Tutorial do Slack: comandos de barra (1a geração)


Neste tutorial, você aprenderá a usar o Cloud Run functions para implementar um comando de barra do Slack que pesquisa a API Knowledge Graph do Google.

Objetivos

  • Criar um Slash Command no Slack.
  • Escrever e implantar um Cloud Run functions HTTP.
  • Pesquisar a API Google Knowledge Graph usando o Slash Command.

Custos

Neste documento, você vai usar os seguintes componentes faturáveis do Google Cloud:

  • Cloud Run functions

Para gerar uma estimativa de custo baseada na projeção de uso deste tutorial, use a calculadora de preços.

Novos usuários do Google Cloud podem estar qualificados para um teste sem custo financeiro.

Antes de começar

  1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
  2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Roles required to select or create a project

    • Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
    • Create a project: To create a project, you need the Project Creator (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

    Go to project selector

  3. Verify that billing is enabled for your Google Cloud project.

  4. Enable the Cloud Functions, Cloud Build, and Google Knowledge Graph Search APIs.

    Roles required to enable APIs

    To enable APIs, you need the Service Usage Admin IAM role (roles/serviceusage.serviceUsageAdmin), which contains the serviceusage.services.enable permission. Learn how to grant roles.

    Enable the APIs

  5. Install the Google Cloud CLI.

  6. Ao usar um provedor de identidade (IdP) externo, primeiro faça login na gcloud CLI com sua identidade federada.

  7. Para inicializar a gcloud CLI, execute o seguinte comando:

    gcloud init
  8. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Roles required to select or create a project

    • Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
    • Create a project: To create a project, you need the Project Creator (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

    Go to project selector

  9. Verify that billing is enabled for your Google Cloud project.

  10. Enable the Cloud Functions, Cloud Build, and Google Knowledge Graph Search APIs.

    Roles required to enable APIs

    To enable APIs, you need the Service Usage Admin IAM role (roles/serviceusage.serviceUsageAdmin), which contains the serviceusage.services.enable permission. Learn how to grant roles.

    Enable the APIs

  11. Install the Google Cloud CLI.

  12. Ao usar um provedor de identidade (IdP) externo, primeiro faça login na gcloud CLI com sua identidade federada.

  13. Para inicializar a gcloud CLI, execute o seguinte comando:

    gcloud init
  14. Se a gcloud CLI já estiver instalada, atualize-a executando o seguinte comando:

    gcloud components update
  15. Prepare seu ambiente de desenvolvimento.
  16. Como visualizar o fluxo de dados

    O fluxo de dados no aplicativo de tutorial do Slack Slash Command envolve vários passos:

    1. O usuário executa o Slash Command /kg <search_query> em um canal Slack.
    2. O Slack envia o payload do comando ao endpoint do gatilho da função.
    3. A função a seguir envia uma solicitação com a consulta de pesquisa do usuário para a API Knowledge Graph:
    4. A API Knowledge Graph responde com todos os resultados encontrados.
    5. A função formata a resposta em uma mensagem do Slack.
    6. A função envia a mensagem de volta ao Slack.
    7. O usuário vê a resposta formatada no canal do Slack.

    Isto pode ajudar a visualizar os passos:

    Como criar a chave da API Google Knowledge Graph

    Na página Credenciais do consoleGoogle Cloud , clique no botão Criar credenciais e selecione Chave de API. Lembre-se dessa chave, já que ela será usada para acessar a API Knowledge Graph na próxima seção.

    Como preparar a função

    1. Clone o repositório do app de amostra na máquina local:

      Node.js

      git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git

      Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

      Python

      git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git

      Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

      Go

      git clone https://github.com/GoogleCloudPlatform/golang-samples.git

      Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

      Java

      git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git

      Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

      Ruby

      git clone https://github.com/GoogleCloudPlatform/ruby-docs-samples.git

      Outra alternativa é fazer o download da amostra como um arquivo ZIP e extraí-lo.

    2. Mude para o diretório que contém o código de amostra das funções do Cloud Run:

      Node.js

      cd nodejs-docs-samples/functions/slack/

      Python

      cd python-docs-samples/functions/slack/

      Go

      cd golang-samples/functions/slack/

      Java

      cd java-docs-samples/functions/slack/

      Ruby

      cd ruby-docs-samples/functions/slack/

    Como implantar a função

    Para implantar a função executada quando você (ou o Slack) faz uma solicitação HTTP POST para o endpoint da função, execute o comando a seguir no diretório que contém o código da amostra (ou o arquivo pom.xml para Java):

    Substitua YOUR_SLACK_SIGNING_SECRET pelo secret de assinatura fornecido pelo Slack na página Informações básicas da configuração do aplicativo e YOUR_KG_API_KEY pela chave da API Knowledge Graph criada anteriormente.

