a2conf 0.1.15

apache2 configuration file parser and query tool

a2conf is utility and python module to work with apache2 config files.

For all examples we will use file example.conf which is available examples/example.conf. Use export PYTHONPATH=. to use module if it's not installed.

a2conf.py utility

Examples

Just smart grep

$ bin/a2conf examples/example.conf --cmd ServerName ServerAlias
ServerName example.com
ServerAlias www.example.com example.com 1.example.com 2.example.com
ServerName example.com
ServerAlias www.example.com 1.example.com 2.example.com secure.example.com

$ bin/a2conf examples/example.conf --cmd SSLCertificateFile
SSLCertificateFile /etc/letsencrypt/live/example.com/fullchain.pem

Only arguments:

# All arguments (including duplicates)
$ bin/a2conf examples/example.conf --cmd ServerName ServerAlias --args
example.com www.example.com example.com 1.example.com 2.example.com example.com www.example.com 1.example.com 2.example.com secure.example.com

# Only unique arguments
$ bin/a2conf examples/example.conf --cmd ServerName ServerAlias --uargs
secure.example.com 1.example.com www.example.com example.com 2.example.com

Filtering:

# Only SSL hosts. Note: secure.example.com listed
$ bin/a2conf examples/example.conf --cmd ServerName ServerAlias --uargs --filter sslengine on
1.example.com example.com secure.example.com 2.example.com www.example.com

# Inverted filtering, hosts without SSLEngine on. Note: secure.example.com not listed
$ bin/a2conf examples/example.conf --cmd ServerName ServerAlias --uargs --filter sslengine on --neg
example.com 2.example.com 1.example.com www.example.com

Per-vhost info:

# show documentroot for virtualhosts
$ bin/a2conf examples/example.conf  --cmd servername serveralias --uargs --vhost '{vhostargs} {servername} {documentroot}'
*:80 example.com /var/www/example
*:443 example.com /var/www/example

# ... only for virtualhosts with SSLEngine On
$ bin/a2conf examples/example.conf  --cmd servername serveralias --uargs --vhost '{vhostargs} {servername} {documentroot}' --filter sslengine on
*:443 example.com /var/www/example

# What certfile we use for secure.example.com ?
$ bin/a2conf examples/example.conf --vhost '{servername} {sslcertificatefile}' --filter ServerName,ServerAlias secure.example.com
example.com /etc/letsencrypt/live/example.com/fullchain.pem

# What certfile we use for 1.example.com (more good-style error-prone approach) ?
$ bin/a2conf examples/example.conf --vhost '{servername} {sslcertificatefile}' --filter ServerName,ServerAlias 1.example.com  --undef _skip
example.com /etc/letsencrypt/live/example.com/fullchain.pem

You can get list of all available tokens for --vhost option in verbose mode (-v option).

Node class

Properties and methods

raw - text line as-is, with all spaces, tabs and with comments

cmd - cmd ('ServerName') without args or None (if section)

section - section (e.g. 'VirtualHost')

args - one text line args to cmd or section. for vhost args could be '*:80', for ServerAlias: 'example.com example.org'

name - name of node. cmd if node has cmd, or section name (in brackets) if this is section. e.g. 'ServerName' or ''

content - list of child nodes (possible empty). For container sections (VirtualHost) attribute content is list of children. For usual commands (e.g. ServerName) - empty list.

Methods

__init__(self, read=filename, raw=None, parent=None, name=None, path=None, line=None, includes=True) - In most cases you should not need to use any parameters here except includes and read. read is apache config filename to read. Use includes=False if you want read_file method to ignore Include* directives.

children(name=None, recursive=None) - Main query method, returns generator for all children nodes (e.g. for VirtualHost node). Generator is empty if no children. If name specified, generator will return only nodes with this name (e.g. 'servername' or ''). If recursive is On, generator will return nested nodes too (e.g. what is inside <IfModule> or <Directory> settings). To get just one first element use next(node.children('ServerName')). It will raise StopIteration if node has no such children elements.

first(name, recursive=None) - wrapper for children(). Returns only first element or None. Not raising exceptions.

read_file(filename) - Reads apache config. Called automatically from __init__ if you specified read argument.

dump(fh=sys.stdout, depth=0) - dump loaded config in unified format (indented). if fh not specified, just dumps to stdout()

write_file(filename) - opens file for writing and dump() to this file.

