The output of command systemctl status dnsmasq with pexpect.spawn gets truncated.
pexpect.spawn('systemctl status dnsmasq', encoding='utf-8')
i = child.expect([".*\$ ", pexpect.EOF, pexpect.TIMEOUT])
if i == 1:
child.sendcontrol("c")
print(child.before)
See image of output below:
I tested this for sshd.service and result is same. However for other commands like sudo apt update and sudo apt upgrade, pexpect logs full output. What's causing this behavior and how to correct it?
By default the pty size is 24x80. Some programs would adjust their output format based on the pty size. You can explicitly set the pty size when calling spawn().
child = pexpect.spawn('systemctl status dnsmasq', encoding='utf-8',
dimensions=(9999, 9999) )
# rows, cols
Related
i'm trying to install Oracle11g, and this happened, is there a way to fix this?
i had tried to reboot and run the script runfixup.sh still can't resolve the problem.
I'm trying to install Oracle 11gR2 on Oracle Linux 7.4.
While the installer is performing prerequisite checks, we are getting error:
This is a prerequisite condition to test whether the OS kernel parameter semmni is properly set.
More details :
Expected Value : 128
Actual Value : 0
Now if I execute as root:
/sbin/sysctl -a | grep sem
kernel.sem = 32000 1024000000 500 128
Which means that semmni=128.
Can somebody tell me what I'm I doing wrong?
You need to issue the following command
[root#localhost ~]# /sbin/sysctl -p
the changes to take effect.
And then the value(the rightmost one returning below) might be checked by issuing
[root#localhost ~]# more /proc/sys/kernel/sem
32000 1024000000 500 128
Okay, hopefully I can explain this correctly as I have no idea what's causing this or how to resolve this.
For some reason bash commands (on a CentOS 6.x server) are displaying more information than "normally" and that causes issues with certain scripts. I have no clue if there is a name for this, but hopefully someone knows a solution for this.
First example.
Correct / good server:
[root#goodserver ~]# vzctl enter 3567
entered into CT 3567
[root#example /]#
(this is the correct behaviour)
Incorrect / bad server:
[root#badserver /]# vzctl enter 3127
Entering CT
entered into CT 3127
Open /dev/pts/0
[root#example /]#
With the "bad" server it will display more information as usual, like:
Entering CT
Open /dev/pts/0
It's like it parsing extra information on what it's doing.
Ofcourse the above is purely something cosmetic, however with several bash scripts we use, these issues are really issues.
A part of the script we use, uses the following command (there are more, but this is mainly a example of what's wrong):
DOMAIN=`vzctl exec $VEID 'hostname -d'`
The result of the above information is parsed in /etc/named.conf.
On the GOOD server it would be added in the named.conf like this:
zone "example.com" {
type master;
file "example.com";
allow-transfer {
200.190.100.10;
200.190.101.10;
common-allow-transfer;
};
};
The above is correct.
On the BAD server it would be added in the named.conf like this:
zone "Executing command: hostname -d
example.com" {
type master;
file "Executing command: hostname -d
example.com";
allow-transfer {
200.190.100.10;
200.190.101.10;
common-allow-transfer;
};
};
So it's add stuff of the action it does, in this example "Executing command: hostname -d"
Another example here when I run the command on a good server and on the bad server.
Bad server:
[root#bad-server /]# DOMAIN=`vzctl exec 3333 'hostname -d'`
[root#bad-server /]# echo $DOMAIN
Executing command: hostname -d example.com
Good server:
[root#good-server ~]# DOMAIN=`vzctl exec 4444 'hostname -d'`
[root#good-server ~]# echo $DOMAIN
example.com
My knowledge is limited, but I have tried several things checking rsyslog and the grub.conf, but nothing seems out of the ordinary.
I have no clue why it's displaying the extra information.
Probably it's something simple / stupid, but I have been trying to solve this for hours now and I really have no clue...
So any help is really appreciated.
Added information:
Both servers use: kernel.printk = 7 4 1 7
(I don't know if that's useful)
Well (thanks to Aaron for pointing me in the right direction) I finally found the little culprit which was causing all the issues I experienced with this script (which worked for every other server, so no need to change that obviously).
