installation: Do not use virtualenv tool

The 'virtualenv' tool does not seem to be available in RHEL 9, but
'python3 -m venv' works there.

Switch installation to use 'python3 -m venv' for all distros, it should work
everywhere.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

Author: dedekind

CHANGELOG.md

@@ -5,6 +5,7 @@ Versioning practices: [Semantic Versioning](https://semver.org/spec/v2.0.0.html)
 
 ## [ADD NEW VERSION HERE] - ADD DATE HERE
 ### Fixed
+ - Fix installation on RHEL.
 ### Added
 ### Removed
 ### Changed

docs/guide-install.md

@@ -152,18 +152,19 @@ your system.
 
 **Tools needed for installation:**
 
-- `pip3` and `virtualenv`: required for `pip`-based installation
-   (see [Installation Using pip](#installation-using-pip)).
-- `uv`: an alternative to `pip3` + `virtualenv` (see [Using uv](#using-uv)). Install one or the other.
+- `pip3` and `python3 -m venv`: required for `pip`-based installation
+  (see [Installation Using pip](#installation-using-pip)). On Ubuntu/Debian, `python3 -m venv`
+  requires the `python3-venv` package; the installer will install it automatically if missing.
+- `uv`: an alternative to `pip3` + `python3 -m venv` (see [Using uv](#using-uv)). Install one or the other.
 - `rsync`: used to copy sources to a temporary directory during installation from a local path.
 
 The commands below install the `pip3`-based tools. If you prefer `uv`, install it instead and skip
-`python3-pip` and `python3-virtualenv`.
+`python3-pip`.
 
-**Fedora / CentOS**
+**Fedora / RHEL / CentOS**
 
 ```bash
-sudo dnf install -y util-linux kmod python3-pip python3-virtualenv rsync
+sudo dnf install -y util-linux kmod python3-pip rsync
 ```
 
 **Ubuntu**

pepclibs/helperlibs/ToolChecker.py

@@ -55,7 +55,7 @@
     "xargs":     "findutils",
 }
 
-# CentOS, Fedora, RHEL.
+# Fedora.
 _FEDORA_PKGINFO: Final[dict[str, str]] = {
     **_COMMON_PKGINFO,
     "tc":         "iproute-tc",
@@ -69,6 +69,19 @@
     "virtualenv": "python3-virtualenv",
 }
 
+# CentOS, RHEL.
+_RHEL_PKGINFO: Final[dict[str, str]] = {
+    **_COMMON_PKGINFO,
+    "tc":         "iproute-tc",
+    "bpftool":    "bpftool",
+    "libbpf":     "libbpf-devel",
+    "kill":       "util-linux",
+    "pgrep":      "procps-ng",
+    "pkill":      "procps-ng",
+    "ps":         "procps-ng",
+    "sch_etf.ko": "kernel-modules-extra",
+}
+
 # Ubuntu.
 _UBUNTU_PKGINFO: Final[dict[str, str]] = {
     **_COMMON_PKGINFO,
@@ -102,8 +115,8 @@
 #
 _PKGINFO: Final[dict[str, dict[str, str]]] = {
     "fedora": _FEDORA_PKGINFO,
-    "centos": _FEDORA_PKGINFO,
-    "rhel":   _FEDORA_PKGINFO,
+    "centos": _RHEL_PKGINFO,
+    "rhel":   _RHEL_PKGINFO,
     "ubuntu": _UBUNTU_PKGINFO,
     "debian": _DEBIAN_PKGINFO,
 }

pepctools/InstallPepc.py

@@ -69,7 +69,6 @@ class _CmdlineArgsTypedDict(SSHArgsTypedDict, total=False):
 
 # The tools pepc relies on to be installed and to operate.
 PEPC_DEPENDENCIES: Final[tuple[str, ...]] = (
-    "virtualenv",
     "pip3",
     "cat",
     "dmesg",

pepctools/PythonPrjInstaller.py

@@ -173,6 +173,15 @@ def install_dependencies(self, dependencies: Sequence[str]):
 
         with ToolChecker.ToolChecker(self._pman) as tchk:
             tchk.ensure_tools_available(tuple(tools))
+            # Verify that 'python3 -m venv' works. On Ubuntu/Debian it requires the 'python3-venv'
+            # OS package and is not available by default. Install it if the test fails.
+            venv_test_dir = self._pman.mkdtemp(prefix=f"{self._prjname}-venv-test-")
+            try:
+                _, _, exitcode = self._pman.run(f"python3 -m venv '{venv_test_dir}/testvenv'")
+            finally:
+                self._pman.rmtree(venv_test_dir)
+            if exitcode != 0:
+                tchk.ensure_tools_available(("virtualenv",))
 
     def _run_installation(self, src_path: Path | None):
         """