Fix subnets and the common error: Pool overlaping

environment/docker.go

@@ -2,6 +2,7 @@ package environment
 
 import (
 	"context"
+	"strings"
 	"strconv"
 	"sync"
 
@@ -48,6 +49,12 @@ func ConfigureDocker(ctx context.Context) error {
 		if err := createDockerNetwork(ctx, cli); err != nil {
 			return err
 		}
+
+		// Re-inspect the network after creation to get the actual configuration
+		resource, err = cli.NetworkInspect(ctx, nw.Name, network.InspectOptions{})
+		if err != nil {
+			return errors.Wrap(err, "environment/docker: failed to inspect newly created network")
+		}
 	}
 
 	config.Update(func(c *config.Configuration) {
@@ -64,26 +71,61 @@ func ConfigureDocker(ctx context.Context) error {
 		default:
 			c.Docker.Network.ISPN = false
 		}
+
+		// Update the interface configuration with the actual assigned values from Docker
+		// Skip IPAM processing for special drivers that don't have normal IPAM configs
+		if c.Docker.Network.Driver != "host" && c.Docker.Network.Driver != "overlay" && c.Docker.Network.Driver != "weavemesh" {
+			for _, ipamCfg := range resource.IPAM.Config {
+				if ipamCfg.Subnet == "" {
+					continue
+				}
+				// IPv6 subnets contain colons
+				if strings.Contains(ipamCfg.Subnet, ":") {
+					c.Docker.Network.Interfaces.V6.Subnet = ipamCfg.Subnet
+					if ipamCfg.Gateway != "" {
+						c.Docker.Network.Interfaces.V6.Gateway = ipamCfg.Gateway
+					}
+				} else {
+					c.Docker.Network.Interfaces.V4.Subnet = ipamCfg.Subnet
+					if ipamCfg.Gateway != "" {
+						c.Docker.Network.Interfaces.V4.Gateway = ipamCfg.Gateway
+						c.Docker.Network.Interface = ipamCfg.Gateway
+					}
+				}
+			}
+		}
 	})
 	return nil
 }
 
 // Creates a new network on the machine if one does not exist already.
+// If the configured subnet conflicts with existing networks, it will automatically
+// retry with Docker auto-assigning the subnet to avoid "Pool overlaps" errors.
 func createDockerNetwork(ctx context.Context, cli *client.Client) error {
 	nw := config.Get().Docker.Network
-	enableIPv6 := nw.IPv6 // get the value from the config file, todo add some logic to the IPAM interaface for that.
-	_, err := cli.NetworkCreate(ctx, nw.Name, network.CreateOptions{
+	enableIPv6 := nw.IPv6
+
+	// Build IPAM config with the configured subnets
+	ipamConfigs := []network.IPAMConfig{}
+	if nw.Interfaces.V4.Subnet != "" {
+		ipamConfigs = append(ipamConfigs, network.IPAMConfig{
+			Subnet:  nw.Interfaces.V4.Subnet,
+			Gateway: nw.Interfaces.V4.Gateway,
+		})
+	}
+	if enableIPv6 && nw.Interfaces.V6.Subnet != "" {
+		ipamConfigs = append(ipamConfigs, network.IPAMConfig{
+			Subnet:  nw.Interfaces.V6.Subnet,
+			Gateway: nw.Interfaces.V6.Gateway,
+		})
+	}
+
+	createOpts := network.CreateOptions{
 		Driver:     nw.Driver,
 		EnableIPv6: &enableIPv6,
 		Internal:   nw.IsInternal,
 		IPAM: &network.IPAM{
-			Config: []network.IPAMConfig{{
-				Subnet:  nw.Interfaces.V4.Subnet,
-				Gateway: nw.Interfaces.V4.Gateway,
-			}, {
-				Subnet:  nw.Interfaces.V6.Subnet,
-				Gateway: nw.Interfaces.V6.Gateway,
-			}},
+			Config: ipamConfigs,
 		},
 		Options: map[string]string{
 			"encryption": "false",
@@ -94,14 +136,32 @@ func createDockerNetwork(ctx context.Context, cli *client.Client) error {
 			"com.docker.network.bridge.name":                 "pelican0",
 			"com.docker.network.driver.mtu":                  strconv.FormatInt(nw.NetworkMTU, 10),
 		},
-	})
-	if err != nil {
-		return err
 	}
-	if nw.Driver != "host" && nw.Driver != "overlay" && nw.Driver != "weavemesh" {
-		config.Update(func(c *config.Configuration) {
-			c.Docker.Network.Interface = c.Docker.Network.Interfaces.V4.Gateway
-		})
+
+	// Try to create the network with the configured subnet
+	_, err := cli.NetworkCreate(ctx, nw.Name, createOpts)
+	if err != nil {
+		// Check if the error is a pool overlap issue
+		errStr := err.Error()
+		if strings.Contains(errStr, "Pool overlaps") || strings.Contains(errStr, "invalid pool request") {
+			log.Warn("configured subnet conflicts with existing network, letting Docker auto-assign subnet...")
+
+			// Retry without specifying IPAM config - let Docker auto-assign
+			createOpts.IPAM = &network.IPAM{
+				Driver: "default",
+				// Don't specify Config - let Docker choose available subnets
+			}
+
+			_, err = cli.NetworkCreate(ctx, nw.Name, createOpts)
+			if err != nil {
+				return errors.Wrap(err, "environment/docker: failed to create network even with auto-assigned subnet")
+			}
+
+			log.Info("network created successfully with Docker auto-assigned subnet")
+		} else {
+			return errors.Wrap(err, "environment/docker: failed to create network")
+		}
 	}
+
 	return nil
 }