add slack-classify-image example

README.md

@@ -20,6 +20,7 @@ For more details about **Functions** take a look at [Functions on SAP Help porta
 |[hello-timer](./examples/hello-timer)| Basic example | A function that is triggered according to a CRON expression based schedule |
 |[qrcode-producer](./examples/qrcode-producer)| Basic example | A function produces the current timestamp as QR code |
 |[s4sdk](./examples/s4sdk)| Advanced example | A function leverages the `SAP Cloud SDK for JavaScript` to interact with the `BusinessPartner` API exposed by an `SAP S/4HANA` system |
+|[slack-classify-image](./examples/slack-classify-image)| Advanced example, requires Slack integration | An image post in Slack triggers a function. The function classifies the image via `SAP Leonardo` |
 |[weather](./examples/weather)| Advanced example, requires `OpenWeatherMap` account | Two functions representing a simple web page that handles user input and displays the result |
 |[kafka-producer](./examples/kafka-producer)| Advanced example, requires Kafka broker instance | A function is triggered by a message and produces a message on a Kafka topic |
 

examples/slack-classify-image/README.md

@@ -0,0 +1,42 @@
+# Example: Classify an Image posted in Slack with Leonardo
+
+A function is triggered by an image upload to a Slack channel. The function receives an event about the image upload. It then invokes the __`SAP Leonardo`__ image classification API with the image and waits for the response. The response itself contains a prediction about the possible content of the image. The function then posts the prediction to the channel. 
+
+## Requirements
+
+* A Slack application, for example within a test workspace, is required.
+The Slack application should define a bot user and be subscribed to the __`file_shared`__ bot event.
+Bot events are used, because image classification should be limited to channels where the bot user is invited.
+
+
+## Deployment
+First, create a deployment file to provide credentials.
+Run inside the project directory:
+```bash
+faas-sdk init-values -y values.yaml
+```
+Update the generated file:
+* An api key for the image classification can be obtained at [Leonardo image classification overview](https://api.sap.com/api/image_classification_api/overview).
+* Also specify the Slack bot user token.
+
+And finally, deploy the project :
+```bash
+ xfsrt-cli faas project deploy -y ./deploy/values.yaml -v
+```
+
+## Configure Slack Endpoint
+Go to the Configuration UI of your Slack application, navigate to __`Event Subscriptions`__ and toggle __`Enable Events`__. Configure the HTTP trigger URL as the corresponding slack bot event request endpoint URL.
+The HTTP trigger URL can be retrieved from:
+```
+xfsrt-cli faas project get slack
+```
+The `artifacts` array contains an object with the URL in its `name` property (and a `reference` to HTTP trigger `slack-handler`)
+
+## Test
+Install the Slack application to your workspace. In Slack, create a channel. Invite the bot to your channel.
+Click on the attachment upload button inside the channel, select an image of your choice and upload it.
+As a response, you should get an `SAP Leonardo` powered probability estimation of what is contained in the image. 
+
+## License
+Copyright (c) 2020 SAP SE or an SAP affiliate company. All rights reserved.
+This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the [LICENSE file](../LICENSE.txt).

examples/slack-classify-image/data/services/leonardoapikey

@@ -0,0 +1 @@
+xxx

examples/slack-classify-image/data/services/slacktoken

@@ -0,0 +1 @@
+xxx

examples/slack-classify-image/faas.json

@@ -0,0 +1,28 @@
+{
+  "project": "slack",
+  "version": "0.0.1",
+  "runtime": "nodejs10",
+  "library": "./lib",
+  "secrets": {
+    "slack-classify-image": {
+      "source": "./data/services"
+    }
+  },
+  "functions": {
+    "slack-handler": {
+      "module": "slack-event.js"
+    },
+    "slack-classify": {
+      "module": "classify-image.js",
+      "secrets": [
+        "slack-classify-image"
+      ]
+    }
+  },
+  "triggers": {
+    "slack-handler": {
+      "type": "HTTP",
+      "function": "slack-handler"
+    }
+  }
+}

