Swift HelloWorld App Overview
This project contains a simple Swift hello world application that can be deployed to the IBM Cloud or run locally on your macOS or Ubuntu Linux system. This sample application creates a basic server that returns an HTML greeting to the client. Please note that this is not a production-ready application. Instead, it is for educational purposes to learn about the types of applications you can develop using the Swift programming language.
To compile and run this sample application on your system, you need to install the Swift compiler for your platform. Please note that the Swift language is evolving and changing rapidly. The latest version of this Swift application works with the
5.1+ version of the Swift binaries. You can download this version of the Swift binaries by following this link.
If you are interested in manually deploying the application to the IBM Cloud, you'd need to install the IBM Cloud command line on your system. Once it is installed, you can use it to authenticate and access your IBM Cloud organizations and spaces. You can find further details on how to deploy this sample application to the IBM Cloud in the following sections.
Run the app locally
Once you have installed the Swift compiler and cloned this Git repo, you can now compile and run the application. Go to the root folder of this repo on your system and issue the following command:
$ swift build
You should see an output similar to the following:
Compile Swift Module 'LoggerAPI' (1 sources) Compile Swift Module 'Socket' (3 sources) Compile Swift Module 'HeliumLogger' (2 sources) Compile Swift Module 'Configuration' (7 sources) Compile Swift Module 'CloudFoundryEnv' (5 sources) Compile Swift Module 'HerokuConfig' (1 sources) Compile Swift Module 'CloudFoundryConfig' (2 sources) Compile Swift Module 'AmazonConfig' (1 sources) Compile Swift Module 'Utils' (2 sources) Compile Swift Module 'Server' (1 sources) Linking ./.build/debug/Server
Once the application is successfully compiled, you can run the executable that was generated by the Swift compiler:
$ swift run
You should see an output similar to the following:
Server is listening on port: 8080
To connect to the server, you can use the browser of your preference (e.g. Firefox, Chrome, etc.) to point to the following URL:
<hostname> is the hostname or the IP address of the system where you are running the sample app. If the browser is running on the same system, you can use localhost as the value for the hostname. After you access the server, the browser should render an HTML page with the following message:
Hello from Swift on Linux!
Below the greeting message, you should also see an HTML table that displays the environment variables for the app.
Running the app on the IBM Cloud
Using the magical button
Click the magical button below to automatically deploy this sample application to the IBM Cloud.
When automatically deploying to the IBM Cloud, the
manifest.yml file [included in the repo] is parsed to obtain the name of the application. For further details on the structure of the
manifest.yml file, see the Cloud Foundry documentation.
Using the IBM Cloud command line
You can also manually deploy the app to the IBM Cloud. Though not as magical as using the IBM Cloud button above, manually deploying the app gives you some insights about what is happening behind the scenes. Remember that you'd need the IBM Cloud command line installed on your system to deploy the app to the IBM Cloud.
Using the IBM Cloud command line you can get a list of the buildpacks (along with their versions) that are installed on the IBM Cloud.
ibmcloud cf buildpacks
Executing the above command should result in output similar to the following:
Getting buildpacks... buildpack position enabled locked filename stack liberty-for-java 1 true false buildpack_liberty-for-java_v3.36-20190905-1704.zip sdk-for-nodejs 2 true false buildpack_sdk-for-nodejs_v4.0-20190912-1615.zip dotnet-core 3 true false buildpack_dotnet-core_v2.4-20190912-1554.zip swift_buildpack 4 true false buildpack_swift_v2.1.1-20190821-1903.zip noop-buildpack 5 true false noop-buildpack-20140311-1519.zip xpages_buildpack 6 true false xpages_buildpack_v1.2.2-20170112-1328.zip liberty-for-java_v3_17_1-20180131-1532 7 true false buildpack_liberty-for-java_v3.17.1-20180131-1532.zip liberty_v3_14-20171013-1023 8 true false buildpack_liberty_v3.14-20171013-1023.zip