    Node.js

    gcloud functions deploy kgSearch \
    --runtime nodejs20 \
    --trigger-http \
    --set-env-vars "SLACK_SECRET=YOUR_SLACK_SIGNING_SECRET,KG_API_KEY=YOUR_KG_API_KEY" \
    --allow-unauthenticated

    Use a flag --runtime para especificar o ID do ambiente de execução de uma versão do Node.js compatível a fim de executar a função.

    Python

    gcloud functions deploy kg_search \
    --runtime python312 \
    --trigger-http \
    --set-env-vars "SLACK_SECRET=YOUR_SLACK_SIGNING_SECRET,KG_API_KEY=YOUR_KG_API_KEY" \
    --allow-unauthenticated

    Use a flag --runtime para especificar o ID do ambiente de execução de uma versão compatível do Python a fim de executar a função.

    Go

    gcloud functions deploy KGSearch \
    --runtime go121 \
    --trigger-http \
    --set-env-vars "SLACK_SECRET=YOUR_SLACK_SIGNING_SECRET,KG_API_KEY=YOUR_KG_API_KEY" \
    --allow-unauthenticated

    Use a flag --runtime para especificar o ID do ambiente de execução de uma versão do Go compatível a fim de executar a função.

    Java

    gcloud functions deploy java-slack-function \
    --entry-point functions.SlackSlashCommand \
    --runtime java17 \
    --memory 512MB \
    --trigger-http \
    --set-env-vars "SLACK_SECRET=YOUR_SLACK_SIGNING_SECRET,KG_API_KEY=YOUR_KG_API_KEY" \
    --allow-unauthenticated

    Use a flag --runtime para especificar o ID do ambiente de execução de uma versão compatível do Java a fim de executar a função.

    Ruby

    gcloud functions deploy kg_search --runtime ruby33 \
    -
    -trigger-http \
    -
    -set-env-vars "SLACK_SECRET=YOUR_SLACK_SIGNING_SECRET,KG_API_KEY=YOUR_KG_API_KEY" \
    -
    -allow-unauthenticated

    Use a flag --runtime para especificar o ID do ambiente de execução de uma versão compatível do Ruby a fim de executar a função.

    Configurar o aplicativo

    Depois que a função é implementada, você precisa criar um Comando de barra do Slack que envia a consulta para a função toda vez que o comando for acionado:

    1. Crie um aplicativo Slack para hospedar o Slack Slash Command. Associe-o a uma equipe do Slack onde você tem permissões para instalar integrações.

    2. Vá para os comandos do Slash e clique no botão Criar novo comando.

    3. Insira /kg como o nome do comando.

    4. Digite o URL do comando:

      Node.js

      https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/kgSearch

      Python

      https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/kg_search

      Go

      https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/KGSearch

      Java

      https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/java-slack-function

      Ruby

      https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/kg_search

      em que YOUR_REGION é a região em que a função está implantado e YOUR_PROJECT_ID é seu ID do projeto do Cloud.

      Ambos os valores são visíveis em seu terminal quando sua função termina de ser implantada.

    5. Clique em Salvar.

    6. Vá para Informações básicas.

    7. Clique em Instalar aplicativo no espaço de trabalho e siga as instruções na tela para ativar o aplicativo do seu espaço de trabalho.

      Seu Slack Slash Command ficará on-line em breve.

    Como entender o código

    Como importar dependências

    O aplicativo importa várias dependências para se comunicar com os serviços do Google Cloud Platform:

    Node.js

    const functions = require('@google-cloud/functions-framework');
    const google = require('@googleapis/kgsearch');
    const {verifyRequestSignature} = require('@slack/events-api');
    
    // Get a reference to the Knowledge Graph Search component
    const kgsearch = google.kgsearch('v1');

    Python

    import os
    
    from flask import jsonify
    import functions_framework
    import googleapiclient.discovery
    from slack.signature import SignatureVerifier
    
    
    kgsearch = googleapiclient.discovery.build(
        "kgsearch", "v1", developerKey=os.environ["KG_API_KEY"], cache_discovery=False
    )

    Go

    
    package slack
    
    import (
    	"context"
    	"log"
    	"os"
    
