Hey all,
Once upon a time, I was need to get hostmin/hostmax value from CIDR like famous http://jodies.de/ipcalc do:
Address: 10.16.0.0 00001010.00010000 .00000000.00000000
Netmask: 255.255.0.0 = 16 11111111.11111111 .00000000.00000000
Wildcard: 0.0.255.255 00000000.00000000 .11111111.11111111
=>
Network: 10.16.0.0/16 00001010.00010000 .00000000.00000000 (Class A)
Broadcast: 10.16.255.255 00001010.00010000 .11111111.11111111
HostMin: 10.16.0.1 00001010.00010000 .00000000.00000001
HostMax: 10.16.255.254 00001010.00010000 .11111111.11111110
Hosts/Net: 65534 (Private Internet)
And here is my kludge in Terraform to achieve this:
variable "cidr_block" {
type = string
default = "10.100.0.0/29"
}
locals {
netmask = tonumber(split("/", var.cidr_block)[1])
power = pow(2, 32 - local.netmask) - 2
network = {
gateway = cidrhost(var.cidr_block, 1),
netmask = cidrnetmask(var.cidr_block),
hostmin = cidrhost(var.cidr_block, 2),
hostmax = cidrhost(var.cidr_block, local.power)
}
}
That’s it! Happy terrakludging!