Merge pull request #57 from railwayapp/jr/provider-path-envs

Python virtualenvs and provider paths

examples/python/Procfile

@@ -0,0 +1 @@
+web: gunicorn main:app

src/nixpacks/mod.rs

@@ -428,6 +428,12 @@ impl<'a> AppBuilder<'a> {
             .map(|cmd| format!("RUN {}", cmd))
             .unwrap_or_else(|| "".to_string());
 
+        let path_env = if let Some(paths) = install_phase.paths {
+            format!("ENV PATH {}:$PATH", paths.join(":"))
+        } else {
+            "".to_string()
+        };
+
         // Files to copy for install phase
         // If none specified, copy over the entire app
         let install_files = install_phase
@@ -500,6 +506,7 @@ impl<'a> AppBuilder<'a> {
           # Install
           {install_copy_cmd}
           {install_cmd}
+          {path_env}
 
           # Build
           {build_copy_cmd}
@@ -514,6 +521,7 @@ impl<'a> AppBuilder<'a> {
         args_string=args_string,
         install_copy_cmd=get_copy_command(&install_files, app_dir),
         install_cmd=install_cmd,
+        path_env=path_env,
         build_copy_cmd=get_copy_command(&build_files, app_dir),
         build_cmd=build_cmd,
         start_copy_cmd=get_copy_command(&start_files, app_dir),

src/nixpacks/phase.rs

@@ -46,13 +46,16 @@ pub struct InstallPhase {
 
     #[serde(rename = "onlyIncludeFiles")]
     pub only_include_files: Option<Vec<String>>,
+
+    pub paths: Option<Vec<String>>,
 }
 
 impl InstallPhase {
     pub fn new(cmd: String) -> Self {
         Self {
             cmd: Some(cmd),
             only_include_files: None,
+            paths: None,
         }
     }
 
@@ -64,6 +67,15 @@ impl InstallPhase {
             self.only_include_files = Some(vec![file]);
         }
     }
+
+    pub fn add_path(&mut self, path: String) {
+        if let Some(mut paths) = self.paths.clone() {
+            paths.push(path);
+            self.paths = Some(paths);
+        } else {
+            self.paths = Some(vec![path]);
+        }
+    }
 }
 
 #[serde_with::skip_serializing_none]

src/providers/python.rs

@@ -36,17 +36,28 @@ impl Provider for PythonProvider {
     }
 
     fn install(&self, app: &App, _env: &Environment) -> Result<Option<InstallPhase>> {
+        let env_loc = "/opt/venv";
+        let create_env = format!("python -m venv {}", env_loc);
+        let activate_env = format!(". {}/bin/activate", env_loc);
+
         if app.includes_file("requirements.txt") {
-            let mut install_phase = InstallPhase::new(
-                "python -m ensurepip && python -m pip install -r requirements.txt".to_string(),
-            );
+            let mut install_phase = InstallPhase::new(format!(
+                "{} && {} && pip install -r requirements.txt",
+                create_env, activate_env
+            ));
             install_phase.add_file_dependency("requirements.txt".to_string());
+            install_phase.add_path(format!("{}/bin", env_loc));
             return Ok(Some(install_phase));
         } else if app.includes_file("pyproject.toml") {
-            let mut install_phase =InstallPhase::new("python -m ensurepip && python -m pip install --upgrade build setuptools && python -m pip install .".to_string());
+            let mut install_phase = InstallPhase::new(format!(
+                "{} && {} && pip install --upgrade build setuptools && pip install .",
+                create_env, activate_env
+            ));
             install_phase.add_file_dependency("pyproject.toml".to_string());
+            install_phase.add_path(format!("{}/bin", env_loc));
             return Ok(Some(install_phase));
         }
+
         Ok(None)
     }
 

tests/integration_tests.rs

@@ -216,9 +216,12 @@ pub fn test_python() -> Result<()> {
     assert_eq!(plan.build.unwrap().cmd, None);
     assert_eq!(
         plan.install.unwrap().cmd,
-        Some("python -m ensurepip && python -m pip install -r requirements.txt".to_string())
+        Some("python -m venv /opt/venv && . /opt/venv/bin/activate && pip install -r requirements.txt".to_string())
+    );
+    assert_eq!(
+        plan.start.unwrap().cmd,
+        Some("gunicorn main:app".to_string())
     );
-    assert_eq!(plan.start.unwrap().cmd, Some("python main.py".to_string()));
 
     Ok(())
 }