nginxpack
Version information
This version is compatible with:
- ,
Start using this module
Add this module to your Puppetfile:
mod 'jvaubourg-nginxpack', '0.1.1'
Learn more about managing modules with a PuppetfileDocumentation
#Nginxpack
####Table of Contents
- Overview
- Module Description
- What nginxpack affects
- Usage
- Common Use Cases
- Limitations (only Debian-likes)
- Development
##Overview
This module installs and configures Nginx (lightweight and robust webserver). It's a pack because you can optionally install and configure PHP5 at the same time. There are three types of vhost available (basic, proxy and redirection) and some smart options for Nginx and PHP. This module is full IPv6 compliant because we are in the 21st century.
##Module Description
Features available:
- Install and configure Nginx
- Optionally: install and configure PHP5-FPM or PHP5-FastCGI/Spawn-FCGI
- Optionally: install PHP-MySQL connector and/or others PHP5 modules
- Basic vhosts
- Proxy vhosts
- 301 Redirection vhosts
- SSL support
- SNI support
- AcceptPathInfo support
- Full IPv6 compliant (and still IPv4...) including IPv6-Only
- Automatic blackhole for non-existent domains
- Several options (upload limits with Nginx/PHP, timezone, logrotate, default SSL certificate, htpasswd, listing, XSS injection protection, etc.)
- Custom configuration option for non-supported features
Recipes validated with +200 rspec tests.
##What nginxpack affects
Installed packages:
- nginx
- With
enable_php
andphp_fpm
: php5-fpm (default PHP configuration) - With
enable_php
and nophp_fpm
: php5-cgi, spawn-fcgi - With
php_mysql
: php5-mysql - With
logrotate
: logrotate, psmisc (if not already present)
logrotate is used with a configuration file in /etc/logrotate.d/nginx allowing it to daily rotate vhost logs. The configuration uses killall from psmisc in order to force nginx to update his inodes (this is the classic way). With enable_php
but no php_fpm
, killall is also used in nginxpack::php::cgi
to ensure that PHP is not still running when disabled.
Use nginxpack::php::mod { 'foo': }
involves installing php5-foo (e.g. nginxpack::php::mod { [ 'mcrypt', 'gd' ]: }
).
Added services:
- Use
/etc/init.d/nginx
- With
enable_php
and nophp_fpm
: add/etc/init.d/php-fastcgi
(and associated script/usr/bin/php-fastcgi.sh
) - With
enable_php
andphp_fpm
: use/etc/init.d/php5-fpm
Added files:
- Vhosts: /etc/nginx/sites-{available,enabled}/* and /etc/nginx/include/*
- Logs: /var/log/nginx/<vhostname>/{access,error}.log
- Certificates: /etc/nginx/ssl/*
- Script for automatic blackholes: /etc/nginx/find_default_listen.sh
Use php_timezone
, php_upload_max_filesize
and/or php_upload_max_files
affects /etc/php5/cgi/php.ini (but not overrides it).
##Usage
###Beginning with nginxpack
####Webserver
If you just want a webserver installing with the default options and without PHP you can run:
include 'nginxpack'
And with PHP:
class { 'nginxpack':
enable_php => true,
}
If you want a classical PHP5-FastCGI/Spawn-FCGI instead of PHP5-FPM, you can add:
class { 'nginxpack':
enable_php => true,
php_fpm => false,
}
With PHP-MySQL connector:
class { 'nginxpack':
enable_php => true,
php_mysql => true,
}
Others options for PHP:
class { 'nginxpack':
enable_php => true,
php_timezone => 'Antarctica/Vostok',
php_upload_max_filesize => '1G',
php_upload_max_files => 5,
}
With this example, you will be able to propose uploads of 5 files of 1G max each together. In this case, the POST-data size limit (from PHP) will automatically be configured to accept until 5G.
With LogRotate (enabled by default):
class { 'nginxpack':
logrotate => true,
logrotate_frequency => 'weekly',
logrotate_rotate => 52,
}
LogRotate values given in this example are the default ones. logrotate_rotate
corresponds to the number of rotating before being removed (zero means that old versions are removed rather than rotated).
You can also configure default https configuration here. See the first common use case.
####Basic Vhost
Standard vhost.
