diff options
authorLoïc Hoguin <[email protected]>2017-12-11 11:00:47 +0100
committerLoïc Hoguin <[email protected]>2017-12-11 11:00:47 +0100
commit4c22bdbcb75ecc8176e0f42899ed8c03729cc628 (patch)
parent17719a136dbe520436ae4aa5dd4827a19b1a5348 (diff)
Document 2.2 changes and the new stream_trailers function
7 files changed, 208 insertions, 5 deletions
diff --git a/doc/src/guide/book.asciidoc b/doc/src/guide/book.asciidoc
index e614c3b..335cdb1 100644
--- a/doc/src/guide/book.asciidoc
+++ b/doc/src/guide/book.asciidoc
@@ -73,6 +73,8 @@ include::middlewares.asciidoc[Middlewares]
= Additional information
+include::migrating_from_2.1.asciidoc[Migrating from Cowboy 2.1 to 2.2]
include::migrating_from_2.0.asciidoc[Migrating from Cowboy 2.0 to 2.1]
include::migrating_from_1.0.asciidoc[Migrating from Cowboy 1.0 to 2.0]
diff --git a/doc/src/guide/migrating_from_2.1.asciidoc b/doc/src/guide/migrating_from_2.1.asciidoc
new file mode 100644
index 0000000..3c0681f
--- /dev/null
+++ b/doc/src/guide/migrating_from_2.1.asciidoc
@@ -0,0 +1,107 @@
+== Migrating from Cowboy 2.1 to 2.2
+Cowboy 2.2 focused on adding features required for writing
+gRPC servers and on completing test suites for the core
+HTTP RFCs, fixing many bugs along the way.
+=== Features added
+* Add support for sending trailers at the end of response bodies.
+ Trailers are additional header fields that may be sent after the
+ body to add more information to the response. Their usage is
+ required in gRPC servers. They are optional and may be discarded
+ in other scenarios (for example if the request goes through an
+ HTTP/1.0 proxy, as HTTP/1.0 does not support trailers).
+* The `max_skip_body_length` option was added to `cowboy_http`.
+ It controls how much of a request body Cowboy is willing to skip
+ when the handler did not touch it. If the remaining body size is
+ too large Cowboy instead closes the connection. It defaults to 1MB.
+* The CONNECT and TRACE methods are now rejected as they are
+ currently not implemented and must be handled differently than
+ other methods. They will be implemented in a future release.
+=== New functions
+* The function `stream_trailers/2` has been added. It terminates
+ a stream and adds trailer fields at the end of the response. A
+ corresponding stream handler command `{trailers, Trailers}`
+ has also been added.
+=== Bugs fixed
+* Test suites for the core HTTP RFCs RFC7230, RFC7231 and RFC7540
+ have been completed. Many of the bugs listed here were fixed as
+ a result of this work.
+* Many HTTP/2 edge cases when clients are misbehaving have been
+ corrected. This includes many cases where the request is malformed
+ (for example when a pseudo-header is present twice).
+* When the HTTP/2 SETTINGS_INITIAL_WINDOW_SIZE value changes,
+ Cowboy now properly updates the flow control windows.
+* HTTP/2 could mistakenly log stray messages that actually were
+ expected. This is no longer the case.
+* We no longer send a GOAWAY frame when the HTTP/2 preface is invalid.
+* Some values in the Req object of pushed requests were in the
+ wrong type. They are now the expected binary instead of iolist.
+* A response body was sometimes sent in response to HEAD requests
+ when using HTTP/2. The body is now ignored.
+* The `max_headers` option for `cowboy_http` was not always respected
+ depending on the contents of the buffer. The limit is now strict.
+* When an early error occurred on the HTTP/1.1 request line, the
+ partial Req given to stream handlers was missing the `ref` and
+ `peer` information. This has been corrected.
+* Absolute URIs with a userinfo component, or without an authority
+ component, are now properly rejected for HTTP/1.0 and HTTP/1.1.
+* Whitespace is no longer allowed in header lines before the colon.
+* 408 responses to HTTP/1.1 requests now properly include a
+ connection: close header indicating that we are going to
+ close the connection. This header will also be sent for
+ other early errors resulting in the closing of the connection.
+* When both the transfer-encoding and content-length headers are
+ sent in an HTTP/1.1 request, the transfer-encoding now takes
+ precedence over the content-length header and the latter is
+ removed from the Req object.
+* A 400 response is now returned when the transfer-encoding
+ header is invalid or contains any transfer-coding other
+ than chunked.
+* Invalid chunk sizes are now rejected immediately.
+* Chunk extensions are now limited to 129 characters. They are
+ not used in practice and are still ignored by Cowboy. The limit
+ is not configurable.
+* The final chunk was mistakenly sent in responses to HEAD
+ requests. This is now corrected.
+* `OPTIONS *` requests were broken in Cowboy 2.0. They are now
+ working again. Both the routing and `cowboy_req:uri/1,2` have
+ been corrected.
+* 204 responses no longer include a content-length header.
+* A packet could be lost when switching to Websocket or any
+ other protocol via the `switch_protocol` command. This is
+ now fixed.
+* A 426 response will now be sent when a handler requires
+ the client to upgrade to Websocket and the request did not
+ include the required headers.