    	"google.golang.org/api/kgsearch/v1"
    	"google.golang.org/api/option"
    )
    
    var (
    	entitiesService *kgsearch.EntitiesService
    	kgKey           string
    	slackSecret     string
    )
    
    func setup(ctx context.Context) {
    	kgKey = os.Getenv("KG_API_KEY")
    	slackSecret = os.Getenv("SLACK_SECRET")
    
    	if entitiesService == nil {
    		kgService, err := kgsearch.NewService(ctx, option.WithAPIKey(kgKey))
    		if err != nil {
    			log.Fatalf("kgsearch.NewService: %v", err)
    		}
    		entitiesService = kgsearch.NewEntitiesService(kgService)
    	}
    }
    

    Java

    private static final Logger logger = Logger.getLogger(SlackSlashCommand.class.getName());
    private static final String API_KEY = getenv("KG_API_KEY");
    private static final String SLACK_SECRET = getenv("SLACK_SECRET");
    private static final Gson gson = new Gson();
    
    private final String apiKey;
    private final Kgsearch kgClient;
    private final SlackSignature.Verifier verifier;
    
    public SlackSlashCommand() throws IOException, GeneralSecurityException {
      this(new SlackSignature.Verifier(new SlackSignature.Generator(SLACK_SECRET)));
    }
    
    SlackSlashCommand(SlackSignature.Verifier verifier) throws IOException, GeneralSecurityException {
      this(verifier, API_KEY);
    }
    
    SlackSlashCommand(SlackSignature.Verifier verifier, String apiKey)
        throws IOException, GeneralSecurityException {
      this.verifier = verifier;
      this.apiKey = apiKey;
      this.kgClient = new Kgsearch.Builder(
          GoogleNetHttpTransport.newTrustedTransport(), new GsonFactory(), null).build();
    }
    
    // Avoid ungraceful deployment failures due to unset environment variables.
    // If you get this warning you should redeploy with the variable set.
    private static String getenv(String name) {
      String value = System.getenv(name);
      if (value == null) {
        logger.warning("Environment variable " + name + " was not set");
        value = "MISSING";
      }
      return value;
    }

    Ruby

    require "functions_framework"
    require "slack-ruby-client"
    require "google/apis/kgsearch_v1"
    
    # This block is executed during cold start, before the function begins
    # handling requests. This is the recommended way to create shared resources
    # and objects.
    FunctionsFramework.on_startup do
      # Create a global handler object, configured with the environment-provided
      # API key and signing secret.
      kg_search = KGSearch.new kg_api_key:     ENV["KG_API_KEY"],
                               signing_secret: ENV["SLACK_SECRET"]
      set_global :kg_search, kg_search
    end
    
    # The KGSearch class implements the logic of validating and responding
    # to requests. More methods of this class are shown below.
    class KGSearch
      def initialize kg_api_key:, signing_secret:
        # Create the global client for the Knowledge Graph Search Service,
        # configuring it with your API key.
        @client = Google::Apis::KgsearchV1::KgsearchService.new
        @client.key = kg_api_key
    
        # Save signing secret for use by the signature validation method.
        @signing_secret = signing_secret
      end

    Como receber o webhook

    A função a seguir é executada quando você ou o Slack fazem uma solicitação HTTP POST para o ponto de extremidade da função.

    Node.js

    /**
     * Receive a Slash Command request from Slack.
     *
     * Trigger this function by creating a Slack slash command with the HTTP Trigger URL.
     * You can find the HTTP URL in the Cloud Console or using `gcloud functions describe`
     *
     * @param {object} req Cloud Function request object.
     * @param {object} req.body The request payload.
     * @param {string} req.rawBody Raw request payload used to validate Slack's message signature.
     * @param {string} req.body.text The user's search query.
     * @param {object} res Cloud Function response object.
     */
    functions.http('kgSearch', async (req, res) => {
      try {
        if (req.method !== 'POST') {
          const error = new Error('Only POST requests are accepted');
          error.code = 405;
          throw error;
        }
    
        if (!req.body.text) {
          const error = new Error('No text found in body.');
          error.code = 400;
          throw error;
        }
    
        // Verify that this request came from Slack
        verifyWebhook(req);
    
        // Make the request to the Knowledge Graph Search API
        const response = await makeSearchRequest(req.body.text);
    
        // Send the formatted message back to Slack
        res.json(response);
    
        return Promise.resolve();
      } catch (err) {
        console.error(err);
        res.status(err.code || 500).send(err);
        return Promise.reject(err);
      }
    });

