For testing purposes I want to use socat to create virtual serial ports to use in my Python program.
I have limited success, but struggle again and again with the many options in socat. I use this command in Ubuntu Linux:
sudo socat -d -d pty,b9600,raw,echo=0,link=/dev/ttyS90 pty,b9600,raw,echo=0,link=/dev/ttyS91
As it should, it creates the virtual ports like /dev/pts/2 and 4, and links them to /dev/ttyS90 and *91. It does not work without sudo (it fails with unable to unlink for the *90, *91 ports, although the regular user is in the dialout group).
But as you see the permissions 'lrwxrwxrwx' look like reading/writing for everybody. However, this is NOT true: I CANNOT use these devices unless I am root. The file manager (=Nemo) gives this result:
The permissions are significantly different. Huh?
After issuing 'sudo chmod 777 /dev/ttyS90' (and same for *91) nothing changes in the terminal output, because it is already, but incorrectly, showing 777 permissions, but the Nemo output changes to
And now I can use the ports as regular user! How comes? Am I doing something wrong?
And one more socat problem: the above socat command gives an 8-bit, no-parity connection, but I really need a 7-bit, even-parity connection. My attempts to implement this by juggling some of the many options all failed. I am lost; any insight?
Try changing the permission on /dev/pts/2 and /dev/pts/4 instead of on the link
I would like to use a nginx front server on my Synology NAS for reverse-proxying pruposes. The goal is to provide a facade for the non-standard port numbers used by diverse webservers hosted the NAS. nginx should be listening on port 80, otherwise all this wouldn't make any sense.
However DSM comes out of the box with an Apache server that is already listening on port 80. What it does is really silly : it simply redirects to port 5000, which is the entry point to the NAS web manager (DSM).
What I would like to do is disable this functionality, making the port 80 available for my nginx server. How can I do this ?
Since Google redirects to here also for recent Synology DSM, I answer for DSM6 (based on http://tonylawrence.com/posts/unix/synology/freeing-port-80/)
From DSM6, nginx is used as HTTP server and redirection place. The following commands will leave ngingx in place, put run it at port 8880 instead of 80.
ssh into your Synology
sudo -s
cd /usr/syno/share/nginx
Make a backup of server.mustache, DSM.mustache, WWWService.mustache
cp server.mustache server.mustache.bak
cp DSM.mustache DSM.mustache.bak
cp WWWService.mustache WWWService.mustache.bak
sed -i "s/80/8880/g" server.mustache
sed -i "s/80/8880/g" DSM.mustache
sed -i "s/80/8880/g" WWWService.mustache
Optionally, you can also move 443 to 8881:
sed -i "s/443/8881/g" server.mustache
sed -i "s/443/8881/g" DSM.mustache
sed -i "s/443/8881/g" WWWService.mustache
Quit the shell (e.g., via Ctrl+D)
Go to the Control Panel and change any setting (e.g. the Application portal -> Reverse Proxy to forward http://YOURSYNOLOGYHOSTNAME:80 to http://localhost:8181 - 8181 is the port suggested by the pi-hole on DSM tutorial).
tl;dr Edit /usr/syno/etc/synoservice.d/httpd-user.cfg to look like:
{
"init_job_map":{"upstart":["httpd-user"]},
"user_controllable":"no",
"mtu_sensitive":"yes",
"auto_start":"no"
}
Then edit the stop on runlevel to be [0123456] in /etc/init/httpd-user.conf:
Syno-Server> cat /etc/init/httpd-user.conf
description "start httpd-user daemon"
author "Development Infrastructure Team"
console log
reload signal SIGUSR1
start on syno.share.ready and syno.network.ready
stop on runlevel [0123456]
...
... then reboot.
Background infrormation
The answer given by Backslash36 is not the easiest solution and it may also be more difficult to maintain. Here, I give a solution that also doesn't involve starting webstation, which most other solutions demand. Note, for updated documentation see here, which gives a lot of info in general about the synology systems.
It is important to note that the new DSM (> 5.x) use upstart now, so much of the previous documentation is not correct. There are two httpd jobs which run by default on the synology machines:
httpd-sys : serves the administration page(s) and is located on 5000/5001 by default.
httpd-user : this, somewhat confusingly, always runs even if the webstation program is not enabled.
