= HOW I CREATED A NEW VM AT RETHEMHOSTING (CYMRU) FOR MUMBLE

A quick guide for how to make VMs.

18 Sep 2015

== WHAT YOU WILL NEED

  • Access to many git repositories
  • Sudo access all over the place
  • GPG key that can decrypt files in those git repositories
  • Your ssh configuration file set up to use the appropriate ProxyCommand magic to ssh into various .torproject.org hosts.
  • Enough Unix shell skillz to be dangerous to yourself and others

== THE STEPS

  • Go to the approach for rethemhosting. You can find it in hosts-extra-info in the tor-passwords repository.

    If your browser hates you when you do this, it's possible that rethemhosting still hasn't upgraded their DH parameters to something non-embarrassing. Disable the DHE ciphersuites and try again. Very sorry. I emailed them about it.

  • Pick an onion species name:

    https://en.wikipedia.org/wiki/List_of_Allium_species

    (I went with "tuburosum", since I have some of that in my fridge. Try not to pick something that has the first 3 characters in common with some other host.)

  • In the rethemhosting interface, go to the list of instances, then select "add instance" (currently towards the top right.)

    It will walk you through a wizard.

    1: Select ISO

    2: Select "my ISOs", then tor-debian-7.8-20150221.

    (If there is something more recent than that, ask weasel if it is safe to use!)

    You will have only one option for hypervisor.

    3: Configure the CPU/RAM requirements as needed

    4: Select 20 GB disk, always. More disks can get added later.

    5: Is easy; nothing to do here.

    6: Select 'Tor External Dual', then make it the default, then deselect the original network.

    Weasel explains: "one is I think an internal network that isn't routed anywhere, and the two external things are two networks that are in the internet but with different address space. I think the first tor external one is full."

    7: Give it a name. No group.

  • Launch the VM! It will boot from a custom install CD.

  • Did you think you were done? Lolololollol11ol!

  • Once the VM is running, click on it in the rethem interface, and go to the NICs tab. Learn the IP addresses (v4 and v6) and gateways for the new VM.

  • Edit the domains git repository. (It is at git@git-rw.torproject.org:admin/dns/domains.)

    DO NOT EDIT torproject.org!!!!!!

    Instead, add the reverse-dns records as appropriate to the *.arpa files.

    ipv6cal can help with ipv6 reverse fu. e.g.:

    weasel@defiant:~$ ipv6calc --in ipv6addr --out revnibbles.arpa 2607:8500:5:1::5a2c c.2.a.5.0.0.0.0.0.0.0.0.0.0.0.0.1.0.0.0.5.0.0.0.0.0.5.8.7.0.6.2.ip6.arpa.

    Commit and push when you are done; magic will happen.

  • Now you need to get console access to the new VM: Click the rightmost icon on the details screen at the rethem cloudstack thing.

    The debian installer is about to ask you for some advice:

    • Tell it the IP address to use.
    • Tell it a netmask
    • Tell it a gateway.
    • Tell it the hostname.

    It might ask you if you want to create a swap partition. You don't.

    It will ask you if you want to write the new partition map to the the disk. You do.

    Now it will do a debian installation! This will take a while.

  • You need to add the new host to nagios.

    git clone git@git-rw.torproject.org:admin/tor-nagios

    cd config

    edit nagios-master.cfg

    Add the new host right below the most recently added host. By default, you should put it in these hostgroups: computers, syslog-ng-hosts, no-ntp-peer.

    (Other hostgroups are documented at XXXXXXXXXXXXX.)

    Run make. Did that work?

    If so, run make install.

    Commit and push.

  • ssh into your shiny new host! (as root.)

    (The root password is the one marked as "rethemhosting torproject.org preseed debian-install image default root password" in hosts-extra-info in tor-passwords.git. Don't worry, we'll change it.)

    (Use -o HostKeyAlgorithms=ssh-rsa to avoid a warning later on.)

  • If you got in, detach the ISO.

    It's one of the icons in the cloudstack thing. It looks like a paperclip.

  • Get a shell on alberti, then run:

    ldapvi -ZZ --encoding=ASCII --ldap-conf -h db.torproject.org -D uid=nickm,ou=users,dc=torproject,dc=org

    You will need to use your ldap password.

    Now you are editing the LDAP database!

    Look for the last host= entry for a rethemhosting host in the file.

    Copy that whole block to the end of the file, and replace the number with the word "add". Then set the hostname correctly, and update the other stuff. (like memory, ssh host key, ip addresses, purpose.) drop or replace allowedGroups.

    Use dpkg --print-architecture if you don't know what the architecture is. (It's amd64.)

    Save and quit, then say yes.

  • Open an editor on the new host as root, and edit /etc/network/interfaces. Edit it to be a copy of the one on the most recently created host, except fill in the correct values for this host. I got:


auto lo iface lo inet loopback

The primary network interface

allow-hotplug eth0 iface eth0 inet static address 154.35.132.152/28 gateway 154.35.132.145 iface eth0 inet6 static address 2607:8500:5:1::5a2c/64 gateway 2607:8500:5:1::1

accept_ra 0

Your IP will vary.
  • Edit /etc/resolv.conf and /etc/hosts so that they include the proper domain. (It is probably torproject.org, not rethemhosting.)

  • Reboot the new host (with shutdown -r now), and make sure it comes up with the right IP.

  • Now you are going to read new-machine-cymru on alberti! It lives in /src/db.torproject.org.

    Follow its instructions on the new host as root.

  • You will be told to recursively follow the instructions in new-machine on alberti, which lives in the same repository. Do so.

    Some notes:

     - You will need to be root for nearly all of this.
     - If something just won't work, try puppet agent -t on the
       new host again, and give it another try.
     - Use weasel's magical pws scripts to manage the
       tor-passwords repository.
    
  • On the new host, if there is an /etc/apt/sources.list.d/debian.list, remove /etc/apt/sources.list, then apt-get update.

  • Run one last "apt-get update && apt-get dist-upgrade && apt-get clean"

  • Reboot again for good measure!

  • (Unless you used -o HostKeyAlgorithms=ssh-rsa before:) When you next ssh into the new host, the key will probably have changed. That's because it switched from ECDSA to RSA. Don't worry, but make sure you got the right one.

NOW YOU HAVE A HOST!

But, nobody can log into it. That's sad.

I wanted to set it up so that ioerror could log in and become a new "tormumble" role and administer the stuff.

= So here's how I made the tormumble role and stuff!

  • Do the magic thing on alberti again to edit the ldap database.

    Create a role account and associated group in ldap - ldapvi and copy one from before, picking a free uid/gid number pair.

    Add the group to the allowedGroups for the host.

    Add the group to the supplemenataryGids for the users who should be in it.

    Then, in puppet:

    /usr/sbin/visudo -f ./modules/sudo/files/sudoers

    And add a line of the form:

    %rolename hostname=(groupname) ALL

  • Then on the host, you need to log in as the role user to create their homedir and stuff. Do su - to do this, then log out again.

    If you couldn't log in, then the LDAP info hasn't propagated yet. Run this on alberti: sudo -u sshdist ud-generate And this on the new host as root: ud-replicate

  • Move the home directory to the right place:

    mkdir /srv/.torproject.org mv /home/ to /srv/$foo/home

    , then replace the original location with a symlink

    Also, chown /srv/.torproject.org to the new :