    Python

    @functions_framework.http
    def kg_search(request):
        if request.method != "POST":
            return "Only POST requests are accepted", 405
    
        verify_signature(request)
        kg_search_response = make_search_request(request.form["text"])
        return jsonify(kg_search_response)
    
    

    Go

    
    // Package slack is a Cloud Function which recieves a query from
    // a Slack command and responds with the KG API result.
    package slack
    
    import (
    	"bytes"
    	"crypto/hmac"
    	"crypto/sha256"
    	"encoding/hex"
    	"encoding/json"
    	"fmt"
    	"io"
    	"log"
    	"net/http"
    	"strconv"
    	"strings"
    	"time"
    )
    
    type oldTimeStampError struct {
    	s string
    }
    
    func (e *oldTimeStampError) Error() string {
    	return e.s
    }
    
    const (
    	version                     = "v0"
    	slackRequestTimestampHeader = "X-Slack-Request-Timestamp"
    	slackSignatureHeader        = "X-Slack-Signature"
    )
    
    type attachment struct {
    	Color     string `json:"color"`
    	Title     string `json:"title"`
    	TitleLink string `json:"title_link"`
    	Text      string `json:"text"`
    	ImageURL  string `json:"image_url"`
    }
    
    // Message is the a Slack message event.
    // see https://api.slack.com/docs/message-formatting
    type Message struct {
    	ResponseType string       `json:"response_type"`
    	Text         string       `json:"text"`
    	Attachments  []attachment `json:"attachments"`
    }
    
    // KGSearch uses the Knowledge Graph API to search for a query provided
    // by a Slack command.
    func KGSearch(w http.ResponseWriter, r *http.Request) {
    	setup(r.Context())
    
    	bodyBytes, err := io.ReadAll(r.Body)
    	if err != nil {
    		log.Fatalf("Couldn't read request body: %v", err)
    	}
    	r.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
    
    	if r.Method != "POST" {
    		http.Error(w, "Only POST requests are accepted", http.StatusMethodNotAllowed)
    	}
    	if err := r.ParseForm(); err != nil {
    		http.Error(w, "Couldn't parse form", 400)
    		log.Fatalf("ParseForm: %v", err)
    	}
    
    	// Reset r.Body as ParseForm depletes it by reading the io.ReadCloser.
    	r.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
    	result, err := verifyWebHook(r, slackSecret)
    	if err != nil {
    		log.Fatalf("verifyWebhook: %v", err)
    	}
    	if !result {
    		log.Fatalf("signatures did not match.")
    	}
    
    	if len(r.Form["text"]) == 0 {
    		log.Fatalf("empty text in form")
    	}
    	kgSearchResponse, err := makeSearchRequest(r.Form["text"][0])
    	if err != nil {
    		log.Fatalf("makeSearchRequest: %v", err)
    	}
    	w.Header().Set("Content-Type", "application/json")
    	if err = json.NewEncoder(w).Encode(kgSearchResponse); err != nil {
    		log.Fatalf("json.Marshal: %v", err)
    	}
    }
    

    Java

    /**
     * Receive a Slash Command request from Slack.
     *
     * @param request Cloud Function request object.
     * @param response Cloud Function response object.
     * @throws IOException if Knowledge Graph request fails
     */
    @Override
    public void service(HttpRequest request, HttpResponse response) throws IOException {
    
      // Validate request
      if (!"POST".equals(request.getMethod())) {
        response.setStatusCode(HttpURLConnection.HTTP_BAD_METHOD);
        return;
      }
    
      // reader can only be read once per request, so we preserve its contents
      String bodyString = request.getReader().lines().collect(Collectors.joining());
    
      // Slack sends requests as URL-encoded strings
      //   Java 11 doesn't have a standard library
      //   function for this, so do it manually
      Map<String, String> body = new HashMap<>();
      for (String keyValuePair : bodyString.split("&")) {
        String[] keyAndValue = keyValuePair.split("=");
        if (keyAndValue.length == 2) {
          String key = keyAndValue[0];
          String value = keyAndValue[1];
    
          body.put(key, value);
        }
      }
    
      if (body == null || !body.containsKey("text")) {
        response.setStatusCode(HttpURLConnection.HTTP_BAD_REQUEST);
        return;
      }
    
      if (!isValidSlackWebhook(request, bodyString)) {
        response.setStatusCode(HttpURLConnection.HTTP_UNAUTHORIZED);
        return;
      }
    
      String query = body.get("text");
    
      // Call knowledge graph API
      JsonObject kgResponse = searchKnowledgeGraph(query);
    
