Source code for kong.response
# AUTO GENERATED BASED ON Kong 3.4.x, DO NOT EDIT
# Original source path: kong/pdk/response.lua
from typing import TypeVar, Any, Union, List, Mapping, Tuple, Optional
number = TypeVar('number', int, float)
table = TypeVar('table', List[Any], Mapping[str, Any])
# XXX
cdata = Any
err = str
[docs]class response():
[docs] @staticmethod
def add_header(name: str, value: Any) -> None:
"""
Adds a response header with the given value. Unlike
`kong.response.set_header()`, this function does not remove any existing
header with the same name. Instead, another header with the same name is
added to the response. If no header with this name already exists on
the response, then it is added with the given value, similarly to
`kong.response.set_header().`
Phases:
rewrite, access, header_filter, response, admin_api
Example:
kong.response.add_header("Cache-Control", "no-cache")
kong.response.add_header("Cache-Control", "no-store")
:parameter name: The header name.
:type name: str
:parameter value: The header value.
:type value: Any
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def clear_header(name: str) -> None:
"""
Removes all occurrences of the specified header in the response sent to
the client.
Phases:
rewrite, access, header_filter, response, admin_api
Example:
kong.response.set_header("X-Foo", "foo")
kong.response.add_header("X-Foo", "bar")
kong.response.clear_header("X-Foo")
# from here onwards, no X-Foo headers will exist in the response
:parameter name: The name of the header to be cleared
:type name: str
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def error(status: number, message: Optional[str], headers: Optional[table]) -> None:
"""
This function interrupts the current processing and produces an error
response.
It is recommended to use this function in conjunction with the `return`
operator, to better reflect its meaning:
```lua
return kong.response.error(500, "Error", {["Content-Type"] = "text/html"})
```
1. The `status` argument sets the status code of the response that
is seen by the client. The status code must an error code, that is,
greater than 399.
2. The optional `message` argument sets the message describing
the error, which is written in the body.
3. The optional `headers` argument can be a table specifying response
headers to send. If specified, its behavior is similar to
`kong.response.set_headers()`.
This method sends the response formatted in JSON, XML, HTML or plaintext.
The actual format is determined using one of the following options, in
this order:
- Manually specified in the `headers` argument using the `Content-Type`
header.
- Conforming to the `Accept` header from the request.
- If there is no setting in the `Content-Type` or `Accept` header, the
response defaults to JSON format. Also see the `Content-Length`
header in the produced response for convenience.
Phases:
rewrite, access, admin_api, header_filter, only, if, body, is, nil
Example:
return kong.response.error(403, "Access Forbidden", {
["Content-Type"] = "text/plain",
["WWW-Authenticate"] = "Basic"
})
# -
return kong.response.error(403, "Access Forbidden")
# -
return kong.response.error(403)
:parameter status: The status to be used (>399).
:type status: number
:parameter message: The error message to be used.
:type message: str
:parameter headers: The headers to be used.
:type headers: table
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def exit(status: number, body: Optional[bytes], headers: Optional[table]) -> None:
"""
This function interrupts the current processing and produces a response.
It is typical to see plugins using it to produce a response before Kong
has a chance to proxy the request (e.g. an authentication plugin rejecting
a request, or a caching plugin serving a cached response).
It is recommended to use this function in conjunction with the `return`
operator, to better reflect its meaning:
```lua
return kong.response.exit(200, "Success")
```
Calling `kong.response.exit()` interrupts the execution flow of
plugins in the current phase. Subsequent phases will still be invoked.
For example, if a plugin calls `kong.response.exit()` in the `access`
phase, no other plugin is executed in that phase, but the
`header_filter`, `body_filter`, and `log` phases are still executed,
along with their plugins. Plugins should be programmed defensively
against cases when a request is **not** proxied to the Service, but
instead is produced by Kong itself.
1. The first argument `status` sets the status code of the response that
is seen by the client.
In L4 proxy mode, the `status` code provided is primarily for logging
and statistical purposes, and is not visible to the client directly.
In this mode, only the following status codes are supported:
* 200 - OK
* 400 - Bad request
* 403 - Forbidden
* 500 - Internal server error
* 502 - Bad gateway
* 503 - Service unavailable
2. The second, optional, `body` argument sets the response body. If it is
a string, no special processing is done, and the body is sent
as-is. It is the caller's responsibility to set the appropriate
`Content-Type` header via the third argument.
