add examples to docs site

.github/workflows/ci.yml

@@ -3,6 +3,8 @@ name: tests
 on:
   pull_request:
   push:
+    branches:
+      - main
 
 jobs:
   tests:

.github/workflows/pages.yml

@@ -6,7 +6,6 @@ on:
       - main
     paths:
       - 'docs/**'
-  pull_request:
 
 jobs:
   deploy:

CONTRIBUTING.md

@@ -46,3 +46,11 @@ Build and serve the static site
     nix run '.#docs' serve
 
 which will be available at <http://localhost:1313>.
+
+### Examples
+
+Examples are written at [./docs/content/examples](./docs/content/examples) and are (or will, really) also used as tests which can be executed with
+
+    nix flake check
+
+In general, that just means: don't directly put nix snippets into a markdown doc; instead use the shortcode provided to pull them in so they don't have to be parsed out for testing.

README.md

@@ -45,7 +45,7 @@ Or, if you're not using flakes, a `default.nix` file (build with `nix-build`):
 
 Either way the JSON manifests will be written to `./result`.
 
-See [./docs/examples](./docs/examples) for more.
+See the [examples](/examples/pod) for more.
 
 ## CLI
 

docs/.gitignore

@@ -3,3 +3,4 @@ resources/
 *.lock
 options.json
 content/modules/*.md
+!_index.md

docs/assets/_custom.scss

@@ -87,5 +87,25 @@ details {
 }
 
 aside.book-menu span {
+  // make menu headers bold
   font-weight: bold;
 }
+
+.source {
+  position: relative;
+  .filename {
+      position: absolute;
+      right: 0px;
+      margin: 0;
+      line-height: 0;
+      font-size: 0.8rem;
+      background-color: transparent;
+      color: #d8dee9;
+  }
+}
+
+// directory listing on examples page
+.listing {
+  position: absolute;
+  bottom: 10px;
+}

docs/content/examples/_index.md

@@ -0,0 +1,3 @@
+---
+weight: 20
+---

docs/content/examples/default.nix

@@ -0,0 +1,4 @@
+{
+  deployment = import ./deployment { };
+  testing = import ./testing { };
+}

docs/content/examples/deployment/_index.md

@@ -0,0 +1,11 @@
+As a more complete example, let's define some high-level variables and then split our module out into another file as we start to grow.
+
+{{< source "default.nix" >}}
+
+Now we create a module which does a few related things:
+
+- create a `Deployment`
+- mount a `ConfigMap` into its pod
+- define a `Service`
+
+{{< source "module.nix" >}}

docs/content/examples/deployment/default.nix

@@ -0,0 +1,9 @@
+{kubenix ? import ../../../..}:
+kubenix.evalModules.x86_64-linux {
+  module = {kubenix, ...}: {
+    imports = [./module.nix];
+
+    kubenix.project = "example";
+    kubernetes.version = "1.24";
+  };
+}

docs/content/examples/deployment/module.nix

@@ -4,13 +4,8 @@
   pkgs,
   kubenix,
   ...
-}:
+}: {
-with lib; let
+  imports = with kubenix.modules; [k8s];
-  nginx = pkgs.callPackage ./image.nix {};
-in {
-  imports = with kubenix.modules; [k8s docker];
-
-  docker.images.nginx.image = nginx;
 
   kubernetes.resources = {
     deployments.nginx.spec = {
@@ -21,7 +16,7 @@ in {
         spec = {
           securityContext.fsGroup = 1000;
           containers.nginx = {
-            image = config.docker.images.nginx.path;
+            image = "nginx";
             imagePullPolicy = "IfNotPresent";
             volumeMounts = {
               "/etc/nginx".name = "config";

docs/content/examples/helm/_index.md

@@ -0,0 +1,9 @@
+To define a helm release, use the {{< option "kubernetes.helm.releases" >}} option.
+
+{{< source "default.nix" >}}
+
+Fetch and render the chart just as we did with plain manifests:
+
+```sh
+nix eval -f . --json config.kubernetes.generated
+```

docs/content/examples/helm/default.nix

@@ -1,5 +1,5 @@
-{evalModules}:
+{kubenix ? import ../../../..}:
-(evalModules {
+kubenix.evalModules.${builtins.currentSystem} {
   module = {kubenix, ...}: {
     imports = with kubenix.modules; [helm];
     kubernetes.helm.releases.example = {
@@ -8,9 +8,9 @@
         repo = "https://charts.bitnami.com/bitnami";
         sha256 = "sha256-wP3tcBnySx+kvZqfW2W9k665oi8KOI50tCcAl0g9cuw=";
       };
+      values = {
+        replicaCount = 2;
+      };
     };
   };
-})
+}
-.config
-.kubernetes
-.result