      // Format response to Slack
      // See https://api.slack.com/docs/message-formatting
      BufferedWriter writer = response.getWriter();
    
      writer.write(formatSlackMessage(kgResponse, query));
    
      response.setContentType("application/json");
    }

    Ruby

    # Handler for the function endpoint.
    FunctionsFramework.http "kg_search" do |request|
      # Return early if the request is not a POST.
      unless request.post?
        return [405, {}, ["Only POST requests are accepted."]]
      end
    
      # Access the global Knowledge Graph Search client
      kg_search = global :kg_search
    
      # Verify the request signature and return early if it failed.
      unless kg_search.signature_valid? request
        return [401, {}, ["Signature validation failed."]]
      end
    
      # Query the Knowledge Graph and format a Slack message with the response.
      # This method returns a nested hash, which the Functions Framework will
      # convert to JSON automatically.
      kg_search.make_search_request request.params["text"]
    end

    A função a seguir autentica a solicitação recebida verificando o cabeçalho X-Slack-Signature fornecido pelo Slack:

    Node.js

    /**
     * Verify that the webhook request came from Slack.
     *
     * @param {object} req Cloud Function request object.
     * @param {string} req.headers Headers Slack SDK uses to authenticate request.
     * @param {string} req.rawBody Raw body of webhook request to check signature against.
     */
    const verifyWebhook = req => {
      const signature = {
        signingSecret: process.env.SLACK_SECRET,
        requestSignature: req.headers['x-slack-signature'],
        requestTimestamp: req.headers['x-slack-request-timestamp'],
        body: req.rawBody,
      };
    
      // This method throws an exception if an incoming request is invalid.
      verifyRequestSignature(signature);
    };

    Python

    def verify_signature(request):
        request.get_data()  # Decodes received requests into request.data
    
        verifier = SignatureVerifier(os.environ["SLACK_SECRET"])
    
        if not verifier.is_valid_request(request.data, request.headers):
            raise ValueError("Invalid request/credentials.")
    
    

    Go

    
    // verifyWebHook verifies the request signature.
    // See https://api.slack.com/docs/verifying-requests-from-slack.
    func verifyWebHook(r *http.Request, slackSigningSecret string) (bool, error) {
    	timeStamp := r.Header.Get(slackRequestTimestampHeader)
    	slackSignature := r.Header.Get(slackSignatureHeader)
    
    	t, err := strconv.ParseInt(timeStamp, 10, 64)
    	if err != nil {
    		return false, fmt.Errorf("strconv.ParseInt(%s): %w", timeStamp, err)
    	}
    
    	if ageOk, age := checkTimestamp(t); !ageOk {
    		return false, &oldTimeStampError{fmt.Sprintf("checkTimestamp(%v): %v %v", t, ageOk, age)}
    		// return false, fmt.Errorf("checkTimestamp(%v): %v %v", t, ageOk, age)
    	}
    
    	if timeStamp == "" || slackSignature == "" {
    		return false, fmt.Errorf("either timeStamp or signature headers were blank")
    	}
    
    	body, err := io.ReadAll(r.Body)
    	if err != nil {
    		return false, fmt.Errorf("io.ReadAll(%v): %w", r.Body, err)
    	}
    
    	// Reset the body so other calls won't fail.
    	r.Body = io.NopCloser(bytes.NewBuffer(body))
    
    	baseString := fmt.Sprintf("%s:%s:%s", version, timeStamp, body)
    
    	signature := getSignature([]byte(baseString), []byte(slackSigningSecret))
    
    	trimmed := strings.TrimPrefix(slackSignature, fmt.Sprintf("%s=", version))
    	signatureInHeader, err := hex.DecodeString(trimmed)
    
    	if err != nil {
    		return false, fmt.Errorf("hex.DecodeString(%v): %w", trimmed, err)
    	}
    
    	return hmac.Equal(signature, signatureInHeader), nil
    }
    
    func getSignature(base []byte, secret []byte) []byte {
    	h := hmac.New(sha256.New, secret)
    	h.Write(base)
    
    	return h.Sum(nil)
    }
    
    // Arbitrarily trusting requests time stamped less than 5 minutes ago.
    func checkTimestamp(timeStamp int64) (bool, time.Duration) {
    	t := time.Since(time.Unix(timeStamp, 0))
    
    	return t.Minutes() <= 5, t
    }
    

    Java

    /**
     * Verify that the webhook request came from Slack.
     *
     * @param request Cloud Function request object in {@link HttpRequest} format.
     * @param requestBody Raw body of webhook request to check signature against.
     * @return true if the provided request came from Slack, false otherwise
     */
    boolean isValidSlackWebhook(HttpRequest request, String requestBody) {
      // Check for headers
      Optional<String> maybeTimestamp = request.getFirstHeader("X-Slack-Request-Timestamp");
      Optional<String> maybeSignature = request.getFirstHeader("X-Slack-Signature");
      if (!maybeTimestamp.isPresent() || !maybeSignature.isPresent()) {
        return false;
      }
    
