Multiple Components

This tutorial will show you how to configure hubctl with your simple component options.

In This Tutorial

This tutorials covers the following topics:

How to add parameters of stack and components
How to deploy a stack with multiple components
How to apply different configuration per component

About

hub.yaml file has components and parameters fields where you describe your options.

kind: stack                                                                   # mandatory, defines a stack manifest
version: 1                                                                    # stack manifest schema version
meta:                                                                         # optional
  name: My second deployment                                                  # optional human readable name

components:                                                                   # mandatory, list of components
  - name: my-first-component                                                  # mandatory, name of the first component
    source:                                                                   # mandatory, component source
      dir: components/hello-hubctl                                            # mandatory, local path where to find component
      git:                                                                    # optional, git source to download component from
        remote: https://github.com/epam/hubctl.io.git                         # mandatory, git repository remote url
        subDir: docs/tutorials/010-hubctl-stack-init/components/hello-hubctl  # mandatory, subdirectory in the repository
        ref: main                                                             # optional, git reference (branch, tag, commit)
  - name: my-second-component                                                 # mandatory, name of the second component
    source:                                                                   # mandatory, component source
      dir: components/hello-hubctl                                            # mandatory, local path where to find component

parameters:                                                                   # optional, stack input parameters (best practice, split to separate file or files)
  - name: message                                                             # mandatory, parameter name
    value: baz                                                                # optional, value for parameter
  - name: message                                                             # mandatory, parameter name
    component: my-first-component                                             # optional, special parameter that always bounds to component name defined in `hub.yaml`
    value: baz-first                                                          # optional, value for parameter

Deploy Stack with one Component

Similar to the tutorial the previous tutorial, we will deploy a stack with one component.

Create an empty directory and change your working directory to it.
Initialize a stack with hubctl stack init command.

hubctl stack init -f "https://raw.githubusercontent.com/epam/hubctl.io/main/docs/tutorials/015-hubctl-stack-configure/hub.yaml"

Wait when stack will be initialized and component will be downloaded in the directory components/hello-hubctl

Now let's update the configuration and deploy this stack with the following commands:

hubctl stack configure

hubctl stack deploy

You can confirm stack has been deployed with command

hubctl show
## ...
##   hub.stackName: My first deployment
##   message: baz-first
## status:
##   status: deployed

As a result, you will see the deployment components with parameters and status. The my-first-component message is "base-first" because "hub.yaml" has a special message parameter for the my-first-component component.

Add a New Component

Let's open the hubfile "hub.yaml" and add following to components field:

 -  name: my-second-component
    source:
        dir: components/hello-hubctl

Let's update the configuration and deploy the second component. Run the following commands:

hubctl stack configure

hubctl stack deploy

As a result, you will see the deployment components my-first-component and my-second-component.

## --- File: deploy.sh
# Component my-first-component is saying: baz-first
# Component my-first-component deployed successfully!

# Component my-second-component is saying: baz
# Component my-second-component deployed successfully!

Let's create a special parameter for the my-second-component component. To do this, add the following to the parameters field of the hub file "hub.yaml":

 -  name: message
    component: my-second-component
    value: baz-second

Update the configuration and deployment:

hubctl stack configure

hubctl stack deploy

As you can see, the message parameter has changed for the my-second-component component

## --- File: deploy.sh
# Component my-second-component is saying: baz-second
# Component my-second-component deployed successfully!

Inspect parameters for both components. Run the following commands:
```
hubctl show -c "my-first-component"
```

hubctl show -c "my-second-component"

Now let's undeploy the second component and run the echo command. To start undeploying for one or more components (provided as a comma-separated value), run the following command.

hubctl stack undeploy -c "my-second-component"

Conclusions

In this tutorial, we added our own parameters and deployed a new configuration. We made sure that the new component was deployed and the next step was to undeploy this component.

What's Next?

Next, we will create a component from scratch, digging into hubctl and its additional features. Go to the next tutorial

Last update: August 30, 2023