swift_buildpack_v2_0_18-20190303-1915 9 true false buildpack_swift_v2.0.18-20190303-1915.zip swift_buildpack_v2_0_20-20190401-2122 10 true false buildpack_swift_v2.0.20-20190401-2122.zip staticfile_buildpack 11 true false staticfile-buildpack-cflinuxfs3-v1.4.35.zip cflinuxfs3 java_buildpack 12 true false java-buildpack-cflinuxfs3-v4.16.1.zip cflinuxfs3 ruby_buildpack 13 true false ruby-buildpack-cflinuxfs3-v1.7.27.zip cflinuxfs3 nodejs_buildpack 14 true false nodejs-buildpack-cflinuxfs3-v1.6.34.zip cflinuxfs3 go_buildpack 15 true false go-buildpack-cflinuxfs3-v1.8.29.zip cflinuxfs3 python_buildpack 16 true false python-buildpack-cflinuxfs3-v1.6.23.zip cflinuxfs3 php_buildpack 17 true false php-buildpack-cflinuxfs3-v4.3.64.zip cflinuxfs3 binary_buildpack 18 true false binary-buildpack-cflinuxfs3-v1.0.27.zip cflinuxfs3 swift_buildpack_cflinuxfs3_v2_1_0-20190404-1206 19 true false buildpack_swift_cflinuxfs3_v2.1.0-20190404-1206.zip cflinuxfs3 liberty-for-java_v3_35-20190813-1755 20 true false buildpack_liberty-for-java_v3.35-20190813-1755.zip liberty-for-java_v3_36-20190905-1704 21 true false buildpack_liberty-for-java_v3.36-20190905-1704.zip dotnet-core_v2_3-20190609-2145 22 true false buildpack_dotnet-core_v2.3-20190609-2145.zip dotnet-core_v2_4-20190912-1554 23 true false buildpack_dotnet-core_v2.4-20190912-1554.zip sdk-for-nodejs_v3_28-20190722-1336 24 true false buildpack_sdk-for-nodejs_v3.28-20190722-1336.zip sdk-for-nodejs_v4_0-20190912-1615 25 true false buildpack_sdk-for-nodejs_v4.0-20190912-1615.zip
Looking at the output above, we can see that the Swift buildpack (v2.1.0) is installed on the IBM Cloud. This will allow a seamless deployment of the starter application to the IBM Cloud. After you have cloned this Git repo, go to its root folder on your system and issue the following command:
ibmcloud app push
Executing the IBM Cloud push command will parse the contents of the
manifest.yml file and upload the application to the IBM Cloud. The following is example output from executing the
ibmcloud app push command on the Swift
5.0 version of this application:
Using manifest file /Users/gvalenc/git/DevX/swift-helloworld/manifest.yml Getting app info... Creating app with these attributes... + name: swift-helloworld-swift51 path: /Users/gvalenc/git/DevX/swift-helloworld buildpacks: + https://github.com/IBM-Swift/swift-buildpack#2.2.0 + instances: 1 + memory: 128M routes: + swift-helloworld-swift51-shiny-lemur.mybluemix.net Creating app swift-helloworld-swift51... Mapping routes... Comparing local files to remote cache... Packaging files to upload... Uploading files... 14.73 KiB / 14.73 KiB [==================================================================================] 100.00% 1s Waiting for API to complete processing files... Staging app and tracing logs... Cell ca3309ff-c7c4-4aaf-b47e-3ef8e1e2e07f creating container for instance 880e2117-2039-4b9d-9eb2-00c5a0f1689f Cell ca3309ff-c7c4-4aaf-b47e-3ef8e1e2e07f successfully created container for instance 880e2117-2039-4b9d-9eb2-00c5a0f1689f Downloading app package... Downloaded app package (14.7K) -----> Buildpack version 2.2.0 -----> Default supported Swift version is 5.1 -----> Configure for apt-get installs... -----> Writing profile script... -----> Copying deb files to installation folder... -----> No Aptfile found. -----> Getting swift-5.1 Downloaded swift-5.1 -----> Unpacking swift-5.1.tar.gz -----> Getting clang-8.0.0 Downloaded clang-8.0.0 -----> Unpacking clang-8.0.0.tar.xz -----> .ssh directory and config file not found. -----> Skipping cache restore (new swift signature) -----> Fetching Swift packages and parsing Package.swift files... Fetching https://github.com/apple/swift-log.git Fetching https://github.com/IBM-Swift/CloudEnvironment.git Fetching https://github.com/IBM-Swift/LoggerAPI.git Fetching https://github.com/IBM-Swift/Configuration.git Fetching https://github.com/IBM-Swift/BlueSocket.git Fetching https://github.com/IBM-Swift/HeliumLogger.git Fetching https://github.com/IBM-Swift/Swift-cfenv.git Fetching https://github.com/IBM-Swift/FileKit.git Completed resolution in 19.21s Cloning https://github.com/IBM-Swift/Swift-cfenv.git Resolving https://github.com/IBM-Swift/Swift-cfenv.git at 6.0.3 Cloning https://github.com/IBM-Swift/BlueSocket.git Resolving https://github.com/IBM-Swift/BlueSocket.git at 1.0.49 Cloning https://github.com/apple/swift-log.git