Resolve pylint warnings (#488)

* Suppress the import outside toplevel pylint rule -- I think we want to save memory

* Resolve pylint warnings

src/.pylintrc

@@ -133,7 +133,8 @@ disable=print-statement,
         xreadlines-attribute,
         deprecated-sys-function,
         exception-escape,
-        comprehension-escape
+        comprehension-escape,
+        import-outside-toplevel
 
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option

src/web/file_cmds.py

@@ -239,7 +239,9 @@ def download_file_to_iso(url):
         return {"status": False, "msg": req_proc["msg"]}
 
     iso_proc = run(
-        ["genisoimage", "-hfs", "-o", iso_filename, tmp_full_path], capture_output=True
+        ["genisoimage", "-hfs", "-o", iso_filename, tmp_full_path],
+        capture_output=True,
+        check=True,
     )
     if iso_proc.returncode != 0:
         return {"status": False, "msg": iso_proc.stderr.decode("utf-8")}

src/web/pi_cmds.py

@@ -40,12 +40,20 @@ def running_env():
     env is the various system information where this app is running
     """
     ra_git_version = (
-        subprocess.run(["git", "rev-parse", "HEAD"], capture_output=True)
+        subprocess.run(
+            ["git", "rev-parse", "HEAD"],
+            capture_output=True,
+            check=True,
+            )
         .stdout.decode("utf-8")
         .strip()
     )
     pi_version = (
-        subprocess.run(["uname", "-a"], capture_output=True)
+        subprocess.run(
+            ["uname", "-a"],
+            capture_output=True,
+            check=True,
+            )
         .stdout.decode("utf-8")
         .strip()
     )
@@ -57,7 +65,11 @@ def running_proc(daemon):
     Takes (str) daemon
     Returns (int) proc, which is the number of processes currently running
     """
-    process = subprocess.run(["ps", "aux"], capture_output=True)
+    process = subprocess.run(
+            ["ps", "aux"],
+            capture_output=True,
+            check=True,
+            )
     output = process.stdout.decode("utf-8")
     from re import findall
     proc = findall(daemon, output)
@@ -68,7 +80,11 @@ def is_bridge_setup():
     """
     Returns (bool) True if the rascsi_bridge network interface exists
     """
-    process = subprocess.run(["brctl", "show"], capture_output=True)
+    process = subprocess.run(
+            ["brctl", "show"],
+            capture_output=True,
+            check=True,
+            )
     output = process.stdout.decode("utf-8")
     if "rascsi_bridge" in output:
         return True

src/web/socket_cmds.py

@@ -3,6 +3,7 @@ Module for sending and receiving data over a socket connection with the RaSCSI b
 """
 
 import logging
+from flask import abort
 
 def send_pb_command(payload):
     """
@@ -32,7 +33,6 @@ def send_pb_command(payload):
     logging.error(error_msg)
 
     # After failing all attempts, throw a 404 error
-    from flask import abort
     abort(404, "The RaSCSI Web Interface failed to connect to RaSCSI at " + str(host) + \
             ":" + str(port) + " with error: " + error_msg + \
             ". The RaSCSI service is not running or may have crashed.")
@@ -64,7 +64,6 @@ def send_over_socket(sock, payload):
         while bytes_recvd < response_length:
             chunk = sock.recv(min(response_length - bytes_recvd, 2048))
             if chunk == b'':
-                from flask import abort
                 logging.error(
                     "Read an empty chunk from the socket. "
                     "Socket connection has dropped unexpectedly. "
@@ -80,7 +79,6 @@ def send_over_socket(sock, payload):
         response_message = b''.join(chunks)
         return response_message
 
-    from flask import abort
     logging.error(
         "The response from RaSCSI did not contain a protobuf header. "
         "RaSCSI may have crashed."

src/web/web.py

@@ -401,9 +401,17 @@ def show_logs():
 
     from subprocess import run
     if scope != "default":
-        process = run(["journalctl", "-n", lines, "-u", scope], capture_output=True)
+        process = run(
+                ["journalctl", "-n", lines, "-u", scope],
+                capture_output=True,
+                check=True,
+                )
     else:
-        process = run(["journalctl", "-n", lines], capture_output=True)
+        process = run(
+                ["journalctl", "-n", lines],
+                capture_output=True,
+                check=True,
+                )
 
     if process.returncode == 0:
         headers = {"content-type": "text/plain"}
@@ -455,18 +463,18 @@ def daynaport_attach():
         "https://github.com/akuker/RASCSI/wiki/Dayna-Port-SCSI-Link")
 
     if interface.startswith("wlan"):
-        if not introspect_file("/etc/sysctl.conf", "^net\.ipv4\.ip_forward=1$"):
+        if not introspect_file("/etc/sysctl.conf", r"^net\.ipv4\.ip_forward=1$"):
             flash("IPv4 forwarding is not enabled. " + error_msg, "error")
             return redirect(url_for("index"))
         if not Path("/etc/iptables/rules.v4").is_file():
             flash("NAT has not been configured. " + error_msg, "error")
             return redirect(url_for("index"))
     else:
-        if not introspect_file("/etc/dhcpcd.conf", "^denyinterfaces " + interface + "$"):
+        if not introspect_file("/etc/dhcpcd.conf", r"^denyinterfaces " + interface + r"$"):
             flash("The network bridge hasn't been configured. " + error_msg, "error")
             return redirect(url_for("index"))
         if not Path("/etc/network/interfaces.d/rascsi_bridge").is_file():
-            flash(f"The network bridge hasn't been configured. " + error_msg, "error")
+            flash("The network bridge hasn't been configured. " + error_msg, "error")
             return redirect(url_for("index"))
 
     kwargs = {"device_type": "SCDP"}
@@ -976,10 +984,10 @@ if __name__ == "__main__":
         read_config(DEFAULT_CONFIG)
 
     if len(argv) > 1:
-        port = int(argv[1])
+        PORT = int(argv[1])
     else:
-        port = 8080
+        PORT = 8080
 
     import bjoern
     print("Serving rascsi-web...")
-    bjoern.run(APP, "0.0.0.0", port)
+    bjoern.run(APP, "0.0.0.0", PORT)