A service
is like a project. It's where you define your Azure Functions, the events
that trigger them and any resources
they require, all in a file called serverless.yml
.
To get started building your first Serverless Framework project, create a service
.
In the beginning of an application, many people use a single Service to define all of the Functions, Events and Resources for that project. This is what we recommend in the beginning.
myService/
serverless.yml # Contains all functions and infrastructure resources
However, as your application grows, you can break it out into multiple services. A lot of people organize their services by workflows or data models, and group the functions related to those workflows and data models together in the service.
users/
serverless.yml # Contains 4 functions that do Users CRUD operations and the Users database
posts/
serverless.yml # Contains 4 functions that do Posts CRUD operations and the Posts database
comments/
serverless.yml # Contains 4 functions that do Comments CRUD operations and the Comments database
This makes sense since related functions usually use common infrastructure resources, and you want to keep those functions and resources together as a single unit of deployment, for better organization and separation of concerns.
To get started, you can simply use the create
command to generate a new service:
serverless create -t azure-nodejs --path <my-app>
Alternatively, you can use the
install
command to create a new service, based on an existing GitHub boilerplate:serverless install --url https://github.com/azure/boilerplate-azurefunctions --name my-app
You'll see the following files in your working directory:
serverless.yml
handler.js
Each service
configuration is managed in the serverless.yml
file. The main responsibilities of this file are:
- Declare a Serverless service
- Define one or more functions in the service
- Define the provider the service will be deployed to (and the runtime if provided)
- Define any custom plugins to be used
- Define events that trigger each function to execute (e.g. HTTP requests)
- Allow events listed in the
events
section to automatically create the resources required for the event upon deployment - Allow flexible configuration using Serverless Variables
You can see the name of the service, the provider configuration and the first function inside the functions
definition which points to the handler.js
file. Any further service configuration will be done in this file.
# serverless.yml
service: azfx-node-http
provider:
name: azure
location: West US
plugins:
- serverless-azure-functions
functions:
hello:
handler: handler.hello
events:
- http: true
x-azure-settings:
authLevel : anonymous
The handler.js
file contains your function code. The function definition in serverless.yml
will point to this handler.js
file and the function exported here.
Create this file and add event data so you can invoke your function with the data via serverless invoke -p event.json
When you deploy a Service, all of the Functions, and Events in your serverless.yml
are translated into calls to the platform API to dynamically define those resources.
To deploy a service, use the deploy
command:
serverless deploy
Check out the deployment guide to learn more about deployments and how they work. Or, check out the deploy command docs for all the details and options.
To easily remove your Service from your Azure Functions account, you can use the remove
command.
Run serverless remove -v
to trigger the removal process. As in the deploy step we're also running in the verbose
mode so you can see all details of the remove process.
Serverless will start the removal and informs you about it's process on the console. A success message is printed once the whole service is removed.
The removal process will only remove the service on your provider's infrastructure. The service directory will still remain on your local machine so you can still modify and (re)deploy it to another stage, region or provider later on.
The Serverless framework is usually installed globally via npm install -g serverless
. This way you have the Serverless CLI available for all your services.
Installing tools globally has the downside that the version can't be pinned inside package.json. This can lead to issues if you upgrade Serverless, but your colleagues or CI system don't. You can now use a new feature in your serverless.yml which is available only in the latest version without worrying that your CI system will deploy with an old version of Serverless.
To configure version pinning define a frameworkVersion
property in your serverless.yaml. Whenever you run a Serverless command from the CLI it checks if your current Serverless version is matching the frameworkVersion
range. The CLI uses Semantic Versioning so you can pin it to an exact version or provide a range. In general we recommend to pin to an exact version to ensure everybody in your team has the exact same setup and no unexpected problems happen.
# serverless.yml
frameworkVersion: "=1.0.3"
…
# serverless.yml
frameworkVersion: ">=1.0.0 <2.0.0"
…