The Knative projects can be built without a vendor directory. This is a convenience for developers, and brings a number of benefits:

• It is easier to see the changes to the code and review them.
• It is easier to maintain the build and CI scripts, as they don't need to filter out the vendor directory.
• The project doesn't look dated (the proper dependency management tools are available for Go since 1.13+).
• No vendor directory means less possibility of accidentally traversing into it by symlinks or scripts.

For more details and reasons for avoiding the vendor directory, see knative/infra#134.

The knative/infra#134 is ongoing effort. Currently, it is possible to use make projects vendorless, only if they don't use Knative nor Kubernetes code-generation tools. See the epic issue for current status.

The following steps are required to migrate a project to be vendorless:

1. Update the knative.dev/hack dependency to the latest version.
2. Update the project scripts to use the scripts inflation:

   -source $(dirname $0)/../vendor/knative.dev/hack/release.sh
   +source "$(go run knative.dev/hack/cmd/script release.sh)"

3. Update the hack/tools.go file to refer to the knative.dev/hack/cmd/script tool:

   package hack
   
   import (
   	_ "knative.dev/hack/cmd/script"
   )

4. Remove the vendor directory.
5. Run hack/update-deps.sh to update the go.mod file(s).

• knative/func#1966
• knative-extensions/kn-plugin-event#307