rewrite infest-cac-CentOS-7-64bit

README.md

@@ -0,0 +1,32 @@
+
+
+# Turn a Cloud at Cost CentOS-7-64bit server into NixOS
+
+1. Configure the system (`$systemname`) you'd like to install (see Configuration below).
+2. Create new server instance (either Custom or cloudpro) using "CentOS-7-64bit".
+   Note the servername (something like c731445864-cloudpro-388922936).
+3. `cac_login=xxx cac_key=yyy ./infest-cac-CentOS-7-64bit.sh servername:$servername $systename`
+4. Enjoy. (`ssh root@$systename`)
+
+# Configuration
+
+Configure your system in modules/$systemname
+See modules/cd/default.nix as an example.
+
+Notice that modules/$systemname/networking will be autogenerated (but not committed).
+
+secrets/$systemname/nix/foo can be accessed as `<secrets/foo>` from within the configuration.
+
+You might want `secrets/$systemname/rsync/etc/tinc/retiolum/rsa_key.priv`.
+
+You might want `secrets/$systemname/nix/hashedPasswords.nix`, which looks like
+
+```nix
+_: { users.extraUsers.root.hashedPassword = "XXX"; }
+```
+
+`XXX` can be generated with e.g.
+
+```
+mkpasswd -m sha-512 -S $(openssl rand -base64 16 | tr -d '+=' | head -c 16)
+```

bin/_cac_curl_api_v1

@@ -1,10 +0,0 @@
-#! /bin/sh
-set -euf
-
-exec _cac_exec curl -fsS "$1" "https://panel.cloudatcost.com/api/v1/$2.php" $(
-  shift 2
-  set -- "$@" login="$cac_login" key="$cac_key"
-  for arg; do
-    echo -d $(printf '%s' "$arg" | urlencode)
-  done
-)

bin/_cac_exec

@@ -1,8 +0,0 @@
-#! /bin/sh
-set -euf
-
-if test -z "${cac_via-}"; then
-  exec "$@"
-else
-  exec ssh -q "$cac_via" -t "$@"
-fi

bin/_cac_get_api_v1

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_curl_api_v1 -G "$@"

bin/_cac_post_api_v1

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_curl_api_v1 -XPOST "$@"

bin/cac-cloudpro-build

@@ -1,5 +0,0 @@
-#! /bin/sh
-set -euf
-
-# default os=26 is CentOS-7-64bit
-exec _cac_post_api_v1 cloudpro/build cpu="$1" ram="$2" storage="$3" os="${4-26}"

bin/cac-cloudpro-delete

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 cloudpro/delete sid="$1"

bin/cac-cloudpro-resources

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_get_api_v1 cloudpro/resources

bin/cac-console

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 console sid="$1"

bin/cac-get-server-by

@@ -1,17 +0,0 @@
-#! /bin/sh
-set -euf
-
-cac-listservers \
-  | jq \
-    --arg k "$1" \
-    --arg v "$2" \
-    '
-      map(select(.[$k]==$v)) |
-      if (. | length) == 0 then
-        null
-      elif (. | length) == 1 then
-        .[0]
-      else
-        .
-      end
-    '

bin/cac-listservers

@@ -1,12 +0,0 @@
-#! /bin/sh
-set -euf
-
-listservers=$(_cac_get_api_v1 listservers)
-status=$(echo "$listservers" | jq -r .status)
-
-if [ "$status" = ok ]; then
-  echo "$listservers" | jq -r .data
-else
-  echo "$0: bad listservers status: $status" >&2
-  exit 1
-fi

bin/cac-listtasks

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_get_api_v1 listtasks

bin/cac-listtemplates

@@ -1,4 +0,0 @@
-#! /bin/sh
-set -euf
-
-exec _cac_get_api_v1 listtemplates

bin/cac-powerop

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 powerop sid="$1" action="$2"

bin/cac-rdns

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 rdns sid="$1" hostname="$2"

bin/cac-renameserver

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 renameserver sid="$1" name="$2"

bin/cac-runmode

@@ -1,3 +0,0 @@
-#! /bin/sh
-set -euf
-exec _cac_post_api_v1 rdns sid="$1" mode="$2"

