[WIP] Add repo provider for MECA Bundles

binderhub/app.py

@@ -63,6 +63,7 @@
     GitLabRepoProvider,
     GitRepoProvider,
     HydroshareProvider,
+    MecaRepoProvider,
     RepoProvider,
     ZenodoProvider,
 )
@@ -586,6 +587,7 @@ def _default_build_namespace(self):
             "figshare": FigshareProvider,
             "hydroshare": HydroshareProvider,
             "dataverse": DataverseProvider,
+            "meca": MecaRepoProvider,
         },
         config=True,
         help="""

binderhub/event-schemas/launch.json

@@ -14,7 +14,8 @@
         "Zenodo",
         "Figshare",
         "Hydroshare",
-        "Dataverse"
+        "Dataverse",
+        "MECA"
       ],
       "description": "Provider for the repository being launched"
     },

binderhub/main.py

@@ -22,6 +22,7 @@
     "figshare": "Figshare",
     "hydroshare": "Hydroshare",
     "dataverse": "Dataverse",
+    "meca": "MECA",
 }
 
 

binderhub/repoproviders.py

@@ -15,9 +15,11 @@
 import time
 import urllib.parse
 from datetime import datetime, timedelta, timezone
-from urllib.parse import urlparse
+from hashlib import md5
+from urllib.parse import unquote, urlparse, urlunparse
 
 import escapism
+import validators as val
 from prometheus_client import Gauge
 from tornado.httpclient import AsyncHTTPClient, HTTPError, HTTPRequest
 from tornado.httputil import url_concat
@@ -263,6 +265,114 @@ def get_build_slug(self):
         return f"zenodo-{self.record_id}"
 
 
+class MecaRepoProvider(RepoProvider):
+    """BinderHub Provider that can handle the contents of a MECA bundle
+
+    Users must provide a spec consisting of a public URL to the bundle
+    The URL origin must be included in the list of allowed_origins when that trait is set
+    """
+
+    name = Unicode("MECA Bundle")
+
+    display_name = "MECA Bundle"
+
+    labels = {
+        "text": "MECA Bundle URL (https://journals.curvenote.com/journal/submissions/12345/meca.zip)",
+        "tag_text": "<no tag required>",
+        "ref_prop_disabled": True,
+        "label_prop_disabled": True,
+    }
+
+    validate_bundle = Bool(config=True, help="Validate the file as MECA Bundle").tag(
+        default=True
+    )
+
+    allowed_origins = List(
+        config=True,
+        help="""List of allowed origins for the URL
+
+        If set, the URL must be on one of these origins.
+
+        If not set, the URL can be on any origin.
+        """,
+    )
+
+    @default("allowed_origins")
+    def _allowed_origins_default(self):
+        return []
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        url = unquote(self.spec)
+
+        if not val.url(url):
+            raise ValueError(f"[MecaRepoProvider] Invalid URL {url}")
+
+        if (
+            len(self.allowed_origins) > 0
+            and urlparse(self.spec).hostname not in self.allowed_origins
+        ):
+            raise ValueError("URL is not on an allowed origin")
+
+        self.url = url
+
+        self.log.info(f"MECA Bundle URL: {self.url}")
+        self.log.info(f"MECA Bundle raw spec: {self.spec}")
+
+    def get_hashed_slug(self, url, changes_with_content):
+        """Return a unique slug that is invariant to query parameters in the url"""
+        parsed_url = urlparse(url)
+        stripped_url = urlunparse(
+            (parsed_url.scheme, parsed_url.netloc, parsed_url.path, "", "", "")
+        )
+        return (
+            "meca-" + md5(f"{stripped_url}-{changes_with_content}".encode()).hexdigest()
+        )
+
+    async def get_resolved_ref(self):
+        # Check the URL is reachable
+        client = AsyncHTTPClient()
+        req = HTTPRequest(self.url, method="HEAD", user_agent="BinderHub")
+        self.log.info(f"get_resolved_ref() HEAD: {self.url}")
+        try:
+            r = await client.fetch(req)
+            self.log.info(f"URL is reachable: {self.url}")
+            self.hashed_slug = self.get_hashed_slug(
+                self.url, r.headers.get("ETag") or r.headers.get("Content-Length")
+            )
+        except Exception as e:
+            raise RuntimeError(f"URL is unreachable ({e})")
+
+        self.log.info(f"hashed_slug: {self.hashed_slug}")
+        return self.hashed_slug
+
+    async def get_resolved_spec(self):
+        if not hasattr(self, "hashed_slug"):
+            await self.get_resolved_ref()
+        self.log.info(f"get_resolved_spec(): {self.hashed_slug}")
+        return self.spec
+
+    async def get_resolved_ref_url(self):
+        self.log.info(f"get_resolved_ref_url(): {self.url}")
+        return self.url
+
+    def get_repo_url(self):
+        """This is passed to repo2docker and is the URL that is to be fetched
+        with a `http[s]+meca` protocol string. We do this by convention to enable
+        detection of meca urls by the MecaContentProvider.
+        """
+        parsed = urlparse(self.url)
+        parsed = parsed._replace(scheme=f"{parsed.scheme}+meca")
+        url = urlunparse(parsed)
+        self.log.info(f"get_repo_url(): {url}")
+        return url
+
+    def get_build_slug(self):
+        """Should return a unique build slug"""
+        return self.hashed_slug
+
+
 class FigshareProvider(RepoProvider):
     """Provide contents of a Figshare article
 

binderhub/static/js/src/form.js

@@ -18,7 +18,7 @@ export function getBuildFormValues() {
     repo = repo.replace(/^(https?:\/\/)?github.com\//, "");
     repo = repo.replace(/^(https?:\/\/)?gitlab.com\//, "");
   }
-  // trim trailing or leading '/' on repo
+  // trim trailing or leading "/" on repo
   repo = repo.replace(/(^\/)|(\/?$)/g, "");
   // git providers encode the URL of the git repository as the repo
   // argument.
@@ -31,7 +31,8 @@ export function getBuildFormValues() {
     providerPrefix === "zenodo" ||
     providerPrefix === "figshare" ||
     providerPrefix === "dataverse" ||
-    providerPrefix === "hydroshare"
+    providerPrefix === "hydroshare" ||
+    providerPrefix === "meca"
   ) {
     ref = "";
   }

docs/source/reference/repoproviders.rst

@@ -65,6 +65,12 @@ Module: :mod:`binderhub.repoproviders`
 .. autoconfigurable:: DataverseProvider
     :members:
 
+:class:`MecaRepoProvider`
+---------------------------
+
+.. autoconfigurable:: MecaRepoProvider
+    :members:
+
 
 :class:`GitRepoProvider`
 ---------------------------

requirements.txt

@@ -9,3 +9,4 @@ pyjwt>=2
 python-json-logger
 tornado>=5.1
 traitlets
+validators