mongo_migrate

#!/bin/sh

### BEGIN INFO
# Provides:          Mongodb migration manager
# Author:            Emerson Macedo - http://github.com/emerleite - http://codificando.com 
# Description:       Generate migration script 
### END INFO

### SCRIPT FUNCTIONS

usage() {
    echo "Usage: mongo_migrate [options] [params]
        -g       generate
        -r       run
        -t       target (up or down)
        -f       migration_file|migration_name
        -c       configuration file" >&2
	  echo ""
    exit 1
}

ensure_installed() {
    if [ ! `type -P $1` ]
    then
        echo "$1 is not installed. Please install before continue."
        exit 127
    fi
}

ensure_migration_dir() {
    if [ ! -d $MIGRATION_DIR ]
    then
        echo "Migration dir does not exist: $MIGRATION_DIR\n"
        exit 1
    fi
}

ensure_database() {
    if [ -z $MONGO_DATABASE ]; then
        echo "MONGO_DATABASE not defined"
        echo "Define it at config.cfg\n"
        exit 1
    fi
}

generate_migration_file_name() {
    echo "`date -u +%Y%m%d%H%M%S`_$1.js"
}

get_migration_file_name() {
    if [ -e $MIGRATION_DIR$1 ];
    then
      echo $MIGRATION_DIR$1
    else
      echo "$MIGRATION_DIR$(find ./$MIGRATION_DIR -name '[0-9]*' |grep --color=never _$1.js |awk -F/ '{print $NF}')"
    fi
}

check_migration() {
    local file=`get_migration_file_name $1`
    local total_files=`get_migration_file_name $1 |wc -l`

    if [ ! $total_files = '1' ]; then 
        echo "You have 2 files, please use the full file name"
        echo "Files:"
        echo "$file\n"
        exit 1
    fi

    if [ ! -f $file ]; then
        echo "Migration not found at $MIGRATION_DIR\n"
        exit 1
    fi
}

generate() {
    echo "Generating migration ${1}"
    local file=`generate_migration_file_name ${1}`
    cp template/migration_template.js $MIGRATION_DIR$file
    echo "Migration ${MIGRATION_DIR}${file} generated"
}

run_migration() {
    local name=$1
    local target=$2

    echo "running migration ${name} ${target}\n"
    ensure_installed mongo
    ensure_database

    if [[ $target != "up" && $target != "down" ]];then usage; fi

    local file=`get_migration_file_name ${name}`

    check_migration $name
    
    mongo $MONGO_HOST/$MONGO_DATABASE $auth --eval "target='${target}'" $file
    if [ $? -ne 0 ];
    then
        echo "\nerror executing migration.\n"
        exit 1
    fi

    [ $target = "up" ] && local inc="+1" || local inc="-1"
    local migration_name="$(echo $file |awk -F/ '{print $NF}')"
    local migration_time="$(echo $migration_name |cut -d_ -f1 |bc)"

    update_current_migration `echo "$migration_time$inc"|bc`

    echo "Migration ${name} ${target} executed\n"
}

get_current_migration() {
    echo "`mongo $MONGO_HOST/$MONGO_DATABASE $auth --quiet ./get_current.js`"
}

update_current_migration() {
    mongo $MONGO_HOST/$MONGO_DATABASE $auth --quiet --eval "current='${1}'" ./update_current.js
}

all_up() {
    local current_migration=`get_current_migration|bc`

    local migrations="$(find $MIGRATION_DIR -name \*.js |sort -n)"
    for migration in $migrations
    do
        local migration_name="$(echo $migration |awk -F/ '{print $NF}')"
        local migration_time="$(echo $migration_name |cut -d_ -f1 |bc)"
        if [[ $migration_time -gt $current_migration ]]; then
            run_migration $migration_name up
        fi
    done
}

all_down() {
    local current_migration=`get_current_migration|bc`

    local migrations="$(find $MIGRATION_DIR -name \*.js |sort -nr)"
    for migration in $migrations
    do
        local migration_name="$(echo $migration |awk -F/ '{print $NF}')"
        local migration_time="$(echo $migration_name |cut -d_ -f1 |bc)"
        if [[ $migration_time -lt $current_migration ]]; then
            run_migration $migration_name down
        fi
    done
}

run_all() {
    local target=$1

    if [[ $target = "up" ]]; then
        all_up
    elif [[ $target = "down" ]]; then
        all_down
    else
        usage
        exit 1
    fi
}

## SCRIPT RUN

#Convention configs
MONGO_HOST=localhost
MIGRATION_DIR="db/migrate/"
CONFIG_PATH=./config.cfg

#Parameter extraction
while getopts "hf:c:t:gr" OPT; do
  case "$OPT" in
  "h") usage;; # exibir ajuda
  "f") FILE_NAME=$OPTARG;;
  "c") CONFIG_PATH=$OPTARG;;
  "g") GENERATE=true;;
  "r") RUN=true;;
  "t") TARGET=$OPTARG;;
  "?") exit -1;;
  esac
  done

#Check script invocation
[ -n "$GENERATE" -a -n "$RUN" ] && usage
[ -n "$GENERATE" -a -z "$FILE_NAME" ] && usage

[ -n "$RUN" -a "$TARGET" != "up" -a "$TARGET" != "down" ] && usage

#load custom configs (overrides defaults)
source $CONFIG_PATH

#ensure trailing slash on MIGRATION_DIR
MIGRATION_DIR=${MIGRATION_DIR%/}/

#Check migration dir
ensure_migration_dir
#Construct authentication phrase
auth=""
if [ $MONGO_USR ]; then
	auth="$auth -u $MONGO_USR "
fi

if [ $MONGO_PWD ]; then
	auth="$auth -p $MONGO_PWD "
fi

# Script running flow
if [ $GENERATE ]; then
    generate $FILE_NAME
elif [ $RUN ]; then
    if [ -z "$FILE_NAME" ]; then
        run_all $TARGET
    else
        run_migration $FILE_NAME $TARGET
    fi
else
    usage
fi

exit 0