feat: launch django & tests with keyboard interrupt

So can run tests or django locally & kill it + database on
keyboard interrupt via 'Ctrl+C'

.github/workflows/tests.yml

@@ -31,12 +31,33 @@ jobs:
       shell: sh
     - run: devenv ci
     - run: devenv shell run-tests
-    - name: Show Postgres startup logs
+    - name: Install dependencies
+      run: |
+        OUTPUT=$(devenv shell echo "Dependencies installed!")
+
+        # If poetry environment is broken then recache all Python dependencies ...
+        if [[ "$OUTPUT" == *"POETRY_STATUS=broken"* ]]; then
+          echo "POETRY_STATUS=broken" >> $GITHUB_ENV
+        else
+          echo "POETRY_STATUS=clean" >> $GITHUB_ENV
+        fi
+
+        echo $OUTPUT >> /tmp/dependencies.log
+    - name: Run tests
+      run: devenv shell test-all
+    - name: Show logs from dependency installation
+      if: always()
+      run: cat /tmp/dependencies.log
+    - name: Show logs from test database setup
       if: always()
       run: cat /tmp/devenv.log
+    - name: Show environment variables
+      if: always()
+      run: |
+        echo "POETRY_STATUS=${{ env.POETRY_STATUS }}"
     - name: Cache python dependencies
       uses: actions/cache/save@v3
-      if: always() && steps.cache.outputs.cache-hit != 'true'
+      if: always() && steps.cache.outputs.cache-hit != 'true' || ${{ env.POETRY_STATUS }} == 'broken'
       with:
         path: ~/.cache/pypoetry
         key: ${{ runner.os }}-poetry-${{ hashFiles('poetry.lock') }}

README.md

@@ -37,5 +37,5 @@ Specifically,  `devenv` uses `nix` to install system level packages like `postgr
 
 `devenv` enables defining scripts in `devenv.nix` that are automatically added to the shell path ...
 
-- Run tests via `run-tests`
-- Launch a development server via `devenv up`
+- Launch a development server via `launch-django`
+- Run tests via `test-all`

devenv.nix

@@ -3,9 +3,10 @@
 let
   db_user = "postgres";
   db_host = "localhost";
-  db_port = "5432";
+  db_port = 5432;
   db_name = "db";
   python_version = "3.10";
+  django_port = "8000";
 in
 {
   packages = [ pkgs.git pkgs.postgresql_14 ];
@@ -17,71 +18,107 @@ in
 
   env = {
     PYTHON_VERSION = python_version;
-    DATABASE_URL = "postgresql://${db_user}@${db_host}:${db_port}/${db_name}";
+    DATABASE_URL = "postgresql://${db_user}@${db_host}:${builtins.toString db_port}/${db_name}";
     DEBUG = true;
     STATIC_ROOT = "/tmp/static";
   };
 
   enterShell = ''
-    # Activate poetry environment on shell entry
-    # https://pythonspeed.com/articles/activate-virtualenv-dockerfile/
-    VIRTUAL_ENV=`poetry env info --path` && export VIRTUAL_ENV 
-    export PATH="$VIRTUAL_ENV/bin:$PATH";
+    # If poetry environment is broken we can check this env var in CI & recache
+    export POETRY_STATUS=$(check-poetry-status)
+    echo "POETRY_STATUS=$POETRY_STATUS"
   '';
 
   services.postgres = {
     enable = true;
     initialScript = "CREATE USER ${db_user} SUPERUSER;";
     initialDatabases = [ { name = db_name; } ];
     listen_addresses = db_host;
-  };
-
-  processes = {
-    runserver.exec = ''
-      devenv shell python manage.py runserver
-    '';
+    port = db_port;
   };
 
   scripts = {
-    start-processes-in-background.exec = ''
-      echo
-      psql --version
-
-      # Start Postgres if not running ...
-      if ! nc -z ${db_host} ${db_port};
+    dj.exec = ''
+      python manage.py $@
+    '';
+    check-poetry-status.exec = ''
+      STATUS=$(poetry check)
+      if [[ "$STATUS" == 'All set!' ]]; then
+        echo "clean"
+      else
+        echo "broken"
+      fi
+    '';
+    start-services-in-background.exec = ''
+      if ! nc -z ${db_host} ${builtins.toString db_port};
       then
-        echo "Starting Database in the background on ${db_host}:${db_port} ..."
+        printf "Starting database in background ...\n"
         nohup devenv up > /tmp/devenv.log 2>&1 &
       fi
     '';
+    kill-services.exec = ''
+      printf "Killing background services ...\n"
+      fuser -k ${builtins.toString db_port}/tcp
+      fuser -k ${django_port}/tcp
+    '';
     wait-for-db.exec = ''
-      echo
-      echo "Waiting for database to start .."
-      echo "(if wait exceeds 100%, check /tmp/devenv.log for errors!)"
-      
+      printf "Waiting for database to start ...\n"
+      printf "(if wait exceeds 100 percent then check /tmp/devenv.log for errors)\n"
+
+      n_loops=100;
       timer=0;
-      n_steps=99;
       while true;
       do
-        if nc -z ${db_host} ${db_port}; then
+        if nc -z ${db_host} ${builtins.toString db_port}; then
           printf "\nDatabase is running!\n\n"
           exit 0
-        elif [ $timer -gt $n_steps ]; then
+        elif [ $timer -gt $n_loops ]; then
           printf "\nDatabase failed to launch!\n\n"
           exit 1
         else
           sleep 0.1
           let timer++
-          printf "%-*s" $((timer+1)) '[' | tr ' ' '#'
-          printf "%*s%3d%%\r"  $((100-timer))  "]" "$timer"
+          percent=$((timer*100/n_loops))
+          bar+="#"
+          printf "\r[%-100s] %d%%" "$bar" "$percent"
         fi
       done
     '';
-    run-tests.exec = ''
-      start-processes-in-background
-      wait-for-db || exit 1
-      python manage.py collectstatic --noinput
-      python manage.py test
+    launch-django.exec = ''
+      interrupt_handler() {
+        kill-services
+        exit 1
+      }
+
+      trap 'interrupt_handler' SIGINT
+
+      launch_django() {
+        printf "Launching Django ...\n\n"
+        start-services-in-background
+        wait-for-db || exit 1 # if wait-for-db fails, exit!
+        dj runserver ${django_port}
+      }
+
+      launch_django
+    '';
+    test-all.exec = ''
+      interrupt_handler() {
+        kill-services
+        exit 1
+      }
+
+      trap 'interrupt_handler' SIGINT
+
+      run_tests() {
+        printf "Running tests...\n\n"
+        start-services-in-background
+        wait-for-db || exit 1 # if wait-for-db fails, exit!
+        dj collectstatic --noinput
+        dj test $@
+        interrupt_handler
+      }
+
+      run_tests
     '';
   };
 }