feat: refactor file structure module interfaces and other

lib/helm/chart2json.nix

@@ -0,0 +1,51 @@
+{ stdenvNoCC, lib, kubernetes-helm, gawk, remarshal, jq }:
+
+with lib;
+
+{
+  # chart to template
+  chart
+
+  # release name
+, name
+
+  # namespace to install release into
+, namespace ? null
+
+  # values to pass to chart
+, values ? {}
+
+  # kubernetes version to template chart for
+, kubeVersion ? null }: let
+  valuesJsonFile = builtins.toFile "${name}-values.json" (builtins.toJSON values);
+in stdenvNoCC.mkDerivation {
+  name = "${name}.json";
+  buildCommand = ''
+    # template helm file and write resources to yaml
+    helm template --name "${name}" \
+      ${optionalString (kubeVersion != null) "--kube-version ${kubeVersion}"} \
+      ${optionalString (namespace != null) "--namespace ${namespace}"} \
+      ${optionalString (values != {}) "-f ${valuesJsonFile}"} \
+      ${chart} >resources.yaml
+
+    # split multy yaml file into multiple files
+    awk 'BEGIN{i=1}{line[i++]=$0}END{j=1;n=0; while (j<i) {if (line[j] ~ /^---/) n++; else print line[j] >>"resource-"n".yaml"; j++}}' resources.yaml
+
+    # join multiple yaml files in jsonl file
+    for file in ./resource-*.yaml
+    do
+      remarshal -i $file -if yaml -of json >>resources.jsonl
+    done
+
+    # convert jsonl file to json array, remove null values and write to $out
+    cat resources.jsonl | jq -Scs 'walk(
+      if type == "object" then
+        with_entries(select(.value != null))
+      elif type == "array" then
+        map(select(. != null))
+      else
+        .
+      end)' > $out
+  '';
+  nativeBuildInputs = [ kubernetes-helm gawk remarshal jq ];
+}

lib/helm/default.nix

@@ -0,0 +1,6 @@
+{ pkgs }:
+
+{
+  chart2json = pkgs.callPackage ./chart2json.nix { };
+  fetch = pkgs.callPackage ./fetchhelm.nix { };
+}

lib/helm/fetchhelm.nix

@@ -0,0 +1,48 @@
+{ stdenvNoCC, lib, kubernetes-helm, cacert }:
+
+let
+  cleanName = name: lib.replaceStrings ["/"] ["-"] name;
+
+in {
+  # name of the chart
+  chart
+
+  # chart url to fetch from custom location
+, chartUrl ? null
+
+  # version of the chart
+, version ? null
+
+# chart hash
+, sha256
+
+# whether to extract chart
+, untar ? true
+
+# use custom charts repo
+, repo ? null
+
+# pass --verify to helm chart
+, verify ? false
+
+# pass --devel to helm chart
+, devel ? false }: stdenvNoCC.mkDerivation {
+  name = "${cleanName chart}-${if version == null then "dev" else version}";
+
+  buildCommand = ''
+    export HOME="$PWD"
+    helm init --client-only >/dev/null
+    ${if repo == null then "" else "helm repo add repository ${repo}"}
+    helm fetch -d ./chart \
+      ${if untar then "--untar" else ""} \
+      ${if version == null then "" else "--version ${version}"} \
+      ${if devel then "--devel" else ""} \
+      ${if verify then "--verify" else ""} \
+      ${if chartUrl == null then (if repo == null then chart else "repository/${chart}") else chartUrl}
+    cp -r chart/*/ $out
+  '';
+  outputHashMode = "recursive";
+  outputHashAlgo = "sha256";
+  outputHash = sha256;
+  nativeBuildInputs = [ kubernetes-helm cacert ];
+}

lib/helm/test.nix

@@ -0,0 +1,43 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+let
+  fetchhelm = pkgs.callPackage ./fetchhelm.nix {  };
+  chart2json = pkgs.callPackage ./chart2json.nix {  };
+in rec {
+  postgresql-chart = fetchhelm {
+    chart = "stable/postgresql";
+    version = "0.18.1";
+    sha256 = "1p3gfmaakxrqb4ncj6nclyfr5afv7xvcdw95c6qyazfg72h3zwjn";
+  };
+
+  istio-chart = fetchhelm {
+    chart = "istio";
+    version = "1.1.0";
+    repo = "https://storage.googleapis.com/istio-release/releases/1.1.0-rc.0/charts";
+    sha256 = "0ippv2914hwpsb3kkhk8d839dii5whgrhxjwhpb9vdwgji5s7yfl";
+  };
+
+  istio-official-chart = pkgs.fetchgit {
+    url = "https://github.com/fyery-chen/istio-helm";
+    rev = "47e235e775314daeb88a3a53689ed66c396ecd3f";
+    sha256 = "190sfyvhdskw6ijy8cprp6hxaazn7s7mg5ids4snshk1pfdg2q8h";
+  };
+
+  postgresql-json = chart2json {
+    name = "postgresql";
+    chart = postgresql-chart;
+    values = {
+      networkPolicy.enabled = true;
+    };
+  };
+
+  istio-json = chart2json {
+    name = "istio";
+    chart = istio-chart;
+  };
+
+  istio-official-json = chart2json {
+    name = "istio-official";
+    chart = "${istio-official-chart}/istio-official";
+  };
+}