feat(py_image_layer): support multiple binaries

e2e/cases/oci/py_image_layer/BUILD.bazel

@@ -1,9 +1,10 @@
-load("@aspect_rules_py//py:defs.bzl", "py_binary", "py_image_layer", "py_layer_tier", "py_test")
+load("@aspect_rules_py//py:defs.bzl", "py_binary", "py_image_layer", "py_layer_tier", "py_library", "py_test")
 load("@bazel_lib//lib:transitions.bzl", "platform_transition_filegroup")
 load("@bazel_skylib//rules:build_test.bzl", "build_test")
 load("@container_structure_test//:defs.bzl", "container_structure_test")
 load("@rules_oci//oci:defs.bzl", "oci_image", "oci_load")
 load("//tools:asserts.bzl", "assert_tar_listing")
+load(":image_layer_analysis_tests.bzl", "image_layer_analysis_test_suite")
 
 platform(
     name = "aarch64_linux",
@@ -98,9 +99,9 @@ py_image_layer(
 )
 
 # Multi-member group coverage: two pip packages mapped to the same group name
-# go through the _merge_aspect path (no per-package tars; single merged tar
-# from both install_dirs). Binary also adds pyproject_hooks to make the
-# closure non-trivial. Zstd-compressed to exercise _compression_ext.
+# produce a single merged tar from both install_dirs. Binary also adds
+# pyproject_hooks to make the closure non-trivial. Zstd-compressed to exercise
+# _compression_ext.
 py_binary(
     name = "my_app_multi_bin",
     srcs = ["__main__.py"],
@@ -131,6 +132,153 @@ py_image_layer(
     layer_tier = ":my_app_multi_tier",
 )
 
