mps: torrent web seed + torrent_file_url for CDN-bootstrapped swarm

- embed CDN URL as BEP 19 web seed in .torrent + magnet link
- store torrent_file_url (CDN path to .torrent) on Product
- migration adds torrent_file_url column alongside magnet_link
- content page shows Magnet + .torrent download buttons
- product edit shows Copy Magnet + Open + .torrent download
- cdn_endpoint flows from request.shop_cdn_endpoint through async thread

make_post_sell/lib/torrent.py

@@ -51,7 +51,7 @@ def _make_client(creds):
     )
 
 
-def _build_torrent(file_path, name, trackers):
+def _build_torrent(file_path, name, trackers, webseeds=None):
     """Create a torf.Torrent from a local file and return (torrent, magnet_uri)."""
     try:
         import torf
@@ -64,6 +64,7 @@ def _build_torrent(file_path, name, trackers):
         path=file_path,
         name=name,
         trackers=[[tr] for tr in trackers],
+        webseeds=webseeds or [],
         private=False,
         comment="permacomputer.com — CWE-407 patched OS image",
         source="permacomputer",
@@ -74,17 +75,24 @@ def _build_torrent(file_path, name, trackers):
 
 
 def generate_torrent(s3_client, bucket, s3_key, s3_path, product_id,
-                     session_factory, trackers=None):
-    """Download file from S3, generate .torrent, upload, save magnet link.
+                     session_factory, trackers=None, cdn_endpoint=None):
+    """Download file from S3, generate .torrent, upload, save magnet + torrent URL.
 
     Designed to run in a background thread — never call directly from a request.
+    cdn_endpoint: base CDN URL (e.g. "https://cdn.example.com") — embedded as web seed
+                  so clients can download via HTTP and then seed to peers (BEP 19).
     """
     if trackers is None:
         trackers = DEFAULT_TRACKERS
 
     name = os.path.basename(s3_key)
 
-    log.info("torrent: generating for product=%s key=%s", product_id, s3_key)
+    # Web seed URL: CDN serves the product file directly (BEP 19)
+    webseed_url = f"{cdn_endpoint}/{s3_key}" if cdn_endpoint else None
+    webseeds = [webseed_url] if webseed_url else []
+
+    log.info("torrent: generating for product=%s key=%s webseed=%s",
+             product_id, s3_key, webseed_url)
 
     with tempfile.TemporaryDirectory() as tmpdir:
         local_path = os.path.join(tmpdir, name)
@@ -96,7 +104,7 @@ def generate_torrent(s3_client, bucket, s3_key, s3_path, product_id,
 
         # 2. Build .torrent + extract magnet link
         log.info("torrent: building torrent for %s", local_path)
-        torrent_obj, magnet_uri = _build_torrent(local_path, name, trackers)
+        torrent_obj, magnet_uri = _build_torrent(local_path, name, trackers, webseeds=webseeds)
 
         # 3. Write .torrent file
         torrent_obj.write(torrent_path)
@@ -117,22 +125,28 @@ def generate_torrent(s3_client, bucket, s3_key, s3_path, product_id,
         )
         log.info("torrent: uploaded .torrent to s3://%s/%s", bucket, torrent_s3_key)
 
-    # 5. Save magnet link to DB
+    # CDN URL of the .torrent file itself
+    torrent_file_url = (
+        f"{cdn_endpoint}/{torrent_s3_key}" if cdn_endpoint else None
+    )
+
+    # 5. Save magnet link + torrent file URL to DB
     try:
         with session_factory() as session:
             from ..models.product import Product
             product = session.get(Product, product_id)
             if product is not None:
                 product.torrent_magnet_link = magnet_uri
+                product.torrent_file_url = torrent_file_url
                 session.add(product)
                 session.commit()
-                log.info("torrent: saved magnet link for product=%s", product_id)
+                log.info("torrent: saved magnet + torrent_file_url for product=%s", product_id)
     except Exception:
-        log.exception("torrent: failed to save magnet link for product=%s", product_id)
+        log.exception("torrent: failed to save torrent data for product=%s", product_id)
 
 
 def generate_torrent_async(s3_client, bucket, s3_key, s3_path, product_id,
-                           session_factory, trackers=None):
+                           session_factory, trackers=None, cdn_endpoint=None):
     """Fire-and-forget: generate torrent in a daemon thread."""
     creds = _capture_s3_creds(s3_client)
 
