functions

# functions - Common functions used by DevStack components
#
# ENABLED_SERVICES is used by is_service_enabled()


# Save trace setting
XTRACE=$(set +o | grep xtrace)
set +o xtrace


# apt-get wrapper to set arguments correctly
# apt_get operation package [package ...]
function apt_get() {
    [[ "$OFFLINE" = "True" || -z "$@" ]] && return
    local sudo="sudo"
    [[ "$(id -u)" = "0" ]] && sudo="env"
    $sudo DEBIAN_FRONTEND=noninteractive \
        http_proxy=$http_proxy https_proxy=$https_proxy \
        apt-get --option "Dpkg::Options::=--force-confold" --assume-yes "$@"
}


# Gracefully cp only if source file/dir exists
# cp_it source destination
function cp_it {
    if [ -e $1 ] || [ -d $1 ]; then
        cp -pRL $1 $2
    fi
}


# Prints "message" and exits
# die "message"
function die() {
    local exitcode=$?
    set +o xtrace
    echo $@
    exit $exitcode
}


# Checks an environment variable is not set or has length 0 OR if the
# exit code is non-zero and prints "message" and exits
# NOTE: env-var is the variable name without a '$'
# die_if_not_set env-var "message"
function die_if_not_set() {
    (
        local exitcode=$?
        set +o xtrace
        local evar=$1; shift
        if ! is_set $evar || [ $exitcode != 0 ]; then
            set +o xtrace
            echo $@
            exit -1
        fi
    )
}


# Grab a numbered field from python prettytable output
# Fields are numbered starting with 1
# Reverse syntax is supported: -1 is the last field, -2 is second to last, etc.
# get_field field-number
function get_field() {
    while read data; do
        if [ "$1" -lt 0 ]; then
            field="(\$(NF$1))"
        else
            field="\$$(($1 + 1))"
        fi
        echo "$data" | awk -F'[ \t]*\\|[ \t]*' "{print $field}"
    done
}


# Determine OS Vendor, Release and Update
# Tested with OS/X, Ubuntu, RedHat, CentOS, Fedora
# Returns results in global variables:
# os_VENDOR - vendor name
# os_RELEASE - release
# os_UPDATE - update
# os_PACKAGE - package type
# os_CODENAME - vendor's codename for release
# GetOSVersion
GetOSVersion() {
    # Figure out which vendor we are
    if [[ -n "`which sw_vers 2>/dev/null`" ]]; then
        # OS/X
        os_VENDOR=`sw_vers -productName`
        os_RELEASE=`sw_vers -productVersion`
        os_UPDATE=${os_RELEASE##*.}
        os_RELEASE=${os_RELEASE%.*}
        os_PACKAGE=""
        if [[ "$os_RELEASE" =~ "10.7" ]]; then
            os_CODENAME="lion"
        elif [[ "$os_RELEASE" =~ "10.6" ]]; then
            os_CODENAME="snow leopard"
        elif [[ "$os_RELEASE" =~ "10.5" ]]; then
            os_CODENAME="leopard"
        elif [[ "$os_RELEASE" =~ "10.4" ]]; then
            os_CODENAME="tiger"
        elif [[ "$os_RELEASE" =~ "10.3" ]]; then
            os_CODENAME="panther"
        else
            os_CODENAME=""
        fi
    elif [[ -x $(which lsb_release 2>/dev/null) ]]; then
        os_VENDOR=$(lsb_release -i -s)
        os_RELEASE=$(lsb_release -r -s)
        os_UPDATE=""
        if [[ "Debian,Ubuntu" =~ $os_VENDOR ]]; then
            os_PACKAGE="deb"
        else
            os_PACKAGE="rpm"
        fi
        os_CODENAME=$(lsb_release -c -s)
    elif [[ -r /etc/redhat-release ]]; then
        # Red Hat Enterprise Linux Server release 5.5 (Tikanga)
        # CentOS release 5.5 (Final)
        # CentOS Linux release 6.0 (Final)
        # Fedora release 16 (Verne)
        os_CODENAME=""
        for r in "Red Hat" CentOS Fedora; do
            os_VENDOR=$r
            if [[ -n "`grep \"$r\" /etc/redhat-release`" ]]; then
                ver=`sed -e 's/^.* \(.*\) (\(.*\)).*$/\1\|\2/' /etc/redhat-release`
                os_CODENAME=${ver#*|}
                os_RELEASE=${ver%|*}
                os_UPDATE=${os_RELEASE##*.}
                os_RELEASE=${os_RELEASE%.*}
                break
            fi
            os_VENDOR=""
        done
        os_PACKAGE="rpm"
    fi
    export os_VENDOR os_RELEASE os_UPDATE os_PACKAGE os_CODENAME
}


# git clone only if directory doesn't exist already.  Since ``DEST`` might not
# be owned by the installation user, we create the directory and change the
# ownership to the proper user.
# Set global RECLONE=yes to simulate a clone when dest-dir exists
# git_clone remote dest-dir branch
function git_clone {
    [[ "$OFFLINE" = "True" ]] && return