docs/content/examples/image/_index.md

@@ -0,0 +1,66 @@
+---
+weight: 30
+---
+
+Instead of deploying a 3rd party image, we can build our own.
+
+We rely on the upstream [`dockerTools`](https://github.com/NixOs/nixpkgs/tree/master/pkgs/built-support/docker) package here.
+Specifically, we can use the `buildImage` function to define our image:
+
+{{< source "image.nix" >}}
+
+Then we can import this package into our `docker` module:
+
+{{< source "default.nix" >}}
+
+Now build the image with
+
+```sh
+nix build -f . --json config.docker.export
+```
+
+Render the generated manifests again and see that it now refers to the newly built tag:
+
+```json
+{
+  "apiVersion": "v1",
+  "items": [
+    {
+      "apiVersion": "v1",
+      "kind": "Pod",
+      "metadata": {
+        "annotations": {
+          "kubenix/k8s-version": "1.24",
+          "kubenix/project-name": "kubenix"
+        },
+        "labels": {
+          "kubenix/hash": "ac7e4794c3d37f0884e4512a680a30d20e1d6454"
+        },
+        "name": "example"
+      },
+      "spec": {
+        "containers": [
+          {
+            "image": "docker.somewhere.io/nginx:w7c63alk7kynqh2mqnzxy9n1iqgdc93s",
+            "name": "custom"
+          }
+        ]
+      }
+    }
+  ],
+  "kind": "List",
+  "labels": {
+    "kubenix/hash": "ac7e4794c3d37f0884e4512a680a30d20e1d6454",
+    "kubenix/k8s-version": "1.24",
+    "kubenix/project-name": "kubenix"
+  }
+}
+```
+
+Of course, to actually deploy, we need to push the image to our registry. The script defined at {{< option "docker.copyScript" >}} does just that.
+
+```sh
+$(nix build -f . --json config.docker.copyScript | jq -r '.[].outputs.out')
+```
+
+ <!-- TODO: can we make that `nix run -f . config.docker.copyScript` ? -->

docs/content/examples/image/default.nix

@@ -0,0 +1,13 @@
+{ kubenix ? import ../../../.. }:
+kubenix.evalModules.${builtins.currentSystem} {
+  module = {kubenix, config, pkgs, ...}: {
+    imports = with kubenix.modules; [k8s docker];
+    docker = {
+      registry.url = "docker.somewhere.io";
+      images.example.image =  pkgs.callPackage ./image.nix {};
+    };
+    kubernetes.resources.pods.example.spec.containers = {
+      custom.image = config.docker.images.example.path;
+    };
+  };
+}

docs/content/examples/pod/_index.md

@@ -0,0 +1,67 @@
+---
+weight: 10
+---
+
+The simplest, but not incredibly useful, example is likely deploying a bare pod.
+
+Which we can do with the `kubernetes.resources.pods` option:
+
+{{< source "default.nix" >}}
+
+Here, `example` is an arbitrary string which identifies the pod (just as `ex` identifies a container within the pod).
+
+{{< hint info >}}
+**NOTE**
+
+The format under {{< option "kubernetes.resources" true >}} largely mirrors that of the [Kubernetes API](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.25/) which can generally be explored with `kubectl`; e.g.
+
+```sh
+kubectl explain poc.spec.containers
+```
+
+However, our format uses the plural form and injects resource names where appropriate.
+{{< /hint >}}
+
+Create a json manifest with:
+
+```sh
+nix eval -f . --json config.kubernetes.generated
+```
+
+which should output something like this:
+
+```json
+{
+  "apiVersion": "v1",
+  "items": [
+    {
+      "apiVersion": "v1",
+      "kind": "Pod",
+      "metadata": {
+        "annotations": {
+          "kubenix/k8s-version": "1.24",
+          "kubenix/project-name": "kubenix"
+        },
+        "labels": {
+          "kubenix/hash": "6e6ccbb6787f9b600737f8882d2487eeef84af9f"
+        },
+        "name": "example"
+      },
+      "spec": {
+        "containers": [
+          {
+            "image": "nginx",
+            "name": "ex"
+          }
+        ]
+      }
+    }
+  ],
+  "kind": "List",
+  "labels": {
+    "kubenix/hash": "6e6ccbb6787f9b600737f8882d2487eeef84af9f",
+    "kubenix/k8s-version": "1.24",
+    "kubenix/project-name": "kubenix"
+  }
+}
+```

