benchmarking: Add destroy role

Add an additional role to tear down a benchmarking instance when it is
no longer required.

This also removes the destroyed instances' host keys from known hosts
as GCP will frequently re-use the same IP address on new nodes. This
causes host key verification errors if we don't clean up known hosts.

4 files changed, 22 insertions, 0 deletions

diff --git a/_support/benchmarking/destroy-benchmark-instance b/_support/benchmarking/destroy-benchmark-instance
new file mode 100755
index 000000000..f5eaf5128
--- /dev/null
+++ b/_support/benchmarking/destroy-benchmark-instance
@@ -0,0 +1,2 @@
+#!/bin/sh
+exec ansible-playbook -i hosts.ini destroy.yml "$@"
diff --git a/_support/benchmarking/destroy.yml b/_support/benchmarking/destroy.yml
new file mode 100644
index 000000000..da95995fb
--- /dev/null
+++ b/_support/benchmarking/destroy.yml
@@ -0,0 +1,7 @@
+---
+- name: Destroy benchmark cluster
+  hosts: localhost
+  roles:
+    - destroy
+  become: false
+  gather_facts: no
diff --git a/_support/benchmarking/roles/destroy/handlers/main.yml b/_support/benchmarking/roles/destroy/handlers/main.yml
new file mode 100644
index 000000000..b2bb0d182
--- /dev/null
+++ b/_support/benchmarking/roles/destroy/handlers/main.yml
@@ -0,0 +1,5 @@
+---
+- name: Remove SSH keys from known hosts
+  command: "ssh-keygen -R {{ item }}"
+  loop: "{{ groups['gitaly'] | list + groups['client'] }}"
+  listen: remove hostkeys
diff --git a/_support/benchmarking/roles/destroy/tasks/main.yml b/_support/benchmarking/roles/destroy/tasks/main.yml
new file mode 100644
index 000000000..38c0d1f12
--- /dev/null
+++ b/_support/benchmarking/roles/destroy/tasks/main.yml
@@ -0,0 +1,8 @@
+---
+- name: terraform destroy
+  terraform:
+    project_path: "{{ playbook_dir }}/terraform"
+    variables_file: terraform.tfvars
+    state: absent
+  notify:
+    - remove hostkeys