T3356: Add progressbars to FTP transfers

Allow ports to be specified in URL strings

1 files changed, 133 insertions, 60 deletions

diff --git a/python/vyos/remote.py b/python/vyos/remote.py
index 7d371b3c0..6c98f3219 100644
--- a/python/vyos/remote.py
+++ b/python/vyos/remote.py
@@ -14,6 +14,7 @@
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 from ftplib import FTP
+import math
 import os
 import shutil
 import socket
@@ -29,77 +30,141 @@ from paramiko import SSHClient, SSHException, MissingHostKeyPolicy
 
 known_hosts_file = os.path.expanduser('~/.ssh/known_hosts')
 
-def print_error(str):
+class InteractivePolicy(MissingHostKeyPolicy):
+    """
+    Policy for interactively querying the user on whether to proceed with
+     SSH connections to unknown hosts.
+    """
+    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 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)
+                client.save_host_keys(client._host_keys_filename)
+        else:
+            raise SSHException(f"Cannot connect to unknown host '{hostname}'.")
+
+
+## Helper routines
+def print_error(str='', end='\n'):
     """
+    Print `str` to stderr, terminated with `end`.
     Used for warnings and out-of-band messages to avoid mangling precious
-    stdout output.
+     stdout output.
     """
     sys.stderr.write(str)
-    sys.stderr.write('\n')
+    sys.stderr.write(end)
     sys.stderr.flush()
 
+def make_progressbar(increment: float):
+    """
+    Return a generator that displays progressbar whose length is determined
+     by the width of the terminal with every iteration.
+    First call displays it at 0% and every subsequent iteration displays it
+     at `increment` increments where 0.0 < `increment` < 1.0
+    """
+    col, _ = shutil.get_terminal_size()
+    # Try for 20 columns if the terminal is too narrow. Let it overflow.
+    col = max(col - 15, 20)
+    total = 0.0
+    while True:
+        length = min(round(total * col), col)
+        percentage = str(math.floor(total * 100)).rjust(3)
+        print_error(f'[{length * "#"}{(col - length) * "_"}] {percentage}%', '\r')
+        if total >= 1.0:
+            # Print a newline so that the subsequent prints don't overwrite the bar.
+            print_error()
+            break
+        # Add a new increment with each iteration.
+        yield
+        total = min(total + increment, 1.0)
+    # Ignore further calls.
+    while True:
+        yield
+
 def get_authentication_variables(default_username=None, default_password=None):
     """
-    Returns the environment variables `$REMOTE_USERNAME` and `$REMOTE_PASSWORD` and
-    returns the defaults provided if environment variables are empty or nonexistent.
+    Return the environment variables `$REMOTE_USERNAME` and `$REMOTE_PASSWORD` and
+     return the defaults provided if environment variables are empty or nonexistent.
     """
     username, password = os.getenv('REMOTE_USERNAME'), os.getenv('REMOTE_PASSWORD')
     # Fall back to defaults if the username variable doesn't exist or is an empty string.
+    # Note that this is different from `os.getenv('REMOTE_USERNAME', default=default_username)`,
+    #  as we want the username and the password to have the same behaviour.
     if not username:
         return (default_username, default_password)
     else:
         return (username, password)
 
-class InteractivePolicy(MissingHostKeyPolicy):
+def get_port_from_url(url):
     """
-    Policy for interactively querying the user on whether to proceed with
-    SSH connections to unknown hosts.
+    Return the port number from the given `url` named tuple, fall back to
+     the default if there isn't one.
     """
-    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 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)
-                client.save_host_keys(client._host_keys_filename)
-        else:
-            raise SSHException(f"Cannot connect to unknown host '{hostname}'.")
+    defaults = {"http": 80, "https": 443, "ftp": 21, "tftp": 69,\
+                "ssh": 22, "scp": 22, "sftp": 22}
+    if url.port:
+        return url.port
+    else:
+        return defaults[url.scheme]
 
 
 ## FTP routines
-def transfer_ftp(mode, local_path, hostname, remote_path,\
-                 username='anonymous', password='', port=21, source=None):
+def upload_ftp(local_path, hostname, remote_path,\
+               username='anonymous', password='', port=21,\
+               source=None, progressbar=False):
+    size = os.path.getsize(local_path)
+    blocksize = 8192
     with FTP(source_address=source) as conn:
         conn.connect(hostname, port)
         conn.login(username, password)
-        if mode == 'upload':
-            with open(local_path, 'rb') as file:
-                conn.storbinary(f'STOR {remote_path}', file)
-        elif mode == 'download':
-            with open(local_path, 'wb') as file:
-                conn.retrbinary(f'RETR {remote_path}', file.write)
-        elif mode == 'size':
-            size = conn.size(remote_path)
-            if size:
-                return size
+        with open(local_path, 'rb') as file:
+            if progressbar and size:
+                progress = make_progressbar(blocksize / size)
+                next(progress)
+                callback = lambda block: next(progress)
             else:
-                # SIZE is an extension to the FTP specification, although it's extremely common.
-                raise ValueError('Failed to receive file size from FTP server. \
-                Perhaps the server does not implement the SIZE command?')
+                callback = None
+            conn.storbinary(f'STOR {remote_path}', file, blocksize, callback)
 
