Slack 教學課程:斜線指令 (第 1 代)


本教學課程示範如何使用 Cloud Run 函式實作 Slack Slash 指令,藉此搜尋 Google Knowledge Graph API

目標

  • 在 Slack 中建立 Slash Command。
  • 編寫及部署 HTTP Cloud Run 函式
  • 使用 Slash Command 搜尋 Google 知識圖譜 API。

費用

在本文件中,您會使用 Google Cloud的下列計費元件:

  • Cloud Run functions

如要根據預測用量估算費用,請使用 Pricing Calculator

初次使用 Google Cloud 的使用者可能符合免費試用資格。

事前準備

  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. 如果您使用外部識別資訊提供者 (IdP),請先 使用聯合身分登入 gcloud CLI

  7. 如要初始化 gcloud CLI,請執行下列指令:

    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. 如果您使用外部識別資訊提供者 (IdP),請先 使用聯合身分登入 gcloud CLI

  13. 如要初始化 gcloud CLI,請執行下列指令:

    gcloud init
  14. 如果您已安裝 gcloud CLI,請執行下列指令來更新:

    gcloud components update
  15. 準備開發環境。 <0x
  16. 視覺化資料流動過程

    Slack Slash Command 教學課程應用程式中的資料流動過程涉及數個步驟:

    1. 使用者在 Slack 頻道中執行 /kg <search_query> Slash 指令。
    2. Slack 會將指令的有效負載傳送至函式的觸發端點。
    3. 該函式會將使用者的搜尋查詢傳送至 Knowledge Graph API。
    4. 知識圖譜 API 以任何相符的結果回應。
    5. 函式會將回應格式化為 Slack 訊息
    6. 函式會將訊息傳回 Slack。
    7. 使用者在 Slack 頻道中看見設定好格式的回應。

    以下可能有助於透過視覺化的方式瞭解步驟:

    建立 Knowledge Graph API 金鑰

    Google Cloud 控制台的「憑證」頁面中,按一下「建立憑證」按鈕,然後選取「API 金鑰」。請記下這組金鑰,因為您會在下一節使用這組金鑰存取 Knowledge Graph API。

    準備函式

    1. 將應用程式存放區範例複製到本機電腦中:

      Node.js

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

      您也可以 下載 zip 格式的範例,然後解壓縮該檔案。

      Python

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

      您也可以 下載 zip 格式的範例,然後解壓縮該檔案。

      Go

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

      您也可以 下載 zip 格式的範例,然後解壓縮該檔案。

      Java

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

      您也可以 下載 zip 格式的範例,然後解壓縮該檔案。

      Ruby

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

      您也可以 下載 zip 格式的範例,然後解壓縮該檔案。

    2. 變更為包含 Cloud Run 函式程式碼範例的目錄:

      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/

    部署函式

    如要部署函式,在您 (或 Slack) 對函式端點發出 HTTP POST 要求時執行,請在包含範例程式碼 (或 Java 的 pom.xml 檔案) 的目錄中執行下列指令:

    YOUR_SLACK_SIGNING_SECRET 替換為 Slack 在應用程式設定的「基本資訊」頁面中提供的簽署密鑰,並將 YOUR_KG_API_KEY 替換為您先前建立的 Knowledge Graph API 金鑰。

    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

    使用 --runtime 標記指定支援的 Node.js 版本執行階段 ID,以執行函式。

    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

    使用 --runtime 標記指定支援的 Python 版本執行階段 ID,以執行函式。

    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

    使用 --runtime 標記指定支援的 Go 版本執行階段 ID,以執行函式。

    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

    使用 --runtime 標記指定支援的 Java 版本執行函式的執行階段 ID。

    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

    使用 --runtime 標記指定支援的 Ruby 版本執行階段 ID,以執行函式。

    設定應用程式

    部署函式後,您需要建立 Slack 斜線指令,在每次觸發指令時將查詢傳送至函式:

    1. 建立 Slack 應用程式,以託管 Slack Slash 指令。將其與您有權安裝整合功能的 Slack 團隊建立關聯。

    2. 前往「Slash commands」 並按一下 [Create new command] 按鈕。

    3. 輸入 /kg 做為指令名稱。

    4. 輸入指令的網址:

      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

      其中 YOUR_REGION 是函式部署的區域,YOUR_PROJECT_ID 則是 Cloud 專案 ID。

      當您的函式部署完成時,這兩個值都可以在您的終端機中看見。

    5. 按一下 [Save]

    6. 前往「Basic Information」

    7. 按一下「將應用程式安裝到工作區」,然後按照畫面上的指示,為工作區啟用應用程式。

      您的 Slack Slash Command 應該很快就會上線。

    瞭解程式碼

    匯入依附元件

    應用程式必須匯入數個依附元件,才能與 Google Cloud Platform 服務通訊:

    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

    接收 webhook

    下列函式會在您 (或 Slack) 對函式端點提出 HTTP POST 要求時執行:

    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

    下列函式會驗證 Slack 提供的 X-Slack-Signature 標頭,藉此驗證傳入的要求:

    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

    查詢知識圖譜 API

    下列函式將含有使用者搜尋查詢的要求傳送至知識圖譜 API:

    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

    設定 Slack 訊息格式

    最後,下列函式將知識圖譜結果的格式設定為豐富格式的 Slack 訊息,並顯示給使用者:

    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

    Slack API 逾時

    Slack API 預期函式會在收到 Webhook 要求後3 秒內回覆

    本教學課程中的指令通常會在 3 秒內回應。如果是執行時間較長的指令,建議您設定函式,將要求 (包括其 response_url) 推送至做為工作佇列的 Pub/Sub 主題。

    接著,您可以建立由 Pub/Sub 觸發的第二個函式,處理這些工作並將結果傳回 Slack 的 response_url

    使用 Slash 指令

    1. 將指令輸入到您的 Slack 頻道中:

      /kg giraffe
    2. 觀察記錄以確定執行已經完成:

      gcloud functions logs read --limit 100

    清除所用資源

    如要避免系統向您的 Google Cloud 帳戶收取本教學課程中所用資源的相關費用,請刪除含有該項資源的專案,或者保留專案但刪除個別資源。

    刪除專案

    如要避免付費,最簡單的方法就是刪除您為了本教學課程所建立的專案。

    如要刪除專案:

    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.

    刪除函式

    如要刪除您在本教學課程中部署的函式,請執行下列指令:

    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 

    您也可以從Google Cloud 控制台刪除 Cloud Run 函式。