Add tar rule

rules.bzl

@@ -255,6 +255,11 @@ def databuild_graph(name, jobs, lookup, visibility = None):
         exec = "%s.exec" % name,
         visibility = visibility,
     )
+    _databuild_graph_tar(
+        name = "%s.tar" % name,
+        build = "%s.build" % name,
+        visibility = visibility,
+    )
 
 
 # TODO there feels like a lot of boilerplate around wrapping a target with a script - can this be simplified?
@@ -505,6 +510,66 @@ _databuild_graph_build = rule(
     executable = True,
 )
 
+def _databuild_graph_tar_impl(ctx):
+    """Creates a tar archive of the build target and all its runfiles."""
+    # Get the build target
+    build_target = ctx.attr.build
+
+    # Create a tar file containing the build target executable and all its runfiles
+    tar_file = ctx.actions.declare_file(ctx.label.name)
+
+    # Get all runfiles from the build target
+    runfiles_list = []
+
+    # Add the build target executable
+    runfiles_list.append(build_target.files_to_run.executable)
+
+    # Add all runfiles from the build target
+    if hasattr(build_target, "default_runfiles"):
+        runfiles_list.extend(build_target.default_runfiles.files.to_list())
+
+    # Create the tar file
+    args = ctx.actions.args()
+    args.add("--output", tar_file.path)
+    args.add("--directory", "/")
+
+    for f in runfiles_list:
+        # Use the short path to preserve the directory structure
+        dest = f.short_path
+        args.add("--file", "%s=%s" % (f.path, dest))
+
+    ctx.actions.run(
+        inputs = runfiles_list,
+        executable = ctx.executable._build_tar,
+        arguments = [args],
+        outputs = [tar_file],
+        mnemonic = "DataBuildGraphTar",
+        use_default_shell_env = True,
+    )
+
+    return [
+        DefaultInfo(
+            files = depset([tar_file]),
+        ),
+    ]
+
+_databuild_graph_tar = rule(
+    implementation = _databuild_graph_tar_impl,
+    attrs = {
+        "build": attr.label(
+            doc = "The build target to tar up",
+            mandatory = True,
+            executable = True,
+            cfg = "target",
+        ),
+        "_build_tar": attr.label(
+            default = Label("@bazel_tools//tools/build_defs/pkg:build_tar"),
+            executable = True,
+            cfg = "exec",
+        ),
+    },
+)
+
 #def _graph_impl(name):
 #    """
 #