If webstation:
is enabled: then this program serves the user webpages.
is not enabled: then this program sets /usr/syno/synoman/phpsrc/web as its DocumentRoot (/usr/syno/synoman/phpsrc/web/index.cgi -> /usr/syno/synoman/webman/index.cgi), meaning that a call to http://address.of.my.dsm will call the index.cgi file. This cgi file is what drives the redirect to 5000 (or whatever you have set the admin_port to be).
From the command line, you can check what the [secure_]admin_port is set to:
Syno-Server> get_key_value /etc/synoinfo.conf admin_port
5184
Syno-Server> get_key_value /etc/synoinfo.conf secure_admin_port
5185
where I have set mine differently.
Ok, now to the solution. The best solution is simply to stop the httpd-user daemon from starting. This is presumably what you want anyways (e.g. to start another server like `nginx' in a docker). To do this, edit the relevant upstart configuration file:
Syno-Server> cat /usr/syno/etc/synoservice.d/httpd-user.cfg
{
"init_job_map":{"upstart":["httpd-user"]},
"user_controllable":"no",
"mtu_sensitive":"yes",
"auto_start":"no"
}
so that the "auto_start" entry is "no" (as it is above). It will presumably be "yes" on your machine and by default. Then edit the stop on runlevel to be [0123456] in /etc/init/httpd-user.conf:
Syno-Server> cat /etc/init/httpd-user.conf
description "start httpd-user daemon"
author "Development Infrastructure Team"
console log
reload signal SIGUSR1
start on syno.share.ready and syno.network.ready
stop on runlevel [0123456]
...
This last step is to ensure that the httpd-user service does actually start, but then automatically stops. This is because there are otherwise a number of services that depend upon it actually starting. Reboot your machine and you will now see that nothing is listening (or forwarding) on Port 80.
Done ! It was tricky, but now I have it working just fine. Here is how I did it.
What follows requires to connect to the NAS with ssh, and may not be recommended if you want to keep warranty on your product (even though it's completely safe IMHO)
TL;DR : In the following files, replace all occurences of port 80 by a non standard port (for example, 8080). This will release the port 80 and make it available to use by whatever you want.
/etc/httpd/conf/httpd.conf
/etc/httpd/conf/httpd.conf-user
/etc/httpd/conf/httpd.conf-sys
/etc.defaults/httpd/conf/httpd.conf-user
/etc.defaults/httpd/conf/httpd.conf-sys
Note that modifying a subset of these files is probably sufficient (I could observe that the first one is actually computed from several others). I guess modifying the files in /etc.defaults/ would be enough, but if not, worst-case scenario is to modify all those files and you will be just fine.
Once this is done, don't forget to restart your NAS !
For those interested in how I found out
I'm not that familiar with the Linux filesystem, and even less with Apache configuration. But I knew that scripts dealing with startup processes are located in /etc/init. The Apache server that was performing the redirection would be certainly launched from there.
This is where I had to get my hands dirty. I performed some cat <filename> | grep 80 for the files in that directory I considered relevant, hoping to find a configuration line that would set a port number to 80.
That intuition paid off : /etc/init/httpd-user.conf contained the line echo "DocumentRoot \"/usr/syno/synoman/phpsrc/web\"" >> "${HttpdConf}" #port 80 to 5000. Bingo !
Looking at the top of the file, I discovered that the HttpdConf variable was referring to /etc/httpd/conf/httpd.conf. This is where the actual configuration was taking place.
From there it is relatively straightforward, even for those John Snow out there that know nothing about Apache configuration. The trick was to notice that httpd.conf was instantiated from some template at startup (and changing this file was therefore not enough). Performing a find / -name "*httpd.conf*", combined with some grep 80 gave me the list of files to modify.
When you look back all this looks obvious of course.
However I wish Synology gave us more flexibility, so we don't have to perform dirty hacks like that...
I installed rabbitmq using homebrew. I am trying to start rabbitmq server but I always get this error which I am unable to figure out why!
I have erlang installed and there is no other application running on the same port.
