Add daily email for 07/04/25

source/_daily_emails/2025-04-07.md

@@ -0,0 +1,106 @@
+---
+title: Generating presentation slides with Nix and rst2pdf
+date: 2025-04-07
+permalink: daily/2025/04/07/nix-rst2pdf
+tags:
+  - software-development
+  - linux
+  - nix
+  - rst2pdf
+cta: ~
+snippet: |
+  I've recently combined two of my favourite tools - rst2pdf for generating PDF documents, such as presentation slide decks, and Nix.
+---
+
+Since switching to Nix and NixOS, I've been looking for opportunities to use Nix more in addition to managing my laptop and server configurations and creating development shells for projects.
+
+Nix is a build tool, so I've started to use it to build my slide decks which I create using rst2pdf.
+
+I write the rst (reStructuredText) file and compile it to a PDF file.
+
+I had a flake.nix file to add rst2pdf, pdfpc and other tools to my shell, but the compilation to a PDF file was done in a bash script which I've since removed.
+
+Here's how my flake.nix file looks now:
+
+```nix
+{
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { nixpkgs, ... }:
+    let
+      system = "x86_64-linux";
+      pkgs = import nixpkgs { inherit system; };
+
+      inherit (nixpkgs.lib) makeOverridable;
+      inherit (pkgs.stdenvNoCC) mkDerivation;
+
+      shared = mkDerivation {
+        name = "talks-shared";
+        src = ./src;
+
+        installPhase = ''
+          runHook preInstall
+
+          mkdir $out
+          cp -r fonts styles $out
+
+          runHook postInstall
+        '';
+      };
+
+      commonBuildInputs = with pkgs; [
+        (python310.withPackages (p: with p; [ rst2pdf ]))
+      ];
+
+      mkTalk = makeOverridable ({ src }: mkDerivation {
+        inherit shared src;
+
+        name = builtins.head (builtins.attrNames talks);
+
+        buildInputs = commonBuildInputs;
+
+        buildPhase = ''
+          runHook preBuild
+
+          mkdir $out
+
+          rst2pdf slides.rst \
+            --break-level 1 \
+            --fit-background-mode scale \
+            --font-path "${toString shared}/fonts" \
+            --output "$out/slides.pdf" \
+            --stylesheets bw,"${toString shared}/styles/opdavies-light"
+
+          runHook postBuild
+        '';
+      });
+
+      talks = {
+        build-configs = mkTalk { src = ./src/building-build-configs; };
+        sculpin = mkTalk { src = ./src/building-static-websites-sculpin; };
+        tailwind-css = mkTalk { src = ./src/taking-flight-with-tailwind-css; };
+        test-driven-drupal = mkTalk { src = ./src/test-driven-drupal; };
+      };
+    in
+    {
+      devShells.${system}.default = with pkgs; mkShell {
+        packages = with pkgs; commonBuildInputs ++ [
+          ghostscript
+          just
+          pdfpc
+          texliveMedium # includes pdfjam
+        ];
+      };
+
+      packages.${system} = {
+        inherit shared;
+      } // talks;
+    };
+}
+```
+
+Each talk is its own derivation, so I can run `nix run .#test-driven-drupal` and it will generate the appropriate PDF file for me to present or share.
+
+The source code is available at <https://code.oliverdavies.uk/opdavies/talks> if you want to see how I use rst2pdf to create my presentations and I've even [given a presentation about how I create presentations][0].
+
+[0]: {{site.url}}/presentations/building-presenting-slide-decks-rst2pdf