-def upload_ftp(*args, **kwargs):
-    transfer_ftp('upload', *args, **kwargs)
-
-def download_ftp(*args, **kwargs):
-    transfer_ftp('download', *args, **kwargs)
+def download_ftp(local_path, hostname, remote_path,\
+                 username='anonymous', password='', port=21,\
+                 source=None, progressbar=False):
+    blocksize = 8192
+    with FTP(source_address=source) as conn:
+        conn.connect(hostname, port)
+        conn.login(username, password)
+        size = conn.size(remote_path)
+        with open(local_path, 'wb') as file:
+            # No progressbar if we can't determine the size.
+            if progressbar and size:
+                progress = make_progressbar(blocksize / size)
+                next(progress)
+                callback = lambda block: (file.write(block), next(progress))
+            else:
+                callback = file.write
+            conn.retrbinary(f'RETR {remote_path}', callback, blocksize)
 
-def get_ftp_file_size(*args, **kwargs):
-    return transfer_ftp('size', None, *args, **kwargs)
+def get_ftp_file_size(hostname, remote_path,\
+                      username='anonymous', password='', port=21,\
+                      source=None):
+    with FTP(source_address=source) as conn:
+        conn.connect(hostname, port)
+        conn.login(username, password)
+        size = conn.size(remote_path)
+        if size:
+            return size
+        else:
+            # SIZE is an extension to the FTP specification, although it's extremely common.
+            raise ValueError('Failed to receive file size from FTP server. \
+            Perhaps the server does not implement the SIZE command?')
 
 
 ## SFTP/SCP routines
 def transfer_sftp(mode, local_path, hostname, remote_path,\
-                  username=None, password=None, port=22, source=None):
+                  username=None, password=None, port=22,\
+                  source=None, progressbar=False):
     sock = None
     if source:
         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -135,27 +200,29 @@ def get_sftp_file_size(*args, **kwargs):
 
 
 ## TFTP routines
-def upload_tftp(local_path, hostname, remote_path, port=69, source=None):
+def upload_tftp(local_path, hostname, remote_path, port=69, source=None, progressbar=False):
     source_option = f'--interface {source}' if source else ''
+    progress_flag = '--progress-bar' if progressbar else '-s'
     with open(local_path, 'rb') as file:
-        cmd(f'curl {source_option} -s -T - tftp://{hostname}:{port}/{remote_path}',\
+        cmd(f'curl {source_option} {progress_flag} -T - tftp://{hostname}:{port}/{remote_path}',\
             stderr=None, input=file.read()).encode()
 
-def download_tftp(local_path, hostname, remote_path, port=69, source=None):
+def download_tftp(local_path, hostname, remote_path, port=69, source=None, progressbar=False):
     source_option = f'--interface {source}' if source else ''
+    progress_flag = '--progress-bar' if progressbar else '-s'
     with open(local_path, 'wb') as file:
-        file.write(cmd(f'curl {source_option} -s tftp://{hostname}:{port}/{remote_path}',\
+        file.write(cmd(f'curl {source_option} {progress_flag} tftp://{hostname}:{port}/{remote_path}',\
                        stderr=None).encode())
 
 # get_tftp_file_size() is unimplemented because there is no way to obtain a file's size through TFTP,
-# as TFTP does not specify a SIZE command.
+#  as TFTP does not specify a SIZE command.
 
 
 ## HTTP(S) routines
 def install_request_opener(urlstring, username, password):
     """
-    Take`username` and `password` strings and install the appropriate
-    password manager to `urllib.request.urlopen()` for the given `urlstring`.
+    Take `username` and `password` strings and install the appropriate
+     password manager to `urllib.request.urlopen()` for the given `urlstring`.
     """
     manager = urlreq.HTTPPasswordMgrWithDefaultRealm()
     manager.add_password(None, urlstring, username, password)
@@ -163,7 +230,7 @@ def install_request_opener(urlstring, username, password):
 
 # upload_http() is unimplemented.
 
-def download_http(urlstring, local_path, username=None, password=None):
+def download_http(urlstring, local_path, username=None, password=None, progressbar=False):
     """
     Download the file from from `urlstring` to `local_path`.
     Optionally takes `username` and `password` for authentication.
@@ -193,7 +260,7 @@ def get_http_file_size(urlstring, username=None, password=None):
 