Listen on all IPv6/IPv4 available with port 80, no PHP and no SSL:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
}
Using aliases:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com', 'www.foobar.example.com' ]
}
With PHP:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
use_php => true,
}
Since you use use_php
for at least one vhost, you have to use enable_php
with the webserver. For activating AcceptPathInfo, add php_AcceptPathInfo => true
to the vhost (e.g. /foo/index.php/bar/ with PATH_INFO=/bar/).
Listen on a specific IPv6 and all IPv4 available:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
ipv6 => '2001:db8::42',
}
You can use the ipv4
option to listen on a specific IPv4 address. And if you don't want listening on IPv4 you can set ipv6only => true
(and ipv4only
for not listening on IPv6, when it's strictly necessary).
Listen on a specific port:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
port => 8080,
}
With SSL (https://):
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
https => true,
ssl_cert_source => 'puppet:///certificates/foobar.pem',
ssl_key_source => 'puppet:///certificates/foobar.key',
}
Generate pem (crt) and key files (put your full qualified domain name in Common Name):
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout foobar.key -out foobar.pem
You also could use ssl_cert_content
and ssl_key_content
to define the certificate from a string (useful if you use hiera to store your certificates: ssl_cert_content => hiera('foobar-cert')
).
Additional parameters ssl_ocsp_dns1
and ssl_ocsp_dns2
can be set in order to set the DNS resolvers used for obtaining the IP address of the OCSP responder (certificates revocation status). OCSP DNS can be IP addresses (IPv6 starting from Nginx 1.2.2) or names (resolving into IPv6 starting from Nginx 1.5.8). You can set optional ports with IP:port or name:port with Nginx version equal or greater than 1.2.2 (default 53).
The default listening port becomes 443 but you still could force a different one with port
. The SSL configuration is compliant with Cipherli.st recommendations (ssl_stapling options are disabled with Debian Wheezy and Ubuntu Precise).
Other options:
nginxpack::vhost::basic { 'foobar':
domains => [ 'foobar.example.com' ],
enable => false,
files_dir => '/srv/websites/foobar/',
injectionsafe => true,
upload_max_size => '5G',
htpasswd => 'user1:$apr1$EUoQVU1i$kcGRxeBAJaMuWYud6fxZL/',
htpasswd_msg => "Restricted Foobar's access",
forbidden => [ '^/logs/', '^/tmp/', '\.inc$' ],
add_config_content => 'location @barfoo { rewrite ^(.+)$ /files/$1; }',
try_files => '@barfoo =404',
listing => true
}
files_dir
(DocumentRoot) default value is /var/www/<name>/ (e.g. /var/www/foobar/).
injectionsafe
applies these protections against XSS injections. These restrictions might be incompatible with your applications.
upload_max_size
should be in line with php_upload_max_filesize
x php_upload_max_files
listing
corresponds to directory index enabled (auto files indexing)
htpasswd
's value can be generated from a command line tool (apache2-utils):
$ htpasswd -nb user1 secretpassword
If you want to use a specific configuration for a specific vhost, you can use add_config_source
or add_config_content
to inject custom Nginx instructions directly in server { }
.
####Proxy Vhost
Reverse-proxy vhost allowing you to seamlessly redirect the traffic to a remote webserver.
Default listen identical to basic vhosts and remote server reached on port 80 without using SSL:
nginxpack::vhost::proxy { 'foobarlan':
domains => [ 'foobar.example.com' ],
to_domain => 'foobar.lan',
}
Remote SSL and different remote port:
nginxpack::vhost::proxy { 'foobarlan':
domains => [ 'foobar.example.com' ],
to_domain => 'foobar.lan',
to_https => true,
to_port => 8080,
}
Default remote port is 80. In this case it would have been 443 due to to_https
.
SSL (https://) is usable in the same manner as basic vhosts.
Options ipv6
, ipv4
, ipv6only
, ipv4only
, port
, enable
, add_config_source
, add_config_content
and upload_max_size
are also available in the same way as basic vhosts.
####Redirection Vhost
General redirection (using 301 http code) allowing you to officially redirect any requests to a remote domain. In short: http://foobar.example.com/(.*) => http://foobar.com/$1.
Default listen identical to basic vhosts, and remote domain reached on port 80 without using SSL:
nginxpack::vhost::redirection { 'foobarlan':
domains => [ 'foobar.example.com' ],
to_domain => 'www.foobar.com',
}
Options to_https
and to_port
are available in the same way as proxy vhosts.
