Update the tests (#4427)

* unpin the requirements and update all to latest available - needs more work still. see notes in `def host()`

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

* fix py3 monkey patch of testinfra docker using bash

Signed-off-by: Adam Hill <adam@diginc.us>

* update the other test files to use `host` instead of `Pihole`
Address some sticklr and codefactor
update python version from 3.7 to 3.8
preload `git` onto the centos/fedora test images, and switch which with command -v in the passthrough mock
testinfra is deprecated, use pytest-testinfra

Signed-off-by: Adam Warner <me@adamwarner.co.uk>

Co-authored-by: Adam Hill <adam@diginc.us>

test/conftest.py

@@ -1,10 +1,9 @@
 import pytest
 import testinfra
+import testinfra.backend.docker
+import subprocess
 from textwrap import dedent
 
-check_output = testinfra.get_backend(
-    "local://"
-).get_module("Command").check_output
 
 SETUPVARS = {
     'PIHOLE_INTERFACE': 'eth99',
@@ -12,85 +11,42 @@ SETUPVARS = {
     'PIHOLE_DNS_2': '4.2.2.2'
 }
 
+IMAGE = 'pytest_pihole:test_container'
+
 tick_box = "[\x1b[1;32m\u2713\x1b[0m]"
 cross_box = "[\x1b[1;31m\u2717\x1b[0m]"
 info_box = "[i]"
 
 
-@pytest.fixture
-def Pihole(Docker):
-    '''
-    used to contain some script stubbing, now pretty much an alias.
-    Also provides bash as the default run function shell
-    '''
-    def run_bash(self, command, *args, **kwargs):
-        cmd = self.get_command(command, *args)
-        if self.user is not None:
-            out = self.run_local(
-                "docker exec -u %s %s /bin/bash -c %s",
-                self.user, self.name, cmd)
-        else:
-            out = self.run_local(
-                "docker exec %s /bin/bash -c %s", self.name, cmd)
-        out.command = self.encode(cmd)
-        return out
+# Monkeypatch sh to bash, if they ever support non hard code /bin/sh this can go away
+# https://github.com/pytest-dev/pytest-testinfra/blob/master/testinfra/backend/docker.py
+def run_bash(self, command, *args, **kwargs):
+    cmd = self.get_command(command, *args)
+    if self.user is not None:
+        out = self.run_local(
+            "docker exec -u %s %s /bin/bash -c %s", self.user, self.name, cmd
+        )
+    else:
+        out = self.run_local("docker exec %s /bin/bash -c %s", self.name, cmd)
+    out.command = self.encode(cmd)
+    return out
 
-    funcType = type(Docker.run)
-    Docker.run = funcType(run_bash, Docker)
-    return Docker
+
+testinfra.backend.docker.DockerBackend.run = run_bash
 
 
 @pytest.fixture
-def Docker(request, args, image, cmd):
-    '''
-    combine our fixtures into a docker run command and setup finalizer to
-    cleanup
-    '''
-    assert 'docker' in check_output('id'), "Are you in the docker group?"
-    docker_run = "docker run {} {} {}".format(args, image, cmd)
-    docker_id = check_output(docker_run)
+def host():
+    # run a container
+    docker_id = subprocess.check_output(
+        ['docker', 'run', '-t', '-d', '--cap-add=ALL', IMAGE]).decode().strip()
 
-    def teardown():
-        check_output("docker rm -f %s", docker_id)
-    request.addfinalizer(teardown)
+    # return a testinfra connection to the container
+    docker_host = testinfra.get_host("docker://" + docker_id)
 
-    docker_container = testinfra.get_backend("docker://" + docker_id)
-    docker_container.id = docker_id
-    return docker_container
-
-
-@pytest.fixture
-def args(request):
-    '''
-    -t became required when tput began being used
-    '''
-    return '-t -d --cap-add=ALL'
-
-
-@pytest.fixture(params=[
-    'test_container'
-])
-def tag(request):
-    '''
-    consumed by image to make the test matrix
-    '''
-    return request.param
-
-
-@pytest.fixture()
-def image(request, tag):
-    '''
-    built by test_000_build_containers.py
-    '''
-    return 'pytest_pihole:{}'.format(tag)
-
-
-@pytest.fixture()
-def cmd(request):
-    '''
-    default to doing nothing by tailing null, but don't exit
-    '''
-    return 'tail -f /dev/null'
+    yield docker_host
+    # at the end of the test suite, destroy the container
+    subprocess.check_call(['docker', 'rm', '-f', docker_id])
 
 
 # Helper functions
@@ -129,7 +85,7 @@ def mock_command_passthrough(script, args, container):
 
     Example use-case: mocking `git pull` but still allowing `git clone` to work as intended
     '''
-    orig_script_path = check_output('which {}'.format(script))
+    orig_script_path = container.check_output('command -v {}'.format(script))
     full_script_path = '/usr/local/bin/{}'.format(script)
     mock_script = dedent(r'''\
     #!/bin/bash -e
@@ -209,6 +165,7 @@ def mock_command_2(script, args, container):
                                          content=mock_script,
                                          scriptlog=script))
 
+
 def run_script(Pihole, script):
     result = Pihole.run(script)
     assert result.rc == 0