Merge pull request #2 from sparkfabrik/feat/add_create_default_pod_anti_affinity_var

feat: add default podAntiAffinity configuration that can be disabled using a new variable

Author: Monska85

CHANGELOG.md

@@ -8,10 +8,20 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+## [0.3.0] - 2024-07-10
+
+[Compare with previous version](https://github.com/sparkfabrik/terraform-gitlab-kubernetes-gitlab-agent/compare/0.2.0...0.3.0)
+
+### Added
+
+- Add the `create_default_pod_anti_affinity` variable to allow the creation of the default podAntiAffinity rule in the helm values.
+
 ## [0.2.0] - 2024-07-04
 
 [Compare with previous version](https://github.com/sparkfabrik/terraform-gitlab-kubernetes-gitlab-agent/compare/0.1.0...0.2.0)
 
+### Added
+
 - Add dependency on the Gitlab variables to prevent their creation before the helm release.
 - Add the `gitlab_agent_append_to_config_file` variable to allow customizations to the agent configuration file keeping the access for the root namespace managed by the module.
 

README.md

@@ -49,6 +49,7 @@ provider "gitlab" {
 |------|-------------|------|---------|:--------:|
 | <a name="input_agent_kas_address"></a> [agent\_kas\_address](#input\_agent\_kas\_address) | The address of the Gitlab Kubernetes Agent Server (KAS). | `string` | `"kas.gitlab.com"` | no |
 | <a name="input_agent_replicas"></a> [agent\_replicas](#input\_agent\_replicas) | The number of replicas of the Gitlab Agent. | `number` | `1` | no |
+| <a name="input_create_default_pod_anti_affinity"></a> [create\_default\_pod\_anti\_affinity](#input\_create\_default\_pod\_anti\_affinity) | Create default podAntiAffinity rules for the Gitlab Agent pods. | `bool` | `true` | no |
 | <a name="input_create_namespace"></a> [create\_namespace](#input\_create\_namespace) | Create namespace for the helm release. If false, the namespace must be created before using this module. | `bool` | `true` | no |
 | <a name="input_gitlab_agent_append_to_config_file"></a> [gitlab\_agent\_append\_to\_config\_file](#input\_gitlab\_agent\_append\_to\_config\_file) | Append the Gitlab Agent configuration to the configuration file created for the entire root namespace. This variable is only used when `gitlab_agent_grant_access_to_entire_root_namespace` is true. | `string` | `""` | no |
 | <a name="input_gitlab_agent_branch_name"></a> [gitlab\_agent\_branch\_name](#input\_gitlab\_agent\_branch\_name) | The branch name where the Gitlab Agent configuration will be stored. | `string` | `"main"` | no |

files/values.yaml.tftpl

@@ -17,3 +17,21 @@ resources:
   requests:
     cpu: 20m
     memory: 32Mi
+
+%{~ if create_default_pod_anti_affinity }
+# We leverage the Helm standard labels for the helm release name (`app.kubernetes.io/instance`)
+# to create a default pod anti-affinity rule for the agent pods. Refer to the Helm documentation
+# about standard labels here: https://helm.sh/docs/chart_best_practices/labels/#standard-labels.
+affinity:
+  podAntiAffinity:
+      preferredDuringSchedulingIgnoredDuringExecution:
+      - weight: 100
+        podAffinityTerm:
+          labelSelector:
+            matchExpressions:
+            - key: app.kubernetes.io/instance
+              operator: In
+              values:
+              - "${helm_release_name}"
+          topologyKey: kubernetes.io/hostname
+%{~ endif ~}

main.tf

@@ -129,6 +129,9 @@ resource "helm_release" "this" {
           agent_replicas          = var.agent_replicas
           agent_kas_address       = var.agent_kas_address
           agent_token_secret_name = kubernetes_secret_v1.gitlab_agent_token_secret.metadata[0].name
+          # Variables used to configure the default podAntiAffinity for the Gitlab Agent
+          create_default_pod_anti_affinity = var.create_default_pod_anti_affinity
+          helm_release_name                = var.helm_release_name
         }
       ),
     ],

variables.tf

@@ -131,3 +131,9 @@ variable "agent_kas_address" {
   type        = string
   default     = "kas.gitlab.com"
 }
+
+variable "create_default_pod_anti_affinity" {
+  description = "Create default podAntiAffinity rules for the Gitlab Agent pods."
+  type        = bool
+  default     = true
+}