dashboard: own links over the API, and CORS

GET /admin/dashboard/links/own and its event stream: a node's own links,
as LINKS_REPLY carried them, for other members' dashboards with a
token. CORS for the members' dashboard origins and --cors-origins,
without credentials.

Auth plan M3.

3 files changed, 47 insertions, 0 deletions

diff --git a/docs/access.md b/docs/access.md
index e8c5455..71aebea 100644
--- a/docs/access.md
+++ b/docs/access.md
@@ -105,6 +105,12 @@ curl -H "Authorization: Bearer ct1.…" http://other-node:3000/store
 
 `GET /auth/whoami` says who a request's user is, how it proved it, and what it may do.
 
+Pages of other origins, the dashboards of other members, may call a node with a token:
+its own links (`/admin/dashboard/links/own`, and its events), `/auth/refresh` and
+`/auth/whoami`, nothing else. A node allows the origins of the dashboards its member
+list names (`--dashboard-url`) and those of `--cors-origins`; without credentials (no
+cookie or password crosses origins: the page sends its token).
+
 ## Managing users
 
 Through `/admin/users` ([`openapi.yaml`](openapi.yaml), Users): looking needs `read` on
diff --git a/docs/example.toml b/docs/example.toml
index ab8237c..222db52 100644
--- a/docs/example.toml
+++ b/docs/example.toml
@@ -78,6 +78,12 @@ htpasswd = "/etc/continuum/htpasswd"
 # the login's end (session-lifetime).
 # token-lifetime = "12h"
 
+# Origins (scheme://host[:port]) whose pages may read this node's own links and refresh
+# tokens here, with a token (docs/access.md, Tokens): the dashboards of other members are
+# allowed anyway, as the member list names them (dashboard-url). Without credentials: a
+# page sends its token itself.
+# cors-origins = ["https://dashboard.example.org"]
+
 # How long after a login (POST /auth/login) its tokens may be refreshed; then the user
 # logs in again.
 # session-lifetime = "7d"
diff --git a/docs/openapi.yaml b/docs/openapi.yaml
index 64c5b9b..f8fb25d 100644
--- a/docs/openapi.yaml
+++ b/docs/openapi.yaml
@@ -1015,6 +1015,41 @@ paths:
                 type: object
                 required: [node, stats, peers, graph]
                 additionalProperties: true
+  /admin/dashboard/links/own:
+    get:
+      tags: [Admin]
+      summary: This node's own links
+      description: |
+        As it measures them: its ID, its epoch, and each link (what the map draws).
+        Readable by pages of other members' dashboards, with a token (CORS: docs/access.md, Tokens).
+      responses:
+        '200':
+          description: The links.
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  node: { type: string }
+                  epoch: { type: object }
+                  links: { type: array, items: { type: object } }
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+
+  /admin/dashboard/links/own/events:
+    get:
+      tags: [Admin]
+      summary: This node's own links, as they change
+      description: Server-sent events, `links` with what `/admin/dashboard/links/own` answers at once and whenever it changed, `offline` when the node stops. Readable by pages of other members' dashboards, as that is.
+      responses:
+        '200':
+          description: The events.
+          content:
+            text/event-stream:
+              schema: { type: string }
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+
   /admin/dashboard/refresh:
     post:
       tags: [Admin]