Implement general iptables editor support to enable redirect to live side by side with dokcer dns rules

1 files changed, 35 insertions, 9 deletions

diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/Editor.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/Editor.java
index 83954551905..3d4dbcca0e6 100644
--- a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/Editor.java
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/file/Editor.java
@@ -9,6 +9,8 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
 import java.util.logging.Logger;
 
 import static com.yahoo.vespa.hosted.node.admin.task.util.file.IOExceptionUtil.uncheck;
@@ -24,20 +26,36 @@ public class Editor {
 
     private static int maxLength = 300;
 
-    private final Path path;
+    private final Supplier<List<String>> supplier;
+    private final Consumer<List<String>> consumer;
+    private final String name;
     private final LineEditor editor;
 
     public Editor(Path path, LineEditor editor) {
-        this.path = path;
-        this.editor = editor;
+        this(path.toString(),
+                () -> uncheck(() -> Files.readAllLines(path, ENCODING)),
+                (newLines) ->  uncheck(() -> Files.write(path, newLines, ENCODING)),
+                editor);
     }
 
     /**
-     * Read the file which must be encoded in UTF-8, use the LineEditor to edit it,
-     * and any modifications were done write it back and return true.
+     * @param name The name of what is being edited - used in logging
+     * @param supplier Supplies the editor with a list of lines to edit
+     * @param consumer Consumes the lines to presist if any changes is detected
+     * @param editor The line operations to execute on the lines supplied
      */
-    public boolean converge(TaskContext context) {
-        List<String> lines = uncheck(() -> Files.readAllLines(path, ENCODING));
+    public Editor(String name,
+            Supplier<List<String>> supplier,
+                  Consumer<List<String>> consumer,
+                  LineEditor editor) {
+        this.supplier = supplier;
+        this.consumer = consumer;
+        this.name = name;
+        this.editor = editor;
+    }
+
+    public boolean edit(Consumer<String> logConsumer) {
+        List<String> lines = supplier.get();
         List<String> newLines = new ArrayList<>();
         StringBuilder diff = new StringBuilder();
         boolean modified = false;
@@ -80,11 +98,19 @@ public class Editor {
         }
 
         String diffDescription = diffTooLarge(diff) ? "" : ":\n" + diff.toString();
-        context.recordSystemModification(logger, "Patching file " + path + diffDescription);
-        uncheck(() -> Files.write(path, newLines, ENCODING));
+        logConsumer.accept("Patching " + name + diffDescription);
+        consumer.accept(newLines);
         return true;
     }
 
+    /**
+     * Read the file which must be encoded in UTF-8, use the LineEditor to edit it,
+     * and any modifications were done write it back and return true.
+     */
+    public boolean converge(TaskContext context) {
+        return this.edit(line -> context.recordSystemModification(logger, line));
+    }
+
     private static void maybeAdd(StringBuilder diff, List<String> lines) {
         for (String line : lines) {
             if (!diffTooLarge(diff)) {