qemu-metadata-api: allow building without cgo dependencies for linting

hack/qemu-metadata-api/BUILD.bazel

@@ -5,7 +5,10 @@ load("//bazel/go:platform.bzl", "platform_binary")
 
 go_library(
     name = "qemu-metadata-api_lib",
-    srcs = ["main.go"],
+    srcs = [
+        "main.go",
+        "main_cross.go",
+    ],
     importpath = "github.com/edgelesssys/constellation/v2/hack/qemu-metadata-api",
     visibility = ["//visibility:private"],
     deps = [

hack/qemu-metadata-api/main.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 /*
 Copyright (c) Edgeless Systems GmbH
 

hack/qemu-metadata-api/main_cross.go

@@ -0,0 +1,13 @@
+//go:build !cgo
+
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package main
+
+func main() {
+	panic("CGO disabled but started qemu-metadata-api")
+}

hack/qemu-metadata-api/server/server_test.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 /*
 Copyright (c) Edgeless Systems GmbH
 

hack/qemu-metadata-api/virtwrapper/BUILD.bazel

@@ -2,7 +2,11 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "virtwrapper",
-    srcs = ["virtwrapper.go"],
+    srcs = [
+        "virtwrapper.go",
+        "virtwrapper_cgo.go",
+        "virtwrapper_cross.go",
+    ],
     importpath = "github.com/edgelesssys/constellation/v2/hack/qemu-metadata-api/virtwrapper",
     visibility = ["//visibility:public"],
     deps = ["@org_libvirt_go_libvirt//:libvirt"],

hack/qemu-metadata-api/virtwrapper/virtwrapper.go

@@ -6,38 +6,8 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 package virtwrapper
 
-import "libvirt.org/go/libvirt"
-
-// Connect wraps a libvirt connection.
-type Connect struct {
-	Conn *libvirt.Connect
-}
-
-// LookupNetworkByName looks up a network by name.
-func (c *Connect) LookupNetworkByName(name string) (*Network, error) {
-	net, err := c.Conn.LookupNetworkByName(name)
-	if err != nil {
-		return nil, err
-	}
-	return &Network{Net: net}, nil
-}
-
-// Network wraps a libvirt network.
-type Network struct {
-	Net virNetwork
-}
-
-// GetDHCPLeases returns the underlying DHCP leases.
-func (n *Network) GetDHCPLeases() ([]libvirt.NetworkDHCPLease, error) {
-	return n.Net.GetDHCPLeases()
-}
-
-// Free the network resource.
-func (n *Network) Free() {
-	_ = n.Net.Free()
-}
-
-type virNetwork interface {
-	GetDHCPLeases() ([]libvirt.NetworkDHCPLease, error)
-	Free() error
+// NetworkDHCPLease abstracts a libvirt DHCP lease.
+type NetworkDHCPLease struct {
+	IPaddr   string
+	Hostname string
 }

hack/qemu-metadata-api/virtwrapper/virtwrapper_cgo.go

@@ -0,0 +1,56 @@
+//go:build cgo
+
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package virtwrapper
+
+import "libvirt.org/go/libvirt"
+
+// Connect wraps a libvirt connection.
+type Connect struct {
+	Conn *libvirt.Connect
+}
+
+// LookupNetworkByName looks up a network by name.
+func (c *Connect) LookupNetworkByName(name string) (*Network, error) {
+	net, err := c.Conn.LookupNetworkByName(name)
+	if err != nil {
+		return nil, err
+	}
+	return &Network{Net: net}, nil
+}
+
+// Network wraps a libvirt network.
+type Network struct {
+	Net virNetwork
+}
+
+// GetDHCPLeases returns the underlying DHCP leases.
+func (n *Network) GetDHCPLeases() ([]NetworkDHCPLease, error) {
+	leases, err := n.Net.GetDHCPLeases()
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]NetworkDHCPLease, len(leases))
+	for i, l := range leases {
+		ret[i] = NetworkDHCPLease{
+			IPaddr:   l.IPaddr,
+			Hostname: l.Hostname,
+		}
+	}
+	return ret, nil
+}
+
+// Free the network resource.
+func (n *Network) Free() {
+	_ = n.Net.Free()
+}
+
+type virNetwork interface {
+	GetDHCPLeases() ([]libvirt.NetworkDHCPLease, error)
+	Free() error
+}

hack/qemu-metadata-api/virtwrapper/virtwrapper_cross.go

@@ -0,0 +1,33 @@
+//go:build !cgo
+
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package virtwrapper
+
+import "errors"
+
+// Connect wraps a libvirt connection.
+type Connect struct{}
+
+// LookupNetworkByName looks up a network by name.
+// This function errors if CGO is disabled.
+func (c *Connect) LookupNetworkByName(_ string) (*Network, error) {
+	return nil, errors.New("using virtwrapper requires building with CGO")
+}
+
+// Network wraps a libvirt network.
+type Network struct{}
+
+// GetDHCPLeases returns the underlying DHCP leases.
+// This function errors if CGO is disabled.
+func (n *Network) GetDHCPLeases() ([]NetworkDHCPLease, error) {
+	return nil, errors.New("using virtwrapper requires building with CGO")
+}
+
+// Free the network resource.
+// This function does nothing if CGO is disabled.
+func (n *Network) Free() {}