+# Exercise the actual multi-launcher flow with separate lock universes and two
+# interpreter versions. colorama has the same normalized label in both
+# closures, but distinct 3.14/3.12 install trees; both launchers must resolve
+# their own venv and the unioned dependency layers from the shared runfiles tree.
+py_library(
+    name = "worker_support",
+    srcs = ["worker_support.py"],
+    imports = ["."],
+)
+
+py_binary(
+    name = "my_app_launcher_bin",
+    srcs = ["launcher.py"],
+    data = [":my_app_worker_bin"],
+    dep_group = "images",
+    python_version = "3.11",
+    deps = [
+        "@bazel_tools//tools/python/runfiles",
+        "@pypi_oci_py_image_layer//build",
+        "@pypi_oci_py_image_layer//colorama",
+    ],
+)
+
+py_binary(
+    name = "my_app_worker_bin",
+    srcs = ["worker.py"],
+    dep_group = "venv_images",
+    python_version = "3.12",
+    deps = [
+        ":worker_support",
+        "@pypi_oci_py_venv_image_layer//build",
+        "@pypi_oci_py_venv_image_layer//colorama",
+        "@pypi_oci_py_venv_image_layer//pyproject_hooks",
+    ],
+)
+
+alias(
+    name = "my_app_worker_alias",
+    actual = ":my_app_worker_bin",
+)
+
+py_layer_tier(
+    name = "my_app_launchers_tier",
+    groups = {
+        "//oci/py_image_layer:worker_support": "worker_support",
+        "@pip//build": "third_party",
+        "@pip//colorama": "third_party",
+        "@pip//pyproject_hooks": "third_party",
+    },
+    interpreter_group = "interpreter",
+    strip_prefix = "oci/py_image_layer/my_app_bin",
+)
+
+py_image_layer(
+    name = "my_app_launchers_layers",
+    binaries = [
+        ":my_app_launcher_bin",
+        ":my_app_worker_alias",
+    ],
+    layer_tier = ":my_app_launchers_tier",
+)
+
+genrule(
+    name = "my_app_launchers_sources_listing",
+    srcs = [":my_app_launchers_layers_only_src"],
+    outs = ["_my_app_launchers_sources.listing"],
+    cmd = "for f in $(SRCS); do $(BSDTAR_BIN) -tf $$f; done > $@",
+    toolchains = ["@bsd_tar_toolchains//:resolved_toolchain"],
+)
+
+# Default-tier source closures share the interpreter, branding source, and
+# data. The listing test proves the unioned source tar ships each byte once.
+py_binary(
+    name = "my_app_peer_bin",
+    srcs = ["server.py"],
+    data = ["my_app_peer_bin/config.json"],
+    dep_group = "images",
+    python_version = "3.11",
+    deps = ["//oci/py_image_layer/branding"],
+)
+
+py_image_layer(
+    name = "my_app_shared_layers",
+    binaries = [
+        ":my_app_bin",
+        ":my_app_peer_bin",
+    ],
+    launcher_dir = "/custom/bin",
+)
+
+genrule(
+    name = "my_app_shared_sources_listing",
+    srcs = [":my_app_shared_layers_only_src"],
+    outs = ["_my_app_shared_sources.listing"],
+    cmd = "for f in $(SRCS); do $(BSDTAR_BIN) -tf $$f; done > $@",
+    toolchains = ["@bsd_tar_toolchains//:resolved_toolchain"],
+)
+
+py_image_layer(
+    name = "my_app_binaries_layers",
+    binaries = select({
+        ":_python_3_11": [
+            ":my_app_bin",
+            ":my_app_peer_bin",
+        ],
+        "//conditions:default": [
+            ":my_app_peer_bin",
+            ":my_app_bin",
+        ],
+    }),
+    launcher_dir = "/app/bin",
+)
+
+build_test(
+    name = "my_app_binary_api_test",
+    targets = [
+        ":_configured_wheel_collision_layers",
+        ":my_app_binaries_layers",
+        ":my_app_launchers_layers",
+        ":_scalar_default_sources_listing",
+    ],
+)
+
+oci_image(
+    name = "launchers_image",
+    base = "@ubuntu",
+    env = {"RUNFILES_DIR": "/app.runfiles"},
+    tars = [":my_app_launchers_layers"],
+)
+
+platform_transition_filegroup(
+    name = "amd64_launchers_image",
+    srcs = [":launchers_image"],
+    target_platform = ":x86_64_linux",
+)
+
+container_structure_test(
+    name = "launchers_image_command_test",
+    args = ["--verbosity=debug"],
+    configs = ["launchers_image_command_test.yaml"],
+    image = ":amd64_launchers_image",
+    platform = "linux/amd64",
+    tags = ["requires-docker"],
+)
+
+image_layer_analysis_test_suite()
+
 platform_transition_filegroup(
     name = "platform_layers",
     srcs = [":my_app_layers"],
@@ -271,3 +419,42 @@ container_structure_test(
         "requires-docker",
     ],
 )
+
+# Exercise scalar launcher relocation independently from the default `/app`
+# regression above.
+py_layer_tier(
+    name = "server_custom_tier",
+    strip_prefix = "does/not/match",
+)
+
+py_image_layer(
+    name = "server_custom_layers",
+    binary = ":server",
+    launcher_dir = "/custom/bin",
+    layer_tier = ":server_custom_tier",
+)
+
+oci_image(
+    name = "server_custom_image",
+    base = "@ubuntu",
+    entrypoint = ["/custom/bin/server"],
+    env = {"RUNFILES_DIR": "/app.runfiles"},
+    tars = [":server_custom_layers"],
+)
+
+platform_transition_filegroup(
+    name = "amd64_server_custom_image",
+    srcs = [":server_custom_image"],
+    target_platform = ":x86_64_linux",
+)
+
+container_structure_test(
+    name = "server_custom_image_command_test",
+    args = ["--verbosity=debug"],
+    configs = ["server_custom_image_command_test.yaml"],
+    image = ":amd64_server_custom_image",
+    platform = "linux/amd64",
+    tags = [
+        "requires-docker",
+    ],
+)

e2e/cases/oci/py_image_layer/_scalar_strip_collision/data.txt

@@ -0,0 +1 @@
+data