make cluster-config

scripts/merge-env.sh

@@ -0,0 +1,45 @@
+#!/bin/sh
+set -eu
+
+INPUT="${1:?input file required}"
+OUTPUT="${2:?output file required}"
+
+mkdir -p "$(dirname "$OUTPUT")"
+
+awk '
+function trim(s) {
+    sub(/^[[:space:]]+/, "", s)
+    sub(/[[:space:]]+$/, "", s)
+    return s
+}
+
+BEGIN {
+    for (k in ENVIRON) {
+        env[k] = ENVIRON[k]
+    }
+}
+
+/^[[:space:]]*#/ || /^[[:space:]]*$/ {
+    print
+    next
+}
+
+{
+    line = $0
+    eq = index(line, "=")
+
+    if (eq == 0) {
+        print line
+        next
+    }
+
+    key = trim(substr(line, 1, eq - 1))
+    val = substr(line, eq + 1)
+
+    if (key in env) {
+        print key "=" env[key]
+    } else {
+        print line
+    }
+}
+' "$INPUT" > "$OUTPUT"