hack/verify-go-modules.sh: generate list of nested modules

The list is no longer constructed manually.

On-behalf-of: SAP [email protected]
Signed-off-by: Robert Vasek <[email protected]>

Author: gman0

hack/verify-go-modules.sh

@@ -26,23 +26,39 @@ set -o pipefail
 
 REPO_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
 
-# This is the list of directories that host the individual kcp go modules.
-#
-#   KEEP IT UP TO DATE and SORTED!
-#
-# The items must be sorted such that the module that is being dependent on
-# comes before the one that depends on it (i.e. topological order).
-DIRS=(
-  "${REPO_ROOT}/sdk"
-  "${REPO_ROOT}/cli"
-  "${REPO_ROOT}"
-  "${REPO_ROOT}/docs/generators/cli-doc"
+if [[ ! -f "${REPO_ROOT}/go.work" ]]; then
+  (
+    cd "${REPO_ROOT}"
+    go work init
+    go work use -r .
+  )
+fi
+
+# Array of all modules inside the repository, sorted in
+# descending topological order (dependant comes before its dependee).
+mapfile -t MODULE_DIRS < <(
+  for mod in $(tsort <(
+    # Lines in format "<Dependant> <Dependee>" are fed into `tsort` to perform the topological sort.
+    for dir in $(go list -m -json | jq -r '.Dir'); do
+      (
+        cd "${dir}"
+        # Prints the dependency graph where we extract only the direct
+        # github.com/kcp-dev/kcp* dependencies of the currently examined module,
+        # and we discard the dependency version (the line is in format
+        # "<Module> <Dependency>@<Version>", so we split by '@' and get the
+        # first part). We skip when no such deps are found.
+        go mod graph \
+          | grep -E "^$(go mod edit -json | jq -r '.Module.Path') github.com/kcp-dev/kcp" \
+          | cut -d'@' -f1 \
+          || true
+      )
+    done
+  ) | tac); do # We need to reverse the lines (with `tac`) to have a descending order.
+    # We have sorted module paths. We need to convert them into their respective directory locations.
+    go list -m -json "$mod" | jq -r '.Dir'
+  done
 )
 
-# Check that DIRS is up to date.
-[[ "$(printf '%s\n' "${DIRS[@]}" | sort)" == "$(find "${REPO_ROOT}" -name go.mod -print0 | xargs -0 dirname | sort)" ]] \
-  || { echo "Error: DIRS list in ${BASH_SOURCE[0]} is out-of-date, and needs to be manually updated" 1>&2 ; exit 1 ; }
-
 # list_deps lists dependencies of the supplied go.mod file (dependencies
 # with version "v0.0.0" are skipped). The output is a json dictionary in the
 # format `{"<Dependency>": "<Version>", ...}`.
@@ -123,7 +139,7 @@ function gomod_filepath_for {
 k8s_gomod="$(gomod_filepath_for k8s.io/kubernetes)"
 k8s_deps="$(list_deps ${k8s_gomod})"
 
-for dir in "${DIRS[@]}"; do
+for dir in "${MODULE_DIRS[@]}"; do
   (
     cd "$dir"
     echo "Verifying ${dir}"