hack: allow pkg/ to import internal/ packages

The pkg-imports validation prevents reusable library packages from
depending on the whole daemon, accidentally or intentionally. The
allowlist is overly restrictive as it also prevents us from reusing code
in both pkg/ and daemon/ unless that code is also made into a reusable
library package under pkg/. Allow pkg/ packages to import internal/
packages which do not transitively depend on disallowed packages.

Signed-off-by: Cory Snider <csnider@mirantis.com>

hack/make.ps1

@@ -269,6 +269,7 @@ Function Validate-PkgImports($headCommit, $upstreamCommit) {
         # Filter out what we are looking for
         $imports = @() + $imports -NotMatch "^github.com/docker/docker/pkg/" `
                                   -NotMatch "^github.com/docker/docker/vendor" `
+                                  -NotMatch "^github.com/docker/docker/internal" `
                                   -Match "^github.com/docker/docker" `
                                   -Replace "`n", ""
         $imports | ForEach-Object{ $badFiles+="$file imports $_`n" }

hack/validate/pkg-imports

@@ -17,7 +17,12 @@ for f in "${files[@]}"; do
 		continue
 	fi
 	IFS=$'\n'
-	badImports=($(go list -e -f '{{ join .Deps "\n" }}' "$f" | sort -u | grep -vE '^github.com/docker/docker/pkg/' | grep -vE '^github.com/docker/docker/vendor' | grep -E '^github.com/docker/docker' || true))
+	badImports=($(go list -e -f '{{ join .Deps "\n" }}' "$f" | sort -u \
+		| grep -vE '^github.com/docker/docker/pkg/' \
+		| grep -vE '^github.com/docker/docker/vendor' \
+		| grep -vE '^github.com/docker/docker/internal' \
+		| grep -E '^github.com/docker/docker' \
+		|| true))
 	unset IFS
 
 	for import in "${badImports[@]}"; do