The issues were caused by the VERBOSE leven set in vz.conf (located in /etc/vz/ directory). There is an option in there called "VERBOSE" and in my case it was set to 3.
According to OpenVZ's website it does the following:
Increments logging level up from the default. Can be used multiple times.
Default value is set to the value of VERBOSE parameter in the global
configuration file vz.conf(5), or to 0 if not set by VERBOSE parameter.
After I changed VERBOSE=3 to VERBOSE=0 my script worked fine once again (as it did for every other server). :-)
So a big shoutout to Aaron for pointing me in the right direction. The answer is easy when you know where to look!
Sorry to say, but I am kinda disappointed by ndim's reaction. This is the 2nd time he was very unhelpful and rude in his response after that. He clearly didn't read the issue I posted correctly. Oh well.
I would make sure to properly parse the output of the command. In this case, we are only interested in lines of the form
entered into CT 12345
One way of doing this would be to pipe everything through sed and having sed print only the number when the line looks as above (untested, and I always forget which braces/brackets/parens need a backslash in front of them):
whateverthecommand | sed -n 's/^entered into CT ([0-9]{1,})$/\1/p'
I am working on a robot and my goal is to plot the state of the robot.
For now, my workflow is this:
Launch the program
Redirect the output in a file (robot/bash): rosrun explo explo_node > states.txt
Send the file to my local machine (robot/bash): scp states.txt my_desktop:/home/user
Plot the states with octave (desktop/octave): plot_data('states.txt')
Is there a simple solution to have the data in "real time"? For the octave side. I think that I can with not so much difficulty read from a file as an input and plot the data when data is added.
The problem is how do I send the data to a file?
I am opened to other solutions than octave. The thing is that I need to have 2d plot with arrows for the orientation of the robot.
Here's an example of how you could send the data over the network (as Andy suggested) and plot as it is generated (i.e. realtime). I also think this approach is the most flexible / appropriate.
To demonstrate, I will use a bash script that generates an
pair every 10th of a second, for the
function, in the range
:
#!/bin/bash
# script: sin.sh
for i in `seq 0 0.01 31.4`;
do
printf "$i, `echo "s($i)" | bc -l`\n"
sleep 0.1
done
(Don't forget to make this script executable!)
Prepare the following octave script (requires the sockets package!):
% in visualiseRobotData.m
pkg load sockets
s = socket();
bind(s, 9000);
listen(s, 1);
c = accept(s);
figure; hold on;
while ! isempty (a = str2num (char (recv (c, inf))))
plot (a(:,1), a(:,2), '*'); drawnow;
end
hold off;
Now execute things in the following order:
Run the visualiseRobotData script from the octave terminal.
(Note: this will block until a connection is established)
From your bash terminal run: ./sin.sh | nc localhost 9000
And watch the datapoints get plotted as they come in from your sin.sh script.
It's a bit crude, but you can just reload the file in a loop. This one runs for 5 minutes:
for i = 1:300
load Test/sine.txt
plot (sine(:,1), sine(:,2))
sleep (1)
endfor
You can mount remote directory via sshfs:
sshfs user#remote:/path/to/remote_dir local_dir
so you wouldn't have to load remote file. If sshfs is not installed, install it. To unmount remote directory later, execute
fusermount -u local_dir
To get a robot's data from Octave, execute (Octave code)
system("ssh user#host 'cd remote_dir; rosrun explo explo_node > states.txt'")
%% then plot picture from the data in local_dir
%% that is defacto the directory on the remote server
The problem
SNMPD is correctly delegating SNMP polling requests to another program but the response from that program is not valid. A manual run of the program with the same arguments is responding correctly.
The detail
I've installed the correct LSI raid drivers on a server and want to configure SNMP. As per the instructions, I've added the following to /etc/snmp/snmpd.conf to redirect SNMP polling requests with a given OID prefix to a program:
pass .1.3.6.1.4.1.3582 /usr/sbin/lsi_mrdsnmpmain
It doesn't work correctly for SNMP polling requests:
snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1
I get the following response:
Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
What I've tried
SNMPD passes two arguments, -g and <oid> and expects a three line response <oid>, <data-type> and <data-value>.