      Long nowInMs = ZonedDateTime.now().toInstant().toEpochMilli();
    
      return verifier.isValid(maybeTimestamp.get(), requestBody, maybeSignature.get(), nowInMs);
    }

    Ruby

    # slack-ruby-client expects a Rails-style request object with a "headers"
    # method, but the Functions Framework provides only a Rack request.
    # To avoid bringing in Rails as a dependency, we'll create a simple class
    # that implements the "headers" method and delegates everything else back to
    # the Rack request object.
    require "delegate"
    class RequestWithHeaders < SimpleDelegator
      def headers
        env.each_with_object({}) do |(key, val), result|
          if /^HTTP_(\w+)$/ =~ key
            header = Regexp.last_match(1).split("_").map(&:capitalize).join("-")
            result[header] = val
          end
        end
      end
    end
    
    # This is a method of the KGSearch class.
    # It determines whether the given request's signature is valid.
    def signature_valid? request
      # Wrap the request with our class that provides the "headers" method.
      request = RequestWithHeaders.new request
    
      # Validate the request signature.
      slack_request = Slack::Events::Request.new request,
                                                 signing_secret: @signing_secret
      slack_request.valid?
    end

    Como consultar a API Knowledge Graph

    A função a seguir envia uma solicitação com a consulta de pesquisa do usuário para a API Knowledge Graph:

    Node.js

    /**
     * Send the user's search query to the Knowledge Graph API.
     *
     * @param {string} query The user's search query.
     */
    const makeSearchRequest = query => {
      return new Promise((resolve, reject) => {
        kgsearch.entities.search(
          {
            auth: process.env.KG_API_KEY,
            query: query,
            limit: 1,
          },
          (err, response) => {
            console.log(err);
            if (err) {
              reject(err);
              return;
            }
    
            // Return a formatted message
            resolve(formatSlackMessage(query, response));
          }
        );
      });
    };

    Python

    def make_search_request(query):
        req = kgsearch.entities().search(query=query, limit=1)
        res = req.execute()
        return format_slack_message(query, res)
    
    

    Go

    func makeSearchRequest(query string) (*Message, error) {
    	res, err := entitiesService.Search().Query(query).Limit(1).Do()
    	if err != nil {
    		return nil, fmt.Errorf("do: %w", err)
    	}
    	return formatSlackMessage(query, res)
    }
    

    Java

    /**
     * Send the user's search query to the Knowledge Graph API.
     *
     * @param query The user's search query.
     * @return The Knowledge graph API results as a {@link JsonObject}.
     * @throws IOException if Knowledge Graph request fails
     */
    JsonObject searchKnowledgeGraph(String query) throws IOException {
      Kgsearch.Entities.Search kgRequest = kgClient.entities().search();
      kgRequest.setQuery(query);
      kgRequest.setKey(apiKey);
    
      return gson.fromJson(kgRequest.execute().toString(), JsonObject.class);
    }

    Ruby

    # This is a method of the KGSearch class.
    # It makes an API call to the Knowledge Graph Search Service, and formats
    # a Slack message as a nested Hash object.
    def make_search_request query
      response = @client.search_entities query: query, limit: 1
      format_slack_message query, response
    end

    Como formatar a mensagem do Slack

    Por fim, a seguinte função exibe para o usuário o resultado do Knowledge Graph em uma mensagem do Slack ricamente formatada:

    Node.js

    /**
     * Format the Knowledge Graph API response into a richly formatted Slack message.
     *
     * @param {string} query The user's search query.
     * @param {object} response The response from the Knowledge Graph API.
     * @returns {object} The formatted message.
     */
    const formatSlackMessage = (query, response) => {
      let entity;
    
      // Extract the first entity from the result list, if any
      if (
        response &&
        response.data &&
        response.data.itemListElement &&
        response.data.itemListElement.length > 0
      ) {
        entity = response.data.itemListElement[0].result;
      }
    