bin/cac-ssh

@@ -1,17 +0,0 @@
-#! /bin/sh
-set -euf
-
-server=$1
-shift
-
-address=$(echo $server | jq -r .ip)
-target=root@$address
-
-SSHPASS=$(echo $server | jq -r .rootpass)
-export SSHPASS
-
-exec sshpass -e ssh \
-  -o StrictHostKeyChecking=no \
-  -o UserKnownHostsFile=/dev/null \
-  "$target" \
-  "$@"

bin/cacnixos-networking

@@ -1,28 +0,0 @@
-#! /bin/sh
-# cacnixos-networking : cac-server x hostname -> nixos-module
-# TODO use label for hostname
-set -euf
-
-server=$1
-hostname=$2
-
-address=$(echo $server | jq -r .ip)
-gateway=$(echo $server | jq -r .gateway)
-nameserver=8.8.8.8
-netmask=$(echo $server | jq -r .netmask)
-prefix=$(netmask-to-prefix $netmask)
-
-printf '{...}:\n'
-printf '{\n'
-printf '  networking.hostName = "%s";\n' $hostname
-printf '  networking.interfaces.enp2s1.ip4 = [\n'
-printf '    {\n'
-printf '      address = "%s";\n' $address
-printf '      prefixLength = %d;\n' $prefix
-printf '    }\n'
-printf '  ];\n'
-printf '  networking.defaultGateway = "%s";\n' $gateway
-printf '  networking.nameservers = [\n'
-printf '    "%s"\n' $nameserver
-printf '  ];\n'
-printf '}\n'

bin/infest-CentOS-7-64bit

@@ -1,150 +0,0 @@
-#! /bin/sh
-set -euf
-
-server=$1
-hostname=$2
-
-address=$(echo $server | jq -r .ip)
-RSYNC_RSH='sshpass -e ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
-SSHPASS=$(echo $server | jq -r .rootpass)
-export SSHPASS
-export RSYNC_RSH
-
-main="modules/$hostname/default.nix"
-target="root@$address"
-
-cacnixos-networking "$server" $hostname \
-  > modules/$hostname/networking.nix
-
-echo '(
-  set -xeuf
-  type bzip2 || yum install -y bzip2
-  type rsync || yum install -y rsync
-)' \
-  | sshpass -e ssh \
-      -o StrictHostKeyChecking=no \
-      -o UserKnownHostsFile=/dev/null \
-      "root@$address" \
-      /bin/sh
-
-make-rsync-filter "$main" \
-  | rsync -f '. -' -zvrlptD --delete-excluded ./ "$target":/etc/nixos/
-
-#
-#
-#
-echo '(
-  set -xeuf
-  groupadd -g 30000 nixbld || :
-  for i in `seq 1 10`; do
-    useradd -c "foolsgarden Nix build user $i" \
-            -d /var/empty \
-            -s /sbin/nologin \
-            -g 30000 \
-            -G 30000 \
-            -l -u $(expr 30000 + $i) \
-            nixbld$i || :
-    rm -f /var/spool/mail/nixbld$i
-  done
-
-  #curl https://nixos.org/nix/install | sh
-  nix_tar=$nix_basename.tar.bz2
-  if ! echo $nix_sha256 $nix_tar | sha256sum -c; then
-    curl -O -C - $nix_url || :
-    if ! echo $nix_sha256 $nix_tar | sha256sum -c; then
-      curl -O $nix_url || :
