Add a script to filter dependabot dependencies

The new script filters dependabot's configuration to ignore direct
dependencies which are tracked by parent Submariner projects. The
reasoning is that such dependencies end up aligned during the release
process anyway, so there isn't much point in processing PRs across all
the projects to bump dependencies which will catch up later anyway.

Signed-off-by: Stephen Kitt <[email protected]>

scripts/shared/filter_dependabot.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+declare -a seendeps
+
+function depseen() {
+    local dep
+    for dep in "${seendeps[@]}"; do
+	if [ "$dep" = "$1" ]; then
+	    return 0
+	fi
+    done
+    return 1
+}
+
+base="$(pwd)"
+conffile="${base}/.github/dependabot.yml"
+
+for dir in $(yq '(.updates[] | select(.package-ecosystem == "gomod")).directory' "$conffile"); do
+
+    (cd "${base}${dir}" || exit
+
+     # Remove the existing ignores
+     yq -i '(.updates[] | select(.package-ecosystem == "gomod") | select(.directory == "'"$dir"'")).ignore = []' "$conffile"
+
+     # Restore the submariner-io exclusion
+     yq -i '(.updates[] | select(.package-ecosystem == "gomod") | select(.directory == "'"$dir"'")).ignore[0].dependency-name = "github.com/submariner-io/*"' "$conffile"
+     yq -i '(.updates[] | select(.package-ecosystem == "gomod") | select(.directory == "'"$dir"'")).ignore[0] head_comment = "Our own dependencies are handled during releases"' "$conffile"
+
+     # Ignore all parent dependencies
+     for parent in $(GOWORK=off go list -m -mod=mod -json all | jq -r 'select(.Path | contains("/submariner-io/")) | select(.Main != true) .Path | gsub("github.com/submariner-io/"; "")'); do
+	 first=true
+	 for dep in $(GOWORK=off go list -m -mod=mod -json all | jq -r 'select(.Path | contains("/submariner-io") | not) | select(.Indirect != true) | select(.Main != true) .Path'); do
+	     if ! depseen "$dep"; then
+		 if grep -q "$dep" "$base/../$parent/go.mod"; then
+		     yq -i -P '(.updates[] | select(.package-ecosystem == "gomod") | select(.directory == "'"$dir"'")).ignore += { "dependency-name": "'"$dep"'" }' "$conffile"
+		     if $first; then
+			 yq -i -P 'with(.updates[] | select(.package-ecosystem == "gomod") | select(.directory == "'"$dir"'"); .ignore[.ignore | length - 1] head_comment = "Managed in '"$parent"'")' "$conffile"
+			 first=false
+		     fi
+		     seendeps+=("$dep")
+		 fi
+	     fi
+	 done
+     done)
+
+done