diff --git a/devstack/customize_image.sh b/devstack/customize_image.sh
new file mode 100644
index 0000000..669c761
--- /dev/null
+++ b/devstack/customize_image.sh
@@ -0,0 +1,158 @@
+# This script include functions that allow guest image files customization
+# before uploading them to OpenStack image service
+
+# ensure we don't re-source this in the same environment
+[[ -z "$_NEUTRON_TEMPEST_PLUGIN_CUSTOMIZE_IMAGE" ]] || return 0
+declare -r -g _NEUTRON_TEMPEST_PLUGIN_CUSTOMIZE_IMAGE=1
+
+source "${NEUTRON_TEMPEST_PLUGIN_DIR}/functions.sh"
+
+# By default enable guest image customization. It will be automatically skipped
+# for cirros images
+CUSTOMIZE_IMAGE=${CUSTOMIZE_IMAGE:-True}
+
+# Image customization is performed using virt-customize
+# using direct backend by default
+LIBGUESTFS_BACKEND=${LIBGUESTFS_BACKEND:-direct}
+
+# Disable KVM hardware accelleration by default
+LIBGUESTFS_BACKEND_SETTINGS=${LIBGUESTFS_BACKEND_SETTINGS:-force_tcg}
+
+# Install tools required for customizing guest image files
+function install_customize_image_tools {
+    local do_customize=$(trueorfalse True CUSTOMIZE_IMAGE)
+    if [ ${do_customize} == True ]; then
+        # Make sure virt-customize is installed
+        install_package libguestfs-tools
+    fi
+}
+
+# Wraps upload_image function to eventually customize image file before
+# uploading it via "openstack image create" command
+save_function upload_image overridden_upload_image
+function upload_image {
+    local image_url=$1
+
+    # Fork a subshell to have environment restored at the end of this function
+    (
+        # Check user configuration
+        local customize_image=$(trueorfalse True CUSTOMIZE_IMAGE)
+        if [ ${customize_image} == True ]; then
+            # Temporarly wraps openstack command with openstack_image_create
+            # function
+            function openstack {
+                IMAGE_URL=${image_url} upload_custom_image "$@"
+            }
+        fi
+
+        # Execute original upload_image function
+        overridden_upload_image "$@"
+    )
+}
+
+# Wraps "openstack image create" command to customize image file before
+# uploading it to OpenstackImage service.
+# Called only when ${CUSTOMIZE_IMAGE} is True
+function upload_custom_image {
+    # Copy command arguments for later use
+    local args=( "$@" )
+
+    # Look for image create sub-command:
+    # skip any argument before "image" and "create" words
+    local i=0
+    local subcommands=()
+    for subcommand in image create; do
+        for (( ; i < ${#args[@]}; )) {
+            local arg=${args[i]}
+            (( ++i ))
+            if [ "${arg}" == "${subcommand}" ]; then
+                subcommands+=( "${arg}" )
+                break
+            fi
+        }
+    done
+
+    if [ "${subcommands[*]}" == "image create" ]; then
+        # create image subcommand has been detected
+
+        # Put here temporary files to be delete before exiting from this
+        # function
+        local temp_dir=$(mktemp -d)
+        chmod 777 "${temp_dir}"
+
+        # Parse openstack image create subcommand arguments
+        local image_url="${IMAGE_URL}"
+        local image_file=
+        local disk_format=auto
+        local container_format=bare
+
+        for (( ; i < ${#args[@]}; )) {
+            local arg=${args[$i]}
+            (( ++i ))
+
+            if [[ "${arg}" == --* ]]; then
+                # Handle --<option_name>=<option_value> syntax
+                local option_fields=(${arg//=/ })
+                local option_name=${option_fields[0]}
+                local option_value=${option_fields[1]:-}
+
+                case "${option_name}" in
+
+                    --container-format)  # Found container format
+                        container_format=${option_value:-${args[ (( i++ )) ]}}
+                        ;;
+
+                    --disk-format)  # Found disk format
+                        disk_format=${option_value:-${args[ (( i++ )) ]}}
+                        ;;
+
+                   --file)  # Found image file name
+                        image_file=${option_value:-${args[ (( i++ )) ]}}
+                        ;;
+                esac
+            fi
+        }
+
+        if [ "${image_file}" == "" ]; then
+            # Copy image file from stdin to a temporary file
+            image_file=${temp_dir}/$(basename "${image_url}")
+            cat > "${image_file}"
+
+            # Add option to load image from file
+            args+=( --file "${image_file}" )
+        fi
+
+        # Make image file readable and writable by qemu user
+        sudo chmod 666 "${image_file}"
+
+        # Customize image file
+        TEMP_DIR=${temp_dir} \
+            DISK_FORMAT=${disk_format} \
+            customize_image "${image_file}"
+    fi
+
+    # Upload custom image file
+    overridden_openstack "${args[@]}" || local error=$?
+
+    # Finally delete temporary files
+    sudo rm -fR "${temp_dir}" || true
+
+    return ${error:-0}
+}
+
+function overridden_openstack {
+    "$(which openstack)" "$@"
+}
+
+# Execute customization commands on a VM with attached guest image file.
+# Called only when ${CUSTOMIZE_IMAGE} is True
+function customize_image {
+    local image_file=$1
+    local top_dir=$(dirname "${NEUTRON_TEMPEST_PLUGIN_DIR}")
+    (
+        export TEMP_DIR DISK_FORMAT RC_DIR
+        if [[ "$(basename ${image_file})" == ubuntu-* ]]; then
+            "${top_dir}/tools/customize_ubuntu_image" "${image_file}"
+        fi
+    )
+}
diff --git a/devstack/functions.sh b/devstack/functions.sh
new file mode 100644
index 0000000..026f527
--- /dev/null
+++ b/devstack/functions.sh
@@ -0,0 +1,32 @@
+# Generic use functions
+
+# ensure we don't re-source this in the same environment
+[[ -z "$_NEUTRON_TEMPEST_PLUGIN_FUNCTIONS" ]] || return 0
+declare -r -g _NEUTRON_TEMPEST_PLUGIN_FUNCTIONS=1
+
+# Create a function copying the code from an existing one
+function save_function {
+    local old_name=$1
+    local new_name=$2
+
+    # Saving the same function again after redefining it could produce a
+    # recorsive function in case for example this plugin is sourced twice
+    if type -t "${new_name}"; then
+        # Prevent copying the same function twice
+        return 0
+    fi
+
+    # Save xtrace setting
+    _XTRACE_FUNCTIONS=$(set +o | grep xtrace)
+    set +o xtrace
+
+    # Get code of the original function
+    local old_code=$(declare -f ${old_name})
+    # Produce code for the new function
+    local new_code="${new_name}${old_code#${old_name}}"
+    # Define the new function
+    eval "${new_code}"
+
+    # Restore xtrace
+    $_XTRACE_FUNCTIONS
+}
diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index a2009ea..e7e30a9 100644
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -1,6 +1,12 @@
+# Directory where this plugin.sh file is
+NEUTRON_TEMPEST_PLUGIN_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+
+source "${NEUTRON_TEMPEST_PLUGIN_DIR}/customize_image.sh"
+
 # install_neutron_tempest_plugin
 function install_neutron_tempest_plugin {
     setup_dev_lib "neutron-tempest-plugin"
+    install_customize_image_tools
 }
 
