Don't use host-meta in connection tester anymore

This route was removed from the federation and doesn't exist anymore, so
checking for it doesn't make any sense.

But lets check if a server responds to /.well-known/nodeinfo instead.
All other software which supports the diaspora protocol should have this
endpoint by now. Parsing/validating nodeinfo is still handled
gracefully.

closes #8377

3 files changed, 22 insertions, 33 deletions

diff --git a/Changelog.md b/Changelog.md
index fd0fe3075..cf88f2a13 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -11,6 +11,7 @@
 * Upgrade to rails 6.1 [#8366](https://github.com/diaspora/diaspora/pull/8366)
 * Update the suggested Ruby version to 2.7. If you run into trouble during the update and you followed our installation guides, run `rvm install 2.7`. [#8366](https://github.com/diaspora/diaspora/pull/8366)
 * Upgrade to bundler 2 [#8366](https://github.com/diaspora/diaspora/pull/8366)
+* Stop checking `/.well-known/host-meta`, check for `/.well-known/nodeinfo` instead [#8377](https://github.com/diaspora/diaspora/pull/8377)
 
 ## Bug fixes
 * Fix that no mails were sent after photo export [#8365](https://github.com/diaspora/diaspora/pull/8365)
diff --git a/lib/connection_tester.rb b/lib/connection_tester.rb
index 5bc58d75b..0e38f10d9 100644
--- a/lib/connection_tester.rb
+++ b/lib/connection_tester.rb
@@ -1,4 +1,3 @@
-
 # frozen_string_literal: true
 
 class ConnectionTester
@@ -97,16 +96,13 @@ class ConnectionTester
   # * is the SSL certificate valid (only on HTTPS)
   # * does the server return a successful HTTP status code
   # * is there a reasonable amount of redirects (3 by default)
-  # * is there a /.well-known/host-meta (this is needed to work, this can be replaced with a mandatory NodeInfo later)
   # (can't do a HEAD request, since that's not a defined route in the app)
   #
   # @raise [NetFailure, SSLFailure, HTTPFailure] if any of the checks fail
   # @return [Integer] HTTP status code
   def request
     with_http_connection do |http|
-      capture_response_time { http.get("/") }
-      response = http.get("/.well-known/host-meta")
-      handle_http_response(response)
+      capture_response_time { handle_http_response(http.get("/")) }
     end
   rescue HTTPFailure => e
     raise e
@@ -114,8 +110,8 @@ class ConnectionTester
     raise NetFailure, e.message
   rescue Faraday::SSLError => e
     raise SSLFailure, e.message
-  rescue ArgumentError, FaradayMiddleware::RedirectLimitReached, Faraday::ClientError => e
-    raise HTTPFailure, e.message
+  rescue ArgumentError, Faraday::ClientError => e
+    raise HTTPFailure, "#{e.class}: #{e.message}"
   rescue StandardError => e
     unexpected_error(e)
   end
@@ -123,19 +119,21 @@ class ConnectionTester
   # Try to find out the version of the other servers software.
   # Assuming the server speaks nodeinfo
   #
-  # @raise [NodeInfoFailure] if the document can't be fetched
-  #   or the attempt to parse it failed
+  # @raise [HTTPFailure] if the document can't be fetched
+  # @raise [NodeInfoFailure] if the document can't be parsed or is invalid
   def nodeinfo
     with_http_connection do |http|
       ni_resp = http.get(NODEINFO_FRAGMENT)
       nd_resp = http.get(find_nodeinfo_url(ni_resp.body))
       find_software_version(nd_resp.body)
     end
+  rescue Faraday::ClientError => e
+    raise HTTPFailure, "#{e.class}: #{e.message}"
   rescue NodeInfoFailure => e
     raise e
   rescue JSON::Schema::ValidationError, JSON::Schema::SchemaError => e
     raise NodeInfoFailure, "#{e.class}: #{e.message}"
-  rescue Faraday::ResourceNotFound, JSON::JSONError => e
+  rescue JSON::JSONError => e
     raise NodeInfoFailure, e.message[0..255].encode(Encoding.default_external, undef: :replace)
   rescue StandardError => e
     unexpected_error(e)
@@ -175,14 +173,11 @@ class ConnectionTester
   def handle_http_response(response)
     @result.status_code = Integer(response.status)
 
