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docs/ansible/server-wait.md

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+# Waiting for Servers to be Provisioned and Ready
+
+## Overview
+
+Often when working with automated deployments you will want to wait for your servers to be provisioned and ready before running your Ansible playbook. This is a simple bash script you can run before your Ansible playbook to wait for your servers to be ready.
+
+## The Script
+
+The script below assumes a few things, namely:
+* You have a private key file called `private.key` in the root directory of your project
+* You have a terraform directory in the root of your project
+* You have two IP address outputs in your terraform called `server-1-ip-address` and `server-2-ip-address`
+
+```bash [wait-for-servers.sh]
+# Simple script to wait till all the servers are up and running (e.g. not setting up)
+echo 'Trying SSH to new instances, checking cloud-init status... (It will say "Connection refused" until it is ready.)'
+
+# 6 retries x 5 seconds each = maximum approx 30 seconds to wait for SSH, then bail.
+check_instances() {
+    echo now checking...
+    ssh root@"$server_1_ip" -o StrictHostKeyChecking=no -i private.key cloud-init status -w 
+    ssh root@"$server_2_ip" -o StrictHostKeyChecking=no -i private.key cloud-init status -w
+}
+
+echo getting hostnames...
+
+# Navigate to terraform directory 
+cd terraform
+server_1_ip="$(terraform output -raw server-1-ip-address)"
+server_2_ip="$(terraform output -raw server-2-ip-address)"
+
+# Navigate back to root directory
+cd ..
+
+timeout=6
+stopwatch=0
+until check_instances; do
+  stopwatch=$((stopwatch+1))
+  if [[ $stopwatch -ge $timeout ]]; then echo Error: Timed out waiting for instance; exit -1; fi
+  sleep 5
+done
+```