-- Fetches Atom feeds and publishes to PubSub nodes -- -- Depends: http://code.matthewwild.co.uk/lua-feeds -- -- Config: -- Component "pubsub.example.com" "pubsub" -- modules_enabled = { -- "pubsub_feeds"; -- } -- feeds = { -- node -> url -- prosody_blog = "http://blog.prosody.im/feed/atom.xml"; -- } -- feed_pull_interval = 20 -- minutes -- -- Reference -- http://pubsubhubbub.googlecode.com/svn/trunk/pubsubhubbub-core-0.3.html local pubsub = module:depends"pubsub"; local date, time = os.date, os.time; local dt_parse, dt_datetime = require "util.datetime".parse, require "util.datetime".datetime; local uuid = require "util.uuid".generate; local hmac_sha1 = require "util.hmac".sha1; local parse_feed = require "feeds".feed_from_string; local st = require "util.stanza"; --local dump = require"util.serialization".serialize; local xmlns_atom = "http://www.w3.org/2005/Atom"; local use_pubsubhubub = module:get_option_boolean("use_pubsubhubub", true); if use_pubsubhubub then module:depends"http"; end local http = require "net.http"; local formdecode = http.formdecode; local formencode = http.formencode; local urldecode = http.urldecode; local urlencode = http.urlencode; local feed_list = module:shared("feed_list"); local refresh_interval; function module.load() local config = module:get_option("feeds") or { planet_jabber = "http://planet.jabber.org/atom.xml"; prosody_blog = "http://blog.prosody.im/feed/atom.xml"; }; refresh_interval = module:get_option_number("feed_pull_interval", 15) * 60; local new_feed_list = {}; for node, url in pairs(config) do if type(node) == "number" then node = url; end new_feed_list[node] = true; if not feed_list[node] then feed_list[node] = { url = url; node = node; last_update = 0 }; else feed_list[node].url = url; end end for node in pairs(feed_list) do if not new_feed_list[node] then feed_list[node] = nil; end end end function update_entry(item) local node = item.node; module:log("debug", "parsing %d bytes of data in node %s", #item.data or 0, node) local feed = parse_feed(item.data); for _, entry in ipairs(feed) do entry.attr.xmlns = xmlns_atom; local e_published = entry:get_child_text("published"); e_published = e_published and dt_parse(e_published); local e_updated = entry:get_child_text("updated"); e_updated = e_updated and dt_parse(e_updated); local timestamp = e_updated or e_published or nil; --module:log("debug", "timestamp is %s, item.last_update is %s", tostring(timestamp), tostring(item.last_update)); if not timestamp or not item.last_update or timestamp > item.last_update then local id = entry:get_child_text("id"); id = id or item.url.."#"..dt_datetime(timestamp); -- Missing id, so make one up local xitem = st.stanza("item", { id = id }):add_child(entry); -- TODO Put data from /feed into item/source --module:log("debug", "publishing to %s, id %s", node, id); local ok, err = pubsub.service:publish(node, true, id, xitem); if not ok then if err == "item-not-found" then -- try again --module:log("debug", "got item-not-found, creating %s and trying again", node); local ok, err = pubsub.service:create(node, true); if not ok then module:log("error", "could not create node %s: %s", node, err); return; end local ok, err = pubsub.service:publish(node, true, id, xitem); if not ok then module:log("error", "could not create or publish node %s: %s", node, err); return end else module:log("error", "publishing %s failed: %s", node, err); end end end end if use_pubsubhubub and not item.subscription then --module:log("debug", "check if %s has a hub", item.node); local hub = feed.links and feed.links.hub; if hub then item.hub = hub; module:log("debug", "%s has a hub: %s", item.node, item.hub); subscribe(item); end end end function fetch(item, callback) -- HTTP Pull local headers = { }; if item.data and item.last_update then headers["If-Modified-Since"] = date("!%a, %d %b %Y %H:%M:%S %Z", item.last_update); end http.request(item.url, { headers = headers }, function(data, code, req) if code == 200 then item.data = data; if callback then callback(item) end item.last_update = time(); elseif code == 304 then item.last_update = time(); end end); end function refresh_feeds(force) local now = time(); --module:log("debug", "Refreshing feeds"); for node, item in pairs(feed_list) do --FIXME Don't fetch feeds which have a subscription -- Otoho, what if the subscription expires or breaks? if force or item.last_update + refresh_interval < now then --module:log("debug", "checking %s", item.node); fetch(item, update_entry); end end return refresh_interval; end local function format_url(node) return module:http_url(nil, "/callback") .. "?node=" .. urlencode(node); end function subscribe(feed, want) want = want or "subscribe"; feed.token = uuid(); feed.secret = feed.secret or uuid(); local body = formencode{ ["hub.callback"] = format_url(feed.node); ["hub.mode"] = want; ["hub.topic"] = feed.url; ["hub.verify"] = "async"; ["hub.verify_token"] = feed.token; ["hub.secret"] = feed.secret; --["hub.lease_seconds"] = ""; }; --module:log("debug", "subscription request, body: %s", body); --FIXME The subscription states and related stuff feed.subscription = want; http.request(feed.hub, { body = body }, function(data, code, req) module:log("debug", "subscription to %s submitted, status %s", feed.node, tostring(code)); if code >= 400 then module:log("error", "There was something wrong with our subscription request, body: %s", tostring(data)); feed.subscription = "failed"; end end); end function handle_http_request(event) local request = event.request; local method = request.method; local body = request.body; --module:log("debug", "%s request to %s%s with body %s", method, request.url.path, request.url.query and "?" .. request.url.query or "", #body > 0 and body or "empty"); local query = request.url.query or {}; --FIXME if query and type(query) == "string" then query = formdecode(query); --module:log("debug", "GET data: %s", dump(query)); end --module:log("debug", "Headers: %s", dump(request.headers)); local feed = feed_list[query.node]; if not feed then return 404; end if method == "GET" then if query.node then if query["hub.topic"] ~= feed.url then module:log("debug", "Invalid topic: %s", tostring(query["hub.topic"])) return 404 end if query["hub.mode"] ~= feed.subscription then module:log("debug", "Invalid mode: %s", tostring(query["hub.mode"])) return 400 -- Would this work for unsubscribe? -- Also, if feed.subscription is changed here, -- it would probably invalidate the subscription -- when/if the hub asks if it should be renewed end if query["hub.verify_token"] ~= feed.token then module:log("debug", "Invalid verify_token: %s", tostring(query["hub.verify_token"])) return 401; end module:log("debug", "Confirming %s request to %s", feed.subscription, feed.url) return query["hub.challenge"]; end return 400; elseif method == "POST" then if #body > 0 then module:log("debug", "got %d bytes PuSHed for %s", #body, query.node); local signature = request.headers.x_hub_signature; if feed.secret then local localsig = "sha1=" .. hmac_sha1(feed.secret, body, true); if localsig ~= signature then module:log("debug", "Invalid signature, got %s but wanted %s", tostring(signature), tostring(localsig)); return 401; end module:log("debug", "Valid signature"); end feed.data = body; update_entry(feed); feed.last_update = time(); return 202; end return 400; end return 501; end if use_pubsubhubub then module:provides("http", { default_path = "/callback"; route = { GET = handle_http_request; POST = handle_http_request; -- This all? }; }); end module:add_timer(1, refresh_feeds);