-      if ! echo $nix_sha256 $nix_tar | sha256sum -c; then
-        echo $0: cannot download $nix_url >&2
-        exit 5
-      fi
-    fi
-  fi
-
-  if ! test -d $nix_basename; then
-    tar jxf $nix_basename.tar.bz2
-  fi
-
-  nix_find=$nix_basename.find.txt
-  if ! echo $nix_find_sha1sum $nix_find | sha1sum -c; then
-    find $nix_basename | sort > $nix_find
-    if ! echo $nix_find_sha1sum $nix_find | sha1sum -c; then
-      echo $0: cannot unpack $nix_basename.tar.bz2 >&2
-      # TODO we could retry
-      exit 6
-    fi
-  fi
-
-  mkdir -p bin
-  PATH=$HOME/bin:$PATH
-  export PATH
-
-  # generate fake sudo because
-  # sudo: sorry, you must have a tty to run sudo
-  {
-    echo "#! /bin/sh"
-    echo "exec env \"\$@\""
-  } > bin/sudo
-  chmod +x bin/sudo
-
-  ./$nix_basename/install
-
-  . /root/.nix-profile/etc/profile.d/nix.sh
-
-  nixpkgs_expr="import <nixpkgs> { system = builtins.currentSystem; }"
-  nixpkgs_path=$(
-    find /nix/store -mindepth 1 -maxdepth 1 -name *-nixpkgs-* -type d
-  )
-
-  for i in nixos-generate-config nixos-install; do
-    nix-env \
-      --arg config "{ nix.package = ($nixpkgs_expr).nix; }" \
-      --arg pkgs "$nixpkgs_expr" \
-      --arg modulesPath "throw \"no modulesPath\"" \
-      -f $nixpkgs_path/nixpkgs/nixos/modules/installer/tools/tools.nix \
-      -iA config.system.build.$i
-  done
-
-  # TODO following fail when aborted in-between
-  if ! test -d /int; then
-    mkdir -p /int
-    mount --bind /int /mnt
-  fi
-  if ! test -d /mnt/boot; then
-    mkdir -p /mnt/boot
-    mount /dev/sda1 /mnt/boot
-  fi
-
-  mkdir -p /mnt/etc/nixos
-  rsync -zvrlptD --delete-excluded /etc/nixos/ /mnt/etc/nixos/
-
-  mkdir -m 0444 -p /mnt/var/empty
-
-  ln -s $main /mnt/etc/nixos/configuration.nix
-  nixos-install \
-    -I secrets=/etc/nixos/secrets
-
-  find / \
-    1> /root/pre-rsync-find.out \
-    2> /root/pre-rsync-find.err
-
-  rsync -va --force /int/ /
-
-  # find / -type f -mtime +1 -exec rm -v {} \; 2>&1 > rm.log
-  #   ^ too aggressive, kills journal which is bad
-  # shutdown -r now
-  # nix-channel --add https://nixos.org/channels/nixos-unstable nixos
-  # nix-channel --remove nixpkgs
-  # nix-channel --update
-
-)' \
-  | sshpass -e ssh \
-      -o StrictHostKeyChecking=no \
-      -o UserKnownHostsFile=/dev/null \
-      "root@$address" \
-      -T /usr/bin/env \
-        nix_url="$nix_url" \
-        nix_basename="$(basename $nix_url .tar.bz2)" \
-        nix_sha256="$nix_sha256" \
-        nix_find_sha1sum="$nix_find_sha1sum" \
-        main="$main" \
-        /bin/sh

