From 69787b1dc07e5ccc5a36c95480a82341f834a639 Mon Sep 17 00:00:00 2001 From: Eric Litak Date: Sat, 9 Apr 2016 12:39:35 -0700 Subject: [PATCH] optimizations, comments --- nixos-infect | 131 ++++++++++++++++++++++++++++----------------------- 1 file changed, 73 insertions(+), 58 deletions(-) diff --git a/nixos-infect b/nixos-infect index 61c428c..4e239ae 100755 --- a/nixos-infect +++ b/nixos-infect @@ -1,5 +1,9 @@ #! /usr/bin/env bash +# nixos-infect is so named because there's a good chance the system will get +# sick if anything goes wrong, and possibly die, requiring reprovisioning. +# Use with caution. +# # WARNING NB This script wipes out the targeted host's root filesystem when it # runs to completion. Any errors halt execution. set -x is used to help debug, # as often a failed run leaves the system in an inconsistent state, requiring a @@ -32,16 +36,16 @@ set -ex +# If you have another nixos host in the cloud, add it here to speed up the +# package downloads. Use "ssh -A" with your key loaded to run the script! +# This also reduces load on NixOS servers, so please make an effort to use it +# whenever possible. +#nix_options+=" --option ssh-substituter-hosts user@host" + makeConf() { - # NB remember to escape / $ ` in heredocs! - # TODO use appended archive or some curl-able tarball? + # NB <<"EOF" quotes / $ ` in heredocs, < /etc/nixos/networking.nix << EOF -# This file will be populated at runtime with the -# networking details gathered from the active system. -{...}:{} -EOF + local IFS=$'\n'; keys=($(cat /root/.ssh/authorized_keys)) cat > /etc/nixos/configuration.nix << EOF { ... }: { imports = [ @@ -65,6 +69,45 @@ EOF boot.loader.grub.devices = [ "/dev/vda" ]; fileSystems."/" = { device = "/dev/vda1"; fsType = "ext4"; }; } +EOF + + local IFS=$'\n' + ip4s=($(ip address show dev eth0 | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|')) + ip6s=($(ip address show dev eth0 | grep 'inet6 .*global' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|')) + gateway=($(ip route show dev eth0 | grep default | sed -r 's|default via ([0-9.]+).*|\1|')) + gateway6=($(ip -6 route show dev eth0 | grep default | sed -r 's|default via ([0-9a-f:]+).*|\1|')) + ether0=($(ip address show dev eth0 | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|')) + ether1=($(ip address show dev eth1 | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|')) + nameservers=($(grep ^nameserver /etc/resolv.conf | cut -f2 -d' ')) + + cat > /etc/nixos/networking.nix << EOF +{ ... }: { + # This file was populated at runtime with the networking + # details gathered from the active system. + networking = { + nameservers = [$(for a in ${nameservers[@]}; do echo -n " + \"$a\""; done) + ]; + defaultGateway = "${gateway}"; + defaultGateway6 = "${gateway6}"; + interfaces = { + eth0 = { + ip4 = [$(for a in ${ip4s[@]}; do echo -n " + $a"; done) + ]; + ip6 = [$(for a in ${ip6s[@]}; do echo -n " + $a"; done) + ]; + }; + # eth1 is for private networking or something? + eth1.useDHCP = false; + }; + }; + services.udev.extraRules = '' + KERNEL=="eth*", ATTR{address}=="${ether0}", NAME="eth0" + KERNEL=="eth*", ATTR{address}=="${ether1}", NAME="eth1" + ''; +} EOF #! /usr/bin/env bash # NB put your semi-sensitive (not posted to github) configuration in a separate @@ -81,12 +124,13 @@ EOF if [[ `type -t customConfig` == "function" ]]; then customConfig; fi } +swapFile=/tmp/swap makeSwap() { - if [[ ! -e /swap ]]; then - dd if=/dev/zero of=/swap bs=1M count=$((1024*2)) - chmod 0600 /swap - mkswap /swap - swapon /swap + if [[ ! -e $swapFile ]]; then + dd if=/dev/zero of=$swapFile bs=1M count=$((1024*2)) + chmod 0600 $swapFile + mkswap $swapFile + swapon $swapFile fi } @@ -110,66 +154,37 @@ newRootMount=`mktemp -d` oldRootMount=`mktemp -d` export NIXOS_CONFIG=/etc/nixos/configuration.nix -nix-env -i -f /nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos \ - -A config.system.build.nixos-install \ - -A config.system.build.nixos-option \ - -A config.system.build.nixos-generate-config +nix-env -i \ + $nix_options \ + -f /nix/var/nix/profiles/per-user/root/channels/nixpkgs/nixos \ + -A config.system.build.nixos-install + #-A config.system.build.nixos-option \ + #-A config.system.build.nixos-generate-config # XXX GOTCHA NB bindmount causes /bin/bash permission BUG on many # versions (nix 1.10-1.11, nixpkgs 15-16), so we must use loopback image instead. +# See: https://github.com/NixOS/nixpkgs/issues/10230 dd if=/dev/zero of=$newRootImg bs=1M count=$((1024*2)) -mkfs.ext4 $newRootImg +mkfs.ext4 -F $newRootImg mount $newRootImg $newRootMount rsync -aR /./etc/nixos $newRootMount -nixos-install --root $newRootMount +nixos-install $nix_options --root $newRootMount +cp -a {,$newRootMount}/etc/resolv.conf # needed for final rebuild -swapoff /swap +swapoff $swapFile || true mount -B / $oldRootMount + +# Everything up to this point is revertible; this is the truly destructive step. rsync -a --delete --exclude=$(dirname $newRootMount) $newRootMount/ $oldRootMount -# restore access to commands +# Restore access to commands /nix/var/nix/profiles/system/activate source /nix/var/nix/profiles/system/etc/profile -# XXX temporary fix for name resolution -echo nameserver 8.8.4.4 > /etc/resolv.conf - -IFS=$'\n' -ip4s=($(ip address show dev eth0 | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|')) -ip6s=($(ip address show dev eth0 | grep 'inet6 .*global' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|')) -gateway=($(ip route show dev eth0 | grep default | sed -r 's|default via ([0-9.]+).*|\1|')) -gateway6=($(ip -6 route show dev eth0 | grep default | sed -r 's|default via ([0-9a-f:]+).*|\1|')) -ether0=($(ip address show dev eth0 | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|')) -ether1=($(ip address show dev eth1 | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|')) - -cat > /etc/nixos/networking.nix << EOF -{ ... }: { - networking = { - nameservers = [ "8.8.4.4" ]; - defaultGateway = "${gateway}"; - defaultGateway6 = "${gateway6}"; - interfaces = { - eth0 = { - ip4 = [$(for a in ${ip4s[@]}; do echo -n " - $a"; done) - ]; - ip6 = [$(for a in ${ip6s[@]}; do echo -n " - $a"; done) - ]; - }; - # eth1 is for private networking or something? - eth1.useDHCP = false; - }; - }; - services.udev.extraRules = '' - KERNEL=="eth*", ATTR{address}=="${ether0}", NAME="eth0" - KERNEL=="eth*", ATTR{address}=="${ether1}", NAME="eth1" - ''; -} -EOF - # grub/initrd was probably installed incorrectly (using false root device), so we need a final rebuild +# TODO see aszlig's comment in issue about not even having to call rebuild, just nix-build system or something; without ever having to use nixos-install either? and separate ext4fs? +# man nixos-rebuild mentions this!!: nixos-rebuid build == nix-build /path/to/nixpkgs/nixos -A system nixos-rebuild boot --install-grub sync