last correctoins

content/nixos/nix-instantiate.md

@@ -1,13 +1,14 @@
 ---
 title: "nix-instantiate"
-date: 2018-12-05T19:09:36+02:00
+date: 2018-12-27T19:09:36+02:00
 draft: false
 tags:
 - NixOS
+- TerraNix
 - Ansible
 - Terraform
 summary: >
-  a tool to create your JSON generator.
+  A tool to create your JSON generator.
 ---
 
 # nix-instantiate
@@ -156,7 +157,7 @@ let
       modules = [ { imports = [ ./config.nix ]; } ];
     };
 in
-  # we whitelist the resource argument
+  # whitelist the resource attribute
   { resource = (sanitize result.config).resource ; }
 ```
 
@@ -392,14 +393,14 @@ Whoa, a lot of other resources joined the party.
 Additionally, the `additionalFileSize` parameter is
 properly removed from `resource.hcloud_server.test`.
 
-You could also create this very simple example with
+You could also create this very simple example in `HCL` by using 
 `variables`, `locals` and `count`.
 By doing that, you already reached the limits of
 `HCL` but in Nix this is a very simple example.
 
 ## A More Complex Example
 
-Lets create something you wouldn't be able to do in `HCL`
+Let's create something you wouldn't be able to do in `HCL`
 anymore.
 
 Imagine you have an inner circle of admins,
@@ -407,7 +408,7 @@ which need access to all machines created.
 So when a machine is created we also add
 all admin keys.
 
-Let's look at the config first how it would look like.
+Let's look at the `config.nix` first.
 
 ```nix
 {
@@ -433,9 +434,14 @@ Let's look at the config first how it would look like.
 }
 ```
 
+We want to define the admin keys "globally" without setting them
+for every machine explicitly.
+
 ### `admins.nix`
 
-But this time the `admins` module will not create any `resource` directly.
+The `admins` module will not create any `resource` directly.
+Instead it defines options which can be set and used by
+other modules.
 
 ```nix
 # admins.nix
@@ -460,9 +466,13 @@ with lib;
 
 ### hcloud.nix
 
-These options are used in the `hcloud.nix` file and of course every
+The `admins` options are used in the `hcloud.nix` file, and of course every
 other module that create servers.
 
+They are accessed via `config.admins`
+and depending on their content,
+we create `hcloud_ssh_keys` and add them to the servers.
+
 ```nix
 { config, lib, ... }:
 with lib;
@@ -552,10 +562,10 @@ in {
 }
 ```
 
-The `hcloud.nix` starts to get big now, and it is very similar to the version
+The `hcloud.nix` starts to get big now, but it is very similar to the version
 from the privious section.
-Focus on the last section on `mkMerge` and in `config` look closely
-at the end of the `serverResource` definition.
+Focus on the last `let` section and on `mkMerge`.
+Look closely at the end of the `serverResource` definition.
 
 ### Output
 
@@ -564,25 +574,6 @@ Let's look at the resulting JSON:
 ```json
 $> nix-instantiate --eval --strict --json test3.nix --show-trace | jq
 {
-  "admins": {
-    "lass": {
-      "ssh_key": "ssh-rsa AAAAB3NzaC1yc2EAAAA......hKIWndLJ lass@someMachine"
-    },
-    "palo": {
-      "ssh_key": "ssh-rsa AAAAB3NzaC1yc2EAAAA......hKIWndLJ palo@someMachine"
-    },
-    "tv": {
-      "ssh_key": "ssh-rsa AAAAB3NzaC1yc2EAAAA......hKIWndLJ tv@someMachine"
-    }
-  },
-  "hcloud": {
-    "server": {
-      "test": {
-        "image": "ubuntu",
-        "server_type": "cx11"
-      }
-    }
-  },
   "resource": {
     "hcloud_server": {
       "test": {
@@ -625,4 +616,5 @@ Happy Hacking!
 ## Thanks
 
 Thanks to `tv` for his introduction to `nix-instantiate`.
+
 Thanks to `lassulus` and `kmein` for polishing this article.