Add qemu cloudprovider for activation calls

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

cli/qemu/instances.go

@@ -0,0 +1,62 @@
+package qemu
+
+// copy of ec2/instances.go
+
+// TODO(katexochen): refactor into mulitcloud package.
+
+import "errors"
+
+// Instance is a gcp instance.
+type Instance struct {
+	PublicIP  string
+	PrivateIP string
+}
+
+// Instances is a map of gcp Instances. The ID of an instance is used as key.
+type Instances map[string]Instance
+
+// IDs returns the IDs of all instances of the Constellation.
+func (i Instances) IDs() []string {
+	var ids []string
+	for id := range i {
+		ids = append(ids, id)
+	}
+	return ids
+}
+
+// PublicIPs returns the public IPs of all the instances of the Constellation.
+func (i Instances) PublicIPs() []string {
+	var ips []string
+	for _, instance := range i {
+		ips = append(ips, instance.PublicIP)
+	}
+	return ips
+}
+
+// PrivateIPs returns the private IPs of all the instances of the Constellation.
+func (i Instances) PrivateIPs() []string {
+	var ips []string
+	for _, instance := range i {
+		ips = append(ips, instance.PrivateIP)
+	}
+	return ips
+}
+
+// GetOne return anyone instance out of the instances and its ID.
+func (i Instances) GetOne() (string, Instance, error) {
+	for id, instance := range i {
+		return id, instance, nil
+	}
+	return "", Instance{}, errors.New("map is empty")
+}
+
+// GetOthers returns all instances but the one with the handed ID.
+func (i Instances) GetOthers(id string) Instances {
+	others := make(Instances)
+	for key, instance := range i {
+		if key != id {
+			others[key] = instance
+		}
+	}
+	return others
+}