Document updated on Nov 10, 2023
End-to-End Testing for Developers
In addition to checking the syntax of your KrakenD configuration and ensuring that the gateway can start, an essential step in any CI/CD strategy is including 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 when working together with your upstream services.
How E2E testing works
The end-to-end testing definition is quite simple. You must create a folder to hold all the test cases you want to execute (e.g., specs
). Inside the folder, you make a file per test case. Each test case is a JSON file containing the input request you will send to the gateway ( in
) and the form of the expected output ( out
). The test file has a structure supported by a JSON schema definition.
With a folder full of test cases, the krakend e2e
command starts a gateway with the provided configuration and launches all the test cases in the folder. You are creating real traffic to the gateway and the backends and analyzing their responses through the gateway to validate the behavior before setting a configuration online.
Creating e2e test files
schema
property to describe the properties rather than checking their exact values.For instance, you could have the following contents on your disk:
Contents of E2E testing
$tree /etc/krakend
├── krakend.json
└── specs
├── test-foo.json
├── test-bar.json
└── some-other-test.json
KrakenD will run all the tests declared in the folder alphabetically (according to the file sorting of the OS).
Test Case files
Each test case is a simple .json
file containing an object with an in
(the input request you want to do to KrakenD) and an out
(the output you expect in the response).
Sometimes, a test case needs to have multiple calls to validate a scenario. When this happens, you can add a next
entry, an array containing couples of in
and out
objects that will be executed and analyzed in the declared order. The next
does not evaluate until the tool has already processed the siblings in
and out
.
The test case file must follow the e2e schema (explained below) to work correctly, but the tool does not validate the JSON format of each test case during runtime (this makes processing faster).
Here’s an example of test you can save under specs/test1.json
and run it with any KrakenD configuration (debug_endpoint
set to true
required):
{
"$schema": "https://www.krakend.io/schema/v2.6/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": [""]
}
}
}
The test above connects to the URL http://localhost:8080/__debug/something
and analyzes its response out
put, and checks that:
- It returns an HTTP
status_code
equal to200
- That the
body
is literally{"status": "ok"}
, and the entirety of the payload. - It also makes sure that there are three
header
conditions:- The
content-type
andX-Krakend-Completed
have the specified values - The
Cache-Control
header cannot be present (we compare it to an empty string).
- The
Any other headers that are not mapped here are ignored, so the response could have more.
Finally, the $schema
you see at the top of the file points to the E2E JSON Schema that helps you autocomplete and validate from your IDE (provided that it has automatic JSON-schema validation). The value can be either of:
https://www.krakend.io/schema/v2.6/e2e.json
(minor version)https://www.krakend.io/schema/e2e.json
(latest version)
See the format of the test cases below.
Test Case format
Test cases must be in JSON format and might contain two or three top-level attributes:
Fields of Schema validation for End To End testing specs
in
* object- The input request definition. At least you should define the URL used to connect to KrakenD
body
object, array, string- If you want to add a payload in the request, set its body here
header
object- An optional map of headers you want 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"
next
array- Additional checks, in sequential order, of
in
andout
definitions. The outterin
andout
are always executed first.Example:{"next":[{"in":{},"out":{}},{"in":{},"out":{}}]}
Each item is an object with the following properties:in
object- The input request definition. At least you should define the URL used to connect to KrakenD
body
object, array, string- If you want to add a payload in the request, set its body here
header
object- An optional map of headers you want 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
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
Testing non-deterministic responses
When the response of your backend is not deterministic, instead of checking the response against a body
trying to find an exact payload, 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 the date changes between executions. The following test would make sure that it works by comparing the response with a schema:
{
"$schema": "https://www.krakend.io/schema/v2.6/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"]
}
}
}
}
}
The content inside the schema
property is JSON Schema syntax up to a Draft-07 response.
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: 2.6
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 down 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
Only files ending with a .json
extension are taken into account.
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 main point of integration tests is to test KrakenD configurations (not necessarily the backend content itself). Therefore, all tests expect reproducible outputs.
Part of a testing strategy is using mocked data. An easy way to have fake data is to create a mock
folder with static JSON content and offer it via the static-filesystem.
By using static files, you could, for instance, create /mock/
endpoints that return the static files inside your mock folder folder.
E2E utility backend service
In addition to the KrakenD service used to test the configuration, the command e2e
will start on port 8081
(by default) an additional backend service with the following endpoints 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 2.6"
],
"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