remote: T5726: Disable the progressbar if the shell is noninteractive or the terminal is missing capabilities

3 files changed, 45 insertions, 41 deletions

diff --git a/python/vyos/progressbar.py b/python/vyos/progressbar.py
index 1793c445b..7bc9d9856 100644
--- a/python/vyos/progressbar.py
+++ b/python/vyos/progressbar.py
@@ -19,26 +19,35 @@ import signal
 import subprocess
 import sys
 
+from vyos.utils.io import is_dumb_terminal
 from vyos.utils.io import print_error
 
+
 class Progressbar:
     def __init__(self, step=None):
         self.total = 0.0
         self.step = step
+        # Silently ignore all calls if terminal capabilities are lacking.
+        # This will also prevent the output from littering Ansible logs,
+        # as `ansible.netcommon.network_cli' coaxes the terminal into believing
+        # it is interactive.
+        self._dumb = is_dumb_terminal()
     def __enter__(self):
-        # Recalculate terminal width with every window resize.
-        signal.signal(signal.SIGWINCH, lambda signum, frame: self._update_cols())
-        # Disable line wrapping to prevent the staircase effect.
-        subprocess.run(['tput', 'rmam'], check=False)
-        self._update_cols()
-        # Print an empty progressbar with entry.
-        self.progress(0, 1)
+        if not self._dumb:
+            # Recalculate terminal width with every window resize.
+            signal.signal(signal.SIGWINCH, lambda signum, frame: self._update_cols())
+            # Disable line wrapping to prevent the staircase effect.
+            subprocess.run(['tput', 'rmam'], check=False)
+            self._update_cols()
+            # Print an empty progressbar with entry.
+            self.progress(0, 1)
         return self
     def __exit__(self, exc_type, kexc_val, exc_tb):
-        # Revert to the default SIGWINCH handler (ie nothing).
-        signal.signal(signal.SIGWINCH, signal.SIG_DFL)
-        # Reenable line wrapping.
-        subprocess.run(['tput', 'smam'], check=False)
+        if not self._dumb:
+            # Revert to the default SIGWINCH handler (ie nothing).
+            signal.signal(signal.SIGWINCH, signal.SIG_DFL)
+            # Reenable line wrapping.
+            subprocess.run(['tput', 'smam'], check=False)
     def _update_cols(self):
         # `os.get_terminal_size()' is fast enough for our purposes.
         self.col = max(os.get_terminal_size().columns - 15, 20)
@@ -60,7 +69,7 @@ class Progressbar:
         Stateless progressbar taking no input at init and current progress with
         final size at callback (for SSH)
         """
-        if done <= total:
+        if done <= total and not self._dumb:
             length = math.ceil(self.col * done / total)
             percentage = str(math.ceil(100 * done / total)).rjust(3)
             # Carriage return at the end will make sure the line will get overwritten.
diff --git a/python/vyos/remote.py b/python/vyos/remote.py
index 1ca8a9530..4be477d24 100644
--- a/python/vyos/remote.py
+++ b/python/vyos/remote.py
@@ -34,6 +34,7 @@ from requests.packages.urllib3 import PoolManager
 
 from vyos.progressbar import Progressbar
 from vyos.utils.io import ask_yes_no
+from vyos.utils.io import is_interactive
 from vyos.utils.io import print_error
 from vyos.utils.misc import begin
 from vyos.utils.process import cmd
@@ -49,7 +50,7 @@ class InteractivePolicy(MissingHostKeyPolicy):
     def missing_host_key(self, client, hostname, key):
         print_error(f"Host '{hostname}' not found in known hosts.")
         print_error('Fingerprint: ' + key.get_fingerprint().hex())
-        if sys.stdout.isatty() and ask_yes_no('Do you wish to continue?'):
+        if is_interactive() and ask_yes_no('Do you wish to continue?'):
             if client._host_keys_filename\
                and ask_yes_no('Do you wish to permanently add this host/key pair to known hosts?'):
                 client._host_keys.add(hostname, key.get_name(), key)
@@ -250,7 +251,6 @@ class HttpC:
                         allow_redirects=True,
                         timeout=self.timeout) as r:
                 # Abort early if the destination is inaccessible.
-                print('pre-3')
                 r.raise_for_status()
                 # If the request got redirected, keep the last URL we ended up with.
                 final_urlstring = r.url
@@ -323,17 +323,25 @@ def urlc(urlstring, *args, **kwargs):
     except KeyError:
         raise ValueError(f'Unsupported URL scheme: "{url.scheme}"')
 
-def download(local_path, urlstring, *args, **kwargs):
+def download(local_path, urlstring, progressbar=False, check_space=False,
+             source_host='', source_port=0, timeout=10.0):
     try:
-        urlc(urlstring, *args, **kwargs).download(local_path)
+        progressbar = progressbar and is_interactive()
+        urlc(urlstring, progressbar, check_space, source_host, source_port, timeout).download(local_path)
     except Exception as err:
         print_error(f'Unable to download "{urlstring}": {err}')
+    except KeyboardInterrupt:
+        print_error('\nDownload aborted by user.')
 
-def upload(local_path, urlstring, *args, **kwargs):
+def upload(local_path, urlstring, progressbar=False,
+           source_host='', source_port=0, timeout=10.0):
     try:
-        urlc(urlstring, *args, **kwargs).upload(local_path)
+        progressbar = progressbar and is_interactive()
+        urlc(urlstring, progressbar, source_host, source_port, timeout).upload(local_path)
     except Exception as err:
         print_error(f'Unable to upload "{urlstring}": {err}')
+    except KeyboardInterrupt:
+        print_error('\nUpload aborted by user.')
 
 def get_remote_config(urlstring, source_host='', source_port=0):
     """
@@ -346,26 +354,3 @@ def get_remote_config(urlstring, source_host='', source_port=0):
             return f.read()
     finally:
         os.remove(temp)
-
-def friendly_download(local_path, urlstring, source_host='', source_port=0):
-    """
-    Download with a progress bar, reassuring messages and free space checks.
-    """
-    try:
-        print_error('Downloading...')
-        download(local_path, urlstring, True, True, source_host, source_port)
-    except KeyboardInterrupt:
-        print_error('\nDownload aborted by user.')
-        sys.exit(1)
-    except:
-        import traceback
-        print_error(f'Failed to download {urlstring}.')
-        # There are a myriad different reasons a download could fail.
-        # SSH errors, FTP errors, I/O errors, HTTP errors (403, 404...)
-        # We omit the scary stack trace but print the error nevertheless.
-        exc_type, exc_value, exc_traceback = sys.exc_info()
-        traceback.print_exception(exc_type, exc_value, None, 0, None, False)
-        sys.exit(1)
-    else:
-        print_error('Download complete.')
-        sys.exit(0)
diff --git a/python/vyos/utils/io.py b/python/vyos/utils/io.py
index 5fffa62f8..8790cbaac 100644
--- a/python/vyos/utils/io.py
+++ b/python/vyos/utils/io.py
@@ -62,3 +62,13 @@ def ask_yes_no(question, default=False) -> bool:
                 stdout.write("Please respond with yes/y or no/n\n")
         except EOFError:
             stdout.write("\nPlease respond with yes/y or no/n\n")
+
+def is_interactive():
+    """Try to determine if the routine was called from an interactive shell."""
+    import os, sys
+    return os.getenv('TERM', default=False) and sys.stderr.isatty() and sys.stdout.isatty()
+
+def is_dumb_terminal():
+    """Check if the current TTY is dumb, so that we can disable advanced terminal features."""
+    import os
+    return os.getenv('TERM') in ['vt100', 'dumb']