Document updated on Jul 5, 2023
End-to-End Testing for Developers
In addition to checking the syntax of your KrakenD configuration and ensuring that the gateway can start, you can run end-to-end tests to guarantee that all the active software components from beginning to end have the expected flow and that the gateway returns what you planned.
The krakend e2e
command starts a a gateway with the provided configuration, and launches all the integration tests in the specs folder. You have a real server running locally that is able to make test in battery and analyze real responses.
Creating e2e test files
In essence, you must create a specs
folder and place the test files inside. Each file represents one request and one response analysis.
KrakenD will run all the tests declared in the folder alphabetically (according to the file sorting of the OS). Make sure tests are deterministic and reproducible, and that will produce a consistent output in different executions.
For instance, you could have the following contents in your disk:
Contents of E2E testing
$tree /etc/krakend
├── krakend.json
└── specs
├── test-foo.json
├── test-bar.json
└── some-other-test.json
Test file format
Each test file is a simple .json
file containing an object with an in
(the request you want to do) and an out
(what you expect as the response). The file follows the e2e schema (explained below) and describes all attributes of the request and the analysis of the response you want to do.
For instance, save your first test under specs/test1.json
and run it with any KrakenD configuration with the debug_endpoint
set to true
:
{
"$schema": "https://www.krakend.io/schema/v2.4/e2e.json",
"@comment": "Makes sure that the debug endpoint returns a status ok",
"in": {
"url": "http://localhost:8080/__debug/something"
},
"out": {
"status_code": 200,
"body": {
"status": "ok"
}
}
}
The $schema
can point to the current version (https://www.krakend.io/schema/v2.4/e2e.json
), or to the latest version (https://www.krakend.io/schema/e2e.json
).
The test above connects to the url http://localhost:8080/__debug/something
and from its output it checks that an HTTP 200
status code is returned, and that the body contains a {"status": "ok"}
.
The following JSON attributes are recognized in each test specification file:
Fields of Schema validation for End To End testing specs
in
* object- The parameters used to build the request to a running KrakenD with your configuration
body
object, array, string- An optional payload you can send in the request as data.
header
object- An optional map of headers to include in the request.Example:
{"User-Agent":"krakend e2e tool"}
method
- The method sent in the requestPossible values are:
"GET"
,"POST"
,"PUT"
,"PATCH"
,"DELETE"
Defaults to"GET"
url
string- The full URL you want to use in the request, including schema, host, port, path, and any additional query string parameters you might need.Example:
"http://localhost:8080/__debug/something"
out
* object- The expected response from the server* Required any of: (
status_code
) , or (status_code
+body
) , or (status_code
+schema
)body
string, object- The expected returned body by the response as a string or JSON object. Remove this body field when you don’t want to check its contents, when the response does not have a body, or when you want to use the schema instead.Example:
"http://localhost:8080/__debug/something"
header
object- Checks that all headers included in the response match the provided values. You only need to declare the relevant headers you want, as the rest are ignored. As headers, by RFC definition, can be multiple, you must always use an array to express the values you want to check. You can also check that a specific header does not exist in the response declaring an empty value
[""]
.Example:{"Cache-Control":[""],"X-Krakend-Completed":["true"],"content-type":["application/json; charset=utf-8"]}
Properties of
header
can use a name matching the pattern.*
, and their content is anarray
schema
object- A JSON Schema object that validates the response. This option allows you to work with responses that the literal value is not that important and you want to check the structure of the returned document instead. If the response matches the schema definition, the test passes. If you define a
schema
and abody
simultaneously only the schema is validated. status_code
integer- The integer value of the HTTP status code returned by the server.Example:
200
Another example. With the test below, we make sure that the response must contain the content-type
and X-Krakend-Completed
headers with the specified values, plus the Cache-Control
header cannot be present (we compare it to an empty string). Any other headers that are not mapped here are ignored.
{
"$schema": "https://www.krakend.io/schema/v2.4/e2e.json",
"@comment": "Makes sure that the debug endpoint returns a status ok",
"in": {
"method": "GET",
"url": "http://localhost:8080/__debug/something",
"header": {
"User-Agent": "krakend-e2e-tool"
}
},
"out": {
"status_code": 200,
"body": {
"status": "ok"
},
"header": {
"content-type": ["application/json; charset=utf-8"],
"X-Krakend-Completed": ["true"],
"Cache-Control": [""]
}
}
}
Testing against a JSON schema
When the response of your backend is not consistent, instead of checking the response against a body
, you can test it against a JSON Schema, using the schema
attribute.
