In this lab you will create a new API using the OpenAPI definition of an existing RESTful web-service that gets realtime stock quotes. You will then test the deployed API by deploying the IBM Trader Lite application which is a simple stock trading sample, written as a set of microservices. The app uses the API definition that you will create to get realtime stock quotes.
The architecture of the app is shown below:
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Tradr is a Node.js UI for the portfolio service
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The portfolio microservice sits at the center of the application. This microservice:
- persists trade data using JDBC to a MariaDB database
- invokes the stock-quote service that invokes an API defined in API Connect in CP4I to get stock quotes
- calls the trade-history service to store trade data in a PostgreSQL database that can be queried for reporting purposes.
- calls the trade-history service to get aggregated historical trade data.
This lab is broken up into the following steps:
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Download the OpenAPI definition file for the external Stock Quote service
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Verify that the Trader Lite app is calling your API successfully
1.1 In your browser right click on the following link, right click and select Save Link As ... from the context menu. Save the file stock-quote-api.yaml to your local system.
2.1 In a new browser tab open the CP4I Platform Home URL provided to you by your instructors.
2.2 Login with your user??? credentials
2.3 Click on Skip Welcome
2.4 Click on View instances and then click the link for API Connect
2.5 Select the Cloud Dragons LDAP user repository
2.6 Login with your user??? username and password
2.7 Click on the Develop APIs and Products tile
2.8 Click ADD->API
2.9 On the next screen select Existing OpenAPI under Import and then click Next.
2.10 Now choose stock-quote-api.yaml from your local file system and click Next.
2.11 Do not select Activate API. Click Next
2.12 The API should be imported successfully as shown below. Click Edit API.
After importing the existing API, the first step is to configure basic security before exposing it to other developers. By creating a client key you are able to identify the app using the services. Next, we will define the backend endpoints where the API is actually running. API Connect supports pointing to multiple backend endpoints to match your multiple build stage environments.
3.1 Scroll down in the Edit API screen and replace the Host address with $(catalog.host) to indicate that you want calls to the external API to go through API Connect.
3.2 Click Save
3.3 In the Edit API screen click Security Definitions in the left navigation
3.4 In the Security Definition section, click the Add button on the right. This will open a new view titled API Security Definition.
3.5 In the Name field, type client-id.
3.6 Under Type, choose API Key. This will reveal additional settings.
3.7 For Located In choose Header. For Key Type choose Client ID
3.8 Enter X-IBM-Client-Id as the Parameter Name. Your screen should now look like the image below.
3.9 Click the Save button to return to the Security Definitions section.
3.10 Click Security in the left menu. Click Add. Select the client-id as shown below and then click Save.
3.11 Next you'll define the endpoint for the external API. Click on Properties in the left menu.
3.12 Click on the target-url property. Click Add.
3.13 Choose the sandbox catalog and for the URL copy and paste the following URL:
https://stock-trader-quote.us-south.cf.appdomain.cloud
3.14 Click Save to complete the configuration.
In the API designer, you have the ability to test the API immediately after creation in the Assemble view.
4.1 On the top Navigation, click Assemble.
4.2 Click invoke in the flow designer. Note the window on the right with the configuration. The invoke node calls the target-url (ie the external service).
4.3 Modify the URL field to include the request path passed in by the caller as well by appending $(request.path) to the URL.
4.3 Click Save
4.4 Click the play icon as indicated in the image below.
4.5 Click Activate API to publish the API to the gateway for testing.
4.6 After the API is published, your screen should look like the image below.
4.7 Under Operation choose get /stock-quote/djia.
4.8 Note that your client-id is prefilled for you.
4.9 Scroll all the way to the bottom of the browser window and click Invoke.
4.10 If this is the first test of the API, you may see a certificate exception. Simply click on the URL and choose the option to proceed.
4.11 Go back to the test view and click Invoke again.
4.12 Now you should see a Response section with Status code 200 OK and the Body displaying the details of the Dow Jones Industrial Average.
