The cf CLI command
cf push pushes apps to TAS for VMs. There are two main ways to run the
cf push command:
cf push APP-NAME to push an app the easiest way, using default settings. For more information, see Push with Defaults below.
cf push command with flags and helper files to customize:
For more information about custom settings, see Push with Custom Settings below.
For an explanation of what TAS for VMs does when you run
cf push, see How Apps are Staged.
For information about the lifecycle of an app, see App Container Lifecycle.
Before you push your app to TAS for VMs, ensure the following:
Your app is cloud-ready. TAS for VMs behaviors related to file storage, HTTP sessions, and port usage may require modifications to your app. To prepare an app to be pushed to TAS for VMs, see:
Your TAS for VMs deployment supports the type of app you are going to push, or you have the URL of an externally-available buildpack that can stage the app.
All required app resources are uploaded. For example, you may need to include a database driver.
You have your target and credentials:
You are logged into your app’s target org and space.
Your app can access every service that it uses, because an instance of the service runs in, or is shared with, the app’s space.
To push an app with default settings:
Choose a name for the app. The app name must consist of alphanumeric characters and be unique to your TAS for VMs deployment.
cf push APP-NAME
APP-NAME is the name of the app.
An app’s route is the URL at which it runs. TAS for VMs assembles the route for a pushed app from a hostname and a domain.
By default, TAS for VMs sets the hostname and domain as follows:
Hostname: The name of the app, as specified in the
cf push command. If the app name contains underscores, TAS for VMs converts them to hyphens when creating the app’s route.
Domain: The default apps domain for your TAS for VMs deployment.
For example, an app named
example-app running on TAS for VMs with an apps domain
apps.example.com would run at the URL
https://example-app.apps.example.com by default.
For more information about routes and domains, see Routes and Domains.
The following example terminal output for
cf push example-app demonstrates how TAS for VMs assigns default values to an app you push:
Creating app example-app in org example-org / space development as email@example.com... OK Creating route example-app.shared-domain.example.com... OK Binding example-app.shared-domain.example.com to example-app... OK Uploading example-app... Uploading app: 560.1K, 9 files OK Starting app example-app in org example-org / space development as firstname.lastname@example.org... -----> Downloaded app package (552K) OK -----> Using Ruby version: ruby-1.9.3 -----> Installing dependencies using Bundler version 1.3.2 Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin --deployment Installing rack (1.5.1) Installing rack-protection (1.3.2) Installing tilt (1.3.3) Installing sinatra (1.3.4) Using bundler (1.3.2) Updating files in vendor/cache Your bundle is complete! It was installed into ./vendor/bundle Cleaning up the bundler cache. -----> Uploading droplet (23M) 1 of 1 instances running App started Showing health and status for app example-app in org example-org / space development as email@example.com... OK requested state: started instances: 1/1 usage: 1G x 1 instances urls: example-app.shared-domain.example.com state since cpu memory disk logging #0 running 2022-09-14 05:07:18 PM 0.0% 18.5M of 1G 52.5M of 1G 3B/s of 1M/s
Pushing an app with with custom settings typically proceeds as follows:
The sections below detail these steps.
Basic settings to customize when pushing an app include:
Name: You can use any series of alphanumeric characters as the name of your app.
Instances: Generally speaking, the more app instances you run, the less downtime your app will experience. If your app is still in development, running a single instance can simplify troubleshooting. For any production app, VMware recommends a minimum of two instances.
Memory limit: The maximum amount of memory that each instance of your app can consume. If an app instance exceeds this limit, TAS for VMs restarts the instance. If an app instance exceeds its memory limit repeatedly in a short period of time, TAS for VMs delays restarting the app instance.
Disk space limit: The maximum amount of disk space that each instance of your app can consume. If an app instance exceeds this limit, TAS for VMs restarts the instance. If an app instance exceeds its disk space limit repeatedly in a short period of time, TAS for VMs delays restarting the app instance.
Log rate limit: The maximum number of logs that each instance of your app can send to Loggregator. If an app instance exceeds this limit, TAS for VMs drops the excess logs and reports doing so.