bin/infest-cac

@@ -1,21 +0,0 @@
-#! /bin/sh
-set -euf
-
-server=$(cac-get-server-by servername "$1")
-hostname=$2
-
-serverstatus=$(echo $server | jq -r .status)
-case $serverstatus in
-  'Powered On') : ;;
-  *)
-    echo $0: bad server status: $serverstatus >&2
-    exit 2
-esac
-
-template=$(echo $server | jq -r .template)
-case $template in
-  'CentOS-7-64bit') infest-"$template" "$server" "$hostname";;
-  *)
-    echo $0: bad template: $template >&2
-    exit 3
-esac

cac

@@ -0,0 +1,337 @@
+#! /bin/sh
+set -euf
+
+PATH=$PWD/bin:$PATH
+export PATH
+
+cac_listservers_cache=$PWD/tmp/cac_listservers_cache.json
+
+
+cac() {
+  __cac_cli__command=$1
+  shift
+  __cac_cli__"$__cac_cli__command" "$@"
+}
+
+# WIP
+__cac_cli__help() {(
+  exec sed < "$0" -n '
+    s/^__cac_cli__\([^(]\+\)().*/\1/p
+  '
+)}
+
+# usage: console 
+__cac_cli__console() {(
+  server=$(__cac_cli__getserver "$1")
+  sid=$(echo $server | jq -r .sid)
+  # TODO check reply status == ok
+  _cac_post_api_v1 console sid="$sid" | jq -r .console
+)}
+
+__cac_cli__listservers() {
+  jq -r . $cac_listservers_cache
+}
+
+__cac_cli__update() {(
+  umask 0077
+  servers=$(_cac_listservers)
+  echo $servers > $cac_listservers_cache.tmp
+  mv $cac_listservers_cache.tmp $cac_listservers_cache
+)}
+
+__cac_cli__getserver() {(
+
+  case $1 in
+    *:*)
+      k=${1%%:*}
+      v=${1#*:}
+      ;;
+    *)
+      k=label
+      v=${1#*:}
+      ;;
+  esac
+
+  if result=$(jq \
+      -e \
+      --arg k "$k" \
+      --arg v "$v" \
+      '
+        map(select(.[$k]==$v)) |
+        if (. | length) == 1 then
+          .[0]
+        else
+          null
+        end
+      ' \
+        $cac_listservers_cache); then
+    echo $result | jq -r .
+  else
+    echo "$0 getserver $k:$v => not unique server found" >&2
+    exit 23
+  fi
+)}
+
+__cac_cli__generatenetworking() {(
+  server=$(__cac_cli__getserver "$1")
+
+  hostname=$(echo $server | jq -r .label)
+
+  address=$(echo $server | jq -r .ip)
+  gateway=$(echo $server | jq -r .gateway)
+  nameserver=8.8.8.8
+  netmask=$(echo $server | jq -r .netmask)
+  prefix=$(netmask-to-prefix $netmask)
+
+  #printf '# Generated file: %s generatenetworking %s %s\n' "$0" "$1" "$2"
+  #printf '# on %s\n' "$(date -Is)"
+  #printf '\n'
+  printf '_:\n'
+  printf '\n'
+  printf '{\n'
+  printf '  networking.hostName = "%s";\n' $hostname
+  printf '  networking.interfaces.enp2s1.ip4 = [\n'
+  printf '    {\n'
+  printf '      address = "%s";\n' $address
+  printf '      prefixLength = %d;\n' $prefix
+  printf '    }\n'
+  printf '  ];\n'
+  printf '  networking.defaultGateway = "%s";\n' $gateway
+  printf '  networking.nameservers = [\n'
+  printf '    "%s"\n' $nameserver
+  printf '  ];\n'
+  printf '}\n'
+)}
+
+__cac_cli__powerop() {(
+  server=$(__cac_cli__getserver "$1")
+  action=$2
+
+  sid=$(echo $server | jq -r .sid)
+
+  reply=$(_cac_post_api_v1 powerop sid="$sid" action="$action")
+
+  case $(echo $reply | jq -r .status) in
+    ok)
+      echo $reply | jq -r . >&2
+      __cac_cli__update
+      ;;
+    *)
+      echo bad reply: >&2
+      echo $reply | jq -r . >&2
+      exit 23
+      ;;
+  esac
+)}
+__cac_cli__pushconfig() {(
+  server=$(__cac_cli__getserver "$1")
+
+  prefix=${2-/}
+
+  hostname=$(echo $server | jq -r .label)
+
+  address=$(echo $server | jq -r .ip)
+  target=root@$address
+
+  RSYNC_RSH='sshpass -e ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
+  SSHPASS=$(echo $server | jq -r .rootpass)
+  export RSYNC_RSH SSHPASS
+
+  pushgit .                         $prefix/etc/nixos/
+  pushgit hosts                     $prefix/etc/nixos/hosts/
+  pushgit tmp/nixpkgs/$hostname     $prefix/etc/nixos/nixpkgs/
+  pushdir secrets/$hostname/nix     $prefix/etc/nixos/secrets/
+  pushdir secrets/$hostname/rsync   $prefix/
+  echo "_:{imports=[./modules/$hostname];}" \
