewayOf(p, c.Segment)}}
+			e.Nameservers = &nameservers{Addresses: Nameservers}
+		}
+		doc.Ethernets[c.NodeInterface] = e
+	}
+	return yaml.Marshal(doc)
+}
+
+func gatewayOf(p *topology.Plan, segment string) string {
+	for _, s := range p.Segments {
+		if s.Name == segment {
+			return s.Gateway.String()
+		}
+	}
+	return ""
+}
+
+func switchScript(p *topology.Plan, name string) string {
+	var b strings.Builder
+	b.WriteString("#!/bin/sh\nset -eu\nsysctl -qw net.ipv4.ip_forward=1\n")
+	for _, s := range switchSegments(p, name) {
+		fmt.Fprintf(&b, "ip link add %s type bridge stp_state 0 2>/dev/null || true\n", s.Bridge)
+		for _, c := range switchCables(p, name) {
+			if c.Segment != s.Name {
+				continue
+			}
+			fmt.Fprintf(&b, "ip link set dev %s master %s\n", c.SwitchInterface, s.Bridge)
+			fmt.Fprintf(&b, "ip link set dev %s up\n", c.SwitchInterface)
+		}
+		fmt.Fprintf(&b, "ip link set dev %s mtu %d\n", s.Bridge, s.MTU)
+		fmt.Fprintf(&b, "ip addr replace %s/%d dev %s\n", s.Gateway, s.Network.Bits(), s.Bridge)
+		fmt.Fprintf(&b, "ip link set dev %s up\n", s.Bridge)
+	}
+	fmt.Fprintf(&b, "nft -f %s\n", SwitchNFT)
+	return b.String()
+}
+
+func switchNFT(p *topology.Plan, name string) string {
+	var networks []string
+	for _, s := range switchSegments(p, name) {
+		networks = append(networks, s.Network.String())
+	}
+	return fmt.Sprintf(`add table ip lab_nat
+delete table ip lab_nat
+table ip lab_nat {
+	chain postrouting {
+		type nat hook postrouting priority srcnat; policy accept;
+		ip saddr { %s } oifname "%s" masquerade
+	}
+}
+`, strings.Join(networks, ", "), AdminInterface)
+}
+
+func switchUnit() string {
+	return fmt.Sprintf(`[Unit]
+Description=Lab switch: bridges, gateways and NAT
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=%s
+
+[Install]
+WantedBy=multi-user.target
+`, SwitchScript)
+}