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-->
## Name
Fault injection plugin, this plugin can be used with other plugins and will be executed before other plugins. The `abort` attribute will directly return the user-specified http code to the client and terminate the subsequent plugins. The `delay` attribute will delay a request and execute subsequent plugins.
| abort.vars | array[] | optional | | | The rules for executing fault injection will only be executed when the rules are matched. `vars` is a list of expressions, which is from the [lua-resty-expr](https://github.com/api7/lua-resty-expr). |
| delay.vars | array[] | optional | | | Execute the request delay rule, and the request will be delayed only after the rule matches. `vars` is a list of expressions, which is from the [lua-resty-expr](https://github.com/api7/lua-resty-expr). |
The `vars` is a list of expression which is from the `lua-resty-expr`, which can flexibly implement the `and/or` relationship between rules. Example:
```json
[
[
[ "arg_name","==","jack" ],
[ "arg_age","==",18 ]
],
[
[ "arg_name2","==","allen" ]
]
]
```
This means that the relationship between the first two expressions is `and`, and the relationship between the first two expressions and the third expression is `or`.
2. The vars rule is successfully matched and fault injection is performed:
```shell
$ curl "http://127.0.0.1:9080/hello?name=jack" -i
HTTP/1.1 403 Forbidden
Date: Wed, 20 Jan 2021 07:23:37 GMT
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Server: APISIX/2.2
Fault Injection!
```
Example 4: Enable the `fault-injection` plugin for a specific route and specify the vars rule for the delay parameter.
```shell
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"plugins": {
"fault-injection": {
"delay": {
"duration": 2,
"vars": [
[
[ "arg_name","==","jack" ]
]
]
}
}
},
"upstream": {
"nodes": {
"127.0.0.1:1980": 1
},
"type": "roundrobin"
},
"uri": "/hello"
}'
```
Test plugin：
1. The vars rule fails to match and the request is not delayed:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=allen" -i
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 20 Jan 2021 07:26:17 GMT
Server: APISIX/2.2
hello
real 0m0.007s
user 0m0.003s
sys 0m0.003s
```
2. The vars rule is successfully matched, and the request is delayed for two seconds:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=jack" -i
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 20 Jan 2021 07:57:50 GMT
Server: APISIX/2.2
hello
real 0m2.009s
user 0m0.004s
sys 0m0.004s
```
Example 5: Enable the `fault-injection` plugin for a specific route, and specify the vars rules for the abort and delay parameters.
```shell
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"plugins": {
"fault-injection": {
"abort": {
"http_status": 403,
"body": "Fault Injection!\n",
"vars": [
[
[ "arg_name","==","jack" ]
]
]
},
"delay": {
"duration": 2,
"vars": [
[
[ "http_age","==","18" ]
]
]
}
}
},
"upstream": {
"nodes": {
"127.0.0.1:1980": 1
},
"type": "roundrobin"
},
"uri": "/hello"
}'
```
Test plugin：
1. The vars rules of abort and delay fail to match:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=allen" -H 'age: 20' -i
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 20 Jan 2021 08:01:43 GMT
Server: APISIX/2.2
hello
real 0m0.007s
user 0m0.003s
sys 0m0.003s
```
2. The abort vars rule fails to match, no fault injection is performed, but the request is delayed:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=allen" -H 'age: 18' -i
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Transfer-Encoding: chunked
Connection: keep-alive
Date: Wed, 20 Jan 2021 08:19:03 GMT
Server: APISIX/2.2
hello
real 0m2.009s
user 0m0.001s
sys 0m0.006s
```
3. The vars rule of delay fails to match, the request is not delayed, but fault injection is performed:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=jack" -H 'age: 20' -i
HTTP/1.1 403 Forbidden
Date: Wed, 20 Jan 2021 08:20:18 GMT
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Server: APISIX/2.2
Fault Injection!
real 0m0.007s
user 0m0.002s
sys 0m0.004s
```
4. The vars rules of abort and delay parameters match successfully, perform fault injection, and delay the request:
```shell
$ time curl "http://127.0.0.1:9080/hello?name=jack" -H 'age: 18' -i
HTTP/1.1 403 Forbidden
Date: Wed, 20 Jan 2021 08:21:17 GMT
Content-Type: text/plain; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Server: APISIX/2.2
Fault Injection!
real 0m2.006s
user 0m0.001s
sys 0m0.005s
```
Example 6: Enable the `fault-injection` plugin for a specific route, and specify the vars rule of the abort parameter (the relationship of `or`).
```shell
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"plugins": {
"fault-injection": {
"abort": {
"http_status": 403,
"body": "Fault Injection!\n",
"vars": [
[
["arg_name","==","jack"],
["arg_age","!","<",18]
],
[
["http_apikey","==","apisix-key"]
]
]
}
}
},
"upstream": {
"nodes": {
"127.0.0.1:1980": 1
},
"type": "roundrobin"
},
"uri": "/hello"
}'
```
Indicates that when the request parameters name and age satisfy both `name == "jack"` and `age >= 18`, fault injection is performed. Or when the request header apikey satisfies `apikey == "apisix-key"`, fault injection is performed.
Test plugin：
1. The request parameter name and age match successfully, and the request header `apikey` is missing, and fault injection is performed:
