viewvc-install

#!/usr/bin/env python3
# -*-python-*-
#
# Copyright (C) 1999-2020 The ViewCVS Group. All Rights Reserved.
#
# By using this file, you agree to the terms and conditions set forth in
# the LICENSE.html file which can be found at the top level of the ViewVC
# distribution or at http://viewvc.org/license-1.html.
#
# For more information, visit http://viewvc.org/
#
# -----------------------------------------------------------------------
#
# Install script for ViewVC
#
# -----------------------------------------------------------------------


import os
import sys
import re
import traceback
import py_compile
import getopt
import io

try:
    PathLike = os.PathLike
except AttributeError:
    class PathLike(object):
        pass

# Get access to our library modules.
sys.path.insert(0, os.path.join(os.path.dirname(sys.argv[0]), 'lib'))

import viewvc
import difflib
version = viewvc.__version__


## Installer defaults.
DESTDIR = None
ROOT_DIR = None
CLEAN_MODE = None


## List of files for installation.
##    tuple (source path,
##           destination path,
##           mode,
##           boolean -- search-and-replace?
##           boolean -- prompt before replacing?
##           boolean -- compile?)
FILE_INFO_LIST = [
    ("bin/cgi/viewvc.cgi",        "bin/cgi/viewvc.cgi",        0o0755, 1, 0, 0),
    ("bin/wsgi/viewvc.wsgi",      "bin/wsgi/viewvc.wsgi",      0o0755, 1, 0, 0),
    ("bin/wsgi/viewvc.fcgi",      "bin/wsgi/viewvc.fcgi",      0o0755, 1, 0, 0),
    ("bin/standalone.py",         "bin/standalone.py",         0o0755, 1, 0, 0),
    ("bin/loginfo-handler",       "bin/loginfo-handler",       0o0755, 1, 0, 0),
    ("bin/cvsdbadmin",            "bin/cvsdbadmin",            0o0755, 1, 0, 0),
    ("bin/svndbadmin",            "bin/svndbadmin",            0o0755, 1, 0, 0),
    ("bin/make-database",         "bin/make-database",         0o0755, 1, 0, 0),
    ("conf/viewvc.conf.dist",     "viewvc.conf.dist",          0o0644, 0, 0, 0),
    ("conf/viewvc.conf.dist",     "viewvc.conf",               0o0644, 0, 1, 0),
    ("conf/cvsgraph.conf.dist",   "cvsgraph.conf.dist",        0o0644, 0, 0, 0),
    ("conf/cvsgraph.conf.dist",   "cvsgraph.conf",             0o0644, 0, 1, 0),
    ("conf/mimetypes.conf.dist",  "mimetypes.conf.dist",       0o0644, 0, 0, 0),
    ("conf/mimetypes.conf.dist",  "mimetypes.conf",            0o0644, 0, 1, 0),
    ]


## List of directories for installation.
##    type (source path,
##          destination path,
##          boolean -- optional item?,
##          boolean -- prompt before replacing?)
TREE_LIST = [
    ("lib",                       "lib",                       0, 0),
    ("templates",                 "templates",                 0, 1),
    ]


## List of file extensions we can't show diffs for.
BINARY_FILE_EXTS = [
    '.png',
    '.gif',
    '.jpg',
    ]


def _escape(str):
    """Callback function for re.sub().

    re.escape() is no good because it blindly puts backslashes in
    front of anything that is not a number or letter regardless of
    whether the resulting sequence will be interpreted."""
    # Python 3: This is used only for bytes
    return str.replace(b"\\", b"\\\\")


def _actual_src_path(path):
    """Return the real on-disk location of PATH, which is relative to
    the ViewVC source directory."""
    return os.path.join(os.path.dirname(sys.argv[0]),
                        path.replace('/', os.sep))


def error(text, etype=None, evalue=None):
    """Print error TEXT to stderr, pretty printing the optional
    exception type and value (ETYPE and EVALUE, respective), and then
    exit the program with an errorful code."""
    sys.stderr.write("\n[ERROR] %s\n" % (text))
    if etype:
        traceback.print_exception(etype, evalue, None, file=sys.stderr)
    sys.exit(1)