As a convenience, `body` can be specified as a table. In that case,
the `body` is JSON-encoded and has the `application/json` Content-Type
header set.
On gRPC, we cannot send the `body` with this function, so
it sends `"body"` in the `grpc-message` header instead.
* If the body is a table, it looks for the `message` field in the body,
and uses that as a `grpc-message` header.
* If you specify `application/grpc` in the `Content-Type` header, the
body is sent without needing the `grpc-message` header.
In L4 proxy mode, `body` can only be `nil` or a string. Automatic JSON
encoding is not available. When `body` is provided, depending on the
value of `status`, the following happens:
* When `status` is 500, 502 or 503, then `body` is logged in the Kong
error log file.
* When the `status` is anything else, `body` is sent back to the L4 client.
3. The third, optional, `headers` argument can be a table specifying
response headers to send. If specified, its behavior is similar to
`kong.response.set_headers()`. This argument is ignored in L4 proxy mode.
Unless manually specified, this method automatically sets the
`Content-Length` header in the produced response for convenience.
Phases:
preread, rewrite, access, admin_api, header_filter, only, if, body, is, nil
Example:
return kong.response.exit(403, "Access Forbidden", {
["Content-Type"] = "text/plain",
["WWW-Authenticate"] = "Basic"
})
# -
return kong.response.exit(403, [[{"message":"Access Forbidden"}]], {
["Content-Type"] = "application/json",
["WWW-Authenticate"] = "Basic"
})
# -
return kong.response.exit(403, { message = "Access Forbidden" }, {
["WWW-Authenticate"] = "Basic"
})
# -
# In L4 proxy mode
return kong.response.exit(200, "Success")
:parameter status: The status to be used.
:type status: number
:parameter body: The body to be used.
:type body: bytes
:parameter headers: The headers to be used.
:type headers: table
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def get_header(name: str) -> str:
"""
Returns the value of the specified response header, as would be seen by
the client once received.
The list of headers returned by this function can consist of both response
headers from the proxied Service _and_ headers added by Kong (e.g. via
`kong.response.add_header()`).
The return value is either a `string`, or can be `nil` if a header with
`name` is not found in the response. If a header with the same name is
present multiple times in the request, this function returns the value
of the first occurrence of this header.
Phases:
header_filter, response, body_filter, log, admin_api
Example:
# Given a response with the following headers:
# X-Custom-Header: bla
# X-Another: foo bar
# X-Another: baz
kong.response.get_header("x-custom-header") # "bla"
kong.response.get_header("X-Another") # "foo bar"
kong.response.get_header("X-None") # nil
:parameter name: The name of the header.
Header names are case-insensitive and dashes (`-`) can be written as
underscores (`_`). For example, the header `X-Custom-Header` can also be
retrieved as `x_custom_header`.
:type name: str
:return: The value of the header.
:rtype: str
"""
pass
[docs] @staticmethod
def get_headers(max_headers: Optional[number]) -> Tuple[table, str]:
"""
Returns a Lua table holding the response headers. Keys are header names.
Values are either a string with the header value, or an array of strings
if a header was sent multiple times. Header names in this table are
case-insensitive and are normalized to lowercase, and dashes (`-`) can be
written as underscores (`_`). For example, the header `X-Custom-Header` can
also be retrieved as `x_custom_header`.
A response initially has no headers. Headers are added when a plugin
short-circuits the proxying by producing a header
(e.g. an authentication plugin rejecting a request), or if the request has
been proxied, and one of the latter execution phases is currently running.
Unlike `kong.service.response.get_headers()`, this function returns *all*
headers as the client would see them upon reception, including headers
added by Kong itself.
By default, this function returns up to **100** headers (or what has been
configured using `lua_max_resp_headers`). The optional `max_headers` argument
can be specified to customize this limit, but must be greater than **1** and
equal to or less than **1000**.
