Capacity Planning

Introduction

In this example we will discuss capacity planning on top of the TFGrid.

Example

terraform {
  required_providers {
    grid = {
      source = "threefoldtech/grid"
    }
  }
}
provider "grid" {
}

locals {
  name = "testvm"
}

resource "grid_scheduler" "sched" {
  requests {
    name = "node1"
    cru  = 3
    sru  = 1024
    mru  = 2048
    node_exclude = [33] # exlude node 33 from your search
    public_ips_count = 0 # this deployment needs 0 public ips
    public_config = false # this node does not need to have public config
  }
}

resource "grid_network" "net1" {
  name        = local.name
  nodes       = [grid_scheduler.sched.nodes["node1"]]
  ip_range    = "10.1.0.0/16"
  description = "newer network"
}
resource "grid_deployment" "d1" {
  name         = local.name
  node         = grid_scheduler.sched.nodes["node1"]
  network_name = grid_network.net1.name
  vms {
    name       = "vm1"
    flist      = "https://hub.grid.tf/tf-official-apps/base:latest.flist"
    cpu        = 2
    memory     = 1024
    entrypoint = "/sbin/zinit init"
    env_vars = {
      SSH_KEY = "PUT YOUR SSH KEY HERE"
    }
    planetary = true
  }
  vms {
    name       = "anothervm"
    flist      = "https://hub.grid.tf/tf-official-apps/base:latest.flist"
    cpu        = 1
    memory     = 1024
    entrypoint = "/sbin/zinit init"
    env_vars = {
      SSH_KEY = "PUT YOUR SSH KEY HERE"
    }
    planetary = true
  }
}
output "vm1_ip" {
  value = grid_deployment.d1.vms[0].ip
}
output "vm1_planetary_ip" {
  value = grid_deployment.d1.vms[0].planetary_ip
}

output "vm2_ip" {
  value = grid_deployment.d1.vms[1].ip
}
output "vm2_planetary_ip" {
  value = grid_deployment.d1.vms[1].planetary_ip
}

Preparing the Requests

resource "grid_scheduler" "sched" {
  # a machine for the first server instance
  requests {
    name = "server1"
    cru = 1
    sru = 256
    mru = 256
  }
  # a machine for the second server instance
  requests {
    name = "server2"
    cru = 1
    sru = 256
    mru = 256
  }
  # a name workload
  requests {
    name = "gateway"
    public_config = true
  }
}

Here we define a list of requests, each request has a name and filter options e.g cru, sru, mru, hru, having public_config or not, public_ips_count for this deployment, whether or not this node should be dedicated, whether or not this node should be distinct from other nodes in this plannder, farm_id to search in, nodes to exlude from search in node_exclude, and whether or not this node should be certified.

The full docs for the capacity planner scheduler are found here

And after that in our code we can reference the grid_scheduler object with the request name to be used instead of node_id.

For example:

resource "grid_deployment" "server1" {
  node = grid_scheduler.sched.nodes["server1"]
  network_name = grid_network.net1.name
  ip_range = lookup(grid_network.net1.nodes_ip_range, grid_scheduler.sched.nodes["server1"], "")
  vms {
    name = "firstserver"
    flist = "https://hub.grid.tf/omar0.3bot/omarelawady-simple-http-server-latest.flist"
    cpu = 1
    memory = 256
    rootfs_size = 256
    entrypoint = "/main.sh"
    env_vars = {
      SSH_KEY = "ssh-rsa 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 omar@omar-Predator-PT315-52"
    }
    env_vars = {
        PATH = "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
    }

    planetary = true
  }
}

Note: you need to call distinct while specifying the nodes in the network, because the scheduler may assign server1, server2 on the same node. Example:

  resource "grid_network" "net1" {
    name        = local.name
    nodes       = distinct(values(grid_scheduler.sched.nodes))
    ip_range    = "10.1.0.0/16"
    description = "newer network"
  }