-    if response.success?
-      raise HTTPFailure, "redirected to other hostname: #{response.env.url}" unless @uri.host == response.env.url.host
+    raise HTTPFailure, "unsuccessful response code: #{response.status}" unless response.success?
+    raise HTTPFailure, "redirected to other hostname: #{response.env.url}" unless @uri.host == response.env.url.host
 
-      @result.reachable = true
-      @result.ssl = (response.env.url.scheme == "https")
-    else
-      raise HTTPFailure, "unsuccessful response code: #{response.status}"
-    end
+    @result.reachable = true
+    @result.ssl = (response.env.url.scheme == "https")
   end
 
   # walk the JSON document, get the actual document location
diff --git a/spec/lib/connection_tester_spec.rb b/spec/lib/connection_tester_spec.rb
index 01acd20f4..7a11cc0a3 100644
--- a/spec/lib/connection_tester_spec.rb
+++ b/spec/lib/connection_tester_spec.rb
@@ -47,9 +47,8 @@ describe ConnectionTester do
   end
 
   describe "#request" do
-    it "performs a successful GET request on '/' and '/.well-known/host-meta'" do
+    it "performs a successful GET request on '/'" do
       stub_request(:get, url).to_return(status: 200, body: "Hello World!")
-      stub_request(:get, "#{url}/.well-known/host-meta").to_return(status: 200, body: "host-meta")
 
       tester.request
       expect(result.rt).to be > -1
@@ -60,27 +59,22 @@ describe ConnectionTester do
     it "receives a 'normal' 301 redirect" do
       stub_request(:get, url).to_return(status: 301, headers: {"Location" => "#{url}/redirect"})
       stub_request(:get, "#{url}/redirect").to_return(status: 200, body: "Hello World!")
-      stub_request(:get, "#{url}/.well-known/host-meta").to_return(status: 200, body: "host-meta")
 
       tester.request
     end
 
     it "updates ssl after https redirect" do
       tester = ConnectionTester.new("http://pod.example.com/", result)
-      stub_request(:get, "http://pod.example.com/").to_return(status: 200, body: "Hello World!")
-      stub_request(:get, "http://pod.example.com/.well-known/host-meta")
-        .to_return(status: 301, headers: {"Location" => "#{url}/.well-known/host-meta"})
-      stub_request(:get, "#{url}/.well-known/host-meta").to_return(status: 200, body: "host-meta")
+      stub_request(:get, "http://pod.example.com/").to_return(status: 301, headers: {"Location" => url})
+      stub_request(:get, url).to_return(status: 200, body: "Hello World!")
 
       tester.request
       expect(result.ssl).to be_truthy
     end
 
-    it "rejects other hostname after redirect redirect" do
-      stub_request(:get, url).to_return(status: 200, body: "Hello World!")
-      stub_request(:get, "#{url}/.well-known/host-meta")
-        .to_return(status: 301, headers: {"Location" => "https://example.com/.well-known/host-meta"})
-      stub_request(:get, "https://example.com/.well-known/host-meta").to_return(status: 200, body: "host-meta")
+    it "rejects other hostname after redirect" do
+      stub_request(:get, url).to_return(status: 301, headers: {"Location" => "https://example.com/"})
+      stub_request(:get, "https://example.com/").to_return(status: 200, body: "Hello World!")
 
       expect { tester.request }.to raise_error(ConnectionTester::HTTPFailure)
     end
@@ -131,10 +125,9 @@ describe ConnectionTester do
       expect(result.software_version).to eq("diaspora a.b.c.d")
     end
 
-    it "handles a missing nodeinfo document gracefully" do
-      stub_request(:get, "#{url}#{ConnectionTester::NODEINFO_FRAGMENT}")
-        .to_return(status: 404, body: "Not Found")
-      expect { tester.nodeinfo }.to raise_error(ConnectionTester::NodeInfoFailure)
+    it "fails the nodeinfo document is missing" do
+      stub_request(:get, "#{url}#{ConnectionTester::NODEINFO_FRAGMENT}").to_return(status: 404, body: "Not Found")
+      expect { tester.nodeinfo }.to raise_error(ConnectionTester::HTTPFailure)
     end
 
     it "handles a malformed document gracefully" do