For instance, our health endpoint returns the date after every request. It would be impossible to test it literally, as it keeps changing. The following test would make sure that it works by comparing the response with a schema:
{
"$schema": "https://www.krakend.io/schema/v2.4/e2e.json",
"@comment": "Makes sure that the health endpoint contains three fields with the right types",
"in": {
"url": "http://localhost:8080/__health"
},
"out": {
"status_code": 200,
"schema": {
"$schema": "http://json-schema.org/draft-07/schema#",
"required": ["agents","now","status"],
"properties": {
"agents": {
"type": "object"
},
"now": {
"type": "string"
},
"status": {
"type": "string",
"enum": ["ok"]
}
}
}
}
}
Running the e2e tests
The e2e
command can run without additional flags if you use the default naming, but it has several run options. It looks like this:
Term
$krakend e2e -h
╓▄█ ▄▄▌ ╓██████▄µ
▐███ ▄███╨▐███▄██H╗██████▄ ║██▌ ,▄███╨ ▄██████▄ ▓██▌█████▄ ███▀╙╙▀▀███╕
▐███▄███▀ ▐█████▀"╙▀▀"╙▀███ ║███▄███┘ ███▀""▀███ ████▀╙▀███H ███ ╙███
▐██████▌ ▐███⌐ ,▄████████M║██████▄ ║██████████M███▌ ███H ███ ,███
▐███╨▀███µ ▐███ ███▌ ,███M║███╙▀███ ███▄```▄▄` ███▌ ███H ███,,,╓▄███▀
▐███ ╙███▄▐███ ╙█████████M║██▌ ╙███▄`▀███████╨ ███▌ ███H █████████▀
`` `'`
Version: 2.4
Executes an end-to-end test for the gateway based on the configuration file and a set of specs.
Usage:
krakend e2e [flags]
Examples:
krakend e2e -c config.json -s specs
Flags:
-c, --config string Path to the krakend configuration file. (default "./krakend.json")
-d, --delay duration The delay for the delayed backend endpoint. (default 200ms)
-e, --envar string Comma separated list of patterns to use to filter the envars to pass (set to ".*" to pass everything).
-h, --help help for e2e
-l, --log string Path for storing the server logs. (default "./e2e.log")
-r, --no-redirect Disable redirects at the http client.
-p, --port int The port for the mocked backend api. (default 8081)
-s, --specs string Path to the specs folder. (default "./specs")
When you run the tests, KrakenD will tell you the failing ones with a [KO]
and the working ones with an [OK]
. For instance:
Term
$krakend e2e
[OK] test1
1 test(s) completed
Total time: 1.102928274s
The e2e
command starts and shuts downs two services during the tests:
- A KrakenD instance running on port
8080
or the port you have defined in your configuration, on which all test requests are sent. - An additional backend service on port
8081
(or the one you define withkrakend e2e -p
) with a few utility endpoints that you can use to complement your testing (see below)
Skipping tests
If you want to skip a test temporarily, rename the test to a non .json
extension. For instance, you can rename test1.json
to test1.json.skip
.
Using mock data
The point of integration tests is to test KrakenD configuration (not the backend content itself). Therefore, all tests expect reproducible outputs. For example, suppose your test includes getting data from a source that changes between different executions (like relative dates, timestamps, etc.). In that case, you cannot use body
and need to use a schema
instead.
Suppose you don’t want to use a schema
but a body
for any reason. Then, to mitigate this scenario, you can use the deny
attribute to remove specific fields from the tests, or you can use mock data for testing instead. An easy way to have fake data is to create a mock
folder with static JSON content and offer it via the static-filesystem plugin. For instance:
{
"version": 3,
"$schema": "https://www.krakend.io/schema/v2.4/krakend.json",
"host": [
"http://localhost:8080"
],
"plugin": {
"folder": "./plugins/",
"pattern": ".so"
},
"extra_config": {
"plugin/http-server": {
"name": [
"static-filesystem"
],
"static-filesystem": {
"path": "./tests/mock/",
"prefix": "/mock/"
}
}
},
"endpoints": [
{
"@comment": "Uses KrakenD as a backend with mocked data",
"endpoint": "/test/1",
"backend": [
{
"url_pattern": "/mock/sample.json"
}
]
}
]
}
With this configuration, whenever you ask for a route /mock/
to the gateway, it will return the file inside the folder. With a mock, it’s easier to pass your tests.