4.13 Scroll up in the test view until you see the Client ID. Copy the value to to a local text file so it can be used in the Stock Trader application later (Note: this is a shortcut to the regular process of publishing the API and then subscribing to it as a consumer).
4.14 Next we'll get the endpoint for your API. Click on the Home icon (top left) and then click on the Manage Catalogs tile.
4.15 Click on the Sandbox tile.
4.16 Click on the Settings icon and then on API Endpoints. Copy the gateway URL and put it in the same file that you used for the Client ID
5.1 In a separate browser tab go to the OpenShift console URL provided by your instructor for the cluster designated to run the Stock Trader Lite application for the workshop.
5.2 Click on your username in the upper right and select Copy Login Command
5.3 You are prompted to login to the OpenShift console again. Repeat the same login procedure above to login.
5.4 Click the Display Token link.
5.5 Copy the contents of the field Log in with this token to the clipboard. It provides a login command with a valid token for your username.
5.6 In a separate browser tab go to the IBM Cloud URL https://cloud.ibm.com and log in with your ibm.com credentials.
5.7 Click the icon for the IBM Cloud Shell terminal to launch it
5.8 Paste the oc login command in the IBM Cloud Shell terminal and run it
6.1 In the IBM Cloud Shell terminal set an environment variable for the student id assigned to you by the instructors (e.g. user005) by running the following command and replacing user??? with your assigned student id.
export STUDENTID=user???
6.2 From the terminal run the following command
git clone https://github.com/IBMStockTraderLite/traderlite-cp4i.git
6.3 Go to the repo main directory required to run the setup scripts
cd traderlite-cp4i/scripts
6.4 Run the following command to get a list of running pods
oc get pods
6.5 Verify the output shows the Trader Lite operator pod running:
$ oc get pods
NAME READY STATUS RESTARTS AGE
traderlite-operator-6ddd5c4774-l5dcd 1/1 Running 0 20m
You'll install Trader Lite using the Trader Lite operator.
7.1 Run the following script, substituting your API Connect endpoint URL and API Key that you saved previously.
./initialInstall.sh [YOUR API CONNECT EXTERNAL URL] [YOUR API KEY]
7.2 Verify that the output looks like the following:
$ ./initialInstall.sh https://yoururl/ your_client_id
Script being run from correct folder
Validating student id ...
Installing Trader Lite using operator ...
traderlite.operators.clouddragons.com/traderlite created
Trader Lite install successful
Wait for all pods to be in the 'Ready' state before continuing
7.3 Wait for all the pods to start. Run the following command.
oc get pods
Repeat the command until all the pods are in the Ready state as shown below
$ oc get pods
NAME READY STATUS RESTARTS AGE
traderlite-mariadb-0 1/1 Running 0 42s
traderlite-mongodb-fd7f6d55b-q54bl 1/1 Running 0 42s
traderlite-operator-6ddd5c4774-l5dcd 1/1 Running 0 19h
traderlite-portfolio-5d774598fc-tvpdh 1/1 Running 0 42s
traderlite-stock-quote-7965448598-7b66t 1/1 Running 0 42s
traderlite-trade-history-5648f749c4-gmnlm 1/1 Running 0 42s
traderlite-tradr-6cd8d879f4-nxm66 1/1 Running 0 42s
You will verify the configuration that you created that points at the API you created in API Connect.
8.1 From the command line run the following script:
./showTradrUrl.sh
8.2 Copy the URL that is output and access it with your browser
8.3 Log in using the username stock and the password trader
8.4 If the DJIA summary has data then you know that the API you created in API Connect is working !
Congratulations ! You successfully completed the following key steps in this lab:
- Created an API by importing an OpenAPI definition for an existing REST service.
- Configured a ClientID/API Key for security set up a proxy to the existing API.
- Tested the API in the API Connect developer toolkit.
- Deployed the Trader Lite app and configured it to use the API you created.
- Tested the Trader Lite app to make sure it successfully uses your API.