docs/content/examples/pod/default.nix

@@ -0,0 +1,12 @@
+# let's creata a function whose only input is the kubenix package
+{kubenix ? import ../../../..}:
+# evalModules is our main entrypoint
+kubenix.evalModules.${builtins.currentSystem} {
+  # to it, we pass a module that accepts a (different) kubenix object
+  module = {kubenix, ...}: {
+    # in order to define options, we need to import their definitions
+    imports = with kubenix.modules; [k8s];
+    # now we have full access to define Kubernetes resources
+    kubernetes.resources.pods.example.spec.containers.ex.image = "nginx";
+  };
+}

docs/content/examples/secrets/_index.md

@@ -0,0 +1,11 @@
+Secrets management requires some extra care as we want to prevent values from
+ending up in the, world-readable, nix store.
+
+{{< hint "warning" >}}
+**WARNING**
+
+The kubenix secrets story is incomplete. Do not trust it -- it has not been tested.
+{{< /hint >}}
+
+The easiest approach is to avoid writing to the store altogether with `nix eval` instead of `nix build`.
+This isn't a long-term device and we'll explore integrations with other tools soon(TM).

docs/content/examples/testing/_index.md

@@ -0,0 +1,13 @@
+Testing is still very much in flux but here's a rough example.
+
+{{< source "default.nix" >}}
+
+Where we've defined a might look like:
+
+{{< source "test.nix" >}}
+
+Execute with
+
+```sh
+nix eval -f . config.testing.success
+```

docs/content/examples/testing/default.nix

@@ -0,0 +1,17 @@
+{kubenix ? import ../../../..}:
+kubenix.evalModules.x86_64-linux {
+  module = {kubenix, ...}: {
+    imports = with kubenix.modules; [testing];
+    testing = {
+      tests = [./test.nix];
+      common = [
+        {
+          features = ["k8s"];
+          options = {
+            kubernetes.version = "1.24";
+          };
+        }
+      ];
+    };
+  };
+}

docs/content/examples/testing/test.nix

@@ -4,30 +4,22 @@
   kubenix,
   test,
   ...
-}:
+}: {
-with lib; {
+  imports = [kubenix.modules.test];
-  imports = [kubenix.modules.test ./module.nix];
 
   test = {
-    name = "nginx-deployment";
+    name = "example";
-    description = "Test testing nginx deployment";
+    description = "can reach deployment";
     script = ''
       @pytest.mark.applymanifest('${test.kubernetes.resultYAML}')
       def test_nginx_deployment(kube):
           """Tests whether nginx deployment gets successfully created"""
-
           kube.wait_for_registered(timeout=30)
-
           deployments = kube.get_deployments()
           nginx_deploy = deployments.get('nginx')
           assert nginx_deploy is not None
-
           status = nginx_deploy.status()
           assert status.readyReplicas == 10
-
-          # TODO: implement those kind of checks from the host machine into the cluster
-          # via port forwarding, prepare all runtimes accordingly
-          # ${pkgs.curl}/bin/curl http://nginx.default.svc.cluster.local | grep -i hello
     '';
   };
 }

docs/examples/default.nix

@@ -1,7 +0,0 @@
-{
-  system ? builtins.currentSystem,
-  evalModules ? (import ../. {}).evalModules.${system},
-}: {registry ? "docker.io/gatehub"}: {
-  nginx-deployment = import ./nginx-deployment {inherit evalModules registry;};
-  helm-chart = import ./helm-chart {inherit evalModules;};
-}

docs/examples/nginx-deployment/README.md

@@ -1,21 +0,0 @@
-# nginx deployment
-
-A simple example creating an nginx docker image and deployment.
-
-## Usage
-
-### Building and applying kubernetes configuration
-
-    nix eval -f ./. --json result | kubectl apply -f -
-
-### Building and pushing docker images
-
-    nix run -f ./. pushDockerImages -c copy-docker-images
-
-### Running tests
-
-Test will spawn vm with Kubernetes and run test script, which checks if everything
-works as expected.
-
-    nix build -f ./. test-script
-    cat result | jq '.'