+    | $RSYNC_RSH "$target" tee "$prefix/etc/nixos/configuration.nix" \
+      > /dev/null
+
+  ## TODO chmod and chown secrets
+)}
+
+__cac_cli__setlabel() {(
+  server=$(__cac_cli__getserver "$1")
+  label=$2
+
+  sid=$(echo $server | jq -r .sid)
+
+  reply=$(_cac_post_api_v1 renameserver sid="$sid" name="$label")
+
+  case $(echo $reply | jq -r .status) in
+    ok)
+      echo $reply | jq -r . >&2
+      __cac_cli__update
+      ;;
+    *)
+      echo bad reply: >&2
+      echo $reply | jq -r . >&2
+      exit 23
+      ;;
+  esac
+)}
+
+__cac_cli__setmode() {(
+  server=$(__cac_cli__getserver "$1")
+  mode=$2
+
+  sid=$(echo $server | jq -r .sid)
+
+  reply=$(_cac_post_api_v1 runmode sid="$sid" mode="$mode")
+
+  case $(echo $reply | jq -r .status) in
+    ok)
+      echo $reply | jq -r . >&2
+      __cac_cli__update
+      ;;
+    *)
+      echo bad reply: >&2
+      echo $reply | jq -r .
+      exit 23
+      ;;
+  esac
+)}
+
+__cac_cli__ssh() {(
+  server=$(__cac_cli__getserver "$1")
+  shift
+
+  address=$(echo $server | jq -r .ip)
+  target=root@$address
+
+  SSHPASS=$(echo $server | jq -r .rootpass)
+  export SSHPASS
+
+  exec sshpass -e ssh \
+    -S none \
+    -o StrictHostKeyChecking=no \
+    -o UserKnownHostsFile=/dev/null \
+    $target \
+    "$@"
+)}
+
+
+# usage: ./cac waitstatus mode:Safe 'Powered On'
+# blocks until server has specfied state
+__cac_cli__waitstatus() {
+  server=$(__cac_cli__getserver "$1")
+  status=$(echo $server | jq -r .status)
+
+  case $status in
+    $2)
+      return
+      ;;
+  esac
+
+  echo "$(date -Is) Waiting for status: $2; current status: $status ..." >&2
+
+  __cac_cli__waitforcacheupdate __cac_cli__waitstatus "$@"
+}
+
+
+# XXX for __cac_cli__waitforcacheupdate and __cac_cli__poll cache means $cac_listservers_cache
+
+# blocks until cache has been updated then executes "$@"
+__cac_cli__waitforcacheupdate() {
+  case $(inotifywait --format %f -q -e moved_to $(dirname $cac_listservers_cache)) in
+    $(basename $cac_listservers_cache)) "$@";;
+    *) __cac_cli__waitforcacheupdate "$@";;
+  esac
+}
+
+# usage: with cac ./cac poll 60s
+# continuously update cache, sleeping at least $1 between updates
+__cac_cli__poll() {
+  __cac_cli__update
+  t=${1-1m}
+  echo "$(date -Is) cache updated; sleeping $t ..." >&2
+  sleep "$t"
+  __cac_cli__poll "$@"
+}
+
+
+_cac_listservers() {(
+  servers=$(_cac_get_api_v1 listservers)
+  status=$(echo $servers | jq -r .status)
+
+  if [ "$status" = ok ]; then
+    echo "$servers" | jq -r .data
+  else
+    echo "cac_listservers: bad listservers status: $status" >&2
+    exit 1
+  fi
+)}
+
+
+
+
+# rsyncfiles : lines filename |> local-dir x remote-dir -> ? |> ?
+rsyncfiles() {(
+  set -x
+  rsync \
+    --rsync-path="mkdir -p \"$2\" && rsync" \
+    -vzrlptD \
+    --files-from=- \
+    "$1"/ \
+    "$target:$2"
+)}
+
+
+# gitfiles : git-work-tree -> lines filename
+gitfiles() {
+  git -C "$1" archive --format=tar HEAD | tar t | sed '/\/$/d'
+}
+
+# pushgit : git-work-tree x remote-dir -> ?
+pushgit() {
+  gitfiles "$1" | rsyncfiles "$1" "$2"
+}
+
+# dirfiles : local-dir -> lines filename
+dirfiles() {(
+  cd "$1"
+  find . -type f | sed 's/^\.\///'
+)}
+
+# pushgit : local-dir x remote-dir -> ?
+pushdir() {
+  dirfiles "$1" | rsyncfiles "$1" "$2"
+}
+
+
+
+
+
+
+_cac_get_api_v1() {
+  _cac_curl_api_v1 -G "$@"
+}
+
+_cac_post_api_v1() {
+  _cac_curl_api_v1 -XPOST "$@"
+}
+
+_cac_curl_api_v1() {
+  _cac_exec curl -sS "$1" "https://panel.cloudatcost.com/api/v1/$2.php" $(
+    shift 2
+    set -- "$@" login="$cac_login" key="$cac_key"
+    for arg; do
+      echo -d $(printf '%s' "$arg" | urlencode)
+    done
+  )
+}
+
+_cac_exec() {
+  if test -z "${cac_via-}"; then
+    env -- "$@"
+  else
+    ssh -q "$cac_via" -t "$@"
+  fi
+}
+
+
+
+
+
+case ${run-true} in
+  true) cac "$@";;
+esac