      // Prepare a rich Slack message
      // See https://api.slack.com/docs/message-formatting
      const slackMessage = {
        response_type: 'in_channel',
        text: `Query: ${query}`,
        attachments: [],
      };
    
      if (entity) {
        const attachment = {
          color: '#3367d6',
        };
        if (entity.name) {
          attachment.title = entity.name;
          if (entity.description) {
            attachment.title = `${attachment.title}: ${entity.description}`;
          }
        }
        if (entity.detailedDescription) {
          if (entity.detailedDescription.url) {
            attachment.title_link = entity.detailedDescription.url;
          }
          if (entity.detailedDescription.articleBody) {
            attachment.text = entity.detailedDescription.articleBody;
          }
        }
        if (entity.image && entity.image.contentUrl) {
          attachment.image_url = entity.image.contentUrl;
        }
        slackMessage.attachments.push(attachment);
      } else {
        slackMessage.attachments.push({
          text: 'No results match your query...',
        });
      }
    
      return slackMessage;
    };

    Python

    def format_slack_message(query, response):
        entity = None
        if (
            response
            and response.get("itemListElement") is not None
            and len(response["itemListElement"]) > 0
        ):
            entity = response["itemListElement"][0]["result"]
    
        message = {
            "response_type": "in_channel",
            "text": f"Query: {query}",
            "attachments": [],
        }
    
        attachment = {}
        if entity:
            name = entity.get("name", "")
            description = entity.get("description", "")
            detailed_desc = entity.get("detailedDescription", {})
            url = detailed_desc.get("url")
            article = detailed_desc.get("articleBody")
            image_url = entity.get("image", {}).get("contentUrl")
    
            attachment["color"] = "#3367d6"
            if name and description:
                attachment["title"] = "{}: {}".format(entity["name"], entity["description"])
            elif name:
                attachment["title"] = name
            if url:
                attachment["title_link"] = url
            if article:
                attachment["text"] = article
            if image_url:
                attachment["image_url"] = image_url
        else:
            attachment["text"] = "No results match your query."
        message["attachments"].append(attachment)
    
        return message
    
    

    Go

    
    package slack
    
    import (
    	"fmt"
    
    	"google.golang.org/api/kgsearch/v1"
    )
    
    func formatSlackMessage(query string, response *kgsearch.SearchResponse) (*Message, error) {
    	if response == nil {
    		return nil, fmt.Errorf("empty response")
    	}
    
    	if response.ItemListElement == nil || len(response.ItemListElement) == 0 {
    		message := &Message{
    			ResponseType: "in_channel",
    			Text:         fmt.Sprintf("Query: %s", query),
    			Attachments: []attachment{
    				{
    					Color: "#d6334b",
    					Text:  "No results match your query.",
    				},
    			},
    		}
    		return message, nil
    	}
    
    	entity, ok := response.ItemListElement[0].(map[string]interface{})
    	if !ok {
    		return nil, fmt.Errorf("could not parse response entity")
    	}
    	result, ok := entity["result"].(map[string]interface{})
    	if !ok {
    		return nil, fmt.Errorf("error formatting response result")
    	}
    
    	attach := attachment{Color: "#3367d6"}
    	if name, ok := result["name"].(string); ok {
    		if description, ok := result["description"].(string); ok {
    			attach.Title = fmt.Sprintf("%s: %s", name, description)
    		} else {
    			attach.Title = name
    		}
    	}
    	if detailedDesc, ok := result["detailedDescription"].(map[string]interface{}); ok {
    		if url, ok := detailedDesc["url"].(string); ok {
    			attach.TitleLink = url
    		}
    		if article, ok := detailedDesc["articleBody"].(string); ok {
    			attach.Text = article
    		}
    	}
    	if image, ok := result["image"].(map[string]interface{}); ok {
    		if imageURL, ok := image["contentUrl"].(string); ok {
    			attach.ImageURL = imageURL
    		}
    	}
    
    	message := &Message{
    		ResponseType: "in_channel",
    		Text:         fmt.Sprintf("Query: %s", query),
    		Attachments:  []attachment{attach},
    	}
    	return message, nil
    }
    

    Java

    /**
     * Helper method to copy properties between {@link JsonObject}s
     */
    void addPropertyIfPresent(
        JsonObject target, String targetName, JsonObject source, String sourceName) {
      if (source.has(sourceName)) {
        target.addProperty(targetName, source.get(sourceName).getAsString());
      }
    }
    