Resolving https://github.com/apple/swift-log.git at 1.1.1 Cloning https://github.com/IBM-Swift/FileKit.git Resolving https://github.com/IBM-Swift/FileKit.git at 0.0.2 Cloning https://github.com/IBM-Swift/LoggerAPI.git Resolving https://github.com/IBM-Swift/LoggerAPI.git at 1.9.0 Cloning https://github.com/IBM-Swift/CloudEnvironment.git Resolving https://github.com/IBM-Swift/CloudEnvironment.git at 9.1.0 Cloning https://github.com/IBM-Swift/HeliumLogger.git Resolving https://github.com/IBM-Swift/HeliumLogger.git at 1.9.0 Cloning https://github.com/IBM-Swift/Configuration.git Resolving https://github.com/IBM-Swift/Configuration.git at 3.0.4 -----> No additional packages to download. -----> Skipping installation of App Management (debug) -----> Installing system level dependencies... -----> Building Package... -----> Build config: release [1/3] Compiling Logging Locks.swift [2/4] Compiling LoggerAPI Logger.swift [3/6] Compiling FileKit FileKit.swift [4/7] Compiling HeliumLogger HeliumLogHandler.swift [5/7] Compiling Configuration ConfigurationManager.swift [6/8] Compiling Socket Socket.swift [7/8] Compiling CloudFoundryEnv App.swift [8/9] Compiling CloudEnvironment AlertNotificationCredentials.swift [9/10] Compiling Utils HttpResponse.swift [10/11] Compiling Server main.swift [11/11] Linking Server -----> Bin path: /tmp/app/.build/x86_64-unknown-linux/release -----> Copying dynamic libraries -----> Copying binaries to 'bin' -----> Clearing previous swift cache -----> Skipping cache save (disabled by default) -----> Optimizing contents of cache folder... Exit status 0 Uploading droplet, build artifacts cache... Uploading droplet... Uploading build artifacts cache... Uploaded build artifacts cache (1.6K) Uploaded droplet (221.5M) Uploading complete Cell ca3309ff-c7c4-4aaf-b47e-3ef8e1e2e07f stopping instance 880e2117-2039-4b9d-9eb2-00c5a0f1689f Cell ca3309ff-c7c4-4aaf-b47e-3ef8e1e2e07f destroying container for instance 880e2117-2039-4b9d-9eb2-00c5a0f1689f Cell ca3309ff-c7c4-4aaf-b47e-3ef8e1e2e07f successfully destroyed container for instance 880e2117-2039-4b9d-9eb2-00c5a0f1689f Waiting for app to start... name: swift-helloworld-swift51 requested state: started routes: swift-helloworld-swift51-shiny-lemur.mybluemix.net last uploaded: Mon 30 Sep 09:24:42 CDT 2019 stack: cflinuxfs3 buildpacks: https://github.com/IBM-Swift/swift-buildpack#2.2.0 type: web instances: 1/1 memory usage: 128M start command: Server state since cpu memory disk details #0 running 2019-09-30T14:25:23Z 1.5% 36K of 128M 8K of 1G
Once the sample application is pushed to the IBM Cloud, you can access it using its route. You can log on to your IBM Cloud account to find the route of your application or you can inspect the output from the execution of the
ibmcloud app push command. The string value (e.g. swift-helloworld.mybluemix.net) shown next to the urls should contain the route. Use that route as the URL to access the sample server using the browser of your choice. The browser should render an HTML page with the following message at the top:
Hello from Swift on Linux!
Using a different version of Swift on IBM Cloud for your application
If you look closely at the output above returned by the
ibmcloud app push command, you will notice that
5.1 was the Swift version used for compiling and running the sample app on the IBM Cloud. If you have a Swift application that compiles with a different version of the Swift binaries, say
DEVELOPMENT-SNAPSHOT-2016-08-30-a, you'd need to update the contents of the
.swift-version file to:
After updating the
.swift-version file, you can run the
ibmcloud app push command to push your application to IBM Cloud and use the specified version of the Swift binaries for compiling and running your application.
For a complete list of the Swift versions currently supported and cached by the Swift buildpack for IBM Cloud, see the buildpack's manifest file. If you cannot find the version of the Swift binaries you are looking for in this file, then that version is not currently supported in the cache.
Running the application in an IBM Container on the IBM Cloud
This sample application can also be run in an IBM Container on the IBM Cloud. For details on how to do this, see 10 Steps To Running a Swift App in an IBM Container. In this blog post, you will find the necessary steps for creating an IBM Container that executes this starter application.