Here is a more complete example, using EctoNetwork

Migration

Use the type :inet since thats a native Postgrex type

  def change do
    create table(:my_table) do
      ...
      add :net,             :inet
      timestamps()
    end
  end

Schema

Use the type EctoNetwork.INET

  schema "my_table" do
    ....
    field :net,             EctoNetwork.INET
    timestamps()
  end

Insert data

Option 1, insert using native data structures:

iex> Repo.insert %MyTable{net: %Postgrex.INET{address: {1,1,1,1}}}
07:01:58.042 [debug] QUERY OK db=7.8ms queue=1.1ms idle=1872.4ms
INSERT INTO "my_table" ("net","inserted_at","updated_at") VALUES ($1,$2,$3) [%Postgrex.INET{address: {1, 1, 1, 1}, netmask: 32}, ~N[2021-09-08 23:01:58], ~N[2021-09-08 23:01:58]]
{:ok,
 %MyTable{
   __meta__: #Ecto.Schema.Metadata<:loaded, "my_tables">,
   inserted_at: ~N[2021-09-08 23:01:58],
   net: %Postgrex.INET{address: {1, 1, 1, 1}, netmask: nil},
   updated_at: ~N[2021-09-08 23:01:58]
 }}

Option 2, preferred, by casting first (typically in a changeset):

iex> {:ok, addr} = EctoNetwork.INET.cast("1.1.1.1")
{:ok, %Postgrex.INET{address: {1, 1, 1, 1}, netmask: 32}}
iex> Repo.insert %MyTable{net: addr} 

07:11:19.288 [debug] QUERY OK db=1.3ms queue=0.9ms idle=1129.7ms
INSERT INTO "my_table" ("net","inserted_at","updated_at") VALUES ($1,$2,$3) [%Postgrex.INET{address: {1, 1, 1, 1}, netmask: 32}, ~N[2021-09-08 23:11:19], ~N[2021-09-08 23:11:19]]
{:ok,
 %Organization{
   __meta__: #Ecto.Schema.Metadata<:loaded, "my_table">,
   inserted_at: ~N[2021-09-08 23:11:19],
   net: %Postgrex.INET{address: {1, 1, 1, 1}, netmask: 32},
   updated_at: ~N[2021-09-08 23:11:19]
 }}

{127, 0, 0, 1} would need to be cast to EctoNetwork.INET before inserting. It can be done with changeset’s cast or manually with EctoNetwork.INET.cast which, in your case, would just turn the tuple into Postrex.INET struct.. That means if you only want to work with conn.remote_ip, using Postgrex.INET directly is an easy option as well.

Postgrex which the Postgres driver supported by Ecto supports the inet data type so I suspect (but have not tested) that you can define a field of type :inet in your schema and you’re good to go.