Make test infra optional

Author: rcmadhankumar

README.rst

@@ -21,7 +21,7 @@ Find the latest documentation on `dcermak.github.io/pytest_container
 <https://dcermak.github.io/pytest_container/>`_.
 
 ``pytest_container`` is a `pytest <https://pytest.org>`_ plugin
-to test container images via pytest fixtures and `testinfra
+to test container images via pytest fixtures and optionally `testinfra
 <https://testinfra.readthedocs.io/en/latest/>`_. It takes care of all the boring
 tasks, like spinning up containers, finding free ports and cleaning up after
 tests, and allows you to focus on implementing the actual tests.
@@ -55,8 +55,7 @@ instantiating a ``Container`` and parametrizing a test function with the
 The fixture automatically pulls and spins up the container, stops it and removes
 it after the test is completed. Your test function receives an instance of
 ``ContainerData`` with the ``ContainerData.connection`` attribute. The
-``ContainerData.connection`` attribute is a `testinfra
-<https://testinfra.readthedocs.io/en/latest/>`_ connection object. It can be
+``ContainerData.connection`` attribute is a shell connection object. It can be
 used to run basic tests inside the container itself. For example, you can check
 whether files are present, packages are installed, etc.
 

pytest_container/container.py

@@ -11,6 +11,7 @@
 import operator
 import os
 import socket
+import subprocess
 import sys
 import tempfile
 import time
@@ -43,10 +44,10 @@
 import _pytest.mark
 import deprecation
 import pytest
-import testinfra
 from filelock import BaseFileLock
 from filelock import FileLock
 
+from pytest_container import helpers
 from pytest_container.helpers import get_always_pull_option
 from pytest_container.helpers import get_extra_build_args
 from pytest_container.helpers import get_extra_run_args
@@ -877,7 +878,7 @@ def prepare_container(
 @dataclass(frozen=True)
 class ContainerData:
     """Class returned by the ``*container*`` fixtures to the test function. It
-    contains information about the launched container and the testinfra
+    contains information about the launched container and its shell connection
     :py:attr:`connection` to the running container.
 
     """
@@ -887,7 +888,7 @@ class ContainerData:
     image_url_or_id: str
     #: ID of the started container
     container_id: str
-    #: the testinfra connection to the running container
+    #: the shell connection to the running container
     connection: Any
     #: the container data class that has been used in this test
     container: Union[Container, DerivedContainer]
@@ -1013,6 +1014,27 @@ def container_from_pytest_param(
     raise ValueError(f"Invalid pytest.param values: {param.values}")
 
 
+@dataclass(frozen=True)
+class ContainerRemoteEndpoint:
+    _container_id: str
+    _runtime: OciRuntimeBase
+
+    def __post_init__(self) -> None:
+        assert self._container_id, "Container ID must not be empty"
+
+    def check_output(self, cmd: str, strip: bool = True) -> str:
+        """Run a command in the container and return its output."""
+        return helpers.run_command(
+            [
+                self._runtime.runner_binary,
+                "exec",
+                self._container_id,
+                "/bin/sh",
+                "-c",
+                cmd,
+            ],
+        )[1]
+
 @dataclass
 class ContainerLauncher:
     """Helper context manager to setup, start and teardown a container including
@@ -1174,12 +1196,22 @@ def container_data(self) -> ContainerData:
         """
         if not self._container_id:
             raise RuntimeError(f"Container {self.container} has not started")
+        connection: Any = None
+        try:
+            import testinfra
+
+            connection = testinfra.get_host(
+                f"{self.container_runtime.runner_binary}://{self._container_id}"
+            )
+        except ImportError:
+            connection = ContainerRemoteEndpoint(
+                self._container_id, self.container_runtime
+            )
+
         return ContainerData(
             image_url_or_id=self.container.url or self.container.container_id,
             container_id=self._container_id,
-            connection=testinfra.get_host(
-                f"{self.container_runtime.runner_binary}://{self._container_id}"
-            ),
+            connection=connection,
             container=self.container,
             forwarded_ports=self._new_port_forwards,
             _container_runtime=self.container_runtime,

pytest_container/helpers.py

@@ -6,12 +6,14 @@
 
 import logging
 import os
+import subprocess
 from typing import List
 
 from _pytest.config import Config
 from _pytest.config.argparsing import Parser
 from _pytest.python import Metafunc
 
+from pytest_container.logging import _logger
 from pytest_container.logging import set_internal_logging_level
 
 
@@ -157,3 +159,26 @@ def get_always_pull_option() -> bool:
 