Options ipv6
, ipv4
, ipv6only
, ipv4only
, port
, enable
, add_config_source
and add_config_content
are available in the same way as basic vhosts.
###Documentation
The previous section should be clear enough to understand the possibilities of nginxpack.
If you want a detailed documentation of types and options, there is a full documentation in the headers of the Puppet files.
###Default Vhosts
####Automatic Blackholes
Have a determinist way to access to the vhosts is a good practice in web security. If you say that a vhost can be reached via my.example.com, any request using another domain should not success. If you do not have a default vhost with a listen line for each port used on the webserver, Nginx will use a doubful algorithm to determine which vhost is usable in the case of an unknown domain.
Good news! Nginxpack creates this default vhost for you and redirects any request out of your scopes to a blackhole.
You can disable the https blackhole with default_https_blackhole => false
(useful if you have no https vhosts and you don't want Nginx listening on 443).
####Well-known problem with SSL
The full circle is easy to understand:
- Nginx chooses the correct vhost (among those who are listening on the correct port and IP) thanks to the host field (HTTP 1.1).
- When a client initiates a SSL connection, this field is encrypted, until Nginx decrypts the request.
- Informations about decryption (e.g. certificate location) are in the correct vhost. Back to 1.
Thus, if you have several vhosts listening on the same port with the same IP (or all IP) and using SSL, you have a problem.
With Nginx >= 0.7.62 and OpenSSL >= 0.9.8j, you can use SNI, the modern way to solve this problem. You have nothing to do, but your visitors must have recent browsers:
- Opera 8.0;
- MSIE 7.0 (but only on Windows Vista or higher);
- Firefox 2.0 and other browsers using Mozilla Platform rv:1.8.1;
- Safari 3.2.1 (Windows version supports SNI on Vista or higher);
- or Chrome (Windows version supports SNI on Vista or higher, too).
The other constraint is that you cannot use specific addresses (ipv6
and ipv4
options) with SNI.
If you don't want to restrict compatible browsers or you want use specific addresses or you want to manage only one wildcard certificate, the good solution is to use a default vhost, listening on all ports and IP used by SSL vhosts on the webserver and containing the decryption informations. When Nginx will receive a SSL request, it will use this vhost, and so, will be able to decrypt it. Once the host field is readable, it can chose the correct vhost. The latter don't have to propose SSL but it absolutely must listen on port 443 (or another if you use SSL with another one).
Nginxpack creates this default vhost for you, with a default certificate. To replace the default certificate, you can use ssl_default_cert_source
(or ssl_default_cert_key
) and ssl_default_key_source
(or ssl_default_key_source
) options. This certificate should be valid for all domains used, so it will probably be at least a wildcard certificate.
The first common use case in the next section provides an example with this solution.
##Common Use Cases
###Reverse-proxy with IPv4
####Multiple servers and a single IPv4
You are in charge of servers in the wrong decade: there is almost no more IPv4 but you still can't use only IPv6. Thus, your provider has provided you as many IPv6 addresses as there are grains of sand on earth, but only one poor IPv4.
If you have various webservers (on remote machines or in containers beside) behind this access, you need to have a reverse-proxy. In the following examples, we consider that your firewall redirects ports 80 and 443 to the server corresponding to your reverse-proxy for any incoming IPv4 flux (probably by configuring your NATPT on your CPE if you are at home) .
The first example considers that your ISP provides you IPv6 addresses and that you are able to use it. Second example considers that you have a crappy ISP and so no IPv6 addresses available. In both examples, we want a blog (http), a wiki (https) and a members panel (https). For the sake of cleanliness and security reasons, each website must have its own webserver on its own machine/container.
####With usable IPv6 addresses
Goals:
- 1 webserver (1 machine/container) by website and 1 for the reverse-proxy.
- IPv6 clients reach websites directly and can't use the reverse-proxy.
- IPv4 clients reach websites only through the reverse-proxy and can't reach them directly.
- Therefore, communications between the reverse-proxy and the remote websites use IPv6, but it's seamless for (IPv4) clients and there is no problem with IPv6 over the internal network.
