Nix initial support for build the app

.envrc.example

@@ -0,0 +1 @@
+use nix

.gitignore

@@ -37,3 +37,6 @@ htmlcov/
 .coverage
 .coverage.*
 .cache
+
+# nix/direnv
+.envrc

flake.nix

@@ -0,0 +1,91 @@
+{
+  description = "ddapm_test_agent";
+  nixConfig.bash-prompt-prefix = "\[ddapm_test_agent\] ";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+    nixpkgs.url = "github:NixOS/nixpkgs/23.11";
+
+    pyproject-nix.url = "github:nix-community/pyproject.nix";
+
+    nix2containerPkg.url = "github:nlewo/nix2container";
+  };
+
+  outputs = {
+    self,
+    nixpkgs,
+    flake-utils,
+    treefmt-nix,
+    pyproject-nix,
+    nix2containerPkg,
+  }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      project = pyproject-nix.lib.project.loadPyproject {
+        projectRoot = ./.;
+      };
+      pkgs = nixpkgs.legacyPackages.${system};
+      nix2container = nix2containerPkg.packages.${system}.nix2container;
+
+      python = pkgs.python312;
+      pythonPkgs = pkgs.python312Packages;
+
+      packageAttrs = project.renderers.buildPythonPackage {inherit python;};
+      packageDeps = project.renderers.withPackages {inherit python;};
+
+      pythonDevEnv = python.withPackages packageDeps;
+
+      treefmt = treefmt-nix.lib.evalModule pkgs ./treefmt.nix;
+
+      finalPackage = python.pkgs.buildPythonPackage packageAttrs;
+      finalApp = python.pkgs.buildPythonApplication packageAttrs;
+      devEnv = pkgs.buildEnv {
+        name = "root";
+        paths = [pkgs.bashInteractive pkgs.coreutils treefmt.config.build.wrapper pythonDevEnv];
+        pathsToLink = ["/bin"];
+      };
+    in {
+      packages = {
+        python = python;
+        ciContainer = nix2container.buildImage {
+          name = "registry.ddbuild.io/apm-reliability-environment/handmade/nixci";
+
+          copyToRoot = pkgs.buildEnv {
+            name = "root";
+            paths = [devEnv pythonPkgs.pytest];
+            pathsToLink = ["/bin"];
+          };
+        };
+        toolContainer = nix2container.buildImage {
+          name = "registry.ddbuild.io/apm-reliability-environment/handmade/docker-builder";
+          tag = "latest";
+          config = {
+            entrypoint = ["/bin/docker-builder"];
+          };
+
+          copyToRoot = pkgs.buildEnv {
+            name = "root";
+            paths = [finalApp];
+            pathsToLink = ["/bin"];
+          };
+        };
+      };
+
+      packages.default = finalPackage;
+      formatter = treefmt.config.build.wrapper;
+
+      devShells.default =
+        pkgs.mkShell
+        {
+          venvDir = "./.venv";
+          nativeBuildInputs = [pythonDevEnv pythonPkgs.venvShellHook];
+          packages = [
+            devEnv
+            pythonPkgs.pytest
+          ];
+          postShellHook = ''
+            export PYTHONPATH="$PYTHONPATH:$(pwd)" # ensuring pytest invocation works
+          '';
+        };
+    });
+}

shell.nix

@@ -0,0 +1 @@
+(builtins.getFlake ("git+file://" + toString ./.)).devShells.${builtins.currentSystem}.default

treefmt.nix

@@ -0,0 +1,12 @@
+# treefmt.nix
+{pkgs, ...}: {
+  # Used to find the project root
+  projectRootFile = "flake.nix";
+  # Enable the Nix formatter "alejandra"
+  programs.alejandra.enable = true;
+
+  # Format py sources
+  programs.black.enable = true;
+  # Format .sh scripts
+  programs.shfmt.enable = true;
+}