infest

@@ -1,15 +0,0 @@
-#! /bin/sh
-#
-# usage: ./infest cac-servername hostname
-#
-set -euf
-
-PATH="$PWD/bin${PATH+:$PATH}"
-export PATH
-
-nix_url=https://nixos.org/releases/nix/nix-1.8/nix-1.8-x86_64-linux.tar.bz2
-nix_sha256=52fab207b4ce4d098a12d85357d0353e972c492bab0aa9e08e1600363e76fefb
-nix_find_sha1sum=86f8775bd4f0841edd4c816df861cebf509d58c3
-export nix_url nix_sha256 nix_find_sha1sum
-
-exec infest-cac "$@"

infest-cac-CentOS-7-64bit.sh

@@ -0,0 +1,33 @@
+#! /bin/sh
+set -xeuf
+
+serverspec=$1
+systemname=$2
+
+./cac poll 10s 2>/dev/null &
+pollpid=$!
+trap "kill $pollpid; trap - EXIT" EXIT
+
+./cac waitstatus $serverspec 'Powered On'
+
+# TODO don't set label/mode if they're already good
+./cac setlabel $serverspec $systemname
+./cac setmode $systemname normal
+./cac generatenetworking $systemname > modules/$systemname/networking.nix
+
+cat infest.d/cac-CentOS-7-64bit/prepare.sh | ./cac ssh $systemname \
+  nix_url=https://nixos.org/releases/nix/nix-1.9/nix-1.9-x86_64-linux.tar.bz2 \
+  nix_sha256=5c76611c631e79aef5faf3db2d253237998bbee0f61fa093f925fa32203ae32b \
+  /bin/sh
+
+./cac pushconfig $systemname /mnt
+
+# This needs to be run twice because (at least):
+#   Initialized empty Git repository in /var/lib/git/$reponame
+#   chown: invalid user: 'git:nogroup'
+cat infest.d/nixos-install.sh | ./cac ssh $systemname || :
+cat infest.d/nixos-install.sh | ./cac ssh $systemname
+
+cat infest.d/cac-CentOS-7-64bit/finalize.sh | ./cac ssh $systemname
+
+./cac powerop $systemname reset

infest.d/cac-CentOS-7-64bit/finalize.sh

@@ -0,0 +1,66 @@
+#! /bin/sh
+set -eu
+{
+  umount /mnt2
+  umount /mnt/nix
+  umount /mnt/boot
+  umount /mnt
+  umount /boot
+
+  PATH=$(for i in /nix/store/*coreutils*/bin; do :; done; echo $i)
+  export PATH
+
+  mkdir /oldshit
+
+  mv /bin /oldshit/
+  mv /newshit/bin /
+
+  # TODO ensure /boot is empty
+  rmdir /newshit/boot
+
+  # skip /dev
+  rmdir /newshit/dev
+
+  mv /etc /oldshit/
+  mv /newshit/etc /
+
+  # TODO ensure /home is empty
+  rmdir /newshit/home
+
+  # skip /nix (it's already there)
+  rmdir /newshit/nix
+
+  # skip /proc
+  rmdir /newshit/proc
+
+  # skip /run
+  rmdir /newshit/run
+
+  # skip /sys
+  rmdir /newshit/sys
+
+  # skip /tmp
+  # TODO rmdir /newshit/tmp
+
+  mv /usr /oldshit/
+  mv /newshit/usr /
+
+  mv /var /oldshit/
+  mv /newshit/var /
+
+  mv /root /oldshit/
+  mv /newshit/root /
+
+  mv /lib /oldshit/
+  mv /lib64 /oldshit/
+  mv /sbin /oldshit/
+  mv /mnt2 /oldshit/
+  mv /srv /oldshit/
+  mv /opt /oldshit/
+
+
+  mv /newshit /root/  # TODO this one shoult be empty
+  mv /oldshit /root/
+
+  sync
+}

