Show HN: Tail out log files from multiple remote hosts with one command
github.comSo it's basically:
tail -f <(ssh -t host 'tail -f /var/log/sth') <(ssh -t host2 'tail -f /var/log/sth')
I have no problem with people writing cool little tools like this in whatever language, but there seems to be a chronic lack of understanding of what existing tools can do.
Henry Spencer 11/15/87
Those who do not understand Unix are condemned to reinvent it, poorly.
The interface to this tool is far nicer to work with. Can you replicate that interface with your command?
Serious question - I actually would like to see how you'd do it.
You can have something like this in your .bashrc:
This will take the host:file syntax of remtail and turn it into Plugawy's example. I haven't tested it, but if you echo "$com" it'll spit out Plugawy's code.multitail() { com="tail -f " for arg; do IFS=':' read -a array <<< "$arg" host="${array[0]}" file="${array[1]}" com="$com <(ssh -t $host 'tail -f $file')" done eval ${com} }nice solution! bash looping and arrays always seemed overly complex and confusing to me, but this is not nearly as complicated as I expected.
For another display, there's also multitail (http://www.vanheusden.com/multitail/) that you can run with a custom command, such as
ssh host tail -f /path/to/log
I use pssh [1].
pssh -H h1 -H h2 -P "tail -n 1000 /var/log/x.log"
pssh is great.
You'll want -i to avoid the buffered output that would make the log output hard to read.
And if your command doesn't contain anything that you need to escape from the shell, you don't need to quote the command.
And finally, since it implements BSD-style short flags correctly, so you can do "-Pi" instead of "-P -i".
Handy with a pre-defined list of hosts, too:
or a specific set of hosts:pssh -Pi -H "hosts.txt" tail -f /var/log/haproxy.logpssh -Pi -H `cat hosts.txt | grep prod` tail -f /var/log/haproxy.logNice tips, thank you!
> You can optionally use a credentials file in ~/.remtail.json of this format:
http://www.gnu.org/software/inetutils/manual/html_node/The-_...
or ssh config?
ssh config support is the first thing on the roadmap. I'd be happy to take a pull request for it.
Support would be good. I imagine a lot of people use their ssh config like I do; as a directory of servers that I have various scripts work with.
Good implementation but not for my tastes. node.js for this purpose? I think it's a bit heavy in this case.
mssh or cluster ssh is also effective in this manner, with the added flexibility of ssh terminals.
I've also used dsh[1] to accomplish the same thing. Never tried to use username and password for this though so that actually may be more of a pain with dsh. Also tailing multiple files on the same host is pretty cool.
[1] - http://www.tecmint.com/using-dsh-distributed-shell-to-run-li...
In my company, we have hundred machines and tailing done with ansible. If we want customize the log view, we can simply edit the playbook. I think it is very handy compared to we need additional npm package (and not to mention additional effort for customization).
If you want to send that tail output to your browser here is a little app I released last week: