config-replace

#!/bin/bash

APPLY_CHANGES=1

ARCHIVE_RETENTION=30
CONFIG_ARCHIVE="/mnt/flash/config"
TMP_DIR="/var/tmp"

NEW_CONFIG="$1"
RUNNING_CONFIG="/mnt/flash/config/.running-config"
TMP_CONFIG="/var/tmp/new-config"

function error()
{
    echo "$@"
    exit 0
}

function cli()
{
    FastCli -p15 -c "$@"
}

function cleanup()
{
    [ -f "$TMP_CONFIG" ] && rm $TMP_CONFIG
}

trap cleanup EXIT

[ -z "$NEW_CONFIG" ] && error "Configuration file must be set"
[ ! -f "$NEW_CONFIG" ] && error "Configuration file ($NEW_CONFIG) doesn't exist"
[ ! -d "$CONFIG_ARCHIVE" ] && mkdir -p $CONFIG_ARCHIVE

# Backup existing configuration to a file
[ ! -f "/mnt/flash/config/.running-config" ] && UPDATE_RUNNING_CONFIG=1
[ -n "$UPDATE_RUNNING_CONFIG" ] && cli "copy running-config file:/mnt/flash/config/.running-config"

DIFF_PRINT=$(diff -up -I 'last modified at' $RUNNING_CONFIG $NEW_CONFIG)
[ $(echo "$DIFF_PRINT" | wc -l) -le 1 ] && error "Configuration is the same, no changes made"

# Show the existing differences
echo "$DIFF_PRINT"
echo "---"
read -p "Do you want to apply the changes? [y/N]: " APPLY

[[ ! "$APPLY" == "y" ]] && error "Aborted"

diff -I 'last modified at' \
--new-line-format='%l
' \
--old-line-format='no %l
' \
--unchanged-line-format='%l
' \
$RUNNING_CONFIG $NEW_CONFIG | \
sed -E '/^no !$/d; /^$/d; s/^no\s{3}/   no/g' > $TMP_CONFIG

NEGATE_LINE=
while IFS='' read LINE; do
    if [[ "$LINE" == "no"* ]]; then
        NEGATE_LINE=1
    elif [ -n "$NEGATE_LINE" ] && [[ "$LINE" == "   "* ]]; then
        continue
    else
        NEGATE_LINE=
    fi
    echo "$LINE"
done < $TMP_CONFIG > $TMP_CONFIG.tmp
mv $TMP_CONFIG{.tmp,}

if [ -n "$APPLY_CHANGES" ]; then

    cli "copy file:$TMP_CONFIG running-config"

    # Backup and rotate configurations
    while read FILE; do
        IFS='.' read -ra FILE_PARTS <<< "$FILE"
        NEW_FILE="/mnt/flash/config/arista.conf.$(( ${FILE_PARTS[2]} + 1 )).gz"
        mv $FILE $NEW_FILE
        [ -z "$LAST_FILE" ] && LAST_FILE=$NEW_FILE
    done < <(find /mnt/flash/config -type f -name "*.gz" | sort -Vr)
    [ -f "$LAST_FILE" ] && rm $LAST_FILE
    gzip -c /mnt/flash/config/.running-config > $CONFIG_ARCHIVE/arista.conf.0.gz

    find /mnt/flash/config -type f -name "*.gz" | tail -n+${ARCHIVE_RETENTION} | xargs rm
    rm /mnt/flash/config/.running-config

fi

exit
alias load "bash /mnt/flash/bin/config-replace %1"