Add ${DESTROY_VOLUME} operational toggle

This way I can dynamically control whether to destroy and recreate all the
existing infrastructure entirely from scratch.

The advantages of doing so are:
- test the non-existence of local state on every deployment;
- make sure I can always recreate everything from scratch.

The disadvantages are:
- slower deployment times;
- longer downtime during deployments.

2 files changed, 13 insertions, 2 deletions

diff --git a/scripts/box/restore-backup.env.sh b/scripts/box/restore-backup.env.sh
index 2c12f21..5eb575b 100755
--- a/scripts/box/restore-backup.env.sh
+++ b/scripts/box/restore-backup.env.sh
@@ -1,6 +1,13 @@
 #!/usr/bin/env bash
 set -Eeuo pipefail
 
+# Check for ${DOLLAR}{DESTROY_VOLUME} interpolated value
+[[ "${DESTROY_VOLUME}" != "" ]] || {
+  echo "Volume is not fresh."
+  echo "Skipping restoring from backup."
+  exit 0
+}
+
 export BORG_REMOTE_PATH="${BORG_REMOTE_PATH}"
 export BORG_PASSPHRASE="${BORG_PASSPHRASE}"
 
diff --git a/scripts/ci/provision.sh b/scripts/ci/provision.sh
index 5d7b96b..e2a0c72 100755
--- a/scripts/ci/provision.sh
+++ b/scripts/ci/provision.sh
@@ -32,8 +32,12 @@ terraform --version
 terraform init
 echo "Done."
 
-echo "Destroying existing infrastructure..."
-terraform destroy -input=false -auto-approve
+if [[ "${DESTROY_VOLUME:-}" != "" ]]; then
+  echo "Skipping explicit intentional destruction of existing infrastructure..."
+else
+  echo "Destroying existing infrastructure..."
+  terraform destroy -input=false -auto-approve
+fi
 echo "Done."
 
 echo "Running 'terraform plan' and storing the planfile..."