$ rabbitmq-server
{error_logger,{{2013,2,11},{22,37,49}},"Can't set short node name!\nPlease check your configuration\n",[]}
{error_logger,{{2013,2,11},{22,37,49}},crash_report,[[{initial_call,{net_kernel,init,['Argument__1']}},{pid,},{registered_name,[]},{error_info,{exit,{error,badarg},[{gen_server,init_it,6,[{file,"gen_server.erl"},{line,320}]},{proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}]}},{ancestors,[net_sup,kernel_sup,]},{messages,[]},{links,[]},{dictionary,[{longnames,false}]},{trap_exit,true},{status,running},{heap_size,610},{stack_size,24},{reductions,249}],[]]}
{error_logger,{{2013,2,11},{22,37,49}},supervisor_report,[{supervisor,{local,net_sup}},{errorContext,start_error},{reason,{'EXIT',nodistribution}},{offender,[{pid,undefined},{name,net_kernel},{mfargs,{net_kernel,start_link,[[rabbitmqprelaunch1593,shortnames]]}},{restart_type,permanent},{shutdown,2000},{child_type,worker}]}]}
{error_logger,{{2013,2,11},{22,37,49}},supervisor_report,[{supervisor,{local,kernel_sup}},{errorContext,start_error},{reason,shutdown},{offender,[{pid,undefined},{name,net_sup},{mfargs,{erl_distribution,start_link,[]}},{restart_type,permanent},{shutdown,infinity},{child_type,supervisor}]}]}
{error_logger,{{2013,2,11},{22,37,49}},std_info,[{application,kernel},{exited,{shutdown,{kernel,start,[normal,[]]}}},{type,permanent}]}
{"Kernel pid terminated",application_controller,"{application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}}"}
Crash dump was written to: erl_crash.dump
Kernel pid terminated (application_controller) ({application_start_failure,kernel,{shutdown,{kernel,start,[normal,[]]}}})
btw, erl -sname abc gives the same output
Update:
This is what I have in /etc/hosts
127.0.0.1 localhost
255.255.255.255 broadcasthost
check your computer name and your short host name or alias name in /etc/hosts, match this
Check your computer name [wendy#nyc123]$
nyc123 is your computer name
Check your short hostname
[wendy#nyc123]$ hostname -s
[wendy#nyc123]$ nyc456
This error could happen because your computer name and short host name didn't match. To match this, you can change the computer hostname or alias name.
Change computer host name
[wendy#nyc123]$ hostname nyc456
close your terminal and open again
[wendy#nyc456]$
the computer name has changed
or
Change alias name in /etc/hosts
127.0.0.1 nyc123.com nyc123
save and check again
[wendy#nyc123]$ hostname -s
[wendy#nyc123]$ nyc123
Restart your rabbitmq!
[root#nyc123]$ rabbitmq-server start</p>
RabbitMQ 3.6.0. Copyright (C) 2007-2015 Pivotal Software, Inc.</p>
## ## Licensed under the MPL. See http://www.rabbitmq.com/</p>
## ##</p>
########## Logs: /var/log/rabbitmq/rabbitmq#nyc123.com.log</p>
###### ## /var/log/rabbitmq/rabbitmq#nyc123.com-sasl.log</p>
##########</p>
Starting broker... completed with 6 plugins.</p>
I looked for a similar error on google, and it looks like it can happen if your /etc/hosts file is in the wrong format. Try fixing it and see if that helps.
References:
http://www.ejabberd.im/node/18
Explanation on RabbitMQ Mailing list
Edit: For completeness, it seems like setting a long name (of the form abc#abc) worked.
Found the answer here:
control rabbitmq 'name' not 'sname'
Set your machine name to something simple and make it an alias to locahost
I also encountered this problem yesterday and found the root cause:
I had changed my system's hostname to a "long" name, pm3(hc desktop).
If your server's hostname is long or invalid, Linux can still work and no error message is prompted to you. As you just modify the /etc/hostname file and reboot. However, the rabbitmq server may not work and give this "short-name" error message to you.
I changed hostname back to "pm3", rebooted and everything went well.
I solved this issue changing the computer name (on windows 8.1). The problem was that the name had a strange character (é) spanish letter. My computer name was Andrés and I changed it to Andres, restarted my computer and everything worked well. I think that Rabbit could not recognize that name (Andrés) for that strange character.
remove old style config file /etc/rabbitmq/rabbitmq.config
and use rabbitmq.conf
with listeners.tcp.default = 5672
after that restart rabbitmq server again
In my case that solved the issue in ec2 instance