def replace_var(contents, var, value):
    """Replace instances of the variable VAR as found in file CONTENTS
    with VALUE."""
    pattern = re.compile(b'^' + var + br'\s*=\s*.*$', re.MULTILINE)
    if isinstance(ROOT_DIR, str):
        root_dir = ROOT_DIR.encode('utf-8', 'surrogateescape')
    else:
        root_dir = ROOT_DIR
    repl = b'%s = r"%s"' % (var, os.path.join(root_dir, value))
    return re.sub(pattern, _escape(repl), contents)


def replace_paths(contents):
    """Replace all ViewVC path placeholders found in file CONTENTS."""
    # Python 3: contents is bytes here
    if contents[:2] == b'#!':
        shbang = b'#!' + sys.executable.encode('utf-8', 'surrogateescape')
        contents = re.sub(b'^#![^\n]*', _escape(shbang), contents)
    contents = replace_var(contents, b'LIBRARY_DIR', b'lib')
    contents = replace_var(contents, b'CONF_PATHNAME', b'viewvc.conf')
    return contents


def install_file(src_path, dst_path, mode, subst_path_vars,
                 prompt_replace, compile_it):
    """Install a single file whose source is at SRC_PATH (which is
    relative to the ViewVC source directory) into the location
    DST_PATH (which is relative both to the global ROOT_DIR and
    DESTDIR settings), and set the file's MODE.  If SUBST_PATH_VARS is
    set, substitute path variables in the file's contents.  If
    PROMPT_REPLACE is set (and is not overridden by global setting
    CLEAN_MODE), prompt the user for how to deal with already existing
    files that differ from the to-be-installed version.  If COMPILE_IT
    is set, compile the file as a Python module."""

    src_path = _actual_src_path(src_path)
    dst_path = os.path.join(ROOT_DIR, dst_path.replace('/', os.sep))
    destdir_path = DESTDIR + dst_path

    overwrite = None
    if not (prompt_replace and os.path.exists(destdir_path)):
        # If the file doesn't already exist, or we've been instructed to
        # replace it without prompting, then drop in the new file and get
        # outta here.
        overwrite = 1
    else:
        # If we're here, then the file already exists, and we've possibly
        # got to prompt the user for what to do about that.

        # Collect ndiff output from ndiff
        sys.stdout = io.StringIO()
        ndiff_output = ''.join(difflib.ndiff(destdir_path, src_path))

        # Return everything to normal
        sys.stdout = sys.__stdout__

        # Collect the '+ ' and '- ' lines.
        diff_lines = []
        looking_at_diff_lines = 0
        for line in ndiff_output.split('\n'):
            # Print line if it is a difference line
            if line[:2] == "+ " or line[:2] == "- " or line[:2] == "? ":
                diff_lines.append(line)
                looking_at_diff_lines = 1
            else:
                # Compress lines that are the same to print one blank line
                if looking_at_diff_lines:
                    diff_lines.append("")
                    looking_at_diff_lines = 0

        # If there are no differences, we're done here.
        if not diff_lines:
            overwrite = 1
        else:
            # If we get here, there are differences.
            if CLEAN_MODE == 'true':
                overwrite = 1
            elif CLEAN_MODE == 'false':
                overwrite = 0
            else:
                print("File %s exists and is different from source file."
                      % (destdir_path))
                while 1:
                    name, ext = os.path.splitext(src_path)
                    if ext in BINARY_FILE_EXTS:
                        temp = input("Do you want to [O]verwrite or "
                                     "[D]o not overwrite? ")
                    else:
                        temp = input("Do you want to [O]verwrite, [D]o "
                                     "not overwrite, or [V]iew "
                                     "differences? ")
                    if len(temp) == 0:
                        continue
                    temp = temp[0].lower()
                    if temp == "v" and ext not in BINARY_FILE_EXTS:
                        print("""
---------------------------------------------------------------------------""")
                        print('\n'.join(diff_lines) + '\n')
                        print("""
LEGEND
   A leading '- ' indicates line to remove from installed file
   A leading '+ ' indicates line to add to installed file
   A leading '? ' shows intraline differences.
---------------------------------------------------------------------------""")
                    elif temp == "d":
                        overwrite = 0
                    elif temp == "o":
                        overwrite = 1

                    if overwrite is not None:
                        break

    assert overwrite is not None
    if not overwrite:
        print("   preserved %s" % (dst_path))
        return