E2E utility backend service
When running the tests, the command line will start on port 8081
(by default) a backend service with the following endpoints that you can include in your tests.
You can see the code of these endpoints below here.
In addition to the endpoints below, you can also use the echo and debug endpoints of KrakenD (not this service)
Endpoint /param_forwarding/*
An echo endpoint that returns an object containing a map with the request details:
path
: The URL requested to the backendquery
: The different query strings passed to the backendheaders
: All the headers that reached the backendfoo
: An additional object with a hardcoded value42
body
: A string with the data passed in the request’s body. Only dumped when you call the backend with the query string?dump_body=1
.
For example, a call to http://localhost:8081/param_forwarding/hey/yo?a=1&b=1&dumb_body=1
produces the response:
{
"path": "/param_forwarding/hey/yo",
"query": {
"a": 1,
"b": 2,
"dump_body": 1
},
"headers": {
"Accept-Encoding": [
"gzip"
],
"User-Agent": [
"KrakenD Version 2.4"
],
"X-Forwarded-Host": [
"localhost:8080"
]
},
"foo": 42,
"body": {}
}
Endpoint /xml
Returns hardcoded content in XML format. Useful to test a mix of JSON and XML encodings:
<?xml version="1.0" encoding="UTF-8"?>
<user type="admin">
<name>Elliot</name>
<social>
<facebook>https://facebook.com</facebook>
<twitter>https://twitter.com</twitter>
<youtube>https://youtube.com</youtube>
</social>
</user>
Endpoint /collection/*
Returns a collection of 10 objects (an array) with the number of iteration (i
) and the path
used. For instance, calling http://localhost:8081/collection/hi-there
produces:
[
{
"i": 0,
"path": "/collection/hi-there"
},
{
"i": 1,
"path": "/collection/hi-there"
},
{
"i": 2,
"path": "/collection/hi-there"
},
{
"i": 3,
"path": "/collection/hi-there"
},
{
"i": 4,
"path": "/collection/hi-there"
},
{
"i": 5,
"path": "/collection/hi-there"
},
{
"i": 6,
"path": "/collection/hi-there"
},
{
"i": 7,
"path": "/collection/hi-there"
},
{
"i": 8,
"path": "/collection/hi-there"
},
{
"i": 9,
"path": "/collection/hi-there"
}
]
Endpoint /delayed/*
Returns an echo endpoint (as in /param_forwarding
), but it delays the response for 200ms
or any other value you pass using the -d
flag when running the tests.
Endpoint /redirect/*
Returns an HTTP redirection to /param_forwarding/
using the status code passed by query string with ?status=301
. For instance, http://localhost:8081/redirect/hi-there?status=302`.
Endpoint /jwk/symmetric
Returns a fake signing key that validates demo JWT tokens. To be used when you set the jwk_url
if you don’t want to issue real tokens
{
"keys": [
{
"kty": "oct",
"alg": "A128KW",
"k": "GawgguFyGrWKav7AX4VKUg",
"kid": "sim1"
},
{
"kty": "oct",
"k": "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow",
"kid": "sim2",
"alg": "HS256"
}
]
}
The key above validates the following Authorization: Beaerer
demo token:
bearer eyJhbGciOiJIUzI1NiIsImtpZCI6InNpbTIifQ.eyJhdWQiOiJodHRwOi8vYXBpLmV4YW1wbGUuY29tIiwiZXhwIjoxNzM1Njg5NjAwLCJpc3MiOiJodHRwczovL2tyYWtlbmQuaW8iLCJqdGkiOiJtbmIyM3Zjc3J0NzU2eXVpb21uYnZjeDk4ZXJ0eXVpb3AiLCJyb2xlcyI6WyJyb2xlX2EiLCJyb2xlX2IiXSwic3ViIjoiMTIzNDU2Nzg5MHF3ZXJ0eXVpbyJ9.htgbhantGcv6zrN1i43Rl58q1sokh3lzuFgzfenI0Rk