I'm currently using the ad-hoc command ansible ubuntu -a "ls -l /var/run/reboot-required" to get a list of servers that require reboot. However, the end result is a list of all servers, and either the info about the indicated file or an error that the file does not exist.
I'm familiar enough with playbooks to create one that actually does the reboot, but I don't want that. I just want a nice (and relatively neat) list of servers that still require a reboot.
A more generic solution of getting a list of servers that meet some criteria (e.g. have a variable set) would also be quite helpful.
Not easy because the proper way is checking the existence of the file with stat, saving it to a variable and create a list when: var.stat.exists.
If you want to do in one line and you don't mind using bash scripting, do:
ansible ubuntu -m stat -a "path=/var/run/reboot-required" -o | grep -v '{"exists": false}' | awk -F\| '{ print $1 }'
Hope it helps
I want to use wget in sh script but I don't want to download wget url.How can I do this ? This script is getting load average with this code uptime | awk -F'[a-z]:' '{ print $2}' and I'll pass this values to php script with wget.
If you want to pipe the document instead of downloading it to a file, use the -O option:
wget -O - URL | command
Redirecting to the filename - means to send to standard output instead of a file.
I am having trouble understanding your question, but I will attempt to rephrase it and suggest a solution.
My guess is that you want to show the load averages of a remote server on a webpage, via php. With that assumption, let me show you an easier way to do that. This way requires that you have access via ssh to the remote computer, and that your local computer can access the remote computer with a ssh key.
Basically, you will use ssh to execute a command on the remote machine, then save the output (load averages) locally (somewhere that your web server can access them). Then you will include the load average file in your php script.
First, you need to get the load average of the remote computer and save it locally. To do so, run this command:
ssh [remote username]#[address of remote computer] "uptime" | awk -F'[a-z]:' '{ print $2}' > [path to where you want to save the load average]
Here is an example:
ssh jake#10.0.0.147 "uptime" | awk -F'[a-z]:' '{ print $2}' > /var/www/load_average.txt
Next, you need to setup your php script, it will looking something like this:
<?php
include "load_average.txt";
>
You should also setup a cronjob to request the information regularly so that it is up to date.
This one is a puzzler. If I run a command from the command line to copy a file remotely it works perfectly. If I run that same command inside a script on the server (that hosts Hudson), it runs perfectly as well, same for running the job as hudson from the command line. However, if I run that exact command as a function inside a bash script from a Hudson job, it fails with:
cp: cannot stat '/opt/flash_board.tar.gz': No such file or directory
The variable is defined as:
original_tarball=flash_board.tar.gz
and is in scope (variable expansion works correctly in the script).
The original command is:
ssh -n -o stricthostkeychecking=no root#$IP_ADDRESS ssh -n -o stricthostkeychecking=no 169.254.0.2 cp /opt/$original_tarball /opt/$original_tarball.bak
I've also tried it as:
ssh -n -p 1601 -o stricthostkeychecking=no root#$IP_ADDRESS cp /opt/$original_tarball /opt/$original_tarball.bak
which points to the correct port, but fails in exactly the same way.
For reference all the variables have been checked to be valid. I originally thought this was a substitution error, but that doesn't seem to be the case, so then I tried running it with Hudson credentials as:
sudo -u hudson ssh -n -o stricthostkeychecking=no root#$IP_ADDRESS ssh -n -o stricthostkeychecking=no 169.254.0.2 cp /opt/$original_tarball /opt/$original_tarball.bak
I get the exact same results (it works). So it's only when this command is run from a Hudson job that it fails.
Here's the sequence of events:
Hudson job sets parameters & calls a shell script.
A function inside the script tries to copy the files remotely from an embedded Montevista (Linux) board across an SPI bus to a second embedded Arago (Linux) board
Both boards are physically on the same mother board, but there's no way to directly access the Arago board except through a serial console session (which isn't feasible, this is an automation job that runs across the network).
I've tried this using ssh with -p 1601 (the correct port to the Arago side).
Can I use scp to copy a remote file to the same location as the remote file with a different file extension?
Something like:
scp -o stricthostkeychecking=no root#$IP_ADDRESS /opt/$original_tarball /opt/$original_tarball.bak
I had a couple of the devs take a look at this and they were stumped as well. Anyone got any ideas (A) why this fails & (B) how to work around it. I'm pretty sure I can write a script to run locally on the remote machine, but that doesn't seem like it should be necessary.
Oh, and if I run the exact same command on the Montevista board (which means I don't have to go across the SPI bus (169.254.0.2), it works perfectly from the Hudson job.
