From e420a137665517145c584465e7750ec96ffd239e Mon Sep 17 00:00:00 2001
From: Josh Chorlton <jchorl@users.noreply.github.com>
Date: Tue, 2 Jan 2024 00:10:02 +0000
Subject: [PATCH] feat: support passing label to load command (#441)

Co-authored-by: Sahin Yort <thesayyn@gmail.com>
---
 docs/tarball.md                |  3 ++-
 oci/private/tarball.bzl        | 15 ++++++++++++++-
 oci/private/tarball_run.sh.tpl |  6 ++++--
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/docs/tarball.md b/docs/tarball.md
index 54609312..1f1d7dd0 100644
--- a/docs/tarball.md
+++ b/docs/tarball.md
@@ -25,7 +25,7 @@ docker run --rm my-repository:latest
 ## oci_tarball
 
 <pre>
-oci_tarball(<a href="#oci_tarball-name">name</a>, <a href="#oci_tarball-format">format</a>, <a href="#oci_tarball-image">image</a>, <a href="#oci_tarball-repo_tags">repo_tags</a>)
+oci_tarball(<a href="#oci_tarball-name">name</a>, <a href="#oci_tarball-command">command</a>, <a href="#oci_tarball-format">format</a>, <a href="#oci_tarball-image">image</a>, <a href="#oci_tarball-repo_tags">repo_tags</a>)
 </pre>
 
 Creates tarball from OCI layouts that can be loaded into docker daemon without needing to publish the image first.
@@ -39,6 +39,7 @@ Passing anything other than oci_image to the image attribute will lead to build
 | Name  | Description | Type | Mandatory | Default |
 | :------------- | :------------- | :------------- | :------------- | :------------- |
 | <a id="oci_tarball-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/concepts/labels#target-names">Name</a> | required |  |
+| <a id="oci_tarball-command"></a>command |  target for a container cli tool (i.e. docker or podman or other) that will be used to load the image into the local engine when using 'bazel run //my/image'.",   | <a href="https://bazel.build/concepts/labels">Label</a> | optional | <code>None</code> |
 | <a id="oci_tarball-format"></a>format |  Format of image to generate. Options are: docker, oci. Currently, when the input image is an image_index, only oci is supported, and when the input image is an image, only docker is supported. Conversions between formats may be supported in the future.   | String | optional | <code>"docker"</code> |
 | <a id="oci_tarball-image"></a>image |  Label of a directory containing an OCI layout, typically <code>oci_image</code>   | <a href="https://bazel.build/concepts/labels">Label</a> | required |  |
 | <a id="oci_tarball-repo_tags"></a>repo_tags |  a file containing repo_tags, one per line.   | <a href="https://bazel.build/concepts/labels">Label</a> | required |  |
diff --git a/oci/private/tarball.bzl b/oci/private/tarball.bzl
index d2b0118b..8e2313c0 100644
--- a/oci/private/tarball.bzl
+++ b/oci/private/tarball.bzl
@@ -39,6 +39,15 @@ attrs = {
         allow_single_file = [".txt"],
         mandatory = True,
     ),
+    "command": attr.label(
+        doc = """\
+            target for a container cli tool (i.e. docker or podman or other) that will be used to load the image into the local engine when using 'bazel run //my/image'.",
+            """,
+        allow_single_file = True,
+        mandatory = False,
+        executable = True,
+        cfg = "target",
+    ),
     "_run_template": attr.label(
         default = Label("//oci/private:tarball_run.sh.tpl"),
         doc = """ \
@@ -90,12 +99,16 @@ def _tarball_impl(ctx):
         output = exe,
         substitutions = {
             "{{image_path}}": tarball.short_path,
+            "{{command}}": ctx.file.command.path if ctx.file.command else "",
         },
         is_executable = True,
     )
+    runfiles = [tarball]
+    if ctx.file.command:
+        runfiles.append(ctx.file.command)
 
     return [
-        DefaultInfo(files = depset([tarball]), runfiles = ctx.runfiles(files = [tarball]), executable = exe),
+        DefaultInfo(files = depset([tarball]), runfiles = ctx.runfiles(files = runfiles), executable = exe),
     ]
 
 oci_tarball = rule(
diff --git a/oci/private/tarball_run.sh.tpl b/oci/private/tarball_run.sh.tpl
index 1f64ecc6..86445b69 100644
--- a/oci/private/tarball_run.sh.tpl
+++ b/oci/private/tarball_run.sh.tpl
@@ -2,13 +2,15 @@
 set -o pipefail -o errexit -o nounset
 
 readonly IMAGE="{{image_path}}"
-if command -v docker &> /dev/null; then
+if [ -e "{{command}}" ]; then
+    CONTAINER_CLI="{{command}}"
+elif command -v docker &> /dev/null; then
     CONTAINER_CLI="docker"
 elif command -v podman &> /dev/null; then
     CONTAINER_CLI="podman"
 else
     echo >&2 "Neither docker or podman could be found."
-    echo >&2 "If you wish to use another container runtime, please comment on https://github.com/bazel-contrib/rules_oci/issues/295."
+    echo >&2 "If you wish to use another container runtime, you can pass an executable to the 'command' attribute."
     exit 1
 fi