The certificat location is provided on the reverse-proxy for IPv4 clients (see previous section), and on the vhosts for IPv6 clients. Proxy vhosts listen on port 443 but not have SSL capabilities (see again the previous section).
Webserver hosting the reverse-proxy:
# Could be replaced by an internal DNS server
host {
'blog.lan':
ip => '2001:db8::a';
'wiki.lan':
ip => '2001:db8::b';
'members.lan':
ip => '2001:db8::c';
}
# Wildcard certificate (*.example.com)
class { 'nginxpack':
ssl_default_cert_source => 'puppet:///certificates/default.pem',
ssl_default_key_source => 'puppet:///certificates/default.key',
}
nginxpack::vhost::proxy { 'blog':
domains => [ 'blog.example.com' ],
ipv4only => true,
to_domain => 'blog.lan',
}
nginxpack::vhost::proxy { 'wiki':
domains => [ 'wiki.example.com' ],
port => 443,
ipv4only => true,
to_domain => 'wiki.lan',
to_https => true,
}
nginxpack::vhost::proxy { 'members':
domains => [ 'members.example.com' ],
port => 443,
ipv4only => true,
to_domain => 'members.lan',
to_https => true,
}
Webserver hosting blog.example.com:
nginxpack::vhost::basic { 'blog':
domains => [ 'blog.example.com' ],
ipv6only => true,
use_php => true,
}
Webserver hosting wiki.example.com:
nginxpack::vhost::basic { 'wiki':
domains => [ 'wiki.example.com' ],
https => true,
ssl_cert_source => 'puppet:///certificates/default.pem',
ssl_key_source => 'puppet:///certificates/default.key',
ipv6only => true,
use_php => true,
}
Webserver hosting members.example.com:
nginxpack::vhost::basic { 'members':
domains => [ 'members.example.com' ],
https => true,
ssl_cert_source => 'puppet:///certificates/default.pem',
ssl_key_source => 'puppet:///certificates/default.key',
ipv6only => true,
use_php => true,
}
####Without IPv6 addresses
Goals:
- 1 webserver (1 machine/container) by website and 1 for the reverse-proxy.
- Clients reach websites only through the reverse-proxy and can't reach them directly.
- We trust in the internal network so communications between the reverse-proxy and the websites are never encrypted.
Webserver hosting the reverse-proxy:
# Could be replaced by an internal DNS server
host {
'blog.lan':
ip => '10.0.0.10';
'wiki.lan':
ip => '10.0.0.20';
'members.lan':
ip => '10.0.0.30';
}
# Wildcard certificate (*.example.com)
class { 'nginxpack':
ssl_default_cert_source => 'puppet:///certificates/default.pem',
ssl_default_key_source => 'puppet:///certificates/default.key',
}
nginxpack::vhost::proxy { 'blog':
domains => [ 'blog.example.com' ],
to_domain => 'blog.lan',
}
nginxpack::vhost::proxy { 'wiki':
domains => [ 'wiki.example.com' ],
port => 443,
to_domain => 'wiki.lan',
}
nginxpack::vhost::proxy { 'members':
domains => [ 'members.example.com' ],
port => 443,
to_domain => 'members.lan',
}
Webserver hosting blog.example.com:
nginxpack::vhost::basic { 'blog':
domains => [ 'blog.example.com' ],
use_php => true,
}
Webserver hosting wiki.example.com:
nginxpack::vhost::basic { 'wiki':
domains => [ 'wiki.example.com' ],
use_php => true,
}
Webserver hosting members.example.com:
nginxpack::vhost::basic { 'members':
domains => [ 'members.example.com' ],
use_php => true,
}
###Usage of www.
Using www.example.com is so 2005 and you want automatically redirect all requests from http://www.example.com/.* to http://example.com/$1.
nginxpack::vhost::basic { 'eatmytux':
domains => [ 'example.com' ],
use_php => true,
}
nginxpack::vhost::redirection { 'www-eatmytux':
domains => [ 'www.example.com' ],
to_domain => 'example.com',
}
###Port Redirection
Proxy and redirection vhosts use the first value of domains
when to_domain
is absent.
