Use patches in the Helm POC

helm-poc/README.md

@@ -0,0 +1,7 @@
+# Notes
+
+Patch was generated with:
+
+```sh
+diff -ruN kube-prometheus-stack.orig kube-prometheus-stack.new > ../patches/kube-prometheus-stack.patch
+```

helm-poc/default.nix

@@ -10,6 +10,9 @@ let
       version = "57.0.3";
       url = "https://github.com/prometheus-community/helm-charts/releases/download/${name}-${version}/${name}-${version}.tgz";
       hash = "sha256-oZNaFSfFR2dtf5IMUQ0CnXQeVLvoW22JdRqMmgmdtTs=";
+      patches = [
+        ./patches/kube-prometheus-stack.patch
+      ];
     }
     rec {
       name = "cert-manager";

helm-poc/nix/helm.nix

@@ -4,9 +4,16 @@
 , lib ? pkgs.lib
 }:
 let
-  mkHelm = { name, version, url, hash ? lib.fakeSha256 }:
+  mkHelm = {
+    name,
+    version,
+    url,
+    hash ? lib.fakeSha25,
+    namespace ? "",
+    patches ? []
+  }:
     pkgs.stdenv.mkDerivation {
-      inherit name;
+      inherit name patches;
 
       src = pkgs.fetchurl {
         inherit url hash;
@@ -14,13 +21,18 @@ let
 
       phases = [
         "unpackPhase"
+        "patchPhase"
         "build" 
       ];
 
+      namespace = if namespace != "" then "--namespace ${namespace}" else "";
+
       build = ''
         mkdir -p $out
-        ${helm} template ${name} ./ > $out/${name}-${version}.yaml
-        #${helm} version > $out/README 
+        ${helm} template \
+          --namespace ${namespace} \
+          ${name} ./ > $out/${name}-${version}.yaml
+        ${helm} version > $out/VERSION
       '';
     };
 

helm-poc/patches/kube-prometheus-stack.patch

@@ -0,0 +1,11 @@
+diff '--color=auto' -ruN kube-prometheus-stack.orig/templates/alertmanager/alertmanager.yaml kube-prometheus-stack.new/templates/alertmanager/alertmanager.yaml
+--- kube-prometheus-stack.orig/templates/alertmanager/alertmanager.yaml	2024-03-14 23:04:27.000000000 +0100
++++ kube-prometheus-stack.new/templates/alertmanager/alertmanager.yaml	2024-03-21 21:35:56.775410551 +0100
+@@ -1,6 +1,6 @@
+ {{- if .Values.alertmanager.enabled }}
+ apiVersion: monitoring.coreos.com/v1
+-kind: Alertmanager
++kind: Alertmanager # Patch Testaroo
+ metadata:
+   name: {{ template "kube-prometheus-stack.alertmanager.crname" . }}
+   namespace: {{ template "kube-prometheus-stack.namespace" . }}