Cloud Foundry provides a simple way to deploy applications using the `cf push` command. This command allows you to deploy your application to Cloud Foundry with a single command.
To use the `cf push` command, you need to configure your application's push settings. This includes setting the application name, instance count, and memory allocation.
The `manifest.yml` file is used to configure the push settings for your application. This file specifies the application name, instance count, and memory allocation, among other settings.
Cloud Foundry provides a default `manifest.yml` file that you can use as a starting point for your application's configuration.
Prerequisites
Before you push your app to Cloud Foundry, it's essential to ensure your app is "cloud-ready." This means making modifications to address behaviors related to file storage, HTTP sessions, and port usage.
Your Cloud Foundry deployment should support the type of app you're pushing, or you should have the URL of an externally-available buildpack that can stage the app.
To prepare your app, you'll need to upload all required app resources, such as a database driver. This is crucial for a smooth deployment.
You should also have your target and credentials ready. This includes being logged into your app's target org and space.
Make sure your app can access every service it uses, as an instance of the service runs in, or is shared with, the app's space.
Here's a quick checklist to ensure you're ready to push your app:
- Your app is "cloud-ready."
- Your Cloud Foundry deployment supports the type of app you're pushing.
- All required app resources are uploaded.
- You're logged into your app's target org and space.
- Your app can access every service it uses.
Cloud Foundry Push Configuration
You can configure the cf push command to run custom initialization tasks for an app. These tasks run after Cloud Foundry loads the app droplet but before it starts the app.
To run initialization tasks, you need to create a .profile script that contains the initialization tasks and save it to the directory where you run the cf push command.
The .profile script can be used to set environment variables, map values from $VCAP_SERVICES into other environment variables or a config file, and more. For example, you can set a value for the environment variable LANG to allow the app to find out which language to use for error messages and instructions, collating sequences, and date formats.
Here are some things to keep in mind when running initialization tasks:
- Java: Initialization scripts for the Java buildpack require additional configuration.
- PHP: Cloud Foundry does not support initialization scripts for the PHP buildpack versions prior to v4.3.18.
Your app root directory might also include a .profile.d directory that contains bash scripts that perform initialization tasks for the buildpack. Developers must not edit these scripts unless they are using a custom buildpack.
With Defaults
Pushing an app to Cloud Foundry with defaults is a straightforward process. You'll need to choose a unique name for your app, consisting of alphanumeric characters.
To do this, run the command `cf push APP-NAME`, replacing APP-NAME with the name of your app. It's essential to keep in mind that the app name must be unique to your Cloud Foundry deployment.
By default, Cloud Foundry sets the hostname and domain for your app's route. The hostname is the name of your app, and if it contains underscores, they are converted to hyphens.
For example, an app named example-app running on Cloud Foundry with the default apps domain apps.example.com will run at the URL https://example-app.apps.example.com by default.
The default domain for your Cloud Foundry deployment is used as the domain for your app's route.
Here's a summary of the default settings:
TAS for VMs has similar default settings for hostname and domain, making it easy to push apps to this platform as well.
Upload File Limit
Cloud Foundry uploads all app files by default, except version control files and directories with names like .svn, .git, and _darcs.
Explicitly excluding extraneous files can save resources, especially for large apps.
To exclude files from upload, create a .cfignore file that lists the files to exclude.
Save the .cfignore file to the directory where you run the cf push command.
This will prevent those files from being uploaded to the Cloud Foundry platform.
By following these simple steps, you can optimize your app's upload process and save resources.
Configure Initialization
You can configure the cf push command to run custom initialization tasks for an app.
These tasks run after Cloud Foundry loads the app droplet but before it starts the app to allow the initialization script to access the app language runtime environment.
To run initialization tasks, you need to create a .profile script that contains the initialization tasks and save it to the directory where you run the cf push command.
For example, you can use a .profile file to set a value for the environment variable LANG, allowing your app to find out which language to use for error messages and instructions, collating sequences, and date formats.
Java initialization scripts require additional configuration, so be sure to check out the VMware Tanzu Knowledge Base for more information.
PHP initialization scripts are not supported for versions prior to v4.3.18, so if you're using one of these versions, your app will host the .profile script's contents, which can lead to credential leaks.
You can also find bash scripts that perform initialization tasks for the buildpack in the .profile.d directory, but developers must not edit these scripts unless they are using a custom buildpack.
Here are some key points to keep in mind:
- Java initialization scripts require additional configuration.
- PHP initialization scripts are not supported for versions prior to v4.3.18.
- Initialization tasks are also called pre-runtime hooks and .profile tasks.
Deployment
To deploy your first application on Cloud Foundry, you'll want to start by cloning the Stratos project code from the provided repository link. This will give you a web management UI where you can perform nearly every possible action using the CLI.
The manifest.yml file, which is a deployment descriptor for Cloud Foundry, contains settings for the deployed application like the name, available memory, disk space, and more. You'll need to add a service binding to the manifest file, so your app will use one of the databases you've provisioned previously.
You can do this by adding the services section and providing the id of the service, which is “mysql1”. Save the manifest file, and then execute the cf push command to deploy your application to the platform.
The application will be built, deployed to the platform, and the MySQL service will be bound to it, so the app will use the database as its primary data source. This may take a few minutes if you haven't built the application previously.
There are two ways to deploy Stratos to Cloud Foundry: deploying from source or deploying from a docker image. If you choose to deploy from source, you'll need to have the cf CLI command line tool installed and configured to point to your Cloud Foundry cluster.