    /**
     * Format the Knowledge Graph API response into a richly formatted Slack message.
     *
     * @param kgResponse The response from the Knowledge Graph API as a {@link JsonObject}.
     * @param query The user's search query.
     * @return The formatted Slack message as a JSON string.
     */
    String formatSlackMessage(JsonObject kgResponse, String query) {
      JsonObject attachmentJson = new JsonObject();
    
      JsonObject responseJson = new JsonObject();
      responseJson.addProperty("response_type", "in_channel");
      responseJson.addProperty("text", String.format("Query: %s", query));
    
      JsonArray entityList = kgResponse.getAsJsonArray("itemListElement");
    
      // Extract the first entity from the result list, if any
      if (entityList.size() == 0) {
        attachmentJson.addProperty("text", "No results match your query...");
        responseJson.add("attachments", attachmentJson);
    
        return gson.toJson(responseJson);
      }
    
      JsonObject entity = entityList.get(0).getAsJsonObject().getAsJsonObject("result");
    
      // Construct Knowledge Graph response attachment
      String title = entity.get("name").getAsString();
      if (entity.has("description")) {
        title = String.format("%s: %s", title, entity.get("description").getAsString());
      }
      attachmentJson.addProperty("title", title);
    
      if (entity.has("detailedDescription")) {
        JsonObject detailedDescJson = entity.getAsJsonObject("detailedDescription");
        addPropertyIfPresent(attachmentJson, "title_link", detailedDescJson, "url");
        addPropertyIfPresent(attachmentJson, "text", detailedDescJson, "articleBody");
      }
    
      if (entity.has("image")) {
        JsonObject imageJson = entity.getAsJsonObject("image");
        addPropertyIfPresent(attachmentJson, "image_url", imageJson, "contentUrl");
      }
    
      JsonArray attachmentList = new JsonArray();
      attachmentList.add(attachmentJson);
    
      responseJson.add("attachments", attachmentList);
    
      return gson.toJson(responseJson);
    }

    Ruby

    # This is a method of the KGSearch class.
    # It takes a raw SearchResponse from the Knowledge Graph Search Service,
    # and formats a Slack message.
    def format_slack_message query, response
      result = response.item_list_element&.first&.fetch "result", nil
      attachment =
        if result
          name = result.fetch "name", nil
          description = result.fetch "description", nil
          details = result.fetch "detailedDescription", {}
          { "title"      => name && description ? "#{name}: #{description}" : name,
            "title_link" => details.fetch("url", nil),
            "text"       => details.fetch("articleBody", nil),
            "image_url"  => result.fetch("image", nil)&.fetch("contentUrl", nil) }
        else
          { "text" => "No results match your query." }
        end
      { "response_type" => "in_channel",
        "text"          => "Query: #{query}",
        "attachments"   => [attachment.compact] }
    end

    Tempos limite da API Slack

    A API do Slack espera que sua função responda dentro de 3 segundos após receber uma solicitação de webhook.

    Os comandos deste tutorial, no geral, levam menos de 3 segundos para responder. Para comando de execução mais longa, recomendamos configurar uma função para pedidos push (incluindo seu response_url) para um tópico do Pub/Sub que atua como uma fila de tarefas.

    Em seguida, crie uma segunda função acionada por Pub/Sub que processa essas tarefas e envia os resultados de volta para o response_url do Slack.

    Como usar o comando Slash

    1. Digite o comando no canal do Slack:

      /kg giraffe
    2. Verifique os registros para confirmar se as execuções foram concluídas:

      gcloud functions logs read --limit 100

    Limpar

    Para evitar cobranças na sua conta do Google Cloud pelos recursos usados no tutorial, exclua o projeto que os contém ou mantenha o projeto e exclua os recursos individuais.

    Excluir o projeto

    O jeito mais fácil de evitar cobranças é excluindo o projeto que você criou para o tutorial.

    Para excluir o projeto:

    1. In the Google Cloud console, go to the Manage resources page.

      Go to Manage resources

    2. In the project list, select the project that you want to delete, and then click Delete.
    3. In the dialog, type the project ID, and then click Shut down to delete the project.

    Como excluir a função

    Para excluir o Cloud Function implantado neste tutorial, execute o seguinte comando:

    Node.js

    gcloud functions delete kgSearch 

    Python

    gcloud functions delete kg_search 

    Go

    gcloud functions delete KGSearch 

    Java

    gcloud functions delete java-slack-function 

    Ruby

    gcloud functions delete kg_search 

    Também é possível excluir funções do Cloud Run pelo consoleGoogle Cloud .