    ### If we get here, we're creating or overwriting the existing file.

    # Read the source file's contents.
    try:
        contents = open(src_path, "rb").read()
    except IOError as e:
        error(str(e))

    # (Optionally) substitute ViewVC path variables.
    if subst_path_vars:
        contents = replace_paths(contents)

    # Ensure the existence of the containing directories.
    dst_parent = os.path.dirname(destdir_path)
    if not os.path.exists(dst_parent):
        try:
            os.makedirs(dst_parent)
            print("   created   %s%s" % (dst_parent, os.sep))
        except os.error as e:
            if e.errno == 17: # EEXIST: file exists
                return
            if e.errno == 13: # EACCES: permission denied
                error("You do not have permission to create directory %s" \
                      % (dst_parent))
            error("Unknown error creating directory %s" \
                  % (dst_parent, OSError, e))

    # Now, write the file contents to their destination.
    try:
        exists = os.path.exists(destdir_path)
        open(destdir_path, "wb").write(contents)
        print("   %s %s" \
              % (exists and 'replaced ' or 'installed', dst_path))
    except IOError as e:
        if e.errno == 13:
            # EACCES: permission denied
            error("You do not have permission to write file %s" % (dst_path))
        error("Unknown error writing file %s" % (dst_path, IOError, e))

    # Set the files's mode.
    os.chmod(destdir_path, mode)

    # (Optionally) compile the file.
    if compile_it:
        py_compile.compile(destdir_path, destdir_path + "c" , dst_path)


def install_tree(src_path, dst_path, is_optional, prompt_replace):
    """Install a tree whose source is at SRC_PATH (which is relative
    to the ViewVC source directory) into the location DST_PATH (which
    is relative both to the global ROOT_DIR and DESTDIR settings).  If
    PROMPT_REPLACE is set (and is not overridden by global setting
    CLEAN_MODE), prompt the user for how to deal with already existing
    files that differ from the to-be-installed version.  If
    IS_OPTIONAL is set, don't fuss about a missing source item."""

    orig_src_path = src_path
    orig_dst_path = dst_path
    src_path = _actual_src_path(src_path)
    dst_path = os.path.join(ROOT_DIR, dst_path.replace('/', os.sep))
    if not os.path.isdir(src_path):
        print("   skipping  %s" % (dst_path))
        return
    destdir_path = os.path.join(DESTDIR + dst_path)

    # Get a list of items in the directory.
    files = os.listdir(src_path)
    files.sort()
    for fname in files:
        # Ignore some stuff found in development directories, but not
        # intended for installation.
        if fname == 'CVS' or fname == '.svn' or fname == '_svn' \
             or fname[-4:] == '.pyc' or fname[-5:] == '.orig' \
             or fname[-4:] == '.rej' or fname[0] == '.' \
             or fname[-1] ==    '~' or fname == '__pycache__':
            continue

        orig_src_child = orig_src_path + '/' + fname
        orig_dst_child = orig_dst_path + '/' + fname

        # If the item is a subdirectory, recurse.  Otherwise, install the file.
        if os.path.isdir(os.path.join(src_path, fname)):
            install_tree(orig_src_child, orig_dst_child, 0, prompt_replace)
        else:
            set_paths = 0
            compile_it = fname[-3:] == '.py'
            install_file(orig_src_child, orig_dst_child, 0o0644,
                         set_paths, prompt_replace, compile_it)

    # Check for .py and .pyc files that don't belong in installation.
    # (Of course, if we didn't end up actually creating/populating
    # destdir_path, we can skip this altogether.)
    if not os.path.exists(destdir_path):
        return
    for fname in os.listdir(destdir_path):
        if not os.path.isfile(os.path.join(destdir_path, fname)) or \
             not ((fname[-3:] == '.py' and fname not in files) or
                        (fname[-4:] == '.pyc' and fname[:-1] not in files)):
            continue