Here are the deployment steps for Stratos:
- Deploy Stratos from source
- Deploy Stratos from docker image
You can also deploy Stratos using the splatform/stratos docker image, but your Cloud Foundry must have docker support enabled. To do this, you'll need to download the manifest-docker.yml file or create your own manifest file with the following settings:
- Copy applications: -name: console
- docker:image: splatform/stratos:stable
- instances: 1
- memory: 128M
- disk_quota: 384M
Once you have your manifest file, you can simply push it to Cloud Foundry using the cf push command.
Customization
Customization is a key feature of Cloud Foundry's push functionality. You can customize basic app settings, such as the name, instances, memory limit, disk space limit, log rate limit, and start command, to suit your needs.
For instance, you can use any series of alphanumeric characters as the name of your app. It's generally recommended to run a minimum of two instances of your app for production, but you can adjust this based on your specific requirements. You can also set a memory limit to prevent instances from consuming too much memory, and a disk space limit to prevent instances from consuming too much disk space.
You can customize these settings in one of two ways: by including them in the cf push command itself, or by including them in a manifest file. A manifest file is a great way to store your app's configuration settings in one place, making it easier to manage your app's deployment.
Customize Basic Settings
You can use any series of alphanumeric characters as the name of your app.
The more app instances you run, the less downtime your app experiences, but running a single instance can simplify troubleshooting if your app is still in development.
Cloud Foundry recommends a minimum of two instances for any production app.
The maximum amount of memory that each instance of your app can consume is set by the memory limit, and if an app instance exceeds this limit, Cloud Foundry restarts the instance.
If an app instance exceeds its memory limit repeatedly in a short period of time, Cloud Foundry delays restarting the app instance.
The maximum amount of disk space that each instance of your app can consume is set by the disk space limit, and if an app instance exceeds this limit, Cloud Foundry restarts the instance.
If an app instance exceeds its disk space limit repeatedly in a short period of time, Cloud Foundry delays restarting the app instance.
The maximum number of logs that each instance of your app can send to Loggregator is set by the log rate limit, and if an app instance exceeds this limit, Cloud Foundry drops the excess logs and reports doing so.
This is the command that Cloud Foundry uses to start each instance of your app, and this start command differs by app framework.
Memory Usage
Customization gives you the flexibility to tailor your application to meet your specific needs. The memory usage of your application is one aspect that can be customized.
The Stratos Cloud Foundry manifest.yml file allows you to specify the memory requirements of your application. In the case of an Angular2 app, 1512MB of memory is required during the build process.
This is because building an Angular2 app is a memory-intensive process. You can scale down the memory limit after the app has been pushed using the cf CLI.
Stratos Web UI
Stratos Web UI is a web application that can be deployed directly on the Cloud Foundry platform. It provides a web management UI where you can perform nearly every possible action using the CLI.
To get started, you'll need to clone the application code from the provided repository link and take a look at the manifest.yml file, which contains settings for the deployed application like the name, available memory, and disk space.
You can add a service binding to the app, so it uses one of the databases you've provisioned previously, by using the services section and providing the id of the service, which is "mysql1".
To deploy the application, execute the cf push command, which will build, deploy the application to the platform, and bind the MySQL service to it. The buildpack will build both the JS frontend and Go backend for the app in one go.
Here's a summary of the deployment process:
Deploying Your First Stratos Web UI
First, you'll need to clone the Stratos application code from the provided repository link. This will give you the necessary files to deploy your first Stratos Web UI.
The manifest.yml file is a crucial deployment descriptor for Cloud Foundry, containing settings for the deployed application such as name, available memory, and disk space. You should take a look at this file to familiarize yourself with the settings.
To add a service binding to the app, you'll use the services section in the manifest file and provide the id of the service, which is "mysql1". This will allow the app to use one of the databases you've provisioned previously.
You can deploy the application by executing the cf push command. This will build, deploy, and bind the MySQL service to the app. The buildpack will build both the JS frontend and Go backend for the app in one go.
Here are the general steps to follow:
- Clone the Stratos application code
- Update the manifest.yml file with the necessary settings
- Add a service binding to the app
- Execute the cf push command to deploy the application
Note: It may take a few minutes for the application to deploy, especially if you haven't built it previously.
Default Route
The default route for an app is the URL at which it runs. This is automatically assembled by Cloud Foundry from the app's host name and domain.
The host name is set to the app name, which must be unique and consist of alphanumeric characters. If the app name contains underscores, they are converted to hyphens when creating the app's route.
The domain is set to the default apps domain for your Cloud Foundry deployment. This is the same domain used by other apps running on Cloud Foundry.
For example, an app named example-app running on Cloud Foundry with an apps domain apps.example.com runs at the URL https://example-app.apps.example.com by default.
Here's a breakdown of how the default route is assembled:
This means that if you have an app named example-app, it will run at the URL https://example-app.apps.example.com, regardless of the domain you're using.
Frequently Asked Questions
What is the purpose of option under CF push?
The purpose of the option under CF push is to name the host of an application. It allows for simple pushing by choosing the default way, making app deployment easier.
What does the CF push command do in an SAP business application Studio project?
The cf push command deploys your SAP business application to the Cloud Foundry runtime, handling configuration automatically. This command is your gateway to making your app live and accessible.
Sources
- https://docs.cloudfoundry.org/devguide/deploy-apps/deploy-app.html
- https://docs.vmware.com/en/VMware-Tanzu-Application-Service/6.0/tas-for-vms/deploy-apps-deploy-app.html
- https://softwarehut.com/blog/tech/try-cloud-foundry-deploying-application
- https://stackoverflow.com/questions/54772093/how-cf-push-works
- https://stratos.app/docs/deploy/cloud-foundry/cloud-foundry
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