Examples

Just dump apache config

examples/ex1_dump.py just loads config and dumps its structure (without comments) as JSON:

#!/usr/bin/env python3
import sys
import a2conf
import json

root = a2conf.Node(sys.argv[1])

def section_dump(node):
    data = dict()

    for ch in node.children():
        if ch.section and not ch.section.startswith('/'):
            if ch.args:
                key = ch.section + ' ' + ch.args
            else:
                key = ch.section
            data[key] = section_dump(ch)
        elif ch.cmd:
            data[ch.cmd] = ch.args
    return data

data = section_dump(root)
print(json.dumps(data, indent=4))

Output:

$ examples/ex1_dump.py examples/example.conf
{
    "VirtualHost *:80": {
        "DocumentRoot": "/var/www/example",
        "ServerName": "example.com",
        "ServerAlias": "www.example.com example.com 1.example.com 2.example.com",
        "DirectoryIndex": "index.html index.htm default.htm index.php",
        "Options": "-Indexes +FollowSymLinks"
    },
    "VirtualHost *:443": {
        "DocumentRoot": "/var/www/example",
        "ServerName": "example.com",
        "ServerAlias": "www.example.com 1.example.com 2.example.com secure.example.com",
        "DirectoryIndex": "index.html index.htm default.htm index.php",
        "Options": "-Indexes +FollowSymLinks",
        "SSLEngine": "On",
        "SSLCertificateFile": "/etc/letsencrypt/live/example.com/fullchain.pem",
        "SSLCertificateKeyFile": "/etc/letsencrypt/live/example.com/privkey.pem",
        "SSLCertificateChainFile": "/etc/letsencrypt/live/example.com/chain.pem"
    }
}

Note - this is short example just for demo, it's not very good for production: if virtualhost has more then one directive (e.g. ServerAlias, RewriteRule, RewriteCond), only last one will be used.

Query

examples/ex2_query.py print all SSL sites from config:

#!/usr/bin/env python3
import sys
import a2conf
root = a2conf.Node(sys.argv[1])

for vhost in root.children('<VirtualHost>'):
    servername = vhost.first('servername').args # One query method, via first(). Not much fail-safe but short.

    try:
        ssl_option = next(vhost.children('sslengine')).args # Other query method, via children()
        if ssl_option.lower() == 'on':
            print("{} has SSL enabled".format(servername))
    except StopIteration:
        # No SSL Engine directive in this vhost
        continue

Output:

$ examples/ex2_query.py examples/example.conf
example.com has SSL enabled

Replace and delete

examples/ex3_replace_delete.py disables SSLEngine directive:

#!/usr/bin/env python3
import sys
import a2conf
root = a2conf.Node(sys.argv[1])

for vhost in root.children('<VirtualHost>'):
    if vhost.first('sslengine'):
        vhost.delete() # Delete SSL vhost
    else:
        # Modify DocumentRoot
        vhost.first('DocumentRoot').args = '/var/www/example2'
        vhost.first('DocumentRoot').suffix = '# New DocumentRoot!'
        # Delete ServerAlias
        vhost.first('ServerAlias').delete()

root.dump()

Output:

$ examples/ex3_replace_delete.py examples/example.conf
#
# Example config file for a2conf
#
<VirtualHost *:80>
    # Non-ssl site
    DocumentRoot /var/www/example2 # New DocumentRoot!
    ServerName example.com # .... OUR TEST SITE ....
    DirectoryIndex index.html index.htm default.htm index.php
    Options -Indexes +FollowSymLinks
</VirtualHost>