feat: add leave_on_terminate (default true so containers gracefully l…

…eave when ECS stops the task) (#15)

* feat: set leave_on_terminate from variable

* fix: helps if you pass the variable

* fix: convert boolean to string for template

* feat: making this more opinionated, setting leave_on_terminate true by default

The consul default for leave_on_terminate is false; however running
consul in docker means we need to set this to true: when the docker
container exits, local data in the container is lost; therefore we need
to send a graceful leave before exiting. Docker stop (and ECS Stop Task)
send a TERM.

* chore: gitignore

* feat: update variable description and README for leave_on_terminate

.gitignore

@@ -28,4 +28,5 @@ Session.vim
 # auto-generated tag files
 tags
 
-
+# editors
+.idea

README.md

@@ -47,6 +47,7 @@ This module supports two modes. If you pass a single ECS cluster ID into the `ec
 - `oauth2_proxy_htpasswd_file` - Path the htpasswd file defaults to /conf/htpasswd
 - `join_ec2_tag_key` - EC2 Tag Key which consul uses to search to generate a list of IP's to Join. Defaults to Name
 - `raft_multiplier" - An integer multiplier used by Consul servers to scale key Raft timing parameters https://www.consul.io/docs/guides/performance.html defaults to 5
+- `leave_on_terminate` - If enabled, when the agent receives a TERM signal, it will send a Leave message to the rest of the cluster and gracefully leave. Defaults to true in this module so that containers will gracefully leave the consul cluster when ECS stops the task.
 - `region` - AWS Region - defaults to us-east-1
 - `registrator_image` - Image to use when deploying registrator agent, defaults to the gliderlabs registrator:latest image
 - `registrator_memory_reservation` The soft limit (in MiB) of memory to reserve for the container, defaults 32

files/consul.json

@@ -8,7 +8,7 @@
             "environment": [
                 {
                     "name": "CONSUL_LOCAL_CONFIG",
-                    "value": "{ \"retry_join\": [\"provider=aws tag_key=${join_ec2_tag_key} tag_value=${join_ec2_tag}\"], \"raft_protocol\": 3, \"skip_leave_on_interrupt\": true, \"enable_script_checks\": ${enable_script_checks}, \"datacenter\":\"${datacenter}\", \"performance\": { \"raft_multiplier\": ${raft_multiplier} }}"
+                    "value": "{ \"retry_join\": [\"provider=aws tag_key=${join_ec2_tag_key} tag_value=${join_ec2_tag}\"], \"raft_protocol\": 3, \"skip_leave_on_interrupt\": true, \"leave_on_terminate\": ${leave_on_terminate}, \"enable_script_checks\": ${enable_script_checks}, \"datacenter\":\"${datacenter}\", \"performance\": { \"raft_multiplier\": ${raft_multiplier} }}"
                 },
                 {
                     "name": "CONSUL_BIND_INTERFACE",

main.tf

@@ -42,6 +42,7 @@ data "template_file" "consul" {
     oauth2_proxy_client_id         = "${var.oauth2_proxy_client_id}"
     oauth2_proxy_client_secret     = "${var.oauth2_proxy_client_secret}"
     raft_multiplier                = "${var.raft_multiplier}"
+    leave_on_terminate             = "${var.leave_on_terminate ? "true" : "false"}"
     s3_backup_bucket               = "${var.s3_backup_bucket}"
   }
 }

variables.tf

@@ -119,6 +119,11 @@ variable "service_minimum_healthy_percent" {
   default     = "66"
 }
 
+variable "leave_on_terminate" {
+  description = "If enabled, when the agent receives a TERM signal, it will send a Leave message to the rest of the cluster and gracefully leave. Defaults to true in this module so that containers will gracefully leave the consul cluster when ECS stops the task."
+  default     = true
+}
+
 variable "vpc_id" {}
 
 variable "sha_htpasswd_hash" {