Add cloudwatch grafana datasource (#1050)

* Fix rabbit prometheus scrape config on master

Related issue(s):
* #1048

* [Grafana] Add cloudwatch datasource

This lets us build dashboards using cloudwatch metrics (aws managed
resources like RDS or MQ store their prometheus-like metrics there)

Related issue(s):
* #1048

* Hardcode grafana cloudwatch datasource uid

This lets us reuse the same dashboard json without adjusting its uid per
deployment. This is how it works with current architecture design

* Disable cloudwatch datasource for non aws

Author: YuryHrytsuk

services/monitoring/grafana/Makefile

@@ -27,7 +27,7 @@ terraform/plan.cache:
 	@exit 1
 
 .PHONY: terraform-plan
-terraform-plan: $(REPO_CONFIG_LOCATION) $(TF_STATE_FILE) ensure-grafana-online ## terraform plan
+terraform-plan: $(REPO_CONFIG_LOCATION) $(TF_STATE_FILE) ensure-grafana-online assets ## terraform plan
 	# terraform plan
 	@set -a; source $<; set +a; \
 	terraform -chdir=./terraform plan -out=plan.cache

services/monitoring/grafana/terraform/datasources.tf

@@ -23,3 +23,22 @@ resource "grafana_data_source" "tempo" {
   basic_auth_enabled = false
   is_default         = false
 }
+
+resource "grafana_data_source" "cloudwatch" {
+  # This resource is only created if the AWS Deployments
+  count = var.IS_AWS_DEPLOYMENT ? 1 : 0
+
+  type = "cloudwatch"
+  name = "cloudwatch"
+  uid  = "fem2inr5v64n4c"
+
+  json_data_encoded = jsonencode({
+    defaultRegion = var.AWS_DEFAULT_REGION
+    authType      = "keys"
+  })
+
+  secure_json_data_encoded = jsonencode({
+    accessKey = var.GRAFANA_CLOUDWATCH_DATASOURCE_USER_ACCESS_KEY
+    secretKey = var.GRAFANA_CLOUDWATCH_DATASOURCE_USER_SECRET_KEY
+  })
+}

services/monitoring/grafana/terraform/variables.tf

@@ -18,3 +18,26 @@ variable "PROMETHEUS_CATCHALL_URL" {
   description = "Prometheus Catchall URL"
   sensitive   = false
 }
+
+# to be used to create resource only for AWS / non AWS Deployments
+# this is not syncronised / validated with dashboards imported from folders
+variable "IS_AWS_DEPLOYMENT" {
+  description = "Is AWS Deployment"
+  type        = bool
+  default     = false
+}
+
+variable "AWS_DEFAULT_REGION" {
+  description = "AWS Region"
+  sensitive   = false
+}
+
+variable "GRAFANA_CLOUDWATCH_DATASOURCE_USER_ACCESS_KEY" {
+  description = "AWS Grafana Cloudwatch User Access Key"
+  sensitive   = true
+}
+
+variable "GRAFANA_CLOUDWATCH_DATASOURCE_USER_SECRET_KEY" {
+  description = "AWS Grafana Cloudwatch User Secret Key"
+  sensitive   = true
+}