 
 # Dynamic dispatchers
-def download(local_path, urlstring, source=None):
+def download(local_path, urlstring, source=None, progressbar=False):
     """
     Dispatch the appropriate download function for the given `urlstring` and save to `local_path`.
     Optionally takes a `source` address (not valid for HTTP(S)).
@@ -202,6 +269,7 @@ def download(local_path, urlstring, source=None):
     """
     url = urllib.parse.urlparse(urlstring)
     username, password = get_authentication_variables(url.username, url.password)
+    port = get_port_from_url(url)
 
     if url.scheme == 'http' or url.scheme == 'https':
         if source:
@@ -209,15 +277,15 @@ def download(local_path, urlstring, source=None):
         download_http(urlstring, local_path, username, password)
     elif url.scheme == 'ftp':
         username = username if username else 'anonymous'
-        download_ftp(local_path, url.hostname, url.path, username, password, source=source)
+        download_ftp(local_path, url.hostname, url.path, username, password, port, source, progressbar)
     elif url.scheme == 'sftp' or url.scheme == 'scp':
-        download_sftp(local_path, url.hostname, url.path, username, password, source=source)
+        download_sftp(local_path, url.hostname, url.path, username, password, port, source, progressbar)
     elif url.scheme == 'tftp':
-        download_tftp(local_path, url.hostname, url.path, source=source)
+        download_tftp(local_path, url.hostname, url.path, port, source, progressbar)
     else:
         raise ValueError(f'Unsupported URL scheme: {url.scheme}')
 
-def upload(local_path, urlstring, source=None):
+def upload(local_path, urlstring, source=None, progressbar=False):
     """
     Dispatch the appropriate upload function for the given URL and upload from local path.
     Optionally takes a `source` address.
@@ -226,14 +294,15 @@ def upload(local_path, urlstring, source=None):
     """
     url = urllib.parse.urlparse(urlstring)
     username, password = get_authentication_variables(url.username, url.password)
+    port = get_port_from_url(url)
 
     if url.scheme == 'ftp':
         username = username if username else 'anonymous'
-        upload_ftp(local_path, url.hostname, url.path, username, password, source=source)
+        upload_ftp(local_path, url.hostname, url.path, username, password, port, source, progressbar)
     elif url.scheme == 'sftp' or url.scheme == 'scp':
-        upload_sftp(local_path, url.hostname, url.path, username, password, source=source)
+        upload_sftp(local_path, url.hostname, url.path, username, password, port, source, progressbar)
     elif url.scheme == 'tftp':
-        upload_tftp(local_path, url.hostname, url.path, source=source)
+        upload_tftp(local_path, url.hostname, url.path, port, source, progressbar)
     else:
         raise ValueError(f'Unsupported URL scheme: {url.scheme}')
 
@@ -247,14 +316,15 @@ def get_remote_file_size(urlstring, source=None):
     """
     url = urllib.parse.urlparse(urlstring)
     username, password = get_authentication_variables(url.username, url.password)
+    port = get_port_from_url(url)
 
     if url.scheme == 'http' or url.scheme == 'https':
         return get_http_file_size(urlstring, username, password)
     elif url.scheme == 'ftp':
         username = username if username else 'anonymous'
-        return get_ftp_file_size(url.hostname, url.path, username, password, source=source)
+        return get_ftp_file_size(url.hostname, url.path, username, password, port, source)
     elif url.scheme == 'sftp' or url.scheme == 'scp':
-        return get_sftp_file_size(url.hostname, url.path, username, password, source=source)
+        return get_sftp_file_size(url.hostname, url.path, username, password, port, source)
     else:
         raise ValueError(f'Unsupported URL scheme: {url.scheme}')
 
@@ -284,6 +354,8 @@ def get_remote_config(urlstring, source=None):
 
 def friendly_download(local_path, urlstring, source=None):
     """
+    Download from `urlstring` to `local_path` in an informative way.
+    Checks the storage space before attempting download.
     Intended to be called from interactive, user-facing scripts.
     """
     destination_directory = os.path.dirname(local_path)
@@ -298,11 +370,12 @@ def friendly_download(local_path, urlstring, source=None):
             if file_size > free_space:
                 raise OSError(f'Not enough disk space available in "{destination_directory}".')
         except ValueError:
+            # Can't do a storage check in this case, so we bravely continue.
+            file_size = 0
             print_error('Could not determine the file size in advance.')
         else:
-            # TODO: Progress bar
             print_error('Downloading...')
-            download(local_path, urlstring, source)
+            download(local_path, urlstring, source, progressbar=file_size > 1024 * 1024)
     except KeyboardInterrupt:
         print_error('Download aborted by user.')
         sys.exit(1)