So, this turned out to be something completely unrelated to the question. I broke the problem down into little pieces with a test Hudson script, adding more and more complexity from the original script till it failed as before.
It turned out to be pilot error, I'd written an if statement to differentiate between the two boards (Arago & Montevista) and then abstracted out the variables passed to the if statement to the point where it was ambiguous which board was being passed in, so the if logic always grabbed the first match (as it should) and the flash script I was trying to copy on the Arago board didn't exist on the Montevista board (well, it has a different name) so the error returned was absolutely correct.
Sorry for the spin up and thanks for all the effort to help.
cp: cannot stat '/opt/flash_board.tar.gz': No such file or directory
This is saying that Hudson cannot see the file. I would do a ls -la /opt in that shell script of yours. This will show you the permissions on the /opt directory, and whether your script can list that file.
While you're at it, do a du -f on the Hudson machine too and see if that /opt directory is a remote mount or something that could be problematic.
You've already said that you logged in as the user that runs the Hudson task and execute it from the workspace directory.
Right now, I suspect that the directory permission is an issue.
The obvious way that goes wrong is that somehow it is being run on the wrong machine, possibly due to either a line length limit, or to weird quoting issues.
I'd try changing the command to … uname -a or … hostname -f to see if you get the right machine. Or, alternatively, … cp /proc/cpuinfo /tmp/this-machine and then see which machine gets the file.
edit: I see now that OP has answered his own question. I guess I'll leave this here in case it helps any future visitors with similar issues. I guess I should add "or not running the command you thing you're running" to the reasons why it could happen.
I want to install a software library (SWIG) on a list of computers (Jenkins nodes). I'm using the following script to automate this somewhat:
NODES="10.8.255.70 10.8.255.85 10.8.255.88 10.8.255.86 10.8.255.65 10.8.255.64 10.8.255.97 10.8.255.69"
for node in $NODES; do
scp InstallSWIG.sh root#$node:/root/InstallSWIG.sh
ssh root#$node sh InstallSWIG.sh
done
This way it's automated, except for the password request that occur for both the scp and ssh commands.
Is there a way to enter the passwords programmatically?
Security is not an issue. I’m looking for solutions that don’t involve SSH keys.
Here’s an expect example that sshs in to Stripe’s Capture The Flag server and enters the password automatically.
expect <<< 'spawn ssh level01#ctf.stri.pe; expect "password:"; send "e9gx26YEb2\r";'
With SSH the right way to do it is to use keys instead.
# ssh-keygen
and then copy the *~/.ssh/id_rsa.pub* file to the remote machine (root#$node) into the remote user's .ssh/authorized_keys file.
You can perform the task using empty, a small utility from sourceforge. It's similar to expect but probably more convenient in this case. Once you have installed it, your first scp will be accomplished by following two commands:
./empty -f scp InstallSWIG.sh root#$node:/root/InstallSWIG.sh
echo YOUR_SECRET_PASSWORD | ./empty -s -c
The first one starts your command in the background, tricking it into thinking it's running in interactive mode on a terminal. The other one sends it data from stdin. Of course, putting your password anywhere on command line is risky due to shell history being preserved, users being able to see it in ps results etc. Not secure either, but a bit better thing would be to store the password in a file and redirect the second command's input from that file instead of using echo and a pipe.
After copying to the server, you can run the script in a similar manner:
./empty -f ssh root#$node sh InstallSWIG.sh
echo YOUR_SECRET_PASSWORD | ./empty -s -c
You could look into setting up passwordless ssh keys for that. Establishing Batch Mode Connections between OpenSSH and SSH2 is a starting point, you'll find lots of information on this topic on the web.
Wes' answer is the correct one but if you're keen on something dirty and slow, you can use expect to automate this.
I've searched around a bit for similar questions, but other than running one command or perhaps a few command with items such as:
ssh user#host -t sudo su -
However, what if I essentially need to run a script on (let's say) 15 servers at once. Is this doable in bash? In a perfect world I need to avoid installing applications if at all possible to pull this off. For argument's sake, let's just say that I need to do the following across 10 hosts:
Deploy a new Tomcat container
Deploy an application in the container, and configure it
Configure an Apache vhost
Reload Apache
I have a script that does all of that, but it relies on me logging into all the servers, pulling a script down from a repo, and then running it. If this isn't doable in bash, what alternatives do you suggest? Do I need a bigger hammer, such as Perl (Python might be preferred since I can guarantee Python is on all boxes in a RHEL environment thanks to yum/up2date)? If anyone can point to me to any useful information it'd be greatly appreciated, especially if it's doable in bash. I'll settle for Perl or Python, but I just don't know those as well (working on that). Thanks!
