From 9ef499847a76ea41f3d69a9554ab6af10f5bd22b Mon Sep 17 00:00:00 2001
From: Suvanjan Mukherjee <suvanjan@google.com>
Date: Fri, 26 Oct 2018 13:19:33 -0400
Subject: [PATCH] Fix sample project incorporating comments from @mboes

Full comment at https://github.com/tweag/rules_nixpkgs/issues/39#issuecomment-433225268
---
 docker_run.sh      |  2 +-
 project/.bazelrc   |  1 +
 project/BUILD      | 10 ++++++----
 project/WORKSPACE  | 15 ++++++++-------
 project/app.py     |  7 +++++++
 project/python.nix |  3 +++
 project/run.sh     |  2 +-
 7 files changed, 27 insertions(+), 13 deletions(-)
 create mode 100644 project/.bazelrc
 create mode 100644 project/python.nix

diff --git a/docker_run.sh b/docker_run.sh
index 5a12e3c..710cf14 100755
--- a/docker_run.sh
+++ b/docker_run.sh
@@ -2,5 +2,5 @@
 set -ex
 
 IMAGE=$1
-docker run -v $(pwd)/project:/workdir -w=/workdir --entrypoint="/bin/bash" ${IMAGE} run.sh
+docker run -v $(pwd)/project:/workdir -p 8080:8080 -w=/workdir --entrypoint="/bin/bash" ${IMAGE} run.sh
 
diff --git a/project/.bazelrc b/project/.bazelrc
new file mode 100644
index 0000000..d723ccc
--- /dev/null
+++ b/project/.bazelrc
@@ -0,0 +1 @@
+run --python_top=//:python-2.7.15
diff --git a/project/BUILD b/project/BUILD
index 94543ff..64bbd84 100644
--- a/project/BUILD
+++ b/project/BUILD
@@ -2,8 +2,10 @@
 py_binary(
   name="app",
   srcs=["app.py"],
-  deps = [
-      "@python-2.7.15//:python27Packages.python",
-      "@python2.7-Flask-1.0.2//:python27Packages.flask"
-  ]
+)
+
+py_runtime(
+  name="python-2.7.15",
+  files=[],
+  interpreter="@python-2.7.15//:interpreter",
 )
diff --git a/project/WORKSPACE b/project/WORKSPACE
index 5e70f15..2ca0ccd 100644
--- a/project/WORKSPACE
+++ b/project/WORKSPACE
@@ -13,13 +13,14 @@ nixpkgs_git_repository(
 
 nixpkgs_package(
     name= "python-2.7.15",
-    attribute_path= "python27Packages.python",
-    repositories = {"@nixpkgs": "nixpkgs"}
+    nix_file= "//:python.nix",
+    repositories = {"nixpkgs": "@nixpkgs//:default.nix"},
+    build_file_content= """
+package(default_visibility = ["//visibility:public"])
+filegroup(
+    name = "interpreter",
+    srcs = ["bin/python"],
 )
-
-nixpkgs_package(
-    name = "python2.7-Flask-1.0.2",
-    attribute_path= "python27Packages.flask",
-    repositories = { "@nixpkgs": "nixpkgs" }
+"""
 )
 
diff --git a/project/app.py b/project/app.py
index 2edf6f5..f23ab42 100644
--- a/project/app.py
+++ b/project/app.py
@@ -4,3 +4,10 @@
 @app.route('/')
 def hello():
     return "Hello World!"
+
+if __name__ == '__main__':
+    app.run(
+        host='0.0.0.0',
+        port=8080,
+        debug=True
+    )
diff --git a/project/python.nix b/project/python.nix
new file mode 100644
index 0000000..43df4f1
--- /dev/null
+++ b/project/python.nix
@@ -0,0 +1,3 @@
+with (import <nixpkgs> {});
+
+python27.withPackages (pkgs: [pkgs.flask])
diff --git a/project/run.sh b/project/run.sh
index 184bdc7..bbd007c 100644
--- a/project/run.sh
+++ b/project/run.sh
@@ -3,4 +3,4 @@
 
 set -ex
 
-bazel build :app
+bazel run :app