If I manually run the following:
/usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
I correctly get a correct three line response:
.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30
This means that the pass command is working correctly and the /usr/sbin/lsi_mrdsnmpmain program is working correctly in this example
I tried replacing /usr/sbin/lsi_mrdsnmpmain with a bash script. The bash script delegates the call and logs the supplied arguments and output from the delegated call:
#!/bin/bash
echo "In: '$#" > /var/log/snmp-pass-test
RETURN=$(/usr/sbin/lsi_mrdsnmpmain $#)
echo "$RETURN"
echo "Out: '$RETURN'" >> /var/log/snmp-pass-test
And modified the pass command to redirect to the bash script. If I run the bash script manually /usr/sbin/snmp-pass-test -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0 I get the correct three line response as I did when I ran /usr/sbin/lsi_mrdsnmpmain manually and I get the following logged:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: '.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30'
When I rerun the snmpget test, I get the same Error in packet... error and the bash script's logging shows that the captured delegated call output is empty:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: ''
If I modify the bash script to only echo an empty line I also get the same Error in packet... message.
I've also tried ensuring that the environment variables that are present when I manually call /usr/sbin/lsi_mrdsnmpmain are the same for the bash script but I get the same empty output.
Finally, my questions
Why would the bash script behave differently in these two scenarios?
Is it likely that the problem that exists with the bash scripts is the same as originally noticed (manually running program has different output to SNMPD run program)?
Updates
eewanco's suggestions
What user is running the program in each scenario?
I added echo "$(whoami)" > /var/log/snmp-pass-test to the bash script and root was added to the logs
Maybe try executing it in cron
Adding the following to root's crontab and the correct three line response was logged:
* * * * * /usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> /var/log/snmp-test-cron 2>&1
Grisha Levit's suggestion
Try logging the stderr
There aren't any errors logged
Checking /var/log/messages
When I run it via SNMPD, I get MegaRAID SNMP AGENT: Error in getting Shared Memory(lsi_mrdsnmpmain) logged. When I run it directly, I don't. I've done a bit of googling and I may need lm_sensors installed; I'll try this.
I installed lm_sensors & compat-libstdc++-33.i686 (the latter because it said it was a pre-requisite from the instructions and I was missing it), uninstalled and reinstalled the LSI drivers and am experiencing the same issue.
SELinux
I accidently stumbled upon a page about extending snmpd with scripts and it says to check the script has the right SELinux context. I ran grep AVC /var/log/audit/audit.log | grep snmp before and after running a snmpget and the following entry is added as a direct result from running snmpget:
type=AVC msg=audit(1485967641.075:271): avc: denied { unix_read unix_write } for pid=5552 comm="lsi_mrdsnmpmain" key=558265 scontext=system_u:system_r:snmpd_t:s0 tcontext=system_u:system_r:initrc_t:s0 tclass=shm
I'm now assuming that SELinux is causing the call to fail; I'll dig further...see answer for solution.
strace (eewanco's suggestion)
Try using strace with and without snmp and see if you can catch a system call failure or some additional hints
For completeness, I wanted to see if strace would have hinted that SELinux was denying. I had to remove the policy packages using semodule -r <policy-package-name> to reintroduce the problem then ran the following:
strace snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> strace.log 2>&1
The end of strace.log is as follows and unless I'm missing something, it doesn't seem to provide any hints:
...
sendmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\240$\2\4I\264-m\2"..., 61}], msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_IP, cmsg_type=, ...}, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 61
select(4, [3], NULL, NULL, {0, 999997}) = 1 (in [3], left {0, 998475})
brk(0xab9000) = 0xab9000
recvmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\242$\2\4I\264-m\2"..., 65536}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT) = 61
write(2, "Error in packet\nReason: (noSuchN"..., 81Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
) = 81
write(2, "Failed object: ", 15Failed object: ) = 15
write(2, "SNMPv2-SMI::enterprises.3582.5.1"..., 48SNMPv2- SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
) = 48
write(2, "\n", 1
) = 1
brk(0xaa9000) = 0xaa9000
close(3) = 0
exit_group(2) = ?
+++ exited with 2 +++
It was SELinux that was denying snmpd a delegated call to /usr/sbin/lsi_mrdsnmpmain (and probably beyond).