    GIT_REMOTE=$1
    GIT_DEST=$2
    GIT_BRANCH=$3

    if echo $GIT_BRANCH | egrep -q "^refs"; then
        # If our branch name is a gerrit style refs/changes/...
        if [[ ! -d $GIT_DEST ]]; then
            git clone $GIT_REMOTE $GIT_DEST
        fi
        cd $GIT_DEST
        git fetch $GIT_REMOTE $GIT_BRANCH && git checkout FETCH_HEAD
    else
        # do a full clone only if the directory doesn't exist
        if [[ ! -d $GIT_DEST ]]; then
            git clone $GIT_REMOTE $GIT_DEST
            cd $GIT_DEST
            # This checkout syntax works for both branches and tags
            git checkout $GIT_BRANCH
        elif [[ "$RECLONE" == "yes" ]]; then
            # if it does exist then simulate what clone does if asked to RECLONE
            cd $GIT_DEST
            # set the url to pull from and fetch
            git remote set-url origin $GIT_REMOTE
            git fetch origin
            # remove the existing ignored files (like pyc) as they cause breakage
            # (due to the py files having older timestamps than our pyc, so python
            # thinks the pyc files are correct using them)
            find $GIT_DEST -name '*.pyc' -delete
            git checkout -f origin/$GIT_BRANCH
            # a local branch might not exist
            git branch -D $GIT_BRANCH || true
            git checkout -b $GIT_BRANCH
        fi
    fi
}


# Comment an option in an INI file
# optset config-file section option
function inicomment() {
    local file=$1
    local section=$2
    local option=$3
    sed -i -e "/^\[$section\]/,/^\[.*\]/ s|^\($option[ \t]*=.*$\)|#\1|" $file
}


# Get an option from an INI file
# optget config-file section option
function iniget() {
    local file=$1
    local section=$2
    local option=$3
    local line
    line=$(sed -ne "/^\[$section\]/,/^\[.*\]/ { /^$option[ \t]*=/ p; }" $file)
    echo ${line#*=}
}


# Set an option in an INI file
# This is NOT a complete option setter, it assumes that the section and
# option already exist in the INI file.  If the section does not exist,
# nothing happens.
# optset config-file section option value
function iniset() {
    local file=$1
    local section=$2
    local option=$3
    local value=$4
    sed -i -e "/^\[$section\]/,/^\[.*\]/ s|^\($option[ \t]*=[ \t]*\).*$|\1$value|" $file
}


# is_service_enabled() checks if the service(s) specified as arguments are
# enabled by the user in **ENABLED_SERVICES**.
#
# If there are multiple services specified as arguments the test performs a
# boolean OR or if any of the services specified on the command line
# return true.
#
# There is a special cases for some 'catch-all' services::
#   **nova** returns true if any service enabled start with **n-**
#   **glance** returns true if any service enabled start with **g-**
#   **quantum** returns true if any service enabled start with **q-**
function is_service_enabled() {
    services=$@
    for service in ${services}; do
        [[ ,${ENABLED_SERVICES}, =~ ,${service}, ]] && return 0
        [[ ${service} == "nova" && ${ENABLED_SERVICES} =~ "n-" ]] && return 0
        [[ ${service} == "glance" && ${ENABLED_SERVICES} =~ "g-" ]] && return 0
        [[ ${service} == "quantum" && ${ENABLED_SERVICES} =~ "q-" ]] && return 0
    done
    return 1
}


# Distro-agnostic package installer
# install_package package [package ...]
function install_package() {
    if [[ -z "$os_PACKAGE" ]]; then
        GetOSVersion
    fi
    if [[ "$os_PACKAGE" = "deb" ]]; then
        apt_get install "$@"
    else
        yum_install "$@"
    fi
}


# Test if the named environment variable is set and not zero length
# is_set env-var
function is_set() {
    local var=\$"$1"
    if eval "[ -z $var ]"; then
        return 1
    fi
    return 0
}


# pip install wrapper to set cache and proxy environment variables
# pip_install package [package ...]
function pip_install {
    [[ "$OFFLINE" = "True" || -z "$@" ]] && return
    if [[ -z "$os_PACKAGE" ]]; then
        GetOSVersion
    fi
    if [[ "$os_PACKAGE" = "deb" ]]; then
        CMD_PIP=/usr/bin/pip
    else
        CMD_PIP=/usr/bin/pip-python
    fi
    sudo PIP_DOWNLOAD_CACHE=/var/cache/pip \
        HTTP_PROXY=$http_proxy \
        HTTPS_PROXY=$https_proxy \
        $CMD_PIP install --use-mirrors $@
}


# Service wrapper to restart services
# restart_service service-name
function restart_service() {
    sudo /usr/sbin/service $1 restart
}


# Service wrapper to start services
# start_service service-name
function start_service() {
    sudo /usr/sbin/service $1 start
}


# Service wrapper to stop services
# stop_service service-name
function stop_service() {
    sudo /usr/sbin/service $1 stop
}


# Normalize config values to True or False
# VAR=`trueorfalse default-value test-value`
function trueorfalse() {
    local default=$1
    local testval=$2

    [[ -z "$testval" ]] && { echo "$default"; return; }
    [[ "0 no false False FALSE" =~ "$testval" ]] && { echo "False"; return; }
    [[ "1 yes true True TRUE" =~ "$testval" ]] && { echo "True"; return; }
    echo "$default"
}


# yum wrapper to set arguments correctly
# yum_install package [package ...]
function yum_install() {
    [[ "$OFFLINE" = "True" ]] && return
    local sudo="sudo"
    [[ "$(id -u)" = "0" ]] && sudo="env"
    $sudo http_proxy=$http_proxy https_proxy=$https_proxy \
        yum install -y "$@"
}


# Restore xtrace
$XTRACE