webmlmd — WebMLM interface to couriermlm
cp /usr/lib/courier/libexec/courier/webmail/webmlm /var/www/cgi-bin
webmlmd {[start] | [restart] | [stop]} {/etc/courier/webmlmrc}
WebMLM is a service that offers an alternative web-based access to some couriermlm commands, as an alternative to submitting them via E-mail.
At this time, WebMLM implements requests to subscribe and unsubscribe from the mailing list, and configuration of basic mailing list settings.
Before configuring
WebMLM, the mailing list must be set
up using
couriermlm(1).
WebMLM is not a separate application,
it is an add-on to
couriermlm.
WebMLM will not work correctly until
the mailing list is fully configured, and all
.courier files, that correspond to this
list, are installed.
WebMLM consists of three parts:
A configuration file, (default:
/etc/courier/webmlmrc) that enumerates
all
couriermlm-created mailing list
directories for which
WebMLM will offer its services
(a single instance of WebMLM can support multiple
mailing list directories).
The configuration file also specifies the name of a local
filesystem socket (a named pipe) where
webmlm and
webmlmd programs talk to each other,
and several other
configuration parameters.
webmlmd is a background daemon process that reads the configuration file, creates the communication socket specified by the configuration file, and listens for web requests.
webmlm is a small stub program which must
be installed as a script in
Apache http server's
cgi-bin directory.
Apache runs the script to process
every request received from a web client/browser.
webmlm reads web browser's request, reads
the configuration file, opens the communication socket file
specified in the configuration file, sends the request to
the
webmlmd daemon process, and waits for
webmlmd's response, which is forwarded
to the web browser/client.
webmlm is originally installed in the
/usr/lib/courier/libexec/courier/webmail directory, and
must be manually copied to Apache's
cgi-bin directory. Most installable
Courier packages (including the
Courier
RPM package built using its default
RPM build script) have a separate
subpackage that installs
webmlm directly into the
cgi-bin directory. Installing the
subpackage is all that's needed in those cases.
Use the following process to web-enable couriermlm-managed mailing lists:
Configure the LISTNAME,
LISTDESCR, LISTPW
and URL
couriermlm list options.
Set up the webmlmrc configuration
file.
Start webmlmd, and arrange start it automatically during the system boot.
Install webmlm in your web server's
cgi-bin directory.
Use the “couriermlm
set
directory
name=value”
command,
for each couriermlm list
directory to set the following settings:
The mailing list's short title, or caption. Example: “The courier-users mailing list”.
This is a longer, more verbose description of this mailing list. This setting is displayed, as raw HTML, on the list's main page. This is an optional setting.
The URL to the main page for this mailing list. You'll need to figure out what this URL should be set to by planning ahead where webmlm gets installed, in the last step in this installation process.
After installing webmlm in Apache's
cgi-bin directory, the URL for the
webmlm command would probably be something like
“http://servername/cgi-bin/webmlm”.
The list's URL is the name of the list's directory appended
to webmlm's URL.
For example, if the couriermlm mailing list directory
is /var/lists/devel-list, its URL
MUST be
“http://servername/cgi-bin/webmlm/devel-list”.
This is the password to the mailing list administration screen. The password must be set using the couriermlm command.
We are not talking military-grade security, here!
Do not recycle sensitive passwords for this purpose.
The password is saved, in plain text, in the options
file in the mailing list directory.
You should consider removing the world read and execute permissions on
the mailing list directory.
Changing the permissions on the
options file is ineffective, it will be
restored the next time any configuration setting is changed.
Furthermore, authorization for the administration screen is provided by storing the list password in a browser cookie, which also gets transmitted over the network, in the clear. Consider using SSL with webmlmd.
This is a simple password-based implementation. High levels of security require a lot of care to set up, and are usually somewhat complicated to implement and manage. Keep that in mind.
Put apostrophes around each option setting when running
couriermlm.
Most of these configuration settings (especially LISTDESCR)
contain special shell characters and must be quoted.
webmlmrc configuration file
A default webmlmd configuration file is installed
as /etc/courier/webmlmrc. The file contains a description
of each required configuration setting. Briefly:
The filesystem socket port file.
This is a local filesystem socket that's used to process web requests.
The directory that contains the filesystem socket must either be owned by
the same userid that owns the couriermlm mailing list
directory, or webmlmd must be started as root (in the
next step of this installation process).
The default /etc/courier/webmlmrc configuration file
sets the filesystem socket file to a Courier
directory that's only writable by root, so webmlmd needs
to be started by root, in the step step, in the default configuration.
Additionally, the filesystem socket port file must be accessible by the userid
that executes web cgi-bin scripts. This is the nobody
user, in Apache's default configuration.
A colon-separated list of couriermlm mailing list directories, as absolute paths. A single instance of WebMLM is capable of handling multiple lists, provided that:
The names of all mailing list directories, the last components of all directories, are unique.
All mailing list directories are owned by the same userid and groupid.
Otherwise, multiple, separate instances of WebMLM must be set up.
The following command starts webmlmd:
webmlmd start configfile
This command should be added to your system start up script (replacing
configfile with the absolute pathname to the
configuration file).
Most installable Courier packages (including the
Courier RPM package built using
its default RPM build script) install a system
startup script.
The script invokes the appropriate magical incantation if the
configuration file (/etc/courier/webmlmrc) has a
non-empty LISTS setting.
Initially, LISTS is empty and nothing happens.
Once the mailing list directories are defined, the startup script will
take care of starting webmlmd.
The webmlmd command returns immediately, it continues to run as a background daemon process). To stop the daemon process:
webmlmd stop configfile
As mentioned previously, webmlmd must be either invoked
as root, or under the same userid that owns the mailing list directories,
provided that PORT's directory is writable by the userid.
Install the webmlm program by either manually
copying it from the /usr/lib/courier/libexec/courier/webmail
directory to your Apache's cgi-bin directory.
Most pre-built Courier packages typically do not
have a /usr/lib/courier/libexec/courier/webmail directory, but have
have an optional subpackage that installs webmlm
directly into the cgi-bin directory
Sometimes, very specialized environments may require multiple instances of WebMLM. For example, to support mailing list directories that are owned by different userids. This may not be supported by most generic, pre-built, Courier packages, and must be done manually.
Make separate copies of the webmlm program, one
for each instance of WebMLM.
Install them all in
your web server's cgi-bin directory. This can be done
with soft or hard links, but there must be separate instances of
webmlm.
Each instance of webmlm reads a configuration file
whose name is formed by appending “rc” to the command, and
looking for the file in /etc/courier.
For example, the unmodified webmlm reads
/etc/courier/webmlmrc.
If a second copy named webmlm2 exists, it will read
/etc/courier/webmlm2rc.
Additionally, the optional WEBMLMRC_DIR environment variable
overrides the /etc/courier portion of the configuration
filename.
If webmlm finds that this environment variable is set,
its contents replace the “/etc/courier” portion.
For example, a webmlm that reads “/etc/lists”
from WEBMLMRC_DIR
will open the /etc/lists/webmlmrc configuration file.
Similarly, if its own name, in the web server's script directory, is
webmlm2, it will open
/etc/lists/webmlm2rc.
Use Apache's “SetEnv” directory to set environment variables:
SetEnv WEBMLMRC_DIR /etc/lists
Use whatever mechanism makes sense for you to arrange a unique configuration file for each copy of the webmlm command.