     """
     return bool(int(os.getenv("PULL_ALWAYS", "1")))
+
+
+def run_command(
+    cmd: List[str],
+    ignore_errors=True,
+):
+    try:
+        result = subprocess.run(
+            cmd,
+            capture_output=True,
+            text=True,
+            check=not ignore_errors,
+        )
+
+        _logger.debug(
+            f"RUN CMD: {cmd} RC: {result.returncode} STDOUT: {result.stdout} STDERR:{result.stderr}"
+        )
+        return result.returncode, result.stdout, result.stderr
+    except subprocess.CalledProcessError as exc:
+        _logger.debug(
+            f"RUN(Failed) CMD: {cmd} RC: {exc.returncode} STDOUT:{exc.stdout} STDERR:{exc.stderr}"
+        )
+        raise exc

pytest_container/runtime.py

@@ -6,6 +6,7 @@
 
 import json
 import re
+import shutil
 import sys
 from abc import ABC
 from abc import abstractmethod
@@ -20,10 +21,11 @@
 from typing import Optional
 from typing import Union
 
-import testinfra
+
 from _pytest.mark.structures import ParameterSet
 from pytest import param
 
+from pytest_container import helpers
 from pytest_container.inspect import BindMount
 from pytest_container.inspect import Config
 from pytest_container.inspect import ContainerHealth
@@ -411,9 +413,6 @@ def __str__(self) -> str:
         return self.__class__.__name__
 
 
-LOCALHOST = testinfra.host.get_host("local://")
-
-
 def _get_podman_version(version_stdout: str) -> Version:
     if version_stdout[:15] != "podman version ":
         raise RuntimeError(
@@ -424,7 +423,7 @@ def _get_podman_version(version_stdout: str) -> Version:
 
 
 def _get_buildah_version() -> Version:
-    version_stdout = LOCALHOST.check_output("buildah --version")
+    version_stdout = helpers.run_command(["buildah", "--version"])[1]
     build_version_begin = "buildah version "
     if not version_stdout.startswith(build_version_begin):
         raise RuntimeError(
@@ -443,11 +442,11 @@ class PodmanRuntime(OciRuntimeBase):
     """
 
     def __init__(self) -> None:
-        podman_ps = LOCALHOST.run("podman ps")
-        if not podman_ps.succeeded:
-            raise RuntimeError(f"`podman ps` failed with {podman_ps.stderr}")
+        podman_ps = helpers.run_command(["podman", "ps"])
+        if not podman_ps[0] == 0:
+            raise RuntimeError(f"`podman ps` failed with {podman_ps[2]}")
 
-        self._buildah_functional = LOCALHOST.run("buildah").succeeded
+        self._buildah_functional = helpers.run_command(["buildah"])[0] == 0
         super().__init__(
             build_command=(
                 ["buildah", "bud", "--layers", "--force-rm"]
@@ -461,8 +460,11 @@ def __init__(self) -> None:
     @cached_property
     def version(self) -> Version:
         """Returns the version of podman installed on the system"""
+
         return _get_podman_version(
-            LOCALHOST.run_expect([0], "podman --version").stdout
+            helpers.run_command(["podman", "--version"], ignore_errors=False)[
+                1
+            ]
         )
 
     @cached_property
@@ -539,9 +541,9 @@ class DockerRuntime(OciRuntimeBase):
     containers."""
 
     def __init__(self) -> None:
-        docker_ps = LOCALHOST.run("docker ps")
-        if not docker_ps.succeeded:
-            raise RuntimeError(f"`docker ps` failed with {docker_ps.stderr}")
+        docker_ps = helpers.run_command(["docker", "ps"])
+        if not docker_ps[0] == 0:
+            raise RuntimeError(f"`docker ps` failed with {docker_ps[2]}")
 
         super().__init__(
             build_command=["docker", "build", "--force-rm"],
@@ -552,7 +554,9 @@ def __init__(self) -> None:
     def version(self) -> Version:
         """Returns the version of docker installed on this system"""
         return _get_docker_version(
-            LOCALHOST.run_expect([0], "docker --version").stdout
+            helpers.run_command(["docker", "--version"], ignore_errors=False)[
+                1
+            ]
         )
 
     @property
@@ -613,8 +617,8 @@ def get_selected_runtime() -> OciRuntimeBase:
 
     If neither docker nor podman are available, then a ValueError is raised.
     """
-    podman_exists = LOCALHOST.exists("podman")
-    docker_exists = LOCALHOST.exists("docker")
+    podman_exists = shutil.which("podman")
+    docker_exists = shutil.which("docker")
 
     runtime_choice = getenv("CONTAINER_RUNTIME", "podman").lower()
     if runtime_choice not in ("podman", "docker"):

source/prerequisites.rst

@@ -1,7 +1,7 @@
 Prerequisites
 =============
 
-`pytest_container` works with Python 3.6 and later and requires `pytest
+`pytest_container` works with Python 3.6 and later and optionally requires `pytest
 <https://pytest.org/>`_ and `pytest-testinfra
 <https://testinfra.readthedocs.io/>`_. Additionally, for python 3.6, you'll need
 the `dataclasses <https://pypi.org/project/dataclasses/>`_ module.