docs/examples/nginx-deployment/default.nix

@@ -1,59 +0,0 @@
-{
-  evalModules,
-  registry,
-}: let
-  # evaluated configuration
-  inherit
-    ((evalModules {
-      module = {kubenix, ...}: {
-        imports = [
-          kubenix.modules.testing
-          ./module.nix
-        ];
-
-        # commonalities
-        kubenix.project = "nginx-deployment-example";
-        docker.registry.url = registry;
-        kubernetes.version = "1.21";
-
-        testing = {
-          tests = [./test.nix];
-          docker.registryUrl = "";
-          # testing commonalities for tests that exhibit the respective feature
-          common = [
-            {
-              features = ["k8s"];
-              options = {
-                kubernetes.version = "1.20";
-              };
-            }
-          ];
-        };
-      };
-    }))
-    config
-    ;
-in {
-  inherit config;
-
-  # config checks
-  checks = config.testing.success;
-
-  # TODO: e2e test
-  # test = config.testing.result;
-
-  # nixos test script for running the test
-  test-script = config.testing.testsByName.nginx-deployment.script;
-
-  # genreated kubernetes List object
-  inherit (config.kubernetes) generated;
-
-  # JSON file you can deploy to kubernetes
-  inherit (config.kubernetes) result;
-
-  # Exported docker images
-  images = config.docker.export;
-
-  # script to push docker images to registry
-  pushDockerImages = config.docker.copyScript;
-}

docs/layouts/partials/docs/inject/toc-after.html

@@ -0,0 +1,29 @@
+{{/* only show a directory listing on example pages */}}
+{{- if and (eq $.Section "examples") (ne $.Page.File.Path "examples/_index.md") -}}
+
+{{/* get base directory */}}
+{{- $dir := $.Page.File.Dir -}}
+
+{{- $loc := path.Join $.Site.Params.BookRepo "blob" "main" "docs" "content" $.Page.File.Dir -}}
+
+{{/* create a list of nix files */}}
+{{- $files := slice -}}
+{{- range readDir (path.Join "content" $dir) -}}
+  {{- if strings.HasSuffix .Name ".nix" -}}
+    {{- $files = $files | append . -}}
+  {{- end -}}
+{{- end -}}
+
+<pre class="listing">
+<a href="{{ $loc }}">{{- index (split $dir "/") 1 }}</a>/
+{{- range $i, $file := $files }}
+{{- if ne (add $i 1) (len $files) }}
+├──
+{{- else  }}
+└──
+{{- end -}}
+&nbsp;<a href="{{ path.Join $loc $file.Name }}" >{{ $file.Name }}</a>
+{{- end -}}
+</pre>
+
+{{- end -}}

docs/layouts/shortcodes/option.html

@@ -0,0 +1,11 @@
+{{- $option := .Get 0 -}}
+{{- $module := index (strings.Split $option ".") 0 -}}
+
+{{/* should we use markdown instead of html? some envs strip raw html */}}
+{{- $md := .Get 1 | default false -}}
+
+{{- if $md -}}
+[{{ $option }}](/modules/{{ $module }}/#{{ $option }})
+{{- else -}}
+<a href="/modules/{{ $module }}/#{{ $option }}">{{ $option }}</a>
+{{- end -}}

docs/layouts/shortcodes/source.html

@@ -0,0 +1,6 @@
+{{- $file := .Get 0 -}}
+<div class="source">
+  <pre class="filename">{{ $file }}</pre>
+  {{- $file := path.Join .Page.File.Dir $file -}}
+  {{- highlight ($file | readFile | safeHTML) (path.Ext $file) -}}
+</div>

flake.nix

@@ -166,16 +166,14 @@
             if suite.success
             then pkgs.runCommandNoCC "testing-suite-config-assertions-for-${suite.name}-succeeded" {} "echo success > $out"
             else pkgs.runCommandNoCC "testing-suite-config-assertions-for-${suite.name}-failed" {} "exit 1";
-          mkExamples = attrs:
+          examples = import ./docs/content/examples;
-            (import ./docs/examples {inherit evalModules;})
-            ({registry = "docker.io/gatehub";} // attrs);
           mkK8STests = attrs:
             (import ./tests {inherit evalModules;})
             ({registry = "docker.io/gatehub";} // attrs);
         in
           {
             # TODO: access "success" derivation with nice testing utils for nice output
-            nginx-example = wasSuccess (mkExamples {}).nginx-deployment.config.testing;
+            testing = wasSuccess examples.testing.config.testing;
           }
           // builtins.listToAttrs (builtins.map
             (v: {