From the document that you provided, it provides the source code for you, maybe you misunderstand and I will show here:
Option 1: The import path is where the source code in. Example below:
mkdir $HOME/go
export GOPATH=$HOME/go
go get github.com/vmware-tanzu/velero
So you can use the URL https://github.com/vmware-tanzu/velero to find and download the source.
Option 2: The release page will guide you to the page where the source code in, it's in the below of the page. Just find it carefully.
Is it necessary to install Velero locally and a server in the Kube
cluster?
It's all dependent on yourself. From the introduction of the Velero, it has the features here:
- Take backups of your cluster and restore in case of loss.
- Migrate cluster resources to other clusters.
- Replicate your production cluster to development and testing clusters.
It can help you to backup the data in the Kubernetes cluster and migrate cluster resources to other clusters. I will suggest you install it to use its features. Or that's OK if you use another tool instead of the Velero with the same features.