From 142d08a06cbfd372e09ab090a44201e440c8a64f Mon Sep 17 00:00:00 2001
From: Anton Lydike <me@antonlydike.de>
Date: Sun, 30 Aug 2020 20:04:02 +0200
Subject: [PATCH] initial commit

---
 README.md        | 14 +++++++++
 client.py        | 77 ++++++++++++++++++++++++++++++++++++++++++++++++
 default.nix      | 11 +++++++
 requirements.txt |  1 +
 server.py        | 48 ++++++++++++++++++++++++++++++
 5 files changed, 151 insertions(+)
 create mode 100644 README.md
 create mode 100644 client.py
 create mode 100644 default.nix
 create mode 100644 requirements.txt
 create mode 100644 server.py

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e5a1788
--- /dev/null
+++ b/README.md
@@ -0,0 +1,14 @@
+# Beam - a simple video streaming service
+
+Two scripts for setting up local video streaming (audio might work aswell)
+
+## Server
+Run `server.py` with python3, the only dependency is flask and vlc player. This will open a server on port 5005, listening for these two routes: 
+
+* `/open?host=<host>[&port=<port>]` This will run vlc on the server and attempt to stream from `http://<host>:<port>/stream` (default port is 4040). The response will contain the session ID that can be used to control the playback
+* `/close/<id>` will close the vlc player from the specified connection id
+
+
+## Client
+
+Running `client.py <video file>` will create a symlink inside an empty temporary directory and start an http server there. Then it will call the `/open` API of the server specified in the `BEAM_SERVER` variable inside. Once evrything is running, it waits for any user input and will then clean up (stop the server, remove temp dir, call close on the server)
\ No newline at end of file
diff --git a/client.py b/client.py
new file mode 100644
index 0000000..fd8223c
--- /dev/null
+++ b/client.py
@@ -0,0 +1,77 @@
+import os
+import sys
+import socket
+import secrets
+import tempfile
+import http.server
+import socketserver
+
+from threading import Thread
+from urllib.request import urlopen
+
+PORT = 4040
+BEAM_SERVER = '192.168.0.3:5005'
+
+
+d = tempfile.TemporaryDirectory()
+
+print("using tempdir " + d.name)
+
+def handler_for_dir(dir):
+    def myhandler(*args, **kwargs):
+        kwargs['directory'] = dir
+        return http.server.SimpleHTTPRequestHandler(*args, **kwargs)
+
+    return myhandler
+
+def get_request(url):
+    resp = urlopen(url)
+    return (200 <= resp.status <= 299, "\n".join([d.decode() for d in resp.readlines()]))
+
+# get ip address (sourced from https://stackoverflow.com/a/28950776/4141651)
+def get_ip():
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    try:
+        # doesn't even have to be reachable
+        s.connect(('10.255.255.255', 1))
+        IP = s.getsockname()[0]
+    except Exception:
+        IP = '127.0.0.1'
+    finally:
+        s.close()
+    return IP
+
+target = sys.argv[1]
+
+id = secrets.token_hex(16)
+
+# symlink target to tempdir so we only expose a single file
+os.symlink(os.path.abspath(target), d.name  + '/stream')
+
+handler = handler_for_dir(d.name + '/')
+token = None
+
+try:
+    with http.server.HTTPServer(("0.0.0.0", PORT), handler) as httpd:
+        try:
+            print("serving at port", PORT)
+            t = Thread(target=httpd.serve_forever)
+            t.start()
+            print("calling beam target...")
+            host = get_ip()
+            resp = get_request(f'http://{BEAM_SERVER}/open?host={host}&port={PORT}')
+            if resp[0]:
+                token = resp[1].strip()
+                print(f"successfully started video - session {token}")
+                input("Just press enter when you are done...")
+            else:
+                print("Error statrtig video!")
+        finally:
+            print("shutting down server")
+            httpd.shutdown()
+
+finally:
+    print("cleaning up")
+    if token:
+        get_request(f'http://{BEAM_SERVER}/stop/{token}')
+    d.cleanup()
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..52eb62c
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,11 @@
+with import <nixpkgs> {};
+
+stdenv.mkDerivation rec {
+  name = "beam-env";
+
+  buildInputs = [
+    (python3.withPackages (ps: with ps; [
+       flask
+    ]))
+  ];
+}
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..8ab6294
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+flask
\ No newline at end of file
diff --git a/server.py b/server.py
new file mode 100644
index 0000000..cc26e39
--- /dev/null
+++ b/server.py
@@ -0,0 +1,48 @@
+import secrets
+
+from time import sleep
+from flask import Flask, request
+from subprocess import Popen, STDOUT, PIPE
+
+SESSIONS = dict()
+
+app = Flask(__name__)
+
+@app.route('/open')
+def open_stream():
+    url = "http://" + request.args['host'] + ':' + request.args.get('port', '4040') + '/stream'
+    id = secrets.token_hex(16)
+    SESSIONS[id] = {
+        'url': url,
+        'id': id,
+        'proc': Popen(['vlc', url])
+    }
+    return id
+
+@app.route('/stop/<id>')
+def stream_stop(id):
+    if id in SESSIONS:
+        SESSIONS[id]['proc'].terminate()
+        return "true"
+    return "false"
+
+def cleanup_thread():
+    while True:
+        dead_sessions = []
+
+        for session in SESSIONS.values():
+            if session['proc'].poll() != None:
+                # thread has terminated
+                dead_sessions.append(session['id'])
+        
+        for id in dead_sessions:
+            url = SESSIONS[id]['url']
+            print(f"Removing dead session {id} for url {url}")
+            del SESSIONS[id]
+    
+        sleep(10)
+
+t = Thread(target=cleanup_thread)
+t.start()
+    
+app.run(host='0.0.0.0', port=5005)
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