To identify it, I ran grep AVC /var/log/audit/audit.log and for each entry, I ran the following:
echo "<grepped-output>" | audit2allow -a -M <filename>
This creates a SELinux policy package that should allow the delegated call through. The package is then loaded using the following:
semodule -i <filename>.pp
I had to do this 5 times as there were different causes of denial (unix_read unix_write, associate, read write). I'll look to combine the modules into one.
Now when I run snmpget I get the correct delegated output:
SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1 = INTEGER: 34
I am trying to get a list of all the change packages used to update all the files in a PTC project. I used the following command:
si viewproject --recurse --fields=name,creationcpid,cpid,memberrev,indent --project=%Project% --hostname=%Host_name% --port=%port1% -Y
But I do not get all the CP used, only the first one. I also tried the command:
si rlog --recurse --format="{membername},{memberrev},{revision},{cpid},{author}\n" --noHeaderFormat --project=%Project% --hostname=%Host_name% --port=%port1%
Using the following cli command you will get all change packaged used by current user
si viewcps
But, viewcps accept --filter= where you can specify the project
si viewcps --hostname=%Host_name% --port=%port1% --filter=project:%Project%
This command need to be called recursively for each sub project because will return only change packages from first level in the specified project.
Usage: si viewcps options... issue|issue:change package id...; options are:
--fields=field1[:width1],field2[:width2]... where fieldn can be any of: closeddate,cptype,creationdate,deployrequestid,deployrequeststate,deploytarget,description,id,issue,propagated,propagatedby,siserver,stage,stagingsystem,state,summary,user The fields to be displayed
--filter=user:name
issueid:issue
state[:closed|:open|:submitted|:accepted|:rejected|:discarded|:commitfailed]
closeddate:<date>
creationdate:<date>
membertype[:member|:subproject]
member:<expression>
project:<expression>
variant:<expression>
mainline
description:<expression>
summary:<expression>
typemodifier[:committed|:pending]
type[:add|:addfromarchive|:drop|:import|:exclusivelock|:nonexclusivelock|:renamefrom|:renameto|:movememberfrom|:movememberto|:update|:updatearchive|:updaterevision|:createsubproject|:addsubproject|:addsharedsubproject|:configuresubprojectfrom|:configuresubprojectto|:movesubprojectfrom|:movesubprojectto|:dropsubproject]
hasissue
pendingreviewby:name
acceptedby:name[;<date>]
rejectedby:name[;<date>]
cptype[:development|:propagation|:deploy|:staging|:resolution]
stagingsystem:<expression>
stage:<expression>
deploytarget:<expression>
deployrequeststate[|:cancelled|:cleanedup|:cleaningup|:cleanupfailed|:created|:deployed|:executed|:executing|:packageactionsfailed|:packagecontentfailed|:packagingactions|:packagingcontent|:prepared|:preparing|:queuedonsource|:queuedontarget|:readytodeploy|:readytotransfer|:rollbackfailed|:rolledback|:rollingback|:stopped|:transferfailed|:transferring]
deployrequestid:<expression> The filter used to select change packages
--height=value The height in pixels of the windows
--myReviews Show the change packages awaiting review by current user
--query=value The query used to select change packages
--width=value The width in pixels of the windows
-x value The x location in pixels of the window
-y value The y location in pixels of the window
-? Shows the usage for a command
--[no]batch Control batch mode (no user interaction in batch mode)
--cwd=value Act as if command executed in specified directory
-F value Read the selection from a specified file
--forceConfirm=[yes|no] Specify an answer to all confirmation questions
-g User interaction should happen via the GUI
--gui User interaction should happen via the GUI
--hostname=value Hostname of server
-N Responds to all confirmations with "no"
--no Responds to all confirmations with "no"
--password=value Credentials (e.g., password) to login with
--[no]persist Control persistence of CLI views
--port=value TCP/IP port number of server
--quiet Control status display
--selectionFile=value Read the selection from a specified file
--settingsUI=[gui|default] Control UI for command options
--status=[none|gui|default] Control status display
--usage Shows the usage for a command
--user=value Username to login to server with
-Y Responds to all confirmations with "yes"
--yes Responds to all confirmations with "yes"