infest.d/cac-CentOS-7-64bit/prepare.sh

@@ -0,0 +1,104 @@
+#! /bin/sh
+set -euf
+
+: $nix_url
+: $nix_sha256
+
+{
+  #
+  # prepare host
+  #
+
+  type bzip2 2>/dev/null || yum install -y bzip2
+  type rsync 2>/dev/null || yum install -y rsync
+
+  if ! getent group nixbld >/dev/null; then
+    groupadd -g 30000 -r nixbld
+  fi
+  for i in `seq 1 10`; do
+    if ! getent passwd nixbld$i 2>/dev/null; then
+      useradd \
+        -c "CentOS Nix build user $i" \
+        -d /var/empty \
+        -g 30000 \
+        -G 30000 \
+        -l \
+        -M \
+        -s /sbin/nologin \
+        -u $(expr 30000 + $i) \
+        nixbld$i
+      rm -f /var/spool/mail/nixbld$i
+    fi
+  done
+
+  # generate fake sudo because
+  # sudo: sorry, you must have a tty to run sudo
+  mkdir -p bin
+  printf '#! /bin/sh\nexec env "$@"\n' > bin/sudo
+  chmod +x bin/sudo
+
+  PATH=$PWD/bin:$PATH
+  export PATH
+
+  # install nix on host (cf. https://nixos.org/nix/install)
+  if ! test -e /root/.nix-profile/etc/profile.d/nix.sh; then
+    (
+      verify() {
+        echo $nix_sha256  $(basename $nix_url) | sha256sum -c
+      }
+      if ! verify; then
+        curl -C - -O "$nix_url"
+        verify
+      fi
+    )
+    tar jxf $(basename $nix_url)
+    $(basename $nix_url .tar.bz2)/install
+  fi
+
+  MANPATH=/var/empty . /root/.nix-profile/etc/profile.d/nix.sh
+
+  if ! type nixos-install 2>/dev/null; then
+    nixpkgs_expr='import <nixpkgs> { system = builtins.currentSystem; }'
+    nixpkgs_path=$(find /nix/store -mindepth 1 -maxdepth 1 -name *-nixpkgs-* -type d)
+    nix-env \
+      --arg config "{ nix.package = ($nixpkgs_expr).nix; }" \
+      --arg pkgs "$nixpkgs_expr" \
+      --arg modulesPath 'throw "no modulesPath"' \
+      -f $nixpkgs_path/nixpkgs/nixos/modules/installer/tools/tools.nix \
+      -iA config.system.build.nixos-install
+  fi
+
+  #
+  # mount install directory
+  #
+
+  if ! mount | grep -Fq '/dev/mapper/centos-root on /mnt type xfs'; then
+    mkdir -p /newshit
+    mount --bind /newshit /mnt
+  fi
+
+  if ! mount | grep -Fq '/dev/sda1 on /mnt/boot type xfs'; then
+    mkdir -p /mnt/boot
+    mount /dev/sda1 /mnt/boot
+  fi
+
+  if ! mount | grep -Fq '/dev/mapper/centos-root on /mnt/nix type xfs'; then
+    mkdir -p /mnt/nix
+    mount --bind /nix /mnt/nix
+  fi
+
+  mount | grep 'on /mnt\>' >&2
+
+  #
+  # prepare install directory
+  #
+  # XXX This should be done by (?)
+  #   remote_dir=/mnt ./cac pushconfig servername:c731445864-cloudpro-134581046 rmdir
+
+  mkdir -p /mnt/etc/nixos
+  mkdir -m 0555 -p /mnt/var/empty
+
+  # add eye candy
+  address=$(echo $SSH_CONNECTION | awk '{print$3}')
+  echo 'PS1='\''\[\e[1;31m\]\u@'"$address"'\[\e[m\] \[\e[1;32m\]\w\[\e[m\] '\' > .bashrc
+}

infest.d/nixos-install.sh

@@ -0,0 +1,8 @@
+#! /bin/sh
+# usage: cat infest-nixos-install.sh | ./cac ssh ...
+set -euf
+nixos-install \
+    -I secrets=/etc/nixos/secrets \
+    -I retiolum-hosts=/etc/nixos/hosts \
+    -I pubkeys=/etc/nixos/pubkeys \
+    -I nixpkgs=/etc/nixos/nixpkgs