MLIA-460 Revisit backend management

- Provide command for backend installation in case
  if backend is not available
- Fix issue with connection timeout during downloading
- Show installation tools output only in verbose mode

Change-Id: Ic0e495ba19879cc2cda4fd0bce20b57ba896cfeb

5 files changed, 56 insertions, 15 deletions

diff --git a/src/mlia/backend/errors.py b/src/mlia/backend/errors.py
new file mode 100644
index 0000000..bd5da95
--- /dev/null
+++ b/src/mlia/backend/errors.py
@@ -0,0 +1,12 @@
+# SPDX-FileCopyrightText: Copyright 2022, Arm Limited and/or its affiliates.
+# SPDX-License-Identifier: Apache-2.0
+"""Backend errors."""
+
+
+class BackendUnavailableError(Exception):
+    """Backend unavailable error."""
+
+    def __init__(self, msg: str, backend: str) -> None:
+        """Init error."""
+        super().__init__(msg)
+        self.backend = backend
diff --git a/src/mlia/backend/tosa_checker/compat.py b/src/mlia/backend/tosa_checker/compat.py
index e1bcb24..bd21774 100644
--- a/src/mlia/backend/tosa_checker/compat.py
+++ b/src/mlia/backend/tosa_checker/compat.py
@@ -8,6 +8,7 @@ from typing import Any
 from typing import cast
 from typing import Protocol
 
+from mlia.backend.errors import BackendUnavailableError
 from mlia.core.typing import PathOrFileLike
 
 
@@ -45,9 +46,8 @@ def get_tosa_compatibility_info(
     checker = get_tosa_checker(tflite_model_path)
 
     if checker is None:
-        raise Exception(
-            "TOSA checker is not available. "
-            "Please make sure that 'tosa-checker' backend is installed."
+        raise BackendUnavailableError(
+            "Backend tosa-checker is not available", "tosa-checker"
         )
 
     ops = [
diff --git a/src/mlia/cli/main.py b/src/mlia/cli/main.py
index 33a44e1..98fdb63 100644
--- a/src/mlia/cli/main.py
+++ b/src/mlia/cli/main.py
@@ -11,6 +11,7 @@ from inspect import signature
 from pathlib import Path
 
 from mlia import __version__
+from mlia.backend.errors import BackendUnavailableError
 from mlia.cli.commands import all_tests
 from mlia.cli.commands import backend_install
 from mlia.cli.commands import backend_list
@@ -225,6 +226,14 @@ def run_command(args: argparse.Namespace) -> int:
         logger.error("Internal error: %s", err)
     except ConfigurationError as err:
         logger.error(err)
+    except BackendUnavailableError as err:
+        logger.error("Error: Backend %s is not available.", err.backend)
+        # apart from tosa-checker all other backends are currently optional
+        if err.backend in ("tosa-checker",):
+            logger.error(
+                'Please use next command to install it: mlia-backend install "%s"',
+                err.backend,
+            )
     except Exception as err:  # pylint: disable=broad-except
         logger.error(
             "\nExecution finished with error: %s",
diff --git a/src/mlia/utils/download.py b/src/mlia/utils/download.py
index c8d0b69..e00be28 100644
--- a/src/mlia/utils/download.py
+++ b/src/mlia/utils/download.py
@@ -46,9 +46,10 @@ def download(
     show_progress: bool = False,
     label: str | None = None,
     chunk_size: int = 8192,
+    timeout: int = 30,
 ) -> None:
     """Download the file."""
-    with requests.get(url, stream=True, timeout=10.0) as resp:
+    with requests.get(url, stream=True, timeout=timeout) as resp:
         resp.raise_for_status()
         content_chunks = resp.iter_content(chunk_size=chunk_size)
 
diff --git a/src/mlia/utils/py_manager.py b/src/mlia/utils/py_manager.py
index 5f98fcc..d7821d3 100644
--- a/src/mlia/utils/py_manager.py
+++ b/src/mlia/utils/py_manager.py
@@ -3,10 +3,16 @@
 """Util functions for managing python packages."""
 from __future__ import annotations
 
+import logging
+import subprocess  # nosec
 import sys
 from importlib.metadata import distribution
 from importlib.metadata import PackageNotFoundError
-from subprocess import check_call  # nosec
+
+from mlia.core.errors import InternalError
+
+
+logger = logging.getLogger(__name__)
 
 
 class PyPackageManager:
@@ -45,16 +51,29 @@ class PyPackageManager:
         """Execute pip command."""
         assert sys.executable, "Unable to launch pip command"
 
-        check_call(
-            [
-                sys.executable,
-                "-m",
-                "pip",
-                "--disable-pip-version-check",
-                subcommand,
-                *params,
-            ]
-        )
+        try:
+            output = subprocess.check_output(  # nosec
+                [
+                    sys.executable,
+                    "-m",
+                    "pip",
+                    "--disable-pip-version-check",
+                    subcommand,
+                    *params,
+                ],
+                stderr=subprocess.STDOUT,
+                text=True,
+            )
+            returncode = 0
+        except subprocess.CalledProcessError as err:
+            output = err.output
+            returncode = err.returncode
+
+        for line in output.splitlines():
+            logger.debug(line.rstrip())
+
+        if returncode != 0:
+            raise InternalError("Unable to install python package")
 
 
 def get_package_manager() -> PyPackageManager: