GoCloud using Builder pattern to improve user experience

Use Builder pattern for inputting parameters

In order to improve user experience using gocloud, I opened Issue #78.

In GoCloud, existing way to receive user parameters:

alicloud, _ := gocloud.CloudProvider(gocloud.Aliprovider)
create := map[string]interface{}{
    "RegionId":          "cn-qingdao",
    "ImageId":           "centos_7_04_64_20G_alibase_201701015.vhd",
    "InstanceType":      "ecs.xn4.small",
    "SecurityGroupId":   "sg-m5egbo9s5xb21kpu6nk2",
}
resp, err := alicloud.Createnode(create)

In the current way, we cannot prevent user from entering wrong parameter name and missing required parameters.

If we use Builder pattern like this:

alicloud, _ := gocloud.CloudProvider(gocloud.Aliprovider)
createNodeBuilder := ecs.NewCreateNodeBuilder().
	RegionID("cn-qingdao").
	ImageID("centos_7_04_64_20G_alibase_201701015.vhd").
	InstanceType("ecs.xn4.small").
	SecurityGroupID("sg-m5egbo9s5xb21kpu6nk2")
createNode, err := createNodeBuilder.Build()

if err != nil {
	// May miss required parameters
}
resp, err := alicloud.Createnode(createNode)

We can

• Prevent user from inputting wrong parameter name
• Throw an error when user miss input required parameters
• Let user add parameters in different places
• Let user have higher freedom, clearer code

So I tried to use Builder pattern in GoCloud.

I made it and created Pull Request #80:

• Implemented Builder pattern for create node of Ali-cloud
• Unit test for create node of Ali-cloud