Run Drupal migrations on Pantheon

pantheon_drupal_migration.sh

#!/bin/bash

# Script to run Drupal migrations on Pantheon.
# See also https://pantheon.io/blog/running-drupal-8-data-migrations-pantheon-through-drush

# Make sure the command is called with at least 3 arguments. Example:
# ./pantheon_drupal_migration.sh target_environment.multidev source_environment.multidev upgrade_d7_user upgrade_d7_file
[ $# -lt 3 ] && { echo "Usage: $0 [d9_target_site_id.env] [d6_source_site_id.env] [migration_ids]" ; exit 1; }

TARGET=$1
SOURCE=$2

# Accept a list of migration IDs separated by commas or spaces starting in the 3rd argument
IFS=', ' read -r -a MIGRATIONS <<< "${@:3}"

# Wake up Pantheon environments
terminus env:wake -q $SOURCE
terminus env:wake -q $TARGET

for MIGRATION in "${MIGRATIONS[@]}"
do
    START=`date +%s`
    UNPROCESSED_RECORDS="-1"
    PREV_UNPROCESSED_RECORDS=`terminus remote:drush -- $TARGET migrate:status $MIGRATION --field=unprocessed`

    # Before trying to import the migration, check if there is anything else to process.
    if [[ $PREV_UNPROCESSED_RECORDS -eq 0 ]]; then
       echo "No more records to import for $MIGRATION migration"
       break
    fi

    echo "Starting import operation for $MIGRATION migration"

    until [[ $UNPROCESSED_RECORDS -eq 0 ]]
    do
      terminus remote:drush -- $TARGET migrate:import $MIGRATION --feedback=100 --skip-progress-bar
      if [[ $? -ne 0 ]]; then
         echo "Import operation for $MIGRATION migration failed"
         break
      fi

      # Prevent an infinite loop when migration records cannot be imported.
      UNPROCESSED_RECORDS=`terminus remote:drush -- $TARGET migrate:status $MIGRATION --field=unprocessed`
      if [[ $UNPROCESSED_RECORDS -eq $PREV_UNPROCESSED_RECORDS ]]; then
        echo "$MIGRATION cannot process the remaining $UNPROCESSED_RECORDS records"
        break
      else
        echo "$UNPROCESSED_RECORDS more records to process for the $MIGRATION migration"
        terminus env:wake -q $SOURCE
      fi
      PREV_UNPROCESSED_RECORDS=$UNPROCESSED_RECORDS
    done

    END=`date +%s`
    echo "$((END-START)) seconds processing the $MIGRATION migration"
done