What happened:

When running make gen or go generate coredns.go with a third-party external CoreDNS plugin enabled, the zplugin.go will cause the TestImportOrdering unit test to fail. This is because the logic in directives_generate.go does not separate third-party external plugins from CoreDNS plugins in the go import block. This leads to the TestImportOrdering unit test failing, as it requires that third-party imports paths should be in a separate import block.

What you expected to happen:

go generate coredns.go should generate zplugin.go according to the standards enforced in TestImportOrdering.

How to reproduce it (as minimally and precisely as possible):

1. Add an external plugin to CoreDNS by adding it to plugin.cfg, e.g. add ocp_dnsnameresolver:github.com/openshift/coredns-ocp-dnsnameresolver anywhere in plugin.cfg.
2. Run TestImportOrdering unit test:

   === RUN   TestImportOrdering
    presubmit_test.go:195: import path for "github.com/openshift/coredns-ocp-dnsnameresolver" is not of the same type 
   "coredns" in "/home/gspence/src/github.com/coredns/coredns/core/plugin/zplugin.go"
   --- FAIL: TestImportOrdering (0.13s)
   

Anything else we need to know?:

While this issue does not affect the main CoreDNS repo, it can cause unit test failures in forks of CoreDNS that include external third-party plugins. So I understand it's a low priority.

Environment:

• the version of CoreDNS: 1.11.3
• Corefile: N/A
• logs, if applicable: N/A
• OS (e.g: cat /etc/os-release): N/A
• Others: N/A