Phases:
header_filter, response, body_filter, log, admin_api
Example:
# Given an response from the Service with the following headers:
# X-Custom-Header: bla
# X-Another: foo bar
# X-Another: baz
headers = kong.response.get_headers()
headers.x_custom_header # "bla"
headers.x_another[1] # "foo bar"
headers["X-Another"][2] # "baz"
:parameter max_headers: Limits the number of headers parsed.
:type max_headers: number
:return: headers A table representation of the headers in the
response.
:rtype: table
:return: err If more headers than `max_headers` were present,
returns a string with the error `"truncated"`.
:rtype: str
"""
pass
[docs] @staticmethod
def get_source() -> str:
"""
This function helps determine where the current response originated
from. Since Kong is a reverse proxy, it can short-circuit a request and
produce a response of its own, or the response can come from the proxied
Service.
Returns a string with three possible values:
* `"exit"` is returned when, at some point during the processing of the
request, there has been a call to `kong.response.exit()`. This happens
when the request was short-circuited by a plugin or by Kong
itself (e.g. invalid credentials).
* `"error"` is returned when an error has happened while processing the
request. For example, a timeout while connecting to the upstream
service.
* `"service"` is returned when the response was originated by successfully
contacting the proxied Service.
Phases:
header_filter, response, body_filter, log, admin_api
Example:
if kong.response.get_source() == "service":
kong.log("The response comes from the Service")
elseif kong.response.get_source() == "error":
kong.log("There was an error while processing the request")
elseif kong.response.get_source() == "exit":
kong.log("There was an early exit while processing the request")
:return: The source.
:rtype: str
"""
pass
[docs] @staticmethod
def get_status() -> number:
"""
Returns the HTTP status code currently set for the downstream response (as
a Lua number).
If the request was proxied (as per `kong.response.get_source()`), the
return value is the response from the Service (identical to
`kong.service.response.get_status()`).
If the request was _not_ proxied and the response was produced by Kong
itself (i.e. via `kong.response.exit()`), the return value is
returned as-is.
Phases:
header_filter, response, body_filter, log, admin_api
Example:
kong.response.get_status() # 200
:return: status The HTTP status code currently set for the
downstream response.
:rtype: number
"""
pass
[docs] @staticmethod
def set_header(name: str, value: Any) -> None:
"""
Sets a response header with the given value. This function overrides any
existing header with the same name.
Note: Underscores in header names are automatically transformed into dashes
by default. If you want to deactivate this behavior, set the
`lua_transform_underscores_in_response_headers` Nginx config option to `off`.
This setting can be set in the Kong Config file:
nginx_http_lua_transform_underscores_in_response_headers = off
Be aware that changing this setting might break any plugins that
rely on the automatic underscore conversion.
You cannot set Transfer-Encoding header with this function. It will be ignored.
Phases:
rewrite, access, header_filter, response, admin_api
Example:
kong.response.set_header("X-Foo", "value")
:parameter name: The name of the header
:type name: str
:parameter value: The new value for the header.
:type value: Any
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def set_headers(headers: table) -> None:
"""
Sets the headers for the response. Unlike `kong.response.set_header()`,
the `headers` argument must be a table in which each key is a string
corresponding to a header's name, and each value is a string, or an
array of strings.
The resulting headers are produced in lexicographical order. The order of
entries with the same name (when values are given as an array) is
retained.
This function overrides any existing header bearing the same name as those
specified in the `headers` argument. Other headers remain unchanged.
You cannot set Transfer-Encoding header with this function. It will be ignored.
Phases:
rewrite, access, header_filter, response, admin_api
Example:
kong.response.set_headers({
["Bla"] = "boo",
["X-Foo"] = "foo3",
["Cache-Control"] = { "no-store", "no-cache" }
})
# Will add the following headers to the response, in this order:
# X-Bar: bar1
# Bla: boo
# Cache-Control: no-store
# Cache-Control: no-cache
# X-Foo: foo3
:parameter headers:
:type headers: table
:return: throws an error on invalid input.
:rtype: None
"""
pass
[docs] @staticmethod
def set_status(status: number) -> None:
"""
Allows changing the downstream response HTTP status code before sending it
to the client.
Phases:
rewrite, access, header_filter, response, admin_api
Example:
kong.response.set_status(404)
:parameter status: The new status.
:type status: number
:return: throws an error on invalid input.
:rtype: None
"""
pass
pass