You can run a local script as shown by che and Yang, and/or you can use a Here document:
ssh root#server /bin/sh <<\EOF
wget http://server/warfile # Could use NFS here
cp app.war /location
command 1
command 2
/etc/init.d/httpd restart
EOF
Often, I'll just use the original Tcl version of Expect. You only need to have that on the local machine. If I'm inside a program using Perl, I do this with Net::SSH::Expect. Other languages have similar "expect" tools.
The issue of how to run commands on many servers at once came up on a Perl mailing list the other day and I'll give the same recommendation I gave there, which is to use gsh:
http://outflux.net/unix/software/gsh
gsh is similar to the "for box in box1_name box2_name box3_name" solution already given but I find gsh to be more convenient. You set up a /etc/ghosts file containing your servers in groups such as web, db, RHEL4, x86_64, or whatever (man ghosts) then you use that group when you call gsh.
[pdurbin#beamish ~]$ gsh web "cat /etc/redhat-release; uname -r"
www-2.foo.com: Red Hat Enterprise Linux AS release 4 (Nahant Update 7)
www-2.foo.com: 2.6.9-78.0.1.ELsmp
www-3.foo.com: Red Hat Enterprise Linux AS release 4 (Nahant Update 7)
www-3.foo.com: 2.6.9-78.0.1.ELsmp
www-4.foo.com: Red Hat Enterprise Linux Server release 5.2 (Tikanga)
www-4.foo.com: 2.6.18-92.1.13.el5
www-5.foo.com: Red Hat Enterprise Linux Server release 5.2 (Tikanga)
www-5.foo.com: 2.6.18-92.1.13.el5
[pdurbin#beamish ~]$
You can also combine or split ghost groups, using web+db or web-RHEL4, for example.
I'll also mention that while I have never used shmux, its website contains a list of software (including gsh) that lets you run commands on many servers at once. Capistrano has already been mentioned and (from what I understand) could be on that list as well.
Take a look at Expect (man expect)
I've accomplished similar tasks in the past using Expect.
You can pipe the local script to the remote server and execute it with one command:
ssh -t user#host 'sh' < path_to_script
This can be further automated by using public key authentication and wrapping with scripts to perform parallel execution.
You can try paramiko. It's a pure-python ssh client. You can program your ssh sessions. Nothing to install on remote machines.
See this great article on how to use it.
To give you the structure, without actual code.
Use scp to copy your install/setup script to the target box.
Use ssh to invoke your script on the remote box.
pssh may be interesting since, unlike most solutions mentioned here, the commands are run in parallel.
(For my own use, I wrote a simpler small script very similar to GavinCattell's one, it is documented here - in french).
Have you looked at things like Puppet or Cfengine. They can do what you want and probably much more.
For those that stumble across this question, I'll include an answer that uses Fabric, which solves exactly the problem described above: Running arbitrary commands on multiple hosts over ssh.
Once fabric is installed, you'd create a fabfile.py, and implement tasks that can be run on your remote hosts. For example, a task to Reload Apache might look like this:
from fabric.api import env, run
env.hosts = ['host1#example.com', 'host2#example.com']
def reload():
""" Reload Apache """
run("sudo /etc/init.d/apache2 reload")
Then, on your local machine, run fab reload and the sudo /etc/init.d/apache2 reload command would get run on all the hosts specified in env.hosts.
You can do it the same way you did before, just script it instead of doing it manually. The following code remotes to machine named 'loca' and runs two commands there. What you need to do is simply insert commands you want to run there.
che#ovecka ~ $ ssh loca 'uname -a; echo something_else'
Linux loca 2.6.25.9 #1 (blahblahblah)
something_else
Then, to iterate through all the machines, do something like:
for box in box1_name box2_name box3_name
do
ssh $box 'commmands_to_run_everywhere'
done
In order to make this ssh thing work without entering passwords all the time, you'll need to set up key authentication. You can read about it at IBM developerworks.
You can run the same command on several servers at once with a tool like cluster ssh. The link is to a discussion of cluster ssh on the Debian package of the day blog.
Well, for step 1 and 2 isn't there a tomcat manager web interface; you could script that with curl or zsh with the libwww plug in.
For SSH you're looking to:
1) not get prompted for a password (use keys)
2) pass the command(s) on SSH's commandline, this is similar to rsh in a trusted network.
