Merge pull request #391 from cloudfoundry/configure_placement_strategy

Make Concourse worker placement strategy configurable

Author: jochenehret

docs/concourse/README.md

@@ -52,6 +52,10 @@ Also make sure that the GKE version is not outdated:
 
 The latest stable version can be found at [https://cloud.google.com/kubernetes-engine/docs/release-notes]
 
+If you need to fine-tune the [Concourse worker placement strategy](https://concourse-ci.org/container-placement.html), you can configure it with:
+
+* `concourse_container_placement_strategy`
+
 #### 2. Logon to your GCP account
 ```
 gcloud auth login && gcloud auth application-default login

terraform-modules/concourse/app/concourse.tf

@@ -31,6 +31,11 @@ data "helm_template" "concourse" {
     value = ""
   }
 
+  set {
+    name = "concourse.web.containerPlacementStrategy"
+    value = var.concourse_container_placement_strategy
+  }
+
   set {
     name = "worker.replicas"
     value = var.gke_workers_pool_node_count

terraform-modules/concourse/app/variables.tf

@@ -12,6 +12,7 @@ variable "gke_default_pool_node_count" { nullable = false }
 variable "concourse_helm_version" { nullable = false }
 variable "concourse_github_mainTeam" { nullable = false }
 variable "concourse_github_mainTeamUser" { nullable = false }
+variable "concourse_container_placement_strategy" { nullable = false }
 
 variable "load_balancer_ip" { nullable = false }
 variable "load_balancer_dns" { nullable = false }

terragrunt/concourse-wg-ci-test/app/terragrunt.hcl

@@ -51,5 +51,5 @@ inputs = {
 
   concourse_github_mainTeam = local.config.concourse_github_mainTeam
   concourse_github_mainTeamUser = local.config.concourse_github_mainTeamUser
-
+  concourse_container_placement_strategy = local.config.concourse_container_placement_strategy
 }

terragrunt/concourse-wg-ci-test/config.yaml

@@ -20,6 +20,10 @@ gke_name: wg-ci-test
 concourse_github_mainTeam: "cloudfoundry:wg-app-runtime-interfaces-autoscaler-approvers\\,cloudfoundry:wg-app-runtime-interfaces-autoscaler-reviewers\\,cloudfoundry:wg-app-runtime-interfaces-capi-approvers"
 concourse_github_mainTeamUser: ""
 
+# Concourse worker placement strategy: https://concourse-ci.org/container-placement.html
+# Use default strategy for test system
+concourse_container_placement_strategy: "volume-locality"
+
 # Concourse helm chart
 concourse_helm_version: "17.4.0"
 

terragrunt/concourse-wg-ci/app/terragrunt.hcl

@@ -51,5 +51,5 @@ inputs = {
 
   concourse_github_mainTeam = local.config.concourse_github_mainTeam
   concourse_github_mainTeamUser = local.config.concourse_github_mainTeamUser
-
+  concourse_container_placement_strategy = local.config.concourse_container_placement_strategy
 }

terragrunt/concourse-wg-ci/config.yaml

@@ -20,6 +20,10 @@ gke_name: wg-ci
 concourse_github_mainTeam: "cloudfoundry:wg-app-runtime-interfaces-autoscaler-approvers\\,cloudfoundry:wg-app-runtime-interfaces-capi-approvers"
 concourse_github_mainTeamUser: ""
 
+# Concourse worker placement strategy: https://concourse-ci.org/container-placement.html
+# The cloud controller unit tests cause a high system load on workers, so place them on workers with few containers
+concourse_container_placement_strategy: "fewest-build-containers"
+
 # Concourse helm chart
 concourse_helm_version: "17.4.0"