Add feature to install komodo-shims at the end

komodo-shims thus becomes a magic package name that if found,
will always be the last pip-package to be installed. This allows
such a package to overwrite endpoints that are also installed
by other packages.

Author: berland

komodo/cli.py

@@ -19,6 +19,10 @@
 from komodo.shell import pushd, shell
 from komodo.yaml_file_types import ReleaseFile, RepositoryFile
 
+# If this package is included in a build, it will always
+# be installed as the last pip package
+LAST_PIP_PACKAGE_TO_INSTALL = "komodo-shims"
+
 
 class KomodoNamespace(argparse.Namespace):
     """
@@ -288,7 +292,12 @@ def pip_shell_command(
             makeopts,
         ]
 
+    komodo_shims: Optional[Tuple[str, str]] = None
     for pkg, ver in release_file_content.items():
+        if pkg == LAST_PIP_PACKAGE_TO_INSTALL:
+            # This is a magic package name that will always be installed after all other pip packages if found.
+            komodo_shims = (pkg, ver)
+            continue
         pkg_data = repository_file_content[pkg][ver]
         if pkg_data["make"] != "pip":
             continue
@@ -298,6 +307,9 @@ def pip_shell_command(
         )
         print(shell(shell_input))
 
+    if komodo_shims is not None:
+        print(shell(pip_shell_command(komodo_shims[0], komodo_shims[1], None)))
+
 
 def run_post_installation_scripts_if_set(
     postinst: Optional[str], release_path: Path

tests/test_cli.py

@@ -2,9 +2,12 @@
 import shutil
 import sys
 from pathlib import Path
+from unittest.mock import Mock, patch
 
 import pytest
+import yaml
 
+from komodo import cli
 from komodo.cli import cli_main
 from tests import _get_test_root
 
@@ -234,3 +237,54 @@ def count_release_folders_to_be_deleted() -> int:
     assert count_release_folders_to_be_deleted() == len(test_dirs)
     cli_main()
     assert count_release_folders_to_be_deleted() == 0
+
+
+def test_komodo_shims_is_installed_at_the_end(tmpdir):
+    (Path(tmpdir) / "release.yml").write_text(
+        "komodo-shims: 1.0.0\npython: 3-builtin\ntreelib: 1.7.0", encoding="utf-8"
+    )
+    repo = {
+        "python": {
+            "3-builtin": {
+                "make": "pip",  # because why not
+                "maintainer": "foo",
+            }
+        },
+        "treelib": {
+            "1.7.0": {
+                "source": "pypi",
+                "make": "pip",
+                "maintainer": "bar",
+                "depends": ["python"],
+            }
+        },
+        "komodo-shims": {
+            "1.0.0": {"source": "pypi", "make": "pip", "maintainer": "com"}
+        },
+    }
+    (Path(tmpdir) / "repository.yml").write_text(yaml.dump(repo), encoding="utf-8")
+    sys.argv = [
+        "kmd",
+        "--workspace",
+        str(tmpdir),
+        str(tmpdir / "release.yml"),
+        str(tmpdir / "repository.yml"),
+        "--release",
+        "a_komodo_release_with_shims",
+        "--prefix",
+        str(tmpdir),
+    ]
+
+    mocked_shell = Mock(return_value=b"")
+    mocked_fetch = Mock(return_value={})
+    with patch.object(cli, "shell", mocked_shell), patch.object(
+        cli, "fetch", mocked_fetch
+    ):
+        cli_main()
+    pip_install_calls = [
+        shell_call
+        for shell_call in mocked_shell.mock_calls
+        if "'pip', 'install " in str(shell_call.args[0])
+    ]
+    assert len(pip_install_calls) == 3
+    assert "komodo-shims" in str(pip_install_calls[-1])