Other posts have shown you what to do, and I'd probably use sh too but I'd be tempted to use perl like ssh tomcatuser#server perl -e 'do-everything-on-one-line;' or you could do this:
either scp the_package.tbz tomcatuser#server:the_place/.
ssh tomcatuser#server /bin/sh <<\EOF
define stuff like TOMCAT_WEBAPPS=/usr/local/share/tomcat/webapps
tar xj the_package.tbz or rsync rsync://repository/the_package_place
mv $TOMCAT_WEBAPPS/old_war $TOMCAT_WEBAPPS/old_war.old
mv $THE_PLACE/new_war $TOMCAT_WEBAPPS/new_war
touch $TOMCAT_WEBAPPS/new_war [you don't normally have to restart tomcat]
mv $THE_PLACE/vhost_file $APACHE_VHOST_DIR/vhost_file
$APACHECTL restart [might need to login as apache user to move that file and restart]
EOF
You want DSH or distributed shell, which is used in clusters a lot. Here is the link: dsh
You basically have node groups (a file with lists of nodes in them) and you specify which node group you wish to run commands on then you would use dsh, like you would ssh to run commands on them.
dsh -a /path/to/some/command/or/script
It will run the command on all the machines at the same time and return the output prefixed with the hostname. The command or script has to be present on the system, so a shared NFS directory can be useful for these sorts of things.
Creates hostname ssh command of all machines accessed.
by Quierati
http://pastebin.com/pddEQWq2
#Use in .bashrc
#Use "HashKnownHosts no" in ~/.ssh/config or /etc/ssh/ssh_config
# If known_hosts is encrypted and delete known_hosts
[ ! -d ~/bin ] && mkdir ~/bin
for host in `cut -d, -f1 ~/.ssh/known_hosts|cut -f1 -d " "`;
do
[ ! -s ~/bin/$host ] && echo ssh $host '$*' > ~/bin/$host
done
[ -d ~/bin ] && chmod -R 700 ~/bin
export PATH=$PATH:~/bin
Ex Execute:
$for i in hostname{1..10}; do $i who;done
There is a tool called FLATT (FLexible Automation and Troubleshooting Tool) that allows you to execute scripts on multiple Unix/Linux hosts with a click of a button. It is a desktop GUI app that runs on Mac and Windows but there is also a command line java client.
You can create batch jobs and reuse on multiple hosts.
Requires Java 1.6 or higher.
Although it's a complex topic, I can highly recommend Capistrano.
I'm not sure if this method will work for everything that you want, but you can try something like this:
$ cat your_script.sh | ssh your_host bash
Which will run the script (which resides locally) on the remote server.
Just read a new blog using setsid without any further installation/configuration besides the mainstream kernel. Tested/Verified under Ubuntu14.04.
While the author has a very clear explanation and sample code as well, here's the magic part for a quick glance:
#----------------------------------------------------------------------
# Create a temp script to echo the SSH password, used by SSH_ASKPASS
#----------------------------------------------------------------------
SSH_ASKPASS_SCRIPT=/tmp/ssh-askpass-script
cat > ${SSH_ASKPASS_SCRIPT} <<EOL
#!/bin/bash
echo "${PASS}"
EOL
chmod u+x ${SSH_ASKPASS_SCRIPT}
# Tell SSH to read in the output of the provided script as the password.
# We still have to use setsid to eliminate access to a terminal and thus avoid
# it ignoring this and asking for a password.
export SSH_ASKPASS=${SSH_ASKPASS_SCRIPT}
......
......
# Log in to the remote server and run the above command.
# The use of setsid is a part of the machinations to stop ssh
# prompting for a password.
setsid ssh ${SSH_OPTIONS} ${USER}#${SERVER} "ls -rlt"
Easiest way I found without installing or configuring much software is using plain old tmux. Say you have 9 linux servers. Pick a box as your main. Start a tmux session:
tmux
Then create 9 split tmux panes by doing this 8 times:
ctrl-b + %
Now SSH into each box in each pane. You'll need to know some tmux shortcuts. To navigate, press:
ctrl+b <arrow-keys>
Once your logged in to all your boxes on each pane. Now turn on pane synchronization where it lets you type the same thing into each box:
ctrl+b :setw synchronize-panes on
now when you press any keys, it will show up on every pane. to turn it off, just make on to off. to cycle resize panes, press ctrl+b < space-bar >.
This works alot better for me since I need to see each terminal output as sometimes servers crash or hang for whatever reason when downloading or upgrade software. Any issues, you can just isolate and resolve individually.