Move install responsibilities to domU

As we are moving forward to test XenAPI in the gate, it is necessary to
move dom0 related modifications to be performed from domU. For this
purpose, a new user is created, and that user should be used to talk to
dom0 from domU. This change creates that user, makes it possible for
dom0 to log in to domU with that account, and configure that account to
be able to talk down to dom0.

Also move several steps to the nova xenserver plugin:
 - dom0 plugin installation
 - create kernels and images directory
 - install console rotate script
 - configure a cron to execute console rotate script

Configuration changes:
    A new configuration option, DOMZERO_USER has been created, that
    specifies a user account that is configured to be able to do
    passwordless ssh to dom0.

Change-Id: If9de0b297a67b7cdb5de78d8dd0e8b2ca578b601

lib/nova_plugins/hypervisor-xenserver

@@ -56,6 +56,34 @@ function configure_nova_hypervisor() {
     # Need to avoid crash due to new firewall support
     XEN_FIREWALL_DRIVER=${XEN_FIREWALL_DRIVER:-"nova.virt.firewall.IptablesFirewallDriver"}
     iniset $NOVA_CONF DEFAULT firewall_driver "$XEN_FIREWALL_DRIVER"
+
+    local dom0_ip
+    dom0_ip=$(echo "$XENAPI_CONNECTION_URL" | cut -d "/" -f 3-)
+
+    local ssh_dom0
+    ssh_dom0="sudo -u $DOMZERO_USER ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null root@$dom0_ip"
+
+    # install nova plugins to dom0
+    tar -czf - -C $NOVA_DIR/plugins/xenserver/xenapi/etc/xapi.d/plugins/ ./ |
+        $ssh_dom0 'tar -xzf - -C /etc/xapi.d/plugins/ && chmod a+x /etc/xapi.d/plugins/*'
+
+    # install console logrotate script
+    tar -czf - -C $NOVA_DIR/tools/xenserver/ rotate_xen_guest_logs.sh |
+        $ssh_dom0 'tar -xzf - -C /root/ && chmod +x /root/rotate_xen_guest_logs.sh && mkdir -p /var/log/xen/guest'
+
+    # Create a cron job that will rotate guest logs
+    $ssh_dom0 crontab - << CRONTAB
+* * * * * /root/rotate_xen_guest_logs.sh
+CRONTAB
+
+    # Create directories for kernels and images
+    {
+        echo "set -eux"
+        cat $TOP_DIR/tools/xen/functions
+        echo "create_directory_for_images"
+        echo "create_directory_for_kernels"
+    } | $ssh_dom0
+
 }
 
 # install_nova_hypervisor() - Install external components

stackrc

@@ -245,6 +245,10 @@ case "$VIRT_DRIVER" in
     xenserver)
         # Xen config common to nova and neutron
         XENAPI_USER=${XENAPI_USER:-"root"}
+        # This user will be used for dom0 - domU communication
+        #   should be able to log in to dom0 without a password
+        #   will be used to install the plugins
+        DOMZERO_USER=${DOMZERO_USER:-"domzero"}
         ;;
     *)
         ;;

tools/xen/functions

@@ -336,3 +336,11 @@ function max_vcpus() {
     xe vm-param-set uuid=$vm VCPUs-max=$cpu_count
     xe vm-param-set uuid=$vm VCPUs-at-startup=$cpu_count
 }
+
+function get_domid() {
+    local vm_name_label
+
+    vm_name_label="$1"
+
+    xe vm-list name-label="$vm_name_label" params=dom-id minimal=true
+}

tools/xen/install_os_domU.sh

@@ -67,21 +67,6 @@ fi
 
 # Install plugins
 
-## Nova plugins
-NOVA_ZIPBALL_URL=${NOVA_ZIPBALL_URL:-$(zip_snapshot_location $NOVA_REPO $NOVA_BRANCH)}
-EXTRACTED_NOVA=$(extract_remote_zipball "$NOVA_ZIPBALL_URL")
-install_xapi_plugins_from "$EXTRACTED_NOVA"
-
-LOGROT_SCRIPT=$(find "$EXTRACTED_NOVA" -name "rotate_xen_guest_logs.sh" -print)
-if [ -n "$LOGROT_SCRIPT" ]; then
-    mkdir -p "/var/log/xen/guest"
-    cp "$LOGROT_SCRIPT" /root/consolelogrotate
-    chmod +x /root/consolelogrotate
-    echo "* * * * * /root/consolelogrotate" | crontab
-fi
-
-rm -rf "$EXTRACTED_NOVA"
-
 ## Install the netwrap xapi plugin to support agent control of dom0 networking
 if [[ "$ENABLED_SERVICES" =~ "q-agt" && "$Q_PLUGIN" = "openvswitch" ]]; then
     NEUTRON_ZIPBALL_URL=${NEUTRON_ZIPBALL_URL:-$(zip_snapshot_location $NEUTRON_REPO $NEUTRON_BRANCH)}
@@ -90,9 +75,6 @@ if [[ "$ENABLED_SERVICES" =~ "q-agt" && "$Q_PLUGIN" = "openvswitch" ]]; then
     rm -rf "$EXTRACTED_NEUTRON"
 fi
 