@@ -141,7 +155,7 @@ def generate_torrent_async(s3_client, bucket, s3_key, s3_path, product_id,
             fresh_client = _make_client(creds)
             generate_torrent(
                 fresh_client, bucket, s3_key, s3_path, product_id,
-                session_factory, trackers=trackers,
+                session_factory, trackers=trackers, cdn_endpoint=cdn_endpoint,
             )
         except Exception:
             log.exception(

make_post_sell/models/product.py

@@ -112,6 +112,9 @@ class Product(RBase, Base):
     # Optional magnet link for BitTorrent distribution (set when shop.torrent_enabled)
     torrent_magnet_link = Column(UnicodeText, nullable=True)
 
+    # CDN URL of the .torrent file (set alongside torrent_magnet_link)
+    torrent_file_url = Column(UnicodeText, nullable=True)
+
     # a denormalized json field to relate products to bundles, and vice versa.
     json_bundle_metadata = Column(
         UnicodeText, default=DEFAULT_BUNDLE_METADATA, nullable=False

make_post_sell/scripts/alembic/versions/a1b2c3d4e5f6_torrent_magnet_links.py

@@ -26,8 +26,13 @@ def upgrade():
         "mps_product",
         sa.Column("torrent_magnet_link", sa.UnicodeText(), nullable=True),
     )
+    op.add_column(
+        "mps_product",
+        sa.Column("torrent_file_url", sa.UnicodeText(), nullable=True),
+    )
 
 
 def downgrade():
     op.drop_column("mps_shop", "torrent_enabled")
     op.drop_column("mps_product", "torrent_magnet_link")
+    op.drop_column("mps_product", "torrent_file_url")

make_post_sell/templates/content.j2

@@ -157,7 +157,10 @@
         <a href="{{ signed_get_object_url }}" class="product-download-button mps-button" target="_blank" download>&#11123 Download</a>
       {% endif %}
       {% if torrent_magnet_link %}
-        <a href="{{ torrent_magnet_link }}" class="mps-button" style="margin-left:.5rem">&#9697; Torrent</a>
+        <a href="{{ torrent_magnet_link }}" class="mps-button" style="margin-left:.5rem">&#9697; Magnet</a>
+      {% endif %}
+      {% if torrent_file_url %}
+        <a href="{{ torrent_file_url }}" class="mps-button" style="margin-left:.5rem" download>&#8615; .torrent</a>
       {% endif %}
     </div>
     {% endif %}

make_post_sell/templates/product_edit.j2

@@ -289,24 +289,27 @@ Your cover (<code>thumbnail1</code>) will show up on search pages.
     <br />
 
     {% if torrent_enabled %}
-    <label>Magnet Link
+    <label>Torrent Distribution
       <span style="font-weight:normal;color:#888">
         — generated automatically when you upload the product file
       </span>
     </label>
     {% if torrent_magnet_link %}
-      <div style="display:flex;gap:.5rem;align-items:center">
+      <div style="display:flex;gap:.5rem;align-items:center;flex-wrap:wrap">
         <input type="text" id="torrent_magnet_link_display"
                value="{{ torrent_magnet_link }}" readonly
-               class="mps-text-input" style="flex:1;color:#888" />
+               class="mps-text-input" style="flex:1;min-width:0;color:#888" />
         <button type="button"
                 onclick="navigator.clipboard.writeText(document.getElementById('torrent_magnet_link_display').value)"
-                class="mps-button" style="white-space:nowrap">Copy</button>
+                class="mps-button" style="white-space:nowrap">Copy Magnet</button>
         <a href="{{ torrent_magnet_link }}" class="mps-button" style="white-space:nowrap">&#9697; Open</a>
+        {% if torrent_file_url %}
+        <a href="{{ torrent_file_url }}" class="mps-button" style="white-space:nowrap" download>&#8615; .torrent</a>
+        {% endif %}
       </div>
     {% else %}
       <p style="color:#888;margin:.25rem 0">
-        Upload the product file to generate the magnet link automatically.
+        Upload the product file to generate the magnet link and .torrent automatically.
       </p>
     {% endif %}
 

make_post_sell/views/content.py

@@ -111,4 +111,5 @@ def content(request):
         "vocals_url": vocals_url,
         "karaoke_eligible": karaoke_eligible,
         "torrent_magnet_link": product.torrent_magnet_link if product.shop.torrent_enabled else None,
+        "torrent_file_url": product.torrent_file_url if product.shop.torrent_enabled else None,
     }

make_post_sell/views/product.py

@@ -391,6 +391,7 @@ def product_edit(request):
                 product.s3_path,
                 product.id,
                 request.registry["dbsession_factory"],
+                cdn_endpoint=request.shop_cdn_endpoint,
             )
 
         # Generate vocal isolation tracks if this is audio/video
@@ -527,6 +528,7 @@ def product_edit(request):
         "price_history": price_history,
         "torrent_enabled": product.shop.torrent_enabled,
         "torrent_magnet_link": product.torrent_magnet_link or "",
+        "torrent_file_url": product.torrent_file_url or "",
     }