added network-go project

network-go/resolver/resolver.go

@@ -0,0 +1,65 @@
+package resolver
+
+import (
+	"log"
+	"strings"
+
+	"firewall_containers/network-go/config"
+)
+
+// Resolver resolves names to IPs using the networks.json configuration
+type Resolver struct {
+	cfg     *config.NetworksConfig
+	retries int
+}
+
+// NewResolver creates a new name resolver backed by the networks.json config
+func NewResolver(cfg *config.NetworksConfig) *Resolver {
+	return &Resolver{
+		cfg:     cfg,
+		retries: 2,
+	}
+}
+
+// SetConfig updates the config used for name resolution
+func (r *Resolver) SetConfig(cfg *config.NetworksConfig) {
+	r.cfg = cfg
+}
+
+// SetRetries sets the number of retries for resolution
+func (r *Resolver) SetRetries(n int) {
+	r.retries = n
+}
+
+// Resolve resolves a name to one or more IP addresses
+// It looks up the name in the networks.json config by container_name and selector fields
+func (r *Resolver) Resolve(name string) []string {
+	if r.cfg == nil {
+		return nil
+	}
+
+	var ips []string
+
+	// Look up by container_name and selector in the IPs section
+	for _, ipCfg := range r.cfg.IPs {
+		if ipCfg.ContainerName == name || ipCfg.Selector == name {
+			ips = append(ips, ipCfg.IP)
+		}
+	}
+
+	// If no exact match, try prefix matching (extract prefix before first dash)
+	if len(ips) == 0 && strings.Contains(name, "-") {
+		prefix := name[:strings.Index(name, "-")]
+		for _, ipCfg := range r.cfg.IPs {
+			if strings.HasPrefix(ipCfg.ContainerName, prefix) || strings.HasPrefix(ipCfg.Selector, prefix) {
+				ips = append(ips, ipCfg.IP)
+			}
+		}
+	}
+
+	if len(ips) == 0 {
+		log.Printf("RESOLVER: no IP found for %s in networks.json config", name)
+	}
+
+	return ips
+}