rpipe
Table of Contents
1 Overview
Rpipe is a simple tool for forwarding the content of the local file to the stdin of a program running on a remote host via TCP. The tool was created when I needed to run GNU Mailman1 in a docker container without MTA in it.
It implements a slightly modified version of TCPMUX2 protocol. The same
binary (rpipe) serves both as a server (on the remote end) and as a
client (on the local end). See the Example section below.
2 Istallation
To build the program you will need GNU Make. Unpack the tarball, change to the source directory and run
make
To install the program, run
make install
as root. The binary will be installed in /usr/local/bin and the manpage in
/usr/local/share/man/man1. To change these defaults, use the
PREFIX variable. E.g. to install everything under /usr run
make install PREFIX=/usr
A number of variables is available to further fine-tune it:
BINDIRDefault installation directory for the
rpipebinary. Defaults to$(PREFIX)/bin.MANDIRDefault root directory for the manual pages. Defaults to
$(PREFIX)/share/man.MAN1DIRInstallation directory for manuals in Section 1. Defaults to$(MANDIR)/man1.
3 Example
The following configuration allows the system administrator to run mailman in a docker container and to distribute messages via the usual list mechanism using MTA on the host machine.
3.1 Server configuration
The container exposes TCP port 1 and runs the following command:
/usr/bin/rpipe -s -vv -udaemon -gsmmsp /opt/mailman/mail/mailman
The -s option tells it to run as a server. The two -v options select
maximal output verbosity. The diagnostics will be issued to the standard
error. The -u and -g options specify the user and group to run mailman
as. The only non-optional argument supplies the full pathname to the
binary to run when a request is accepted from the client.
For a detailed description of rpipe command line options, see rpipe(1).
The rpipe utility runs in foreground.
3.2 Client configuration
Normally Mailman-based mailing lists are configured as follows (using sendmail-style aliases):
some-list: "|/opt/mailman/mail/mailman post some-list" some-list-admin: "|/opt/mailman/mail/mailman admin some-list" ...
Just replace the program name after the pipe symbol, so that your list setup becomes:
some-list: "|/usr/bin/rpipe -a 172.17.0.2 post some-list" some-list-admin: "|/usr/bin/rpipe -a 172.17.0.2 admin some-list" ...
Replace 172.17.0.2 with the actual IP of the container.
4 Documentation
The documentaion for rpipe is available online.
5 Other references:
6 Bug reports
If you think you found a bug in rpipe or in its documentation, please send a mail to Sergey Poznyakoff or use the web bug tracker.
7 License
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, 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 General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.