migrate.sh

#!/bin/bash

set -e
set -o pipefail


if [[ -n ${DEBUG} ]] ; then
  echo "DEBUG: VCAP_SERVICES:   ${VCAP_SERVICES}"
  echo "DEBUG: fromService:     ${fromService}"
  echo "DEBUG: toService:       ${toService}"
fi


if [[ -z ${VCAP_SERVICES} ]] ; then
  echo "\${VCAP_SERVICES} not set!"
  exit 1
fi
if [[ -z ${fromService} ]] ; then
  echo "\${fromService} not set!"
  exit 1
fi
if [[ -z ${toService} ]] ; then
  echo "\${toService} not set!"
  exit 1
fi

declare -A  from
declare -A  to

from[service_type_name]=${OLD_SERVICE_TYPE_NAME:-mongodb}
to[service_type_name]=${NEW_SERVICE_TYPE_NAME:-mongodb}

from[database]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.database" | tr -d '"')
from[rs]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.replica_set" | tr -d '"')
from[host]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.host" | tr -d '"')
from[port]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.port" | tr -d '"')
from[password]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.password" | tr -d '"')
from[username]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.username" | tr -d '"')

if [[ ${from[rs]} != 'null' ]]; then
  from[uri]=$( echo "${VCAP_SERVICES}" | jq ".\"${from[service_type_name]}\"[] | select( .name == \"${fromService}\" ) | .credentials.uri" | tr -d '"')
  _new_host="${from[rs]}/$( echo "${from[uri]}" | cut -d'@' -f2 | cut -d'/' -f1  )"
  from[host]=${_new_host}
else
  from[port_line]="--port ${from[port]}"
fi

to[database]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.database" | tr -d '"')
to[rs]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.replica_set" | tr -d '"')
to[host]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.host" | tr -d '"')
to[port]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.port" | tr -d '"')
to[password]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.password" | tr -d '"')
to[username]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.username" | tr -d '"')

if [[ ${to[rs]} != 'null' ]]; then
  to[uri]=$( echo "${VCAP_SERVICES}" | jq ".\"${to[service_type_name]}\"[] | select( .name == \"${toService}\" ) | .credentials.uri" | tr -d '"')
  _new_host="${to[rs]}/$( echo "${to[uri]}" | cut -d'@' -f2 | cut -d'/' -f1  )"
  to[host]=${_new_host}
else
  to[port_line]="--port ${to[port]}"
fi

if [[ -n ${DEBUG} ]] ; then
  echo "DEBUG: from[database]: ${from[database]}"
  echo "DEBUG: from[host]:     ${from[host]}"
  echo "DEBUG: from[rs]:     ${from[rs]}"
  echo "DEBUG: from[uri]:     ${from[uri]}"
  echo "DEBUG: from[password]: ${from[password]}"
  echo "DEBUG: from[port]:     ${from[port]}"
  echo "DEBUG: from[username]: ${from[username]}"

  echo "DEBUG: to[database]: ${to[database]}"
  echo "DEBUG: to[host]:     ${to[host]}"
  echo "DEBUG: to[rs]:     ${to[rs]}"
  echo "DEBUG: to[uri]:     ${to[uri]}"
  echo "DEBUG: to[password]: ${to[password]}"
  echo "DEBUG: to[port]:     ${to[port]}"
  echo "DEBUG: to[username]: ${to[username]}"
fi


if [[ -z ${from[database]} ]] ; then
  echo "could not resolve details of \"${fromService}\" from \${VCAP_SERVICES}!"
  exit 1
fi
if [[ -z ${to[database]} ]] ; then
  echo "could not resolve details of \"${toService}\" from \${VCAP_SERVICES}!"
  exit 1
fi

echo "Starting MongoDB Migration"
echo "  from: ${fromService}"
echo "  to:   ${toService}"
echo ""


if [[ -n ${DEBUG} ]] ; then
echo "Going to execute the following command:

mongo ${to[uri]} \
      --eval 'db.dropDatabase()'

mongodump    --host ${from[host]} \
             --db ${from[database]} \
             ${from[port_line]} \
             --authenticationDatabase ${from[database]} \
             --username ${from[username]} \
             --password ${from[password]} \
             --archive | \
mongorestore --host ${to[host]} \
             ${to[port_line]} \
             --authenticationDatabase ${to[database]} \
             --username ${to[username]} \
             --password ${to[password]} \
             --archive \
             --nsFrom=${from[database]}.* \
             --nsTo=${to[database]}.*
"
fi

mongo ${to[uri]} \
      --eval 'db.dropDatabase()'

mongodump    --host ${from[host]} \
             --db ${from[database]} \
             ${from[port_line]} \
             --authenticationDatabase ${from[database]} \
             --username ${from[username]} \
             --password ${from[password]} \
             --archive | \
mongorestore --host ${to[host]} \
             ${to[port_line]} \
             --authenticationDatabase ${to[database]} \
             --username ${to[username]} \
             --password ${to[password]} \
             --archive \
             --nsFrom=${from[database]}.* \
             --nsTo=${to[database]}.*



sourceDb="$(mongo ${from[database]} --host ${from[host]} \
      ${from[port_line]} \
      --authenticationDatabase ${from[database]} \
      --username ${from[username]} \
      --password ${from[password]} \
      --eval 'db.getCollectionNames().reduce(function(acc, c) { if (c.indexOf("system.") == -1) { return acc + db[c].count(); } return acc }, 0)' \
      --quiet)"

targetDb="$(mongo ${to[uri]} \
  --eval 'db.getCollectionNames().reduce(function(acc, c) { if (c.indexOf("system.") == -1) { return acc + db[c].count(); } return acc }, 0)' \
  --quiet | grep -e '^[0-9][0-9]*$')"


dbsizesame=0

if [ "$sourceDb" != "$targetDb" ]; then
  dbsizesame=1
fi

RC=$?
echo "Finished redis Migration with RC: $?"
if [[ ${RC} -eq 0 && ${dbsizesame} -eq 0 ]]; then
  echo "MIGRATION SUCCESSFULL"
else
  echo "MIGRATION FAILED"
fi

while true ; do
  echo "This App can now be deleted"
  sleep 60
done