Implement PCP metrics channel

Co-Authored-By: Allison Karlitskaya <allison.karlitskaya@redhat.com>
Co-Authored-By: Tomas Matus <tomatus777@gmail.com>

pyproject.toml

@@ -31,6 +31,10 @@ module = [
  "libvirt_qemu",
  "pika",
 
+ # run without pcp module types
+ "pcp",
+ "cpmapi",
+
  # run without gobject-introspection (used from cockpit-client for Gtk)
  "gi.*",
 
@@ -196,10 +200,13 @@ labels =
 sitepackages = True
 install_command = python3 -m pip install --no-index --no-build-isolation {opts} {packages}
 wheel_build_env = pkg
+setenv =
+ NO_QUNIT=1
 
 # All other environments (names like py311-lint, py36-pytest, etc) are isolated
 # from the system and get their packages from PyPI, according to the specific
 # test environment being requested. We build the wheel in a common environment.
+# Skip PCP as the PyPi package provides no wheel, requires compilation and is outdated (5.0)
 [testenv]
 package = wheel
 wheel_build_env = venv-pkg
@@ -216,6 +223,7 @@ deps =
 allowlist_externals = test/static-code
 setenv =
  NO_QUNIT=1
+ PYTEST_ADDOPTS=-k 'not pcp'
 commands =
  pytest: python3 -m pytest -opythonpath= {posargs}
  lint: test/static-code --tap

src/cockpit/channels/__init__.py

@@ -20,6 +20,7 @@
 from .http import HttpChannel
 from .metrics import InternalMetricsChannel
 from .packages import PackagesChannel
+from .pcp import PcpMetricsChannel
 from .stream import SocketStreamChannel, SubprocessStreamChannel
 from .trivial import EchoChannel, NullChannel
 
@@ -35,6 +36,7 @@
  InternalMetricsChannel,
  NullChannel,
  PackagesChannel,
+ PcpMetricsChannel,
  SubprocessStreamChannel,
  SocketStreamChannel,
 ]