+* Both experimental stream handlers `cowboy_metrics_h` and
+ `cowboy_tracer_h` received a number of fixes and improvements.
diff --git a/doc/src/manual/cowboy_req.asciidoc b/doc/src/manual/cowboy_req.asciidoc
index b2875bc..9378d2e 100644
--- a/doc/src/manual/cowboy_req.asciidoc
+++ b/doc/src/manual/cowboy_req.asciidoc
@@ -84,6 +84,7 @@ Response:
* link:man:cowboy_req:reply(3)[cowboy_req:reply(3)] - Send the response
* link:man:cowboy_req:stream_reply(3)[cowboy_req:stream_reply(3)] - Send the response headers
* link:man:cowboy_req:stream_body(3)[cowboy_req:stream_body(3)] - Stream the response body
+* link:man:cowboy_req:stream_trailers(3)[cowboy_req:stream_trailers(3)] - Send the response trailers
* link:man:cowboy_req:push(3)[cowboy_req:push(3)] - Push a resource to the client
== Types
diff --git a/doc/src/manual/cowboy_req.stream_body.asciidoc b/doc/src/manual/cowboy_req.stream_body.asciidoc
index e0dbd59..17ba96f 100644
--- a/doc/src/manual/cowboy_req.stream_body.asciidoc
+++ b/doc/src/manual/cowboy_req.stream_body.asciidoc
@@ -24,7 +24,9 @@ function.
The second argument indicates if this call is the final
call. Use the `nofin` value until you know no more data
will be sent. The final call should use `fin` (possibly
-with an empty data value).
+with an empty data value) or be a call to the
Note that not using `fin` for the final call is not an
error; Cowboy will take care of it when the request
@@ -74,4 +76,5 @@ cowboy_req:stream_body(<<"World!\n">>, fin, Req).
== See also
diff --git a/doc/src/manual/cowboy_req.stream_reply.asciidoc b/doc/src/manual/cowboy_req.stream_reply.asciidoc
index 19d46ca..a00dbb0 100644
--- a/doc/src/manual/cowboy_req.stream_reply.asciidoc
+++ b/doc/src/manual/cowboy_req.stream_reply.asciidoc
@@ -34,7 +34,9 @@ If a response body was set before calling this function,
it will not be sent.
Use link:man:cowboy_req:stream_body(3)[cowboy_req:stream_body(3)]
-to stream the response body.
+to stream the response body and optionally
+to send response trailer field values.
You may want to set the content-length header when using
this function, if it is known in advance. This will allow
@@ -106,4 +108,5 @@ link:man:cowboy_req:set_resp_headers(3)[cowboy_req:set_resp_headers(3)],
diff --git a/doc/src/manual/cowboy_req.stream_trailers.asciidoc b/doc/src/manual/cowboy_req.stream_trailers.asciidoc
new file mode 100644
index 0000000..df74c3c
--- /dev/null
+++ b/doc/src/manual/cowboy_req.stream_trailers.asciidoc
@@ -0,0 +1,70 @@
+= cowboy_req:stream_trailers(3)
+== Name
+cowboy_req:stream_trailers - Send the response trailers
+== Description
+stream_trailers(Trailers, Req :: cowboy_req:req()) -> ok
+Trailers :: cowboy:http_headers()
+Send the response trailers and terminate the stream.
+This function can only be called once, after initiating
+a response using
+and sending zero or more body chunks using
+with the `nofin` argument set. The function `stream_trailers/2`
+implies `fin` and automatically terminate the response.
+You must list all field names sent in trailers in the
+trailer header, otherwise they might be dropped by intermediaries
+or clients.
+== Arguments
+Trailer field values to be sent.
+The Req object.
+== Return value
+The atom `ok` is always returned. It can be safely ignored.
+== Changelog
+* *2.2*: Function introduced.
+== Examples
+.Stream a response body with trailers
+Req = cowboy_req:stream_reply(200, #{
+ <<"content-type">> => <<"text/plain">>,
+ <<"trailer">> => <<"expires, content-md5">>
+}, Req0),
+cowboy_req:stream_body(<<"Hello\n">>, nofin, Req),
+cowboy_req:stream_body(<<"World!\n">>, nofin, Req).
+ <<"expires">> => <<"Sun, 10 Dec 2017 19:13:47 GMT">>,
+ <<"content-md5">> => <<"fbf68a8e34b2ded53bba54e68794b4fe">>
+}, Req).
+== See also
diff --git a/doc/src/manual/cowboy_stream.asciidoc b/doc/src/manual/cowboy_stream.asciidoc
index a26d420..103b97e 100644
--- a/doc/src/manual/cowboy_stream.asciidoc
+++ b/doc/src/manual/cowboy_stream.asciidoc
@@ -114,8 +114,8 @@ Initiate a response to the client.
This initiates a response to the client. The stream
-will end when a data command with the `fin` flag is
+will end when a data command with the `fin` flag or
+a trailer command is returned.
=== data
@@ -127,6 +127,16 @@ Send data to the client.
{data, fin(), iodata()}
+=== trailers
+Send response trailers to the client.
+{trailers, cowboy:http_headers()}
=== push
@@ -286,6 +296,13 @@ Same as the xref:data_command[data command].
Sent when the request process streams data to the client.
+=== trailers
+Same as the xref:trailers_command[trailers command].
+Sent when the request process sends the trailer field values
+to the client.
=== push
Same as the xref:push_command[push command].