jpictl: introduce env command

Signed-off-by: Alejandro Mery <amery@jpi.io>

cmd/jpictl/env.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"git.jpi.io/amery/jpictl/pkg/zones"
+)
+
+// Command
+var envCmd = &cobra.Command{
+	Use:   "env",
+	Short: "generates environment variables for shell scripts",
+	RunE: func(_ *cobra.Command, _ []string) error {
+		m, err := zones.New(cfg.Base, cfg.Domain)
+		if err != nil {
+			return err
+		}
+
+		return m.WriteEnv(os.Stdout)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(envCmd)
+}

pkg/zones/env.go

@@ -0,0 +1,97 @@
+package zones
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+)
+
+// WriteEnv generates environment variables for shell scripts
+func (m *Zones) WriteEnv(w io.Writer) error {
+	var buf bytes.Buffer
+
+	m.writeEnvVarFn(&buf, genEnvZones, "ZONES")
+	m.ForEachZone(func(z *Zone) bool {
+		m.writeEnvZone(&buf, z)
+		return false
+	})
+
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+func (m *Zones) writeEnvZone(w io.Writer, z *Zone) {
+	zoneID := z.ID
+
+	// ZONE{zoneID}
+	m.writeEnvVar(w, genEnvZoneNodes(z), "ZONE%v", zoneID)
+
+	// ZONE{zoneID}_NAME
+	m.writeEnvVar(w, z.Name, "ZONE%v_%s", zoneID, "NAME")
+
+	// ZONE{zoneID}_GW
+	firstNodeID := 0
+	gatewayID := 0
+	z.ForEachMachine(func(p *Machine) bool {
+		nodeID := p.ID()
+
+		if firstNodeID == 0 {
+			firstNodeID = nodeID
+		}
+
+		if _, found := p.getRingInfo(0); found {
+			gatewayID = nodeID
+		}
+
+		return gatewayID != 0
+	})
+
+	if gatewayID == 0 {
+		gatewayID = firstNodeID
+	}
+	m.writeEnvVar(w, fmt.Sprintf("%v", gatewayID), "ZONE%v_%s", zoneID, "GW")
+
+	// ZONE{zoneID}_IP
+	ip, _ := RingZeroAddress(zoneID, gatewayID)
+	m.writeEnvVar(w, ip.String(), "ZONE%v_%s", zoneID, "IP")
+}
+
+func (m *Zones) writeEnvVarFn(w io.Writer, fn func(*Zones) string, name string, args ...any) {
+	var value string
+
+	if fn != nil {
+		value = fn(m)
+	}
+
+	m.writeEnvVar(w, value, name, args...)
+}
+
+func (*Zones) writeEnvVar(w io.Writer, value string, name string, args ...any) {
+	if len(args) > 0 {
+		name = fmt.Sprintf(name, args...)
+	}
+
+	if name != "" {
+		value = strings.TrimSpace(value)
+
+		_, _ = fmt.Fprintf(w, "%s=%q\n", name, value)
+	}
+}
+
+func genEnvZones(m *Zones) string {
+	s := make([]string, 0, len(m.Zones))
+	for _, z := range m.Zones {
+		s = append(s, fmt.Sprintf("%v", z.ID))
+	}
+
+	return strings.Join(s, " ")
+}
+
+func genEnvZoneNodes(z *Zone) string {
+	s := make([]string, 0, len(z.Machines))
+	for _, p := range z.Machines {
+		s = append(s, p.Name)
+	}
+	return strings.Join(s, " ")
+}

pkg/zones/machine_rings.go

@@ -60,17 +60,19 @@ func (m *Machine) applyWireguardConfig(ring int, wg *wireguard.Config) error {
 	return nil
 }
 
-func (m *Machine) applyRingInfo(ring int, new *RingInfo) error {
-	var cur *RingInfo
-
+func (m *Machine) getRingInfo(ring int) (*RingInfo, bool) {
 	for _, ri := range m.RingAddresses {
 		if ri.Ring == ring {
-			cur = ri
-			break
+			return ri, true
 		}
 	}
 
-	if cur == nil {
+	return nil, false
+}
+
+func (m *Machine) applyRingInfo(ring int, new *RingInfo) error {
+	cur, found := m.getRingInfo(ring)
+	if !found {
 		// first, append
 		m.RingAddresses = append(m.RingAddresses, new)
 		return nil

pkg/zones/zones.go

@@ -22,6 +22,16 @@ func (z *Zone) String() string {
 	return z.Name
 }
 
+// ForEachMachine calls a function for each Machine in the zone
+// until instructed to terminate the loop
+func (z *Zone) ForEachMachine(fn func(*Machine) bool) {
+	for _, p := range z.Machines {
+		if fn(p) {
+			return
+		}
+	}
+}
+
 // Zones represents all zones in a cluster
 type Zones struct {
 	dir      fs.FS
@@ -32,18 +42,22 @@ type Zones struct {
 }
 
 // ForEachMachine calls a function for each Machine in the cluster
+// until instructed to terminate the loop
 func (m *Zones) ForEachMachine(fn func(*Machine) bool) {
-	for _, z := range m.Zones {
-		for _, p := range z.Machines {
-			if fn(p) {
-				// terminate
-				return
-			}
-		}
-	}
+	m.ForEachZone(func(z *Zone) bool {
+		var term bool
+
+		z.ForEachMachine(func(p *Machine) bool {
+			term = fn(p)
+			return term
+		})
+
+		return term
+	})
 }
 
 // ForEachZone calls a function for each Zone in the cluster
+// until instructed to terminate the loop
 func (m *Zones) ForEachZone(fn func(*Zone) bool) {
 	for _, p := range m.Zones {
 		if fn(p) {