From c52dc9b3f7aadc055361d39ed8875bfbb897ba0e Mon Sep 17 00:00:00 2001
From: Van Thong Nguyen <nvthongswansea@gmail.com>
Date: Tue, 14 Mar 2023 12:15:08 +0100
Subject: [PATCH] Add k8s cluster CIDR (#221)

* allow to set cluster_cidr in k8s rs

* make err message of cluster_cidr immutability clear

* fix cannot set cluster_cidr on k8s creation

Because HasChange = true on k8s creation

* update k8s resource doc

* clarify value of cluster cidr when it is empty
---
 gridscale/resource_gridscale_k8s.go | 40 +++++++++++++++++++++++++++++
 website/docs/r/k8s.html.md          |  2 ++
 2 files changed, 42 insertions(+)

diff --git a/gridscale/resource_gridscale_k8s.go b/gridscale/resource_gridscale_k8s.go
index e13ed5ad2..7a60bd960 100644
--- a/gridscale/resource_gridscale_k8s.go
+++ b/gridscale/resource_gridscale_k8s.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"strings"
 	"time"
@@ -195,6 +196,12 @@ func resourceGridscaleK8s() *schema.Resource {
 							Optional:    true,
 							Default:     true,
 						},
+						"cluster_cidr": {
+							Type:        schema.TypeString,
+							Description: "The cluster CIDR that will be used to generate the CIDR of nodes, services, and pods. The allowed CIDR prefix length is /16. If this field is empty, the default value is \"10.244.0.0/16\"",
+							Optional:    true,
+							Computed:    true,
+						},
 					},
 				},
 			},
@@ -302,6 +309,11 @@ func resourceGridscaleK8sRead(d *schema.ResourceData, meta interface{}) error {
 		"storage":      props.Parameters["k8s_worker_node_storage"],
 		"storage_type": props.Parameters["k8s_worker_node_storage_type"],
 	}
+	// Set cluster CIDR if it is set
+	if _, isClusterCIDRSet := props.Parameters["k8s_cluster_cidr"]; isClusterCIDRSet {
+		nodePool["cluster_cidr"] = props.Parameters["k8s_cluster_cidr"]
+	}
+
 	// Surge node feature is enable if k8s_surge_node_count > 0
 	if surgeNodeCount, ok := props.Parameters["k8s_surge_node_count"].(float64); ok {
 		nodePool["surge_node"] = surgeNodeCount > 0
@@ -388,6 +400,10 @@ func resourceGridscaleK8sCreate(d *schema.ResourceData, meta interface{}) error
 	params["k8s_worker_node_count"] = d.Get("node_pool.0.node_count")
 	params["k8s_worker_node_storage"] = d.Get("node_pool.0.storage")
 	params["k8s_worker_node_storage_type"] = d.Get("node_pool.0.storage_type")
+	// Set cluster CIDR if it is set
+	if clusterCIDR, isClusterCIDRSet := d.GetOk("node_pool.0.cluster_cidr"); isClusterCIDRSet {
+		params["k8s_cluster_cidr"] = clusterCIDR
+	}
 	isSurgeNodeEnabled := d.Get("node_pool.0.surge_node").(bool)
 	if isSurgeNodeEnabled {
 		params["k8s_surge_node_count"] = 1
@@ -585,6 +601,30 @@ func validateK8sParameters(d *schema.ResourceDiff, template gsclient.PaaSTemplat
 		}
 	}
 
+	cluster_cidr_template, cluster_cidr_template_ok := template.Properties.ParametersSchema["k8s_cluster_cidr"]
+	if cluster_cidr, ok := d.GetOk("node_pool.0.cluster_cidr"); ok {
+		// if the template doesn't support cluster_cidr, return error if it is set
+		if !cluster_cidr_template_ok {
+			errorMessages = append(errorMessages, "The template doesn't support cluster_cidr. Please remove it from your configuration.\n")
+		} else {
+			// if the template supports cluster_cidr, validate the value
+			if cluster_cidr.(string) != "" {
+				_, _, err := net.ParseCIDR(cluster_cidr.(string))
+				if err != nil {
+					errorMessages = append(errorMessages, fmt.Sprintf("Invalid 'node_pool.0.cluster_cidr' value. Value must be a valid CIDR.\n"))
+				}
+			}
+			// if cluster_cidr_template is immutable, return error if it is set during k8s creation
+			// and it is changed during k8s update
+			if cluster_cidr_template.Immutable {
+				oldClusterCIDR, _ := d.GetChange("node_pool.0.cluster_cidr")
+				if oldClusterCIDR != "" && d.HasChange("node_pool.0.cluster_cidr") {
+					errorMessages = append(errorMessages, "Cannot change parameter cluster_cidr, because it is immutable.\n")
+				}
+			}
+		}
+	}
+
 	if len(errorMessages) != 0 {
 		return errors.New(strings.Join(errorMessages, ""))
 	}
diff --git a/website/docs/r/k8s.html.md b/website/docs/r/k8s.html.md
index c4bf9896b..8e98f5ef5 100644
--- a/website/docs/r/k8s.html.md
+++ b/website/docs/r/k8s.html.md
@@ -53,6 +53,7 @@ The following arguments are supported:
     * `storage` - (Immutable) Storage per worker node (in GiB).
     * `storage_type` - (Immutable) Storage type (one of storage, storage_high, storage_insane).
     * `surge_node` - Enable surge node to avoid resources shortage during the cluster upgrade (Default: true).
+    * `cluster_cidr` - The cluster CIDR that will be used to generate the CIDR of nodes, services, and pods. The allowed CIDR prefix length is /16. If the cluster CIDR is not set, the cluster will use "10.244.0.0/16" as it default (even though the `cluster_cidr` in the k8s resource is empty).
 
 ## Timeouts
 
@@ -84,6 +85,7 @@ This resource exports the following attributes:
     * `storage` - See Argument Reference above.
     * `storage_type` - See Argument Reference above.
     * `surge_node` - See Argument Reference above.
+    * `cluster_cidr` - See Argument Reference above.
 * `usage_in_minutes` - The amount of minutes the IP address has been in use.
 * `create_time` - The time the object was created.
 * `change_time` - Defines the date and time of the last object change.