-create_directory_for_kernels
-create_directory_for_images
-
 #
 # Configure Networking
 #
@@ -188,7 +170,7 @@ function wait_for_VM_to_halt() {
     set +x
     echo "Waiting for the VM to halt.  Progress in-VM can be checked with vncviewer:"
     mgmt_ip=$(echo $XENAPI_CONNECTION_URL | tr -d -c '1234567890.')
-    domid=$(xe vm-list name-label="$GUEST_NAME" params=dom-id minimal=true)
+    domid=$(get_domid "$GUEST_NAME")
     port=$(xenstore-read /local/domain/$domid/console/vnc-port)
     echo "vncviewer -via root@$mgmt_ip localhost:${port:2}"
     while true
@@ -361,6 +343,37 @@ else
     fi
 fi
 
+# Create an ssh-keypair, and set it up for dom0 user
+rm -f /root/dom0key /root/dom0key.pub
+ssh-keygen -f /root/dom0key -P "" -C "dom0"
+DOMID=$(get_domid "$GUEST_NAME")
+
+xenstore-write /local/domain/$DOMID/authorized_keys/$DOMZERO_USER "$(cat /root/dom0key.pub)"
+xenstore-chmod -u /local/domain/$DOMID/authorized_keys/$DOMZERO_USER r$DOMID
+
+function run_on_appliance() {
+    ssh \
+        -i /root/dom0key \
+        -o UserKnownHostsFile=/dev/null \
+        -o StrictHostKeyChecking=no \
+        -o BatchMode=yes \
+        "$DOMZERO_USER@$OS_VM_MANAGEMENT_ADDRESS" "$@"
+}
+
+# Wait until we can log in to the appliance
+while ! run_on_appliance true; do
+    sleep 1
+done
+
+# Remove authenticated_keys updater cronjob
+echo "" | run_on_appliance crontab -
+
+# Generate a passwordless ssh key for domzero user
+echo "ssh-keygen -f /home/$DOMZERO_USER/.ssh/id_rsa -C $DOMZERO_USER@appliance -N \"\" -q" | run_on_appliance
+
+# Authenticate that user to dom0
+run_on_appliance cat /home/$DOMZERO_USER/.ssh/id_rsa.pub >> /root/.ssh/authorized_keys
+
 # If we have copied our ssh credentials, use ssh to monitor while the installation runs
 WAIT_TILL_LAUNCH=${WAIT_TILL_LAUNCH:-1}
 COPYENV=${COPYENV:-1}

tools/xen/prepare_guest.sh

@@ -18,6 +18,57 @@ set -o xtrace
 GUEST_PASSWORD="$1"
 XS_TOOLS_PATH="$2"
 STACK_USER="$3"
+DOMZERO_USER="$4"
+
+
+function setup_domzero_user() {
+    local username
+
+    username="$1"
+
+    local key_updater_script
+    local sudoers_file
+    key_updater_script="/home/$username/update_authorized_keys.sh"
+    sudoers_file="/etc/sudoers.d/allow_$username"
+
+    # Create user
+    adduser --disabled-password --quiet "$username" --gecos "$username"
+
+    # Give passwordless sudo
+    cat > $sudoers_file << EOF
+    $username ALL = NOPASSWD: ALL
+EOF
+    chmod 0440 $sudoers_file
+
+    # A script to populate this user's authenticated_keys from xenstore
+    cat > $key_updater_script << EOF
+#!/bin/bash
+set -eux
+
+DOMID=\$(sudo xenstore-read domid)
+sudo xenstore-exists /local/domain/\$DOMID/authorized_keys/$username
+sudo xenstore-read /local/domain/\$DOMID/authorized_keys/$username > /home/$username/xenstore_value
+cat /home/$username/xenstore_value > /home/$username/.ssh/authorized_keys
+EOF
+
+    # Give the key updater to the user
+    chown $username:$username $key_updater_script
+    chmod 0700 $key_updater_script
+
+    # Setup the .ssh folder
+    mkdir -p /home/$username/.ssh
+    chown $username:$username /home/$username/.ssh
+    chmod 0700 /home/$username/.ssh
+    touch /home/$username/.ssh/authorized_keys
+    chown $username:$username /home/$username/.ssh/authorized_keys
+    chmod 0600 /home/$username/.ssh/authorized_keys
+
+    # Setup the key updater as a cron job
+    crontab -u $username - << EOF
+* * * * * $key_updater_script
+EOF
+
+}
 
 # Install basics
 apt-get update
@@ -48,6 +99,8 @@ useradd $STACK_USER -s /bin/bash -d /opt/stack -G libvirtd
 echo $STACK_USER:$GUEST_PASSWORD | chpasswd
 echo "$STACK_USER ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers
 
+setup_domzero_user "$DOMZERO_USER"
+
 # Add an udev rule, so that new block devices could be written by stack user
 cat > /etc/udev/rules.d/50-openstack-blockdev.rules << EOF
 KERNEL=="xvd[b-z]", GROUP="$STACK_USER", MODE="0660"

tools/xen/prepare_guest_template.sh

@@ -76,7 +76,7 @@ cp $STAGING_DIR/etc/rc.local $STAGING_DIR/etc/rc.local.preparebackup
 cat <<EOF >$STAGING_DIR/etc/rc.local
 #!/bin/sh -e
 bash /opt/stack/prepare_guest.sh \\
-    "$GUEST_PASSWORD" "$XS_TOOLS_PATH" "$STACK_USER" \\
+    "$GUEST_PASSWORD" "$XS_TOOLS_PATH" "$STACK_USER" "$DOMZERO_USER" \\
     > /opt/stack/prepare_guest.log 2>&1
 EOF