Start command: This is the command that TAS for VMs uses to start each instance of your app. This start command differs by app framework.
To customize an app’s route:
(Optional) Customize the hostname by including the
-n flag followed by a custom hostname in your
cf push command.
(Optional) ustomize the domain by including the
-d flag followed by a custom domain in your
cf push command. The custom domain must be registered, and mapped to the org that contains the app’s target space.
Ensure that the route is unique. The app’s route must be globally unique, whether you customize its host or domain, or let it use the default route described in Default Route above. To help ensure route uniqueness, include the
--random-route flag in your
cf push command. This creates a route that includes the app name and random words.
By default, TAS for VMs uploads all app files except version control files and folders with names such as
VMware recommends that you explicitly exclude extraneous files residing within your app directory, particularly if your app is large. For example, if you build your app locally and push it as a binary, you can save resources by not uploading any of the app’s source code.
To exclude files from upload:
.cfignore file that lists the files to exclude.
.cfignore file to the directory where you run the
cf push command.
For more information, see Ignore Unnecessary Files When Pushing in Considerations for Designing and Running an App in the Cloud.
You can configure
cf push to run custom initialization tasks for an app.
These tasks run after TAS for VMs loads the app droplet but before it launches the app itself to let the initialization script access the app language runtime environment. For example, your script can map values from
$VCAP_SERVICES into other environment variables or a config file that the app uses.
Additional notes for including important information about configuring app initialization when you use certain buildpacks:
Java: Initialization scripts for the Java buildpack require additional configuration.For more information, see How to Modify the Application Container Environment prior to Application Execution in the VMware Tanzu Knowledge Base.
PHP: TAS for VMs does not support initialization scripts for the PHP buildpack versions prior to v4.3.18. If you use one of these buildpack versions, your app hosts the
.profile script’s contents. This means that any app staged using the affected buildpack versions can leak credentials placed in the
To run initialization tasks:
.profile script that contains the initialization tasks.
.profile script to the directory where you run the
cf push command.
The following example
.profile file uses
bash to set a value for the environment variable
# Set the default LANG for your apps export LANG=en_US.UTF-8
Setting this value at the operating system level allows the app to determine which language to use for error messages and instructions, collating sequences, and date formats.
Your app root directory may also include a
.profile.d directory that contains bash scripts that perform initialization tasks for the buildpack. Developers should not edit these scripts unless they are using a custom buildpack. For more information about custom buildpacks, see Custom Buildpacks.
Initialization tasks as described here are also called pre-runtime hooks and
To specify custom options when pushing an app with
cf push, you can include them in one or both of the following:
cf push command itself.
A manifest file.
manifest.ymland reside in the directory where you run
cf pushwith no arguments.
servicesblock that lists service instances for the app to bind to automatically. For more information, see Services in App Manifest Attribute Reference.
For information about how app settings change from push to push, including how command-line options, manifests, and commands like
cf scale interact, see Deploying with App Manifests.
For a full list of
cf push options, see the Cloud Foundry CLI Reference Guide.
If a newly-pushed app has the same name and route as an older app version, the new app retains the service bindings and service configuration of the previously-pushed version.
For apps that are not already set up for the services that they use:
Bind the services to the app. For more information about services, see Services Overview.
(Optional) Configure the app with the service URL and credentials, if needed. For more information, see Configuring Service Connections.
When you push an app that is already running, TAS for VMs stops all existing instances of that app. Users who try to access the app see a
404 Not Found message while
cf push runs.
With some app updates, old and new versions of your code should never run at the same time. A worst-case example is if your app update migrates a database schema, causing old app instances to fail and lose user data. To prevent this, you must stop all running instances of your app before you push the new version.
When old and new versions of your app can run simultaneously, you can avoid app downtime by using the blue-green deployment method to swap routes between app versions running in parallel. For more information, see Using Blue-Green Deployment to Reduce Downtime and Risk.
If your app does not start on TAS for VMs, first ensure that the app can run locally.
To troubleshoot your app in the cloud using the cf CLI, see Troubleshoot App Deployment and Health.