        # If we get here, there's cruft.
        delete = None
        if CLEAN_MODE == 'true':
            delete = 1
        elif CLEAN_MODE == 'false':
            delete = 0
        else:
            print("File %s does not belong in ViewVC %s." \
                  % (dst_path, version))
            while 1:
                temp = input("Do you want to [D]elete it, or [L]eave "
                             "it as is? ")
                temp = temp[0].lower()
                if temp == "l":
                    delete = 0
                elif temp == "d":
                    delete = 1

                if delete is not None:
                    break

        assert delete is not None
        if delete:
            print("   deleted   %s" % (os.path.join(dst_path, fname)))
            os.unlink(os.path.join(destdir_path, fname))
        else:
            print("   preserved %s" % (os.path.join(dst_path, fname)))



def usage_and_exit(errstr=None):
    stream = errstr and sys.stderr or sys.stdout
    stream.write("""Usage: %s [OPTIONS]

Installs the ViewVC web-based version control repository browser.

Options:

    --help, -h, -?    Show this usage message and exit.

    --prefix=DIR      Install ViewVC into the directory DIR.  If not provided,
                      the script will prompt for this information.

    --destdir=DIR     Use DIR as the DESTDIR.  This is generally only used
                      by package maintainers.  If not provided, the script will
                      prompt for this information.

    --clean-mode=     If 'true', overwrite existing ViewVC configuration files
                      found in the target directory, and purge Python modules
                      from the target directory that aren't part of the ViewVC
                      distribution.  If 'false', do not overwrite configuration
                      files, and do not purge any files from the target
                      directory.  If not specified, the script will prompt
                      for the appropriate action on a per-file basis.

""" % (os.path.basename(sys.argv[0])))
    if errstr:
        stream.write("ERROR: %s\n\n" % (errstr))
        sys.exit(1)
    else:
        sys.exit(0)


if __name__ == "__main__":
    # Option parsing.
    try:
        optlist, args = getopt.getopt(sys.argv[1:], "h?",
                                      ['prefix=',
                                       'destdir=',
                                       'clean-mode=',
                                       'help'])
    except getopt.GetoptError as e:
        usage_and_exit(str(e))
    for opt, arg in optlist:
        if opt == '--help' or opt == '-h' or opt == '-?':
            usage_and_exit()
        if opt == '--prefix':
            ROOT_DIR = arg
        if opt == '--destdir':
            DESTDIR = arg
        if opt == '--clean-mode':
            arg = arg.lower()
            if arg not in ('true', 'false'):
                usage_and_exit("Invalid value for --clean-mode parameter.")
            CLEAN_MODE = arg

    # Print the header greeting.
    print("""This is the ViewVC %s installer.

It will allow you to choose the install path for ViewVC.  You will now
be asked some installation questions.  Defaults are given in square brackets.
Just hit [Enter] if a default is okay.
""" % version)

    # Prompt for ROOT_DIR if none provided.
    if ROOT_DIR is None:
        if sys.platform == "win32":
            pf = os.getenv("ProgramFiles", "C:\\Program Files")
            default = os.path.join(pf, "viewvc-" + version)
        else:
            default = "/usr/local/viewvc-" + version
        temp = input("Installation path [%s]: " % (default)).strip()
        print()
        if len(temp):
            ROOT_DIR = temp
        else:
            ROOT_DIR = default

    # Prompt for DESTDIR if none provided.
    if DESTDIR is None:
        default = ''
        temp = input("DESTDIR path (generally only used by package "
                     "maintainers) [%s]: " % (default)).strip()
        print()
        if len(temp):
            DESTDIR = temp
        else:
            DESTDIR = default

    # Install the files.
    print("Installing ViewVC to %s%s:"
          % (ROOT_DIR, DESTDIR and " (DESTDIR = %s)" % (DESTDIR) or ""))
    for args in FILE_INFO_LIST:
        install_file(*args)
    for args in TREE_LIST:
        install_tree(*args)

    # Print some final thoughts.
    print("""

ViewVC file installation complete.

Consult the INSTALL document for detailed information on completing
the installation and configuration of ViewVC on your system.
""")