examples/slack-classify-image/lib/classify-image.js

@@ -0,0 +1,106 @@
+'use strict';
+/** @typedef {import("@sap/faas").Faas.Event} Faas.Event 
+*   @typedef {import("@sap/faas").Faas.Context} Faas.Context 
+*/
+
+const request = require('request');
+const SlackWebClient = require('@slack/client').WebClient;
+
+module.exports = classifyImage;
+
+/**
+ * @param {Faas.Event} event
+ * @param {Faas.Context} context
+ * @return {Promise<any>}
+ */
+async function classifyImage(event, context) {
+
+    // https://api.sap.com/api/image_classification_api/overview
+    const LEONARDO_API_KEY = await context.getSecretValueString('slack-classify-image', 'leonardoapikey');
+    const LEONARDO_ENDPOINT = 'https://sandbox.api.sap.com/mlfs/api/v2/image/classification';
+    const leonardo = {
+        endpoint: LEONARDO_ENDPOINT,
+        apiKey: LEONARDO_API_KEY,
+    };
+
+    // https://api.slack.com/slack-apps#creating_apps
+    const SLACK_CLIENT_TOKEN = await context.getSecretValueString('slack-classify-image', 'slacktoken');
+    const slack = {
+        client: new SlackWebClient(SLACK_CLIENT_TOKEN),
+        token: SLACK_CLIENT_TOKEN,
+    };
+
+    let file, cType;
+
+    switch (event.data.event.type) {
+        case 'file_shared':  // https://api.slack.com/events/file_shared
+            return slack.client.files.info({ file: event.data.event.file_id, count: 0 })
+                // check created file
+                .then((fileDesc) => new Promise((resolve, reject) => {
+                    file = fileDesc.file;
+                    request({
+                        url: file.url_private,
+                        encoding: null,
+                        headers: { 'Authorization': 'Bearer ' + slack.token }
+                    }, (err, response, body) => {
+                        if (err) reject(err);
+                        cType = response.headers['content-type'];
+                        if (!cType.startsWith('image')) reject(new Error(`file mime type ${cType}not supported`));
+
+                        resolve(body);
+                    });
+                }))
+                // post final image to leonardo
+                .then((imgFinal) => new Promise((resolve, reject) => {
+                    request.post({
+                        url: leonardo.endpoint,
+                        headers: {
+                            'Accept': 'application/json',
+                            'APIKey': leonardo.apiKey,
+                        },
+                        formData: {
+                            files: {
+                                value: imgFinal,
+                                options: {
+                                    contentType: cType,
+                                    filename: file.name
+                                }
+                            }
+                        },
+                        preambleCRLF: true,
+                        postambleCRLF: true,
+
+                    }, (err, response, body) => {
+                        if (err) reject(err);
+                        if (response.statusCode === 200) {
+                            resolve(JSON.parse(body));
+                        }
+                        else {
+                            reject();
+                        }
+                    });
+                }))
+
+                // create slack message from leonardo prediction
+                .then((data) => {
+                    const results = (data.predictions.length === 0) ? [] : data.predictions[0].results.reduce(function (result, current) {
+                        result.push(`${current.label} with score ${current.score}`);
+                        return result;
+                    }, []);
+                    const message = `Leonardo thinks image ${file.name} contains ${results.length ? ':\n' + results.join('\n') : ' nothing'}`;
+
+                    return slack.client.chat.postMessage({
+                        channel: file.channels[0],
+                        text: message
+                    });
+                })
+
+                .catch((err) => {
+                    console.log('error during image classification ' + err);
+                });
+        default:
+            console.log(`unknown event "${event.data.event.type}" received`);
+    }
+
+}
+

examples/slack-classify-image/lib/slack-event.js

@@ -0,0 +1,22 @@
+'use strict';
+/**
+ * @namespace Faas
+ * @typedef {import("@sap/faas").Faas.Event} Faas.Event
+ * @typedef {import("@sap/faas").Faas.Context} Faas.Context
+ */
+
+/**
+ * @param {Faas.Event} event
+ * @param {Faas.Context} context
+ * @return {Promise<*>|*}
+ */
+module.exports = function (event, context) {
+    if (event.data.challenge) {
+        return { challenge: event.data.challenge };
+    }
+    context.callFunction('slack-classify', { // do not await
+        type: 'application/json',
+        data: event.data
+    });
+};
+

examples/slack-classify-image/package.json

@@ -0,0 +1,19 @@
+{
+  "dependencies": {
+    "@slack/client": "5.0.2",
+    "request": "2.88.2"
+  },
+  "devDependencies": {
+    "@sap/faas": ">=0.7.0"
+  },
+  "files": [
+    "data",
+    "lib",
+    "faas.json",
+    "package.json"
+  ],
+  "scripts": {
+    "test": "npm run all-tests",
+    "all-tests": "node ./node_modules/mocha/bin/_mocha test/**/test*.js --colors -csdlJson --slow 200"
+  }
+}