fix(k8s): ensure-secrets keeps secret values off command lines

Values were passed as kubectl -p argument and via environment variables,
both visible to other processes. Node now generates the values and writes
the patch into a private temp file (umask 077, removed on exit); kubectl
reads it with --patch-file. Only key names and modes are on the command
line. Also fixes the first key being dropped (node -e argv offset).

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

deploy/k8s/scripts/ensure-secrets.sh

@@ -21,9 +21,14 @@ NS="${NAMESPACE:-apicore}"
 DRY_RUN=false
 [[ "${1:-}" == "--dry-run" ]] && DRY_RUN=true
 
-random_key() {
-  node -e "process.stdout.write(require('crypto').randomBytes(48).toString('base64url'))"
-}
+# Secret values never appear on a command line or in the environment (both
+# are visible to other processes): node writes the patch straight into a
+# private temp file, kubectl reads it with --patch-file.
+umask 077
+PATCH_FILE="$(mktemp)"
+trap 'rm -f "$PATCH_FILE"' EXIT
+# Windows tools (node, kubectl) in Git Bash need the native path.
+PATCH_FILE_NATIVE="$(cygpath -w "$PATCH_FILE" 2>/dev/null || echo "$PATCH_FILE")"
 
 existing_keys() {
   kubectl get secret "$1" -n "$NS" -o jsonpath='{.data}' 2>/dev/null \
@@ -35,19 +40,13 @@ ensure_keys() {
   local secret="$1"; shift
   local have
   have="$(existing_keys "$secret")"
-  local patch="{}" added=()
+  local spec=() added=()
   while (($#)); do
     local key="$1" mode="$2"; shift 2
     if grep -qx "$key" <<<"$have"; then
       continue
     fi
-    local value
-    case "$mode" in
-      random) value="$(random_key)" ;;
-      empty) value="" ;;
-      dummy) value="dummy" ;;
-    esac
-    patch="$(KEY="$key" VALUE="$value" PATCH="$patch" node -e "const p=JSON.parse(process.env.PATCH);p.stringData=p.stringData||{};p.stringData[process.env.KEY]=process.env.VALUE;process.stdout.write(JSON.stringify(p))")"
+    spec+=("$key=$mode")
     added+=("$key")
   done
   if ((${#added[@]} == 0)); then
@@ -58,10 +57,25 @@ ensure_keys() {
     echo "$secret: wuerde ergaenzen: ${added[*]}"
     return
   fi
+  # Only key names and modes go on the command line; values are created here.
+  PATCH_FILE_PATH="$PATCH_FILE_NATIVE" node -e "
+    const crypto = require('crypto');
+    const value = (mode) =>
+      mode === 'random' ? crypto.randomBytes(48).toString('base64url')
+      : mode === 'dummy' ? 'dummy'
+      : '';
+    const stringData = {};
+    for (const entry of process.argv.slice(1)) {
+      const [key, mode] = entry.split('=');
+      stringData[key] = value(mode);
+    }
+    require('fs').writeFileSync(process.env.PATCH_FILE_PATH, JSON.stringify({ stringData }), { mode: 0o600 });
+  " "${spec[@]}"
   if ! kubectl get secret "$secret" -n "$NS" >/dev/null 2>&1; then
     kubectl create secret generic "$secret" -n "$NS" >/dev/null
   fi
-  kubectl patch secret "$secret" -n "$NS" --type merge -p "$patch" >/dev/null
+  kubectl patch secret "$secret" -n "$NS" --type merge --patch-file "$PATCH_FILE_NATIVE" >/dev/null
+  : >"$PATCH_FILE"
   echo "$secret: ergaenzt: ${added[*]}"
 }