Passed cilium connectivity tests as a worker node

scripts/merge-env.sh

@@ -6,6 +6,25 @@ OUTPUT="${2:?output file required}"
 
 mkdir -p "$(dirname "$OUTPUT")"
 
+TMP="$(mktemp)"
+BASE_CREATED=0
+
+if [ -f "$OUTPUT" ]; then
+    BASE="$OUTPUT"
+else
+    BASE="$(mktemp)"
+    BASE_CREATED=1
+    : > "$BASE"
+fi
+
+cleanup() {
+    rm -f "$TMP"
+    if [ "$BASE_CREATED" = "1" ]; then
+        rm -f "$BASE"
+    fi
+}
+trap cleanup EXIT INT TERM
+
 awk '
 function trim(s) {
     sub(/^[[:space:]]+/, "", s)
@@ -13,33 +32,76 @@ function trim(s) {
     return s
 }
 
-BEGIN {
-    for (k in ENVIRON) {
-        env[k] = ENVIRON[k]
-    }
-}
-
-/^[[:space:]]*#/ || /^[[:space:]]*$/ {
-    print
-    next
-}
-
-{
-    line = $0
+function parse_key(line,    eq, key) {
     eq = index(line, "=")
-
     if (eq == 0) {
-        print line
-        next
+        return ""
     }
 
     key = trim(substr(line, 1, eq - 1))
-    val = substr(line, eq + 1)
 
-    if (key in env) {
-        print key "=" env[key]
-    } else {
-        print line
+    if (key !~ /^[A-Za-z_][A-Za-z0-9_]*$/) {
+        return ""
+    }
+
+    return key
+}
+
+function merged_line(key, line) {
+    if (key ~ /^MKS_/ && key in ENVIRON) {
+        return key "=" ENVIRON[key]
+    }
+
+    return line
+}
+
+# First file: INPUT
+phase == 1 {
+    line = $0
+    key = parse_key(line)
+
+    if (key != "") {
+        incoming[key] = merged_line(key, line)
+
+        if (!(key in input_seen)) {
+            input_order[++input_count] = key
+            input_seen[key] = 1
+        }
+    }
+
+    next
+}
+
+# Second file: existing OUTPUT / BASE
+phase == 2 {
+    line = $0
+    key = parse_key(line)
+
+    if (key != "" && key in incoming) {
+        print incoming[key]
+        written[key] = 1
+        next
+    }
+
+    print line
+
+    if (key != "") {
+        written[key] = 1
+    }
+
+    next
+}
+
+END {
+    for (i = 1; i <= input_count; i++) {
+        key = input_order[i]
+
+        if (!(key in written)) {
+            print incoming[key]
+            written[key] = 1
+        }
     }
 }
-' "$INPUT" > "$OUTPUT"
+' phase=1 "$INPUT" phase=2 "$BASE" > "$TMP"
+
+mv "$TMP" "$OUTPUT"