From e7091af96110b8d4d150cfceeaab6cd544a2cdcf Mon Sep 17 00:00:00 2001
From: okjodom <okjodom@gmail.com>
Date: Mon, 6 May 2024 17:13:08 +0300
Subject: [PATCH] feat: build fedimint-clientd oci images

---
 flake.nix | 104 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 77 insertions(+), 27 deletions(-)

diff --git a/flake.nix b/flake.nix
index 1033f88..787ce31 100644
--- a/flake.nix
+++ b/flake.nix
@@ -16,7 +16,7 @@
       inputs.fenix.follows = "fenix";
     };
 
-    flake-utils.url = "github:numtide/flake-utils";
+    flake-utils = { url = "github:numtide/flake-utils"; };
 
     fedimint = {
       url =
@@ -33,33 +33,27 @@
         };
         lib = pkgs.lib;
         flakeboxLib = flakebox.lib.${system} { };
-        rustSrc = flakeboxLib.filterSubPaths {
-          root = builtins.path {
-            name = "fedimint-clientd";
-            path = ./.;
-          };
-          paths = [ "Cargo.toml" "Cargo.lock" ".cargo" "src" ];
-        };
 
-        toolchainArgs = let llvmPackages = pkgs.llvmPackages_11;
-        in {
-          extraRustFlags = "--cfg tokio_unstable";
+        toolchainArgs =
+          let llvmPackages = pkgs.llvmPackages_11;
+          in {
+            extraRustFlags = "--cfg tokio_unstable";
 
-          components = [ "rustc" "cargo" "clippy" "rust-analyzer" "rust-src" ];
+            components = [ "rustc" "cargo" "clippy" "rust-analyzer" "rust-src" ];
 
-          args = {
-            nativeBuildInputs =
-              [ pkgs.wasm-bindgen-cli pkgs.geckodriver pkgs.wasm-pack ]
-              ++ lib.optionals (!pkgs.stdenv.isDarwin) [ pkgs.firefox ];
+            args = {
+              nativeBuildInputs =
+                [ pkgs.wasm-bindgen-cli pkgs.geckodriver pkgs.wasm-pack ]
+                  ++ lib.optionals (!pkgs.stdenv.isDarwin) [ pkgs.firefox ];
+            };
+          } // lib.optionalAttrs pkgs.stdenv.isDarwin {
+            # on Darwin newest stdenv doesn't seem to work
+            # linking rocksdb
+            stdenv = pkgs.clang11Stdenv;
+            clang = llvmPackages.clang;
+            libclang = llvmPackages.libclang.lib;
+            clang-unwrapped = llvmPackages.clang-unwrapped;
           };
-        } // lib.optionalAttrs pkgs.stdenv.isDarwin {
-          # on Darwin newest stdenv doesn't seem to work
-          # linking rocksdb
-          stdenv = pkgs.clang11Stdenv;
-          clang = llvmPackages.clang;
-          libclang = llvmPackages.libclang.lib;
-          clang-unwrapped = llvmPackages.clang-unwrapped;
-        };
 
         # all standard toolchains provided by flakebox
         toolchainsStd = flakeboxLib.mkStdFenixToolchains toolchainArgs;
@@ -74,24 +68,80 @@
             [ pkgs.darwin.apple_sdk.frameworks.SystemConfiguration ];
           nativeBuildInputs = [ pkgs.pkg-config ];
         };
+
+        commonSrc = builtins.path { path = ./.; name = "fedimint-clientd"; };
+
+        filterWorkspaceDepsBuildFilesRegex = [ "Cargo.lock" "Cargo.toml" ".cargo" ".cargo/.*" ".config" ".config/.*" ".*/Cargo.toml" ];
+
+        filterSrcWithRegexes = regexes: src:
+          let
+            basePath = toString src + "/";
+          in
+          lib.cleanSourceWith {
+            filter = (path: type:
+              let
+                relPath = lib.removePrefix basePath (toString path);
+                includePath =
+                  (type == "directory") ||
+                  lib.any
+                    (re: builtins.match re relPath != null)
+                    regexes;
+              in
+              # uncomment to debug:
+                # builtins.trace "${relPath}: ${lib.boolToString includePath}"
+              includePath
+            );
+            inherit src;
+          };
+
+        # Filter only files needed to build project dependencies
+        #
+        # To get good build times it's vitally important to not have to
+        # rebuild derivation needlessly. The way Nix caches things
+        # is very simple: if any input file changed, derivation needs to
+        # be rebuild.
+        #
+        # For this reason this filter function strips the `src` from
+        # any files that are not relevant to the build.
+        #
+        # Like `filterWorkspaceFiles` but doesn't even need *.rs files
+        # (because they are not used for building dependencies)
+        filterWorkspaceDepsBuildFiles = src: filterSrcWithRegexes filterWorkspaceDepsBuildFilesRegex src;
+
+
+        # Filter only files relevant to building the workspace
+        filterWorkspaceBuildFiles = src: filterSrcWithRegexes (filterWorkspaceDepsBuildFilesRegex ++ [ ".*\.rs" ]) src;
+
         outputs = (flakeboxLib.craneMultiBuild { toolchains = toolchainsStd; })
           (craneLib':
             let
               craneLib = (craneLib'.overrideArgs {
                 pname = "flexbox-multibuild";
-                src = rustSrc;
+                src = filterWorkspaceBuildFiles commonSrc;
               }).overrideArgs commonArgs;
-            in rec {
+            in
+            rec {
               workspaceDeps = craneLib.buildWorkspaceDepsOnly { };
+
               workspaceBuild =
                 craneLib.buildWorkspace { cargoArtifacts = workspaceDeps; };
+
               fedimint-clientd = craneLib.buildPackageGroup {
                 pname = "fedimint-clientd";
                 packages = [ "fedimint-clientd" ];
                 mainProgram = "fedimint-clientd";
               };
+
+              fedimint-clientd-oci = pkgs.dockerTools.buildLayeredImage {
+                name = "fedimint-clientd";
+                contents = [ fedimint-clientd ];
+                config = {
+                  Cmd = [ "${fedimint-clientd}/bin/fedimint-clientd" ];
+                };
+              };
             });
-      in {
+      in
+      {
         legacyPackages = outputs;
         packages = { default = outputs.fedimint-clientd; };
         devShells = flakeboxLib.mkShells {