[Bug]: zram_size not passed on

[lennart]

Description

the agent_nodepools/control_plane_nodes option for zram_size is not passed on to the actual host resource, therefore zram swap is not configured (although the corresponding files are in place, they are just not activated)

I guess, zram_size = each.value.zram_size has to be appended right after swap_size in the corresponding files for agents and control_planes

Kube.tf file

locals {
  hcloud_token = "xxxxxxxxxxx"
}
variable "cloudflare_api_token" {
  type = string
  sensitive = true
}
module "kube-hetzner" {
  providers = {
    hcloud = hcloud
  }
  hcloud_token = var.hcloud_token != "" ? var.hcloud_token : local.hcloud_token
  source = "kube-hetzner/kube-hetzner/hcloud"
  ssh_port = 23232
  ssh_public_key = file("~/.ssh/landscape_id_ed25519.pub")
  ssh_private_key = file("~/.ssh/landscape_id_ed25519")
  control_plane_nodepools = [
    {
      name        = "control-plane-fsn1",
      server_type = "cax11",
      location    = "fsn1",
      labels      = [],
      taints      = [],
      count       = 1
      kubelet_args = ["runtime-request-timeout=10m0s"]
      zram_size = "2G"
    },
    {
      name        = "control-plane-nbg1",
      server_type = "cax11",
      location    = "nbg1",
      labels      = [],
      taints      = [],
      count       = 1
      kubelet_args = ["runtime-request-timeout=10m0s"]
      zram_size = "2G"
    },
    {
      name        = "control-plane-hel1",
      server_type = "cax11",
      location    = "hel1",
      labels      = [],
      taints      = [],
      count       = 1
      kubelet_args = ["runtime-request-timeout=10m0s"]
      zram_size = "2G"
    }
  ]
  agent_nodepools = [
    {
      name        = "agent-small",
      server_type = "cx21",
      location    = "fsn1",
      labels      = [],
      taints      = [],
      zram_size = "2G"
      nodes = {
        "1" : {
          append_index_to_node_name = false,
          location                  = "nbg1",
          labels = [
          ]
        },
        "20" : {
          append_index_to_node_name = false,
          labels = [
          ]
        }
      }
      longhorn_volume_size = 0
      kubelet_args = ["runtime-request-timeout=10m0s"]
    },
  ]
  enable_wireguard = true
  load_balancer_type     = "lb11"
  load_balancer_location = "fsn1"
  base_domain = "beta.al0.de"
  enable_longhorn = true
  disable_hetzner_csi = true
  cluster_name = "al0"
  cni_plugin = "cilium"
  disable_kube_proxy = true
  disable_network_policy = true
  dns_servers = [
    "1.1.1.1",
    "8.8.8.8",
    "2606:4700:4700::1111",
  ]
  extra_kustomize_parameters={
    cloudflare_api_token: var.cloudflare_api_token
  }
}
provider "hcloud" {
  token = var.hcloud_token != "" ? var.hcloud_token : local.hcloud_token
}
terraform {
  required_version = ">= 1.5.0"
  required_providers {
    hcloud = {
      source  = "hetznercloud/hcloud"
      version = ">= 1.43.0"
    }
  }
}
output "kubeconfig" {
  value     = module.kube-hetzner.kubeconfig
  sensitive = true
}
variable "hcloud_token" {
  sensitive = true
  default   = ""
}

Screenshots

No response

Platform

Linux

[lennart]

ah, I realize, in current master this is only the case for agents (control planes pass this on...) is this intentional?

[lennart]

also, when specifying zram on a nodepool that has a nodes map, even with the suggested change one still has to explicitly configure zram_size for every node in the mapping, otherwise the nodepool setting is overridden with the default for each node (which is ""):

agent_nodepools = [
    {
      name        = "agent-small",
      server_type = "cx21",
      location    = "fsn1",
      labels      = [],
      taints      = [],
      zram_size = "2G"
      nodes = {
        "1" : {
          append_index_to_node_name = false,
          location                  = "nbg1",
          labels = [
          ]
        },
        "20" : {
          append_index_to_node_name = false,
          labels = [
          ]
        }
      }
      longhorn_volume_size = 0
      kubelet_args = ["runtime-request-timeout=10m0s"]
    },
  ]

I would expect, that if I do not specify zram_size of a node in the mapping, it would use the value specified in the pool (maybe one could use a different default for the nodes in the mapping that is considered unset?)

so currently I ended up with:

agent_nodepools = [
    {
      name        = "agent-small",
      server_type = "cx21",
      location    = "fsn1",
      labels      = [],
      taints      = [],
      nodes = {
        "1" : {
          append_index_to_node_name = false,
          location                  = "nbg1",
          zram_size = "2G"
          labels = [
          ]
        },
        "20" : {
          append_index_to_node_name = false,
          zram_size = "2G"
          labels = [
          ]
        }
      }
      longhorn_volume_size = 0
      kubelet_args = ["runtime-request-timeout=10m0s"]
    },
  ]

and the change in agents.tf that passes on the zram value

[mysticaltech]

@lennart You did well, just merged the PR, we do not want to block this possibility if it's just one line away. Thanks for this.

[lennart]

@mysticaltech thanks!