run-database-migrations

#!/bin/bash
# -----------------------------------------------------------------------------
# Run database migrations
# 1. Update the application's task definition with the latest build, but
#    do not update the service
# 2. Run the "db-migrate" command in the container as a new task
#
# Optional parameters:
#   --workspace <name> – Terraform workspace to select (for PR environments)
#
# Positional parameters:
#   app_name (required) – the name of subdirectory of /infra that holds the
#     application's infrastructure code.
#   image_tag (required) – the tag of the latest build
#   environment (required) – the name of the application environment (e.g. dev,
#     staging, prod)
# -----------------------------------------------------------------------------

set -euo pipefail

workspace=""
while :; do
  case "${1:-}" in
    --workspace)
      workspace="$2"
      shift 2
      ;;
    *)
      break
      ;;
  esac
done

app_name="$1"
image_tag="$2"
environment="$3"

echo "=================="
echo "Running migrations"
echo "=================="
echo "Input parameters"
echo "  app_name=${app_name}"
echo "  image_tag=${image_tag}"
echo "  environment=${environment}"
echo
echo "Step 0. Check if app has a database"

terraform -chdir="infra/${app_name}/app-config" init > /dev/null
terraform -chdir="infra/${app_name}/app-config" apply -auto-approve > /dev/null
has_database=$(terraform -chdir="infra/${app_name}/app-config" output -raw has_database)
if [ "${has_database}" = "false" ]; then
  echo "Application does not have a database, no migrations to run"
  exit 0
fi

db_migrator_user=$(terraform -chdir="infra/${app_name}/app-config" output -json environment_configs | jq -r ".${environment}.database_config.migrator_username")
db_app_user=$(terraform -chdir="infra/${app_name}/app-config" output -json environment_configs | jq -r ".${environment}.database_config.app_username")

./bin/terraform-init "infra/${app_name}/service" "${environment}"

if [ -n "${workspace}" ]; then
  echo "Selecting Terraform workspace: ${workspace}"
  terraform -chdir="infra/${app_name}/service" workspace select "${workspace}"
fi

migrator_role_arn=$(terraform -chdir="infra/${app_name}/service" output -raw migrator_role_arn)

echo

if [ -n "${workspace}" ]; then
  # For PR environments, the task definition was already updated by the caller's
  # terraform apply, so skip the targeted apply (which would reinitialize terraform
  # and reset the workspace).
  echo "Skipping task definition update (already applied in workspace ${workspace})"
else
  echo "::group::Step 1. Update task definition without updating service"

  TF_CLI_ARGS_apply="-input=false -auto-approve -var=image_tag=${image_tag}
    -target=module.service.aws_ecs_task_definition.app
    -target=module.service.aws_iam_role_policy.task_executor" \
    make infra-update-app-service APP_NAME="${app_name}" ENVIRONMENT="${environment}"

  echo "::endgroup::"
fi

echo
echo 'Step 2. Run "db-migrate" command'

command='["db-migrate"]'



# Indent the later lines more to make the output of run-command prettier
environment_variables=$(cat << EOF
[{ "name" : "DB_USER", "value" : "${db_migrator_user}" },
                        { "name" : "APP_USER", "value" : "${db_app_user}" }]
EOF
)

./bin/run-command ${workspace:+--workspace "${workspace}"} --task-role-arn "${migrator_role_arn}" --environment-variables "${environment_variables}" "${app_name}" "${environment}" "${command}"