From c63e2aef29382a74c5d40e6f7ecad53558f801ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Mon, 24 May 2021 00:11:58 +0300
Subject: [PATCH] wip: rootfs

---
 BUILD     |  1 +
 rules.bzl | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 rules.bzl

diff --git a/BUILD b/BUILD
index a5a2102..bc608fb 100644
--- a/BUILD
+++ b/BUILD
@@ -1,4 +1,5 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("//src/undocker:rules.bzl", "rootfs")
 
 go_library(
     name = "go_default_library",
diff --git a/rules.bzl b/rules.bzl
new file mode 100644
index 0000000..bc48244
--- /dev/null
+++ b/rules.bzl
@@ -0,0 +1,31 @@
+def _rootfs_impl(ctx):
+    ctx.actions.run(
+        executable =  ctx.files._undocker,
+        arguments = [
+            ctx.attr.src,
+            ctx.output,
+        ],
+    )
+
+rootfs = rule(
+    doc = "Generate a rootfs from a docker container image",
+    implementation = _rootfs_impl,
+    attrs = {
+        "src": attr.label(
+            doc = "Input container tarball",
+            mandatory = True,
+            allow_single_file = [".tar"],
+        ),
+        "out": attr.output(
+            doc = "Output rootfs tarball",
+            mandatory = True,
+        ),
+        "_undocker": attr.label(
+            doc = "undocker cli; private and may not be overridden",
+            cfg = "host",
+            default = Label("//src/undocker:undocker"),
+            allow_single_file = True,
+            executable = True,
+        ),
+    },
+)