Application Manifest usage in Cloud Foundry

In previous post we have seen how to create a sample application and push it into Cloud Foundry and access the application by using Cloud Foundry Route. The current post we will learn about the Manifest.yml usage in cloud foundry applications.
Manifests are ways to describe and deploy application seamlessly to cloud foundry environment. Basically, using Manifest.yml file we can describe how to push our application. In this process, we need to define application name, how much memory that our application required and services that we need to bind and environment variables..etc in manifest file. There is a huge list of alternatives and benefits for any cloud application that uses manifest.

When we try to push our application by using CF PUSH command, it will try to identify manifest.yml file in same directory, that we are trying to push the application. Once it identifies, that process the properties defined and uses to start the application.  If CF PUSH doesn’t find the manifest file, CF push tries to identify what application it’s trying to push. In this process, since it doesn’t find any yml manifest properties,  Cloud Foundry applies default values for all required fields like name, memory & services etc.

We can even provide external Manifest.yml file to CF PUSH by using -F argument. This argument simply tell to Cloud Foundry, go and find wherever it is exists manifest.yml. Once it is located, then it follows the processing as mentioned previously.

If we are going in the way of manifest, there are few mandatory fields which we need to provide,

• application name
• application memory
• buildpack

Buildpack simply indicate cloud foundry about the environment that application should run on. So if we have a java application, then we should provide a java buildpack.

Manifest.yml files are really helpful for CI/CD. Using a standard way with Manifest.yml, we can make our application run anywhere. Even if we changes or migrate the Cloud environment, we have already have configuration in the Manifest.yml that we need to run our application. So, no need to worry about changes after the environment migration.

Manifest.yml files are designed in a way that we can define more than one application inside it. So, assume that we have group of applications in a space. Then defining these applications configuration and pushing into Cloud Foundry is very simple. We can add all manifest properties inside a file and we can push into Cloud Foundry and it is only one time creation and we can use wherever we need. If we need to new service, just we can configure the service in Manifest.yml and redeploy.

Summary:

• Describe Application Deployment
• CF tried to find Manifest.yml in same directory
• External manifest can be provided
• There are required and optional fileds
• Very useful for CI/CD process
• Define more than one application in single Manigest.yml
• Simplest way to deal with CF Application

We can see default properties of application considered by Cloud foundry while starting the app.

name:              cfgreet

requested state:   started

routes:            cfgreet.cfapps.io

last uploaded:     Wed 03 Oct 18:17:54 IST 2018

stack:             cflinuxfs2

buildpacks:        client-certificate-mapper=1.8.0_RELEASE container-security-provider=1.16.0_RELEASE

                   java-buildpack=v4.16-offline-https://github.com/cloudfoundry/java-buildpack.git#41b8ff8

                   java-main java-opts java-security jvmkill-agent=1.16.0_RELEASE open-jdk-…

type:            web

instances:       1/1

memory usage:    1024M

start command:   JAVA_OPTS=”-agentpath:”

How to create manifest.yml?

Cloud Foundry provides the command called create-app-manifest to create manifest.yml file for your application. It will contains all the application information including services which are bind to application. Command syntax look like,

cf create-app-manifest  -p

Below is the sample manifest file look like,

manifest.yml:

applications:
- name: cfcloudgreet
path: target/CFGreet-0.0.1-SNAPSHOT.jar
buildpack: https://github.com/cloudfoundry/java-buildpack.git
memory: 1G

While pushing the application into cloud foundry we need to provide the path of the manifest file. So, we no need to pass all the properties in command line.

Previous: Create Service Instance in PCF

Next: Internal Process of Application Deployment in Cloud Foundry

Advertisement

PCF Application Services

Service is one of the important factor in recommended 12 factor apps also a commonly used feature in cloud application deployment. Services has to be attached to resources either in the local or in production environment. Cloud Foundry build up on that idea where resource and provides the service instances. The basic idea what we have here is,

On-demand resources = Services

We can manage application services in two ways by using CF CLI and another is form marketplace. Marketplace helps you to use readily available services in Pivotal Cloud Foundry. You simply go to services tab in the Cloud Foundry or Marketplace to look services available. Assume that you want to see MySQL database in Cloud Foundry that locates in Marketplace. As on when you bind that service, you have service ready to use. This is also called as Provisioning.

Cloud Foundry services uses a provisions as a service. There is a command for managing services of application. That is, CF SERVICE command. There are two types of service instances,

Manage Service Instance

User provided Service Instance

Manage Service Instance: An instance which is created from the marketplace service is called as Manage service instance. which all services available in market place to bind with our application, these type of services called as managed services. As part of this, we use only create-service and bind-service commands to create and bind service with our application.

User provided Service Instance: An instance which is created from the user provided service is called as User provided service instance. The services which are not present in marketplace and created by the user is called as User provided services. To create user provided service, we use the command called create-user-provided-service. This command also has the alias name called as cups.

List of Service Commands:

Many service instances are advance that we use in Cloud Foundry itself. Such as the MySQL etc. These services are using Service Broker API to implement their all services. Cloud Foundry Marketplace advertise these all services and shows you all available services you can use.

As on when we select a service there will be options shows start, shutdown and bind. These are manage by Service Broker APIs. Once we can get the instance of manage broker API, we can use of it in our applications through binding. We can use CF BIND command in our manifest file.

So, when we pushed our application into Cloud Foundry, that service will be bind to our application. After that we can start using immediately. We can insert data, pull data and so on, it is a database instance.

Will definitely have demonstration of both the sides like managed and user defined services. User defined services are advance that we can provide to our applications and actual user seemly like to case in the manage services. Let’s assume that we have some environment variables that other people or application developers to use. So, we can create a User defined service and provide your variables through it. It works just like the manage services, so you can manifest to bind it to application or simply go to dashboard and bind it manually with the application.

Multiple Deployment Options:

There are couple of deployment options we have in Cloud Foundry which we can make use of it. So for service to be available for binding on the requirement is that, it should implement Service Broker API.

So assume that, we want to have a service definition, which goes into category of user defined service. We can simply attach that service as a resource to our application or for the other service deployment options, we can have our service defined and deployed in Cloud Foundry. Cloud Foundry platform is really flexible allowing use to know how we want it.

Previous: Cloud Foundry – Push Application into Space

Next: Create Service Instance in PCF

Create Service Instance in PCF

In this post we will look at how to create a service instance in PCF from command line interface. As part of creating service instance we need to use the below 3 commands, which has it’s own specific use,

cf marketplace

cf create-service

cf services

cf marketplace command shows you list of services available in Cloud Foundry marketplace.

cf create-service command will be used to create new service. As part of this command we need to pass what service and what type of plan we are taking along with service service. Below is the example,

cf create-service mongolab sandbox mongoservice

As per the above command,

mongolab is the service instance which I am trying to create

sandbox is one of the basic plan which I am applying for mongolab

mongoservice is my service name

Finally, cf service to know all services which are bind with your application.

What are Spaces, Organizations and Roles?

The below diagram illustrates about the Spaces, Organizations and Roles in Cloud Foundry.

Previous: PCF Application Service

Next: Application Manifest usage in Cloud Foundry