Hello, How about adding:
alias labssh='ssh -i ~/.ssh/id_rsa.work' to your shell profile (.bashrc or whatever)? Then you can just do 'labssh <ip-address>' and the alias expansion makes ssh use the appropriate ID file. Regards, Geoff. Geoff Back What if we're all just characters in someone's nightmares? On 26/11/2022 13:14, Feng Shao wrote: > Thanks for the reply Petr. > Let me explain more about the motivation: I am a developer and our > testers test the code on various environments, including VMs on cloud > and k8s worker nodes from cloud providers. These machines and IPs are > not provisioned/allocated by dnsmasq. For cost reason, these > environments only lives for a short period of time, like one week or > so, and testers provision these IPs directly without awareness of > network administrators, that’s also why we don’t configure hostname > for these machines in DNS system. Also I can not know in advance the > list of possible IPs. > > Whenever tester find some issue or need help, they give me the IP of > the environments and I need to ssh to that environment. Because I will > probably login to that same machine several times since the testers > are testing my code on that machine recently, I want to setup > passwordless login. So I normally ssh-copy-id -i <~/.ssh/id_rsa.work > <http://id_rsa.work>> <IP>first, then ssh to that machine. In order to > instruct ssh to use my ssh key when connecting to that IP, I have > below lines in my .ssh/config: > > Host *.mylab > User root > IdentityFile ~/.ssh/id_rsa.wor <http://id_rsa.work/>k > > And lines like below in /etc/hosts: > address=/123.123.123.123 > <http://123.123.123.123>.mylab/123.123.123.123 <http://123.123.123.123/> > address=/123.123.123.12 <http://123.123.123.123>4.mylab/123.123.123.12 > <http://123.123.123.123/>4 > > So that I can now “ssh 123.123.123.123.mylab” > > As you can see, the problem here is, whenever a new IP comes, I need > to add a new entry in /etc/hosts. So what I want is any <IP>.mylab is > resolved to <IP>. > > A key pair can be specified when creating VM on cloud, but I can not > ask every tester add my ssh key pair when creating VM. > > > Petr Menšík <pemen...@redhat.com>于2022年11月25日 周五19:52写道： > > Did you know that dnsmasq registers all hosts by their name, if > they send their own hostname when requesting DHCP from dnsmasq? > Just use domain=mylab and have that host send hostname. It would > make using names possible without any additional configuration. > > I do not get what is the advantage of having IP suffixed by some > domain. It looks like IP address, but it is even longer. Names of > machines should be easy to remember or use, I doubt that would be > the case here. > > I think we have new feature conf-script, which can generate > dnsmasq configuration on the output. But I doubt we have a > possible code for what you describe. Could you please describe > more about intended usage? Why isn't using just hostname for each > host enough? Using dhcp-host seems enough for similar uses. > > I think DLZ plugins for BIND9 are able to do similar things to > your request, but that would be very heavy-weight solution. I > think more motivation for your current design should be shared, > because I do not understand advantage of your solution. > > Cheers, > Petr > > On 11/23/22 06:47, Feng Shao wrote: >> There are a bunch of machines in our lab, and we normally don't >> have DNS records configured for them, only accessing by IP. In >> order to ssh to them with key auth, I have a config in my >> .ssh/config like >> >> Host *.mylab >> User root >> IdentityFile ~/.ssh/id_rsa.work <http://id_rsa.work/> >> >> and I have some "address=/123.123.123.123 >> <http://123.123.123.123>.mylab/123.123.123.123 >> <http://123.123.123.123/>" line in dnsmasq.conf. The problem here >> is I need to add an entry whenever a new IP comes. >> >> Can this configuration be dynamically? For example, >> "address=/*.mylab/somecmd %1", where "somecmd" is a external >> command and %1 will be replaced by the name in A/AAAA request. So >> that for any DNS request to *.mylab, dnsmasq invoke this external >> command and pass the name as argument, the output of external >> command, which will be interpreted as IPv4/IPv6 addr then >> responsed to client? >> >> _______________________________________________ >> Dnsmasq-discuss mailing list >> Dnsmasq-discuss@lists.thekelleys.org.uk >> https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss > > -- > Petr Menšík > Software Engineer, RHEL > Red Hat, https://www.redhat.com/ > PGP: DFCF908DB7C87E8E529925BC4931CA5B6C9FC5CB > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasq-discuss@lists.thekelleys.org.uk > https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss > > > _______________________________________________ > Dnsmasq-discuss mailing list > Dnsmasq-discuss@lists.thekelleys.org.uk > https://lists.thekelleys.org.uk/cgi-bin/mailman/listinfo/dnsmasq-discuss
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