####Seamlessly
Your out-of-the-box webapp listens on port 8080 but you want use it on port 80 without modifying its configuration:
nginxpack::vhost::proxy { 'mywebapp':
domains => [ 'example.com' ],
to_port => 8080,
}
####Not Seamlessly
Visible location switching (the client will see his URL transformation: http://example.com/.* => http://example.com:8080/$1) means redirection:
nginxpack::vhost::redirection { 'mywebapp':
domains => [ 'example.com' ],
to_port => 8080,
}
####HTTPS Redirection
Spontaneous switching from http to https:
nginxpack::vhost::basic { 'wiki':
domains => [ 'wiki.example.com' ],
https => true,
ssl_cert_source => 'puppet:///certificates/wiki.pem',
ssl_key_source => 'puppet:///certificates/wiki.key',
}
nginxpack::vhost::redirection { 'https-wiki':
domains => [ 'wiki.example.com' ],
to_https => true,
}
####IPv6/IPv4 Proxy
You own a website not available in IPv6 and you cannot have an IPv6 address on its machine. A way to solving this problem is to create a proxy on a dual-stack machine (listening on IPv6 to accept incoming requests and listening on IPv4 to contact the remote webserver):
nginxpack::vhost::proxy { 'foobar':
domains => [ 'example.com' ],
to_domain => 'ip4.example.com',
ipv6only => true,
}
DNS configuration:
example.com
AAAA proxy
A webserver
ip4.example.com
A webserver
This trick could also be used in the opposite case.
##Dependencies
- puppetlabs/stdlib >= 3.x (
file_line
is used to edit php.ini,validate_re
to check some parameters andensure_packages
to install logrotate and psmisc)
##Limitations
This module is only available for Debian-likes.
##Development
I developed this module for my own needs but I think it's generic enough to be useful for someone else.
Feel free to contribute. I'm not a big fan of centralized services like GitHub but I used it to permit easy pull-requests, so show me that's a good idea!
##Thanks
- Lorraine Data Network for testing the module
- Sébastien Badia for adding LogRotate options with comprehensive documention
2014-10-21 - 0.1.1 (jvaubourg)
- Add LogRotate frequency and rotate options (sbadia)
- Remove SSLv3 with HTTPS
- SSL config now compliant with Cipherli.st recommendations
2014-08-12 - 0.1.0 (jvaubourg)
- Fix bug with default index.php
2014-08-06 - 0.0.4 (jvaubourg)
- Add SNI support
- Add PHP5-FPM support ** [WARNING] If you upgrade Nginxpack, you can use "php_fpm => false" if you don't want to switch from classical PHP5-FastCGI to PHP5-FPM. Otherwise, think cleaning useless php5-cgi/spawn-fcgi packages and process (just for cleanness).
- Add HTTP authentication support
- Add possibility to disable blackholes
- Add fake default HTTPS certificate for the blackhole, when using SNI
- Add AcceptPathInfo support
- Add listing (autoindex) support
- Add final "tryfiles" support (useful with add_config*)
- Fix IPv6-Only / IPv4-Only support. But please don't use IPv4-Only.
- Add custom error for blackholes
2013-10-26 - 0.0.3 (jvaubourg)
- Default server_names_hash_bucket_size to 64
- Warnings when PHP vhosts are defined without PHP option for Nginx
- Warnings when SSL vhosts are defined with IPv4 and no default SSL vhost
- Installing php module notifies the php service
- Blackholes return a 400 error instead of 403
- Add_configs are now before other locations (for regex priority)
- Add forbidden option to vhost::basic
2013-10-23 - 0.0.2 (jvaubourg)
- Fix a problem when PHP was never installed
- Proxies no longer transmit Host values (0 downloads so it's a patch)
2013-10-23 - 0.0.1 (jvaubourg)
- First release
Dependencies
- puppetlabs/stdlib (>=3.0.0)
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This License acknowledges your rights of fair use or other equivalent, as provided by copyright law. You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you comply with the terms of this License in conveying all material for which you do not control copyright. Those thus making or running the covered works for you must do so exclusively on your behalf, under your direction and control, on terms that prohibit them from making any copies of your copyrighted material outside their relationship with you. Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary. 3. Protecting Users' Legal Rights From Anti-Circumvention Law. No covered work shall be deemed part of an effective technological measure under any applicable law fulfilling obligations under article 11 of the WIPO copyright treaty adopted on 20 December 1996, or similar laws prohibiting or restricting circumvention of such measures. When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. 4. Conveying Verbatim Copies. You may convey verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice; keep intact all notices stating that this License and any non-permissive terms added in accord with section 7 apply to the code; keep intact all notices of the absence of any warranty; and give all recipients a copy of this License along with the Program. You may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for a fee. 5. Conveying Modified Source Versions. You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions: a) The work must carry prominent notices stating that you modified it, and giving a relevant date. b) The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to "keep intact all notices". c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it. d) If the work has interactive user interfaces, each must display Appropriate Legal Notices; however, if the Program has interactive interfaces that do not display Appropriate Legal Notices, your work need not make them do so. A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an "aggregate" if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate. 6. Conveying Non-Source Forms. You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways: a) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange. b) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge. c) Convey individual copies of the object code with a copy of the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b. d) Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available for as long as needed to satisfy these requirements. e) Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d. A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for incorporation into a dwelling. In determining whether a product is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the way in which the particular user actually uses, or expects or is expected to use, the product. A product is a consumer product regardless of whether the product has substantial commercial, industrial or non-consumer uses, unless such uses represent the only significant mode of use of the product. "Installation Information" for a User Product means any methods, procedures, authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source. The information must suffice to ensure that the continued functioning of the modified object code is in no case prevented or interfered with solely because modification has been made. If you convey an object code work under this section in, or with, or specifically for use in, a User Product, and the conveying occurs as part of a transaction in which the right of possession and use of the User Product is transferred to the recipient in perpetuity or for a fixed term (regardless of how the transaction is characterized), the Corresponding Source conveyed under this section must be accompanied by the Installation Information. But this requirement does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM). The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work that has been modified or installed by the recipient, or for the User Product in which it has been modified or installed. Access to a network may be denied when the modification itself materially and adversely affects the operation of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and with an implementation available to the public in source code form), and must require no special password or key for unpacking, reading or copying. 7. Additional Terms. "Additional permissions" are terms that supplement the terms of this License by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that part may be used separately under those permissions, but the entire Program remains governed by this License without regard to the additional permissions. When you convey a copy of a covered work, you may at your option remove any additional permissions from that copy, or from any part of it. (Additional permissions may be written to require their own removal in certain cases when you modify the work.) You may place additional permissions on material, added by you to a covered work, for which you have or can give appropriate copyright permission. Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright holders of that material) supplement the terms of this License with terms: a) Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or b) Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed by works containing it; or c) Prohibiting misrepresentation of the origin of that material, or requiring that modified versions of such material be marked in reasonable ways as different from the original version; or d) Limiting the use for publicity purposes of names of licensors or authors of the material; or e) Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or f) Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors. All other non-permissive additional terms are considered "further restrictions" within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms. Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way. 8. Termination. You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10. 9. Acceptance Not Required for Having Copies. You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so. 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License. An "entity transaction" is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it. 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor's "contributor version". A contributor's "essential patent claims" are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, "control" includes the right to grant patent sublicenses in a manner consistent with the requirements of this License. Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To "grant" such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. "Knowingly relying" means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid. If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it. A patent license is "discriminatory" if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. 12. No Surrender of Others' Freedom. If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program. 13. Remote Network Interaction; Use with the GNU General Public License. Notwithstanding any other provision of this License, if you modify the Program, your modified version must prominently offer all users interacting with it remotely through a computer network (if your version supports such interaction) an opportunity to receive the Corresponding Source of your version by providing access to the Corresponding Source from a network server at no charge, through some standard or customary means of facilitating copying of software. This Corresponding Source shall include the Corresponding Source for any work covered by version 3 of the GNU General Public License that is incorporated pursuant to the following paragraph. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the work with which it is combined will remain governed by version 3 of the GNU General Public License. 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new versions of the GNU Affero General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU Affero General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU Affero General Public License, you may choose any version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU Affero General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program. Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version. 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. <one line to give the program's name and a brief idea of what it does.> Copyright (C) <year> <name of author> This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. Also add information on how to contact you by electronic and paper mail. If your software can interact with users remotely through a computer network, you should also make sure that it provides a way for users to get its source. For example, if your program is a web application, its interface could display a "Source" link that leads users to an archive of the code. There are many ways you could offer source, and different solutions will be better for different programs; see section 13 for the specific requirements. You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow the GNU AGPL, see <http://www.gnu.org/licenses/>.