pkg/types: add Set to *MachinePoolPlatform

This allows combining values for machine configuration from various
sources like,
1. Defaults decided by installer
2. Platform level defaults in InstallConfig
3. Per pool options.

pkg/types/machinepools.go

@@ -41,6 +41,30 @@ type AWSMachinePoolPlatform struct {
 	EC2RootVolume `json:"rootVolume"`
 }
 
+// Set sets the values from `required` to `a`.
+func (a *AWSMachinePoolPlatform) Set(required *AWSMachinePoolPlatform) {
+	if required == nil || a == nil {
+		return
+	}
+
+	if required.InstanceType != "" {
+		a.InstanceType = required.InstanceType
+	}
+	if required.IAMRoleName != "" {
+		a.IAMRoleName = required.IAMRoleName
+	}
+
+	if required.EC2RootVolume.IOPS != 0 {
+		a.EC2RootVolume.IOPS = required.EC2RootVolume.IOPS
+	}
+	if required.EC2RootVolume.Size != 0 {
+		a.EC2RootVolume.Size = required.EC2RootVolume.Size
+	}
+	if required.EC2RootVolume.Type != "" {
+		a.EC2RootVolume.Type = required.EC2RootVolume.Type
+	}
+}
+
 // EC2RootVolume defines the storage for an ec2 instance.
 type EC2RootVolume struct {
 	// IOPS defines the iops for the instance.
@@ -62,6 +86,27 @@ type OpenStackMachinePoolPlatform struct {
 	OpenStackRootVolume `json:"rootVolume"`
 }
 
+// Set sets the values from `required` to `a`.
+func (o *OpenStackMachinePoolPlatform) Set(required *OpenStackMachinePoolPlatform) {
+	if required == nil || o == nil {
+		return
+	}
+
+	if required.FlavorName != "" {
+		o.FlavorName = required.FlavorName
+	}
+
+	if required.OpenStackRootVolume.IOPS != 0 {
+		o.OpenStackRootVolume.IOPS = required.OpenStackRootVolume.IOPS
+	}
+	if required.OpenStackRootVolume.Size != 0 {
+		o.OpenStackRootVolume.Size = required.OpenStackRootVolume.Size
+	}
+	if required.OpenStackRootVolume.Type != "" {
+		o.OpenStackRootVolume.Type = required.OpenStackRootVolume.Type
+	}
+}
+
 // OpenStackRootVolume defines the storage for a Nova instance.
 type OpenStackRootVolume struct {
 	// IOPS defines the iops for the instance.
@@ -86,3 +131,20 @@ type LibvirtMachinePoolPlatform struct {
 	// E.g. "http://aos-ostree.rhev-ci-vms.eng.rdu2.redhat.com/rhcos/images/cloud/latest/rhcos-qemu.qcow2.gz"
 	Image string `json:"image"`
 }
+
+// Set sets the values from `required` to `a`.
+func (l *LibvirtMachinePoolPlatform) Set(required *LibvirtMachinePoolPlatform) {
+	if required == nil || l == nil {
+		return
+	}
+
+	if required.ImagePool != "" {
+		l.ImagePool = required.ImagePool
+	}
+	if required.ImageVolume != "" {
+		l.ImageVolume = required.ImageVolume
+	}
+	if required.Image != "" {
+		l.Image = required.Image
+	}
+}