ci: add hadolint and flake8 linters

addresses reanahub/reana#450

.flake8

@@ -0,0 +1,20 @@
+[flake8]
+max-line-length = 89
+
+exclude =
+    build
+    modules
+    dist
+    docs
+    coverage.xml
+    reana_job_controller.egg-info
+    .*/
+    env/
+    .git
+    __pycache__
+
+ignore = E203, E231, E266, E501, W503, F403, F401
+
+max-complexity = 18
+
+select = B,C,E,F,W,T4,B9

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ on: [push, pull_request]
 
 jobs:
   lint-shellcheck:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -21,7 +21,7 @@ jobs:
           ./run-tests.sh --check-shellscript
 
   lint-black:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -37,8 +37,25 @@ jobs:
           pip install black==19.10b0
           ./run-tests.sh --check-black
 
+  lint-flake8:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+
+      - name: Check compliance with pep8, pyflakes and circular complexity
+        run: |
+          pip install --upgrade pip
+          pip install flake8
+          ./run-tests.sh --check-flake8
+
   lint-pydocstyle:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -55,7 +72,7 @@ jobs:
           ./run-tests.sh --check-pydocstyle
 
   lint-check-manifest:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -72,7 +89,7 @@ jobs:
           ./run-tests.sh --check-manifest
 
   docs-sphinx:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -97,7 +114,7 @@ jobs:
         run: ./run-tests.sh --check-sphinx
 
   python-tests:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         python-version: [3.6, 3.7, 3.8]
@@ -130,12 +147,20 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: coverage.xml
 
+  lint-dockerfile:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Check Dockerfile compliance
+        run: ./run-tests.sh --check-dockerfile
 
   docker-build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Build docker image
+      - name: Build Docker image
         run: ./run-tests.sh --check-docker-build

Dockerfile

@@ -6,6 +6,7 @@
 
 # Install base image and its dependencies
 FROM python:3.8-slim
+# hadolint ignore=DL3008, DL3009, DL3013, DL3015
 RUN apt-get update && \
     apt-get install -y \
       gcc \
@@ -27,6 +28,7 @@ ARG DEBUG=0
 RUN if [ "${DEBUG}" -gt 0 ]; then pip install -e ".[debug]"; else pip install .; fi;
 
 # Are we building with locally-checked-out shared modules?
+# hadolint ignore=SC2102
 RUN if test -e modules/reana-commons; then pip install -e modules/reana-commons[kubernetes] --upgrade; fi
 RUN if test -e modules/reana-db; then pip install -e modules/reana-db --upgrade; fi
 
@@ -41,4 +43,4 @@ ENV TERM=xterm \
 EXPOSE 5000
 
 # Run server
-CMD uwsgi --ini uwsgi.ini
+CMD ["uwsgi --ini uwsgi.ini"]

MANIFEST.in

@@ -8,6 +8,7 @@ include LICENSE
 include *.rst
 include *.sh
 include *.txt
+include .flake8
 include pytest.ini
 include docs/*.json
 include scripts/*

reana_server/reana_admin.py

@@ -253,7 +253,7 @@ def token_grant(admin_access_token, id_, email):
         )
         send_email(user.email, email_subject, email_body)
 
-    except click.exceptions.Abort as e:
+    except click.exceptions.Abort:
         click.echo("Grant token aborted.")
     except REANAEmailNotificationError as e:
         click.secho(

reana_server/rest/workflows.py

@@ -214,7 +214,7 @@ def get_workflows(**kwargs):  # noqa
     except HTTPError as e:
         logging.error(traceback.format_exc())
         return jsonify(e.response.json()), e.response.status_code
-    except json.JSONDecodeError as e:
+    except json.JSONDecodeError:
         logging.error(traceback.format_exc())
         return jsonify({"message": "Your request contains not valid JSON."}), 400
     except ValueError as e:
@@ -1733,7 +1733,7 @@ def get_workflow_diff(workflow_id_or_name_a, workflow_id_or_name_b):  # noqa
     except HTTPError as e:
         logging.error(traceback.format_exc())
         return jsonify(e.response.json()), e.response.status_code
-    except json.JSONDecodeError as e:
+    except json.JSONDecodeError:
         logging.error(traceback.format_exc())
         return jsonify({"message": "Your request contains not valid JSON."}), 400
     except ValueError as e:

reana_server/utils.py

@@ -101,7 +101,7 @@ def _create_user(email, user_access_token, admin_access_token):
         user = User(**user_parameters)
         Session.add(user)
         Session.commit()
-    except (InvalidRequestError, IntegrityError) as e:
+    except (InvalidRequestError, IntegrityError):
         Session.rollback()
         raise ValueError("Could not create user, " "possible constraint violation")
     return user

run-tests.sh

@@ -64,6 +64,10 @@ check_black () {
     black --check .
 }
 
+check_flake8 () {
+    flake8 .
+}
+
 check_openapi_spec () {
     FLASK_APP=reana_server/app.py python ./scripts/generate_openapi_spec.py
     diff -q -w temp_openapi.json docs/openapi.json
@@ -85,6 +89,10 @@ check_pytest () {
     stop_db_container
 }
 
+check_dockerfile () {
+    docker run -i --rm hadolint/hadolint < Dockerfile
+}
+
 check_docker_build () {
     docker build -t reanahub/reana-server .
 }
@@ -93,10 +101,12 @@ check_all () {
     check_script
     check_pydocstyle
     check_black
+    check_flake8
     check_openapi_spec
     check_manifest
     check_sphinx
     check_pytest
+    check_dockerfile
     check_docker_build
 }
 
@@ -111,10 +121,12 @@ do
         --check-shellscript) check_script;;
         --check-pydocstyle) check_pydocstyle;;
         --check-black) check_black;;
+        --check-flake8) check_flake8;;
         --check-openapi-spec) check_openapi_spec;;
         --check-manifest) check_manifest;;
         --check-sphinx) check_sphinx;;
         --check-pytest) check_pytest;;
+        --check-dockerfile) check_dockerfile;;
         --check-docker-build) check_docker_build;;
         *)
     esac

setup.py

@@ -86,7 +86,7 @@
 
 # Get the version string. Cannot be done with import!
 with open(os.path.join("reana_server", "version.py"), "rt") as f:
-    version = re.search('__version__\s*=\s*"(?P<version>.*)"\n', f.read()).group(
+    version = re.search(r'__version__\s*=\s*"(?P<version>.*)"\n', f.read()).group(
         "version"
     )
 

tests/test_factory.py

@@ -13,4 +13,4 @@
 
 def test_create_app():
     """Test create_app() method."""
-    app = create_app()
+    create_app()