replicant

README

Replicant is a synthetic transaction execution framework named after the bioengineered androids from Blade Runner. (all synthetics came from Blade Runner :)

It allows web application testing using chromedp, and api application testing using Go or Javascript. Provides a test manager, execution scheduler, api and facilities for emitting result data to external systems.

Status

Under heavy development and API changes are expected. Please file an issue if anything breaks.

Requirements

• Go 1.13
• External URL for API tests that require webhook based callbacks
• Chrome with remote debugging (CDP) either in headless mode or in foreground (useful for testing)

Examples

Running the replicant server locally with docker

Using example config from the project root dir.

docker stack deploy -c $PWD/docker-compose.yaml replicant

This will deploy the replicant server and 2 chrome-headless nodes for web tests, persisting data under /data.

Web application testing (local development)

Web application testing support is based on the FQL (Ferret Query Language), documentation.

Test definition (can be also in json format)

POST http://127.0.0.1:8080/api/v1/run
content-type: application/yaml

name: duckduckgo-web-search
driver: web
schedule: '@every 60s'
timeout: 50s
retry_count: 2
inputs:
  url: "https://duckduckgo.com"
  user_agent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.87 Safari/537.36"
  timeout: 5000000
  text: "blade runner"
metadata:
  transaction: website-search
  application: duckduckgo
  environment: production
  component: website
script: |
  LET doc = DOCUMENT('{{ index . "url" }}', { driver: "cdp", userAgent: "{{ index . "user_agent" }}"})
  INPUT(doc, '#search_form_input_homepage', "{{ index . "text" }}")
  CLICK(doc, '#search_button_homepage')
  WAIT_NAVIGATION(doc)
  LET result = ELEMENT(doc, '#r1-0 > div > div.result__snippet.js-result-snippet').innerText
  RETURN {
    failed: result == "",
    message: "search result",
    data: result,
  }

Response

{
  "data": [
    {
      "uuid": "01DSSR5GH2BPX4G5FFCEVPEBKK",
      "name": "duckduckgo-web-search",
      "driver": "web",
      "failed": true,
      "message": "",
      "data": "",
      "time": "2019-11-16T09:19:39.554976Z",
      "metadata": {
        "application": "duckduckgo",
        "component": "website",
        "environment": "production",
        "transaction": "website-search"
      },
      "retry_count": 0,
      "with_callback": false,
      "duration_seconds": 6.967938203,
      "error": "operation timed out: WAIT_NAVIGATION(doc) at 4:0"
    }
  ]
}

API testing (local development)

API testing support is based on interpreted go code, documentation.

Test definition (can be also in json format)

Using the javascript driver

POST http://127.0.0.1:8080/api/v1/run
content-type: application/yaml

name: duckduckgo-api-search
driver: javascript
schedule: '@every 60s'
timeout: 60s
retry_count: 2
inputs:
  url: "https://api.duckduckgo.com"
  text: "blade runner"
metadata:
  transaction: api-search
  application: duckduckgo
  environment: production
  component: api
script: |
  function Run(ctx) {
    req = replicant.http.NewRequest()
    req.URL = "{{ index . "url" }}"
    req.Params.q = "{{ index . "text" }}"
    req.Params.format = "json"
    req.Params.no_redirect = "1"
    resp = replicant.http.Do(req)
    data = JSON.parse(resp.Body)
    rr = replicant.NewResponse()
    switch(data.RelatedTopics && data.RelatedTopics.length > 0) {
      case true:
        rr.Data = data.RelatedTopics[0].Text
        rr.Message = resp.Status
        rr.Failed = false
        break
      case false:
        rr.Data = JSON.stringify(data)
        rr.Message = resp.Status
        rr.Failed = true
        break
    }
    return rr.JSON()
  }

Using the Go driver

POST http://127.0.0.1:8080/api/v1/run
content-type: application/yaml

name: duckduckgo-api-search
driver: go
schedule: '@every 60s'
timeout: 60s
retry_count: 2
inputs:
  url: "https://api.duckduckgo.com/"
  text: "blade runner"
metadata:
  transaction: api-search
  application: duckduckgo
  environment: production
  component: api
script: |
  package transaction
  import "bytes"
  import "context"
  import "fmt"
  import "net/http"
  import "io/ioutil"
  import "net/http"
  import "regexp"
  func Run(ctx context.Context) (m string, d string, err error) {
    req, err := http.NewRequest(http.MethodGet, "{{ index . "url" }}", nil)
      if err != nil {
        return "request build failed", "", err
    }
    req.Header.Add("Accept-Charset","utf-8")
    q := req.URL.Query()
    q.Add("q", "{{ index . "text" }}")
    q.Add("format", "json")
    q.Add("pretty", "1")
    q.Add("no_redirect", "1")
    req.URL.RawQuery = q.Encode()
    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
      return "failed to send request", "", err
    }
    buf, err := ioutil.ReadAll(resp.Body)
    if err != nil {
      return "failed to read response", "", err
    }
    rx, err := regexp.Compile(`"Text"\s*:\s*"(.*?)"`)
    if err != nil {
      return "failed to compile regexp", "", err
    }
    s := rx.FindSubmatch(buf)
    if len(s) < 2 {
      return "failed to find data", "", fmt.Errorf("no match")
    }
    return "search result", fmt.Sprintf("%s", s[1]), nil
  }

Response

{
  "data": [
    {
      "uuid": "01DSSR7ST5Q1Y2Y7HDSQDNS7Y7",
      "name": "duckduckgo-api-search",
      "driver": "go",
      "failed": false,
      "message": "search result",
      "data": "Blade Runner A 1982 American neo-noir science fiction film directed by Ridley Scott, written by Hampton...",
      "time": "2019-11-16T09:20:54.597852Z",
      "metadata": {
        "application": "duckduckgo",
        "component": "api",
        "environment": "production",
        "transaction": "api-search"
      },
      "retry_count": 0,
      "with_callback": false,
      "duration_seconds": 0.486582328,
      "error": ""
    }
  ]
}

API

Method	Resource	Action
POST	/v1/transaction	Add a managed transaction
GET	/v1/transaction	Get all managed transaction definitions
GET	/v1/transaction/:name	Get a managed transaction definition by name
DELETE	/v1/transaction/:name	Remove a managed transaction
POST	/v1/run	Run an ad-hoc transaction
POST	/v1/run/:name	Run a managed transaction by name
GET	/v1/result	Get all managed transaction last execution results
GET	/v1/result/:name	Get the latest result for a managed transaction by name
GET	/metrics	Get metrics (prometheus emitter must be enabled)
GET	/debug/pprof	Get available runtime profile data (debug enabled)
GET	/debug/pprof/:profile	Get profile data (for pprof, debug enabled)

TODO

• Tests
• Developer and user documentation
• Add support for more conventional persistent stores
• Vault integration for secrets (inputs)
• Architecture and API documentation
• Javascript driver transaction support

Related Projects

• Yaegi is Another Elegant Go Interpreter
• Ferret Declarative web scraping

Contact

Bruno Moura brunotm@gmail.com

License

Replicant source code is available under the Apache Version 2.0 License