 if [[ "$1" == "stack" ]]; then
diff --git a/tools/customize_ubuntu_image b/tools/customize_ubuntu_image
index 9c3fd07..3697265 100755
--- a/tools/customize_ubuntu_image
+++ b/tools/customize_ubuntu_image
@@ -31,8 +31,11 @@
     chown _apt.root -fR "${apt_user_folders[@]}"
 
     # Install desired packages to Ubuntu guest image
-    apt-get update -y
-    apt-get install -y "${INSTALL_GUEST_PACKAGES[@]}"
+    (
+        DEBIAN_FRONTEND=noninteractive
+        apt-get update -y
+        apt-get install -y "${INSTALL_GUEST_PACKAGES[@]}"
+    )
 }
 
 function main {
@@ -64,9 +67,12 @@
     bind_dir "${temp_dir}/tmp" "${mount_dir}/var/tmp"
     bind_dir "${temp_dir}/apt" "${mount_dir}/var/lib/apt"
 
-    # Replace /etc/resolv.conf symlink to use the same DNS as this host
-    sudo rm -f "${mount_dir}/etc/resolv.conf"
-    sudo cp /etc/resolv.conf "${mount_dir}/etc/resolv.conf"
+    # Temporarly replace /etc/resolv.conf symlink to use the same DNS as this
+    # host
+    local resolv_file=${mount_dir}/etc/resolv.conf
+    sudo mv -f "${resolv_file}" "${resolv_file}.orig"
+    sudo cp /etc/resolv.conf "${resolv_file}"
+    add_cleanup sudo mv -f "${resolv_file}.orig" "${resolv_file}"
 
     # Makesure /etc/fstab exists and it is readable because it is required by
     # /sbin/dhclient-script