e2e: configurable IP addresses for e2e testnet generator (backport #9592) (#9624)

Co-authored-by: Thane Thomson <connect@thanethomson.com>

test/e2e/pkg/infrastructure.go

@@ -0,0 +1,80 @@
+package e2e
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"os"
+)
+
+const (
+	dockerIPv4CIDR = "10.186.73.0/24"
+	dockerIPv6CIDR = "fd80:b10c::/48"
+
+	globalIPv4CIDR = "0.0.0.0/0"
+)
+
+// InfrastructureData contains the relevant information for a set of existing
+// infrastructure that is to be used for running a testnet.
+type InfrastructureData struct {
+
+	// Provider is the name of infrastructure provider backing the testnet.
+	// For example, 'docker' if it is running locally in a docker network or
+	// 'digital-ocean', 'aws', 'google', etc. if it is from a cloud provider.
+	Provider string `json:"provider"`
+
+	// Instances is a map of all of the machine instances on which to run
+	// processes for a testnet.
+	// The key of the map is the name of the instance, which each must correspond
+	// to the names of one of the testnet nodes defined in the testnet manifest.
+	Instances map[string]InstanceData `json:"instances"`
+
+	// Network is the CIDR notation range of IP addresses that all of the instances'
+	// IP addresses are expected to be within.
+	Network string `json:"network"`
+}
+
+// InstanceData contains the relevant information for a machine instance backing
+// one of the nodes in the testnet.
+type InstanceData struct {
+	IPAddress net.IP `json:"ip_address"`
+}
+
+func NewDockerInfrastructureData(m Manifest) (InfrastructureData, error) {
+	netAddress := dockerIPv4CIDR
+	if m.IPv6 {
+		netAddress = dockerIPv6CIDR
+	}
+	_, ipNet, err := net.ParseCIDR(netAddress)
+	if err != nil {
+		return InfrastructureData{}, fmt.Errorf("invalid IP network address %q: %w", netAddress, err)
+	}
+	ipGen := newIPGenerator(ipNet)
+	ifd := InfrastructureData{
+		Provider:  "docker",
+		Instances: make(map[string]InstanceData),
+		Network:   netAddress,
+	}
+	for name := range m.Nodes {
+		ifd.Instances[name] = InstanceData{
+			IPAddress: ipGen.Next(),
+		}
+	}
+	return ifd, nil
+}
+
+func InfrastructureDataFromFile(p string) (InfrastructureData, error) {
+	ifd := InfrastructureData{}
+	b, err := os.ReadFile(p)
+	if err != nil {
+		return InfrastructureData{}, err
+	}
+	err = json.Unmarshal(b, &ifd)
+	if err != nil {
+		return InfrastructureData{}, err
+	}
+	if ifd.Network == "" {
+		ifd.Network = globalIPv4CIDR
+	}
+	return ifd, nil
+}