add flake

flake.nix

@@ -0,0 +1,121 @@
+{
+  description = "Nix CMake Template";
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    flake-parts = {
+      url = "github:hercules-ci/flake-parts";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, flake-parts, nixpkgs, ... }:
+    flake-parts.lib.mkFlake { inherit self; } {
+      systems = [ "x86_64-linux" ];
+      imports = [
+      ];
+      perSystem = { config, self', inputs', pkgs, system, ... }:
+        let
+          pkgs = inputs'.nixpkgs.legacyPackages;
+          inherit (pkgs) lib;
+
+          makeStatic =
+            let
+              staticPostgresql = (pkgs.postgresql_11.overrideAttrs (o: {
+                dontDisableStatic = true;
+                # https://www.postgresql-archive.org/building-libpq-a-static-library-td5970933.html
+                postConfigure = o.postConfigure + ''
+                  echo -e 'libpq.a: $(OBJS)\n\tar rcs $@ $^'   >> ./src/interfaces/libpq/Makefile
+                '';
+                buildPhase = ''
+                  make world
+                  make -C ./src/interfaces/libpq libpq.a
+                '';
+                postInstall = o.postInstall + ''
+                  cp src/interfaces/libpq/libpq.a $out/lib/
+                  cp src/interfaces/libpq/libpq.a $lib/lib/
+                '';
+              })).override { gssSupport = false; };
+
+              staticPqxx = (pkgs.libpqxx.overrideAttrs (o: { configureFlags = [ ]; })).override {
+                stdenv = pkgs.makeStaticLibraries pkgs.stdenv;
+                postgresql = staticPostgresql;
+              };
+              staticOpenssl = pkgs.openssl.override { static = true; };
+            in
+            drv: (drv.override {
+              static = true;
+              libpqxx = staticPqxx;
+            }).overrideAttrs (o: {
+              buildInputs = o.buildInputs ++ [
+                pkgs.glibc.static
+                staticOpenssl
+                staticPostgresql
+              ];
+              doCheck = false;
+            });
+
+          serverVariants =
+            let
+              fromInputs = { stdenv, boost16x, static }:
+                let
+                  p = pkgs.callPackage ./server/derivation.nix { };
+                  noDots = lib.replaceChars [ "." ] [ "_" ];
+                  staticStr = lib.optionalString static "-static";
+                  name = "${p.name}-${noDots stdenv.cc.cc.name}-${noDots boost16x.name}${staticStr}";
+                  maybeMakeStatic = drv: if static then makeStatic drv else drv;
+                  drv = maybeMakeStatic (p.override { inherit boost16x stdenv; });
+                in
+                lib.nameValuePair name drv;
+
+              inputVariants = lib.cartesianProductOfSets {
+                stdenv = with pkgs;
+                  map (overrideCC stdenv) [ gcc9 gcc10 gcc11 ]
+                  ++ map (overrideCC clangStdenv) [ clang_11 clang_12 clang_13 ];
+                boost16x = with pkgs; [ boost168 boost169 ];
+                static = [ true false ];
+              };
+            in
+            builtins.listToAttrs (builtins.map fromInputs inputVariants);
+
+          integrationTests =
+            let integrationTest = mdbServer: import ./integration_test.nix {
+              inherit pkgs mdbServer;
+              mdbWebservice = self'.packages.mdb-webserver;
+            };
+            in
+            pkgs.lib.mapAttrs' (k: v: pkgs.lib.nameValuePair ("integrationtest-${k}") (integrationTest v));
+        in
+        {
+          packages = serverVariants // {
+            mdb-server = pkgs.callPackage ./server/derivation.nix { };
+            mdb-server-no-python =
+              let # this is useful because libpqxx with python support depends on python2.7
+                # but we don't want python in its closure if we package it into a small
+                # docker image!
+                libpqxxWithoutPython = pkgs.libpqxx.override {
+                  postgresql = pkgs.postgresql.override {
+                    libxml2 = pkgs.libxml2.override { pythonSupport = false; };
+                  };
+                };
+              in self'.packages.mdb-server.override { libpqxx = libpqxxWithoutPython; };
+            mdb-webserver = pkgs.python3Packages.callPackage ./python_client/derivation.nix { };
+          };
+          checks = { } // (integrationTests serverVariants);
+        };
+      flake = {
+        dockerImages =
+          let
+            makeDockerImage = name: entrypoint: nixpkgs.legacyPackages.x86_64-linux.dockerTools.buildImage {
+              inherit name;
+              tag = "latest";
+              config = { Entrypoint = [ entrypoint ]; };
+            };
+          in
+          {
+            mdb-webservice = makeDockerImage "mdb-webservice" "${self.packages.x86_64-linux.mdb-webserver}/bin/webserver";
+            mdb-server = makeDockerImage "mdb-server" "${self.packages.x86_64-linux.mdb-server-no-python}/bin/messagedb-server";
+            mdb-server-static = makeDockerImage "mdb-server" "${self.packages.x86_64-linux.mdb-server-gcc-9_5_0-boost-1_69_0-static}/bin/messagedb-server";
+          };
+      };
+    };
+}