celerity/handlerConfig
v2024-07-22 (draft)
blueprint transform: celerity-2024-07-22
The celerity/handlerConfig resource type is used to define shared configuration for a set of handlers.
This is useful for sharing configurations between multiple handlers in a blueprint.
The metadata.sharedHandlerConfig approach may be preferred when you want all handlers in the blueprint to share the same default configuration.
Annotations
There are no annotations required for linking other resources to a celerity/handlerConfig resource or modifying the behaviour of an API resource.
linkSelector.byLabel can be used to target configuration resources for specific handlers based on their labels.
Specification
The specification is the structure of the resource definition that comes under the spec field of the resource in a blueprint.
codeLocation
The location of the handler code that will be loaded by the runtime, this can be a directory or a file path without the file extension. In an OS-only runtime, this is expected to be a directory containing the handler binary.
type
string
examples
./handlers
runtime
The runtime that handlers will run in. This can be any one of the supported runtimes depending on the chosen target environment.
type
string
examples
python3.12.x
memory
The amount of memory available to the handlers at runtime. The default value is 128MB. This value is used to configure the amount of memory available to the handler in a FaaS1 target environment. In containerised or custom server environments, the highest value across all handlers will be used as a guide to configure the memory available to the runtime.
The minimum and maximum values available depend on the target environment.
type
integer
default value
128
examples
1024
timeout
The maximum amount of time in seconds that handlers can run for before being terminated. This defaults to 30 seconds.
The minimum and maximum values available depend on the target environment.
type
integer
default value
30
tracingEnabled
Whether or not to enable tracing for handlers. The tracing behaviour will vary depending on the target environment. Tracing is not enabled by default.
type
boolean
default value
false
environmentVariables
A mapping of environment variables that will be available to handlers at runtime. When a Celerity application is deployed to containerised or custom server environments, environment variables shared between functions will be merged and made available to the runtime.
type
mapping[string, string]
examples
environmentVariables:
DB_HOST: "${variables.dbHost}"
DB_PORT: "${variables.dbPort}"
Linked From
Links To
Handler configuration resources can not link to other resources.
Runtimes
See the runtimes section of the celerity/handler resource type documentation for a list of supported runtimes.
Examples
The following set of examples include different configurations for the celerity/handlerConfig resource type
along with resource types that would make up a complete application blueprint.
Multiple shared configurations for different handler groups
version: 2023-04-20
transform: celerity-2024-07-22
variables:
dbHost:
type: string
dbPort:
type: integer
resources:
paymentsApi:
type: "celerity/api"
metadata:
displayName: Payments API
linkSelector:
byLabel:
application: "payments"
spec:
protocols: ["http"]
cors:
allowCredentials: true
allowOrigins:
- "https://example.com"
- "https://another.example.com"
allowMethods:
- "GET"
- "POST"
allowHeaders:
- "Content-Type"
- "Authorization"
exposeHeaders:
- "Content-Length"
maxAge: 3600
domain:
domainName: "api.example.com"
basePaths:
- "/"
normalizeBasePath: false
certificateId: "${variables.certificateId}"
securityPolicy: "TLS_1_2"
tracingEnabled: true
getOrder:
type: "celerity/handler"
metadata:
displayName: "Get Order Handler"
labels:
app: "payments"
annotations:
celerity.handler.http: true
celerity.handler.http.method: "GET"
celerity.handler.http.path: "/orders/{orderId}"
spec:
handler: "orders.get_order"
linkSelector:
byLabel:
handlerGroup: "orders"
createOrder:
type: "celerity/handler"
metadata:
displayName: "Create Order Handler"
labels:
app: "payments"
annotations:
celerity.handler.http: true
celerity.handler.http.method: "POST"
celerity.handler.http.path: "/orders"
spec:
handler: "orders.create_order"
linkSelector:
byLabel:
handlerGroup: "orders"
getInvoice:
type: "celerity/handler"
metadata:
displayName: "Get Invoice Handler"
labels:
app: "payments"
annotations:
celerity.handler.http: true
celerity.handler.http.method: "GET"
celerity.handler.http.path: "/invoices/{invoiceId}"
spec:
handler: "billing.get_invoice"
linkSelector:
byLabel:
handlerGroup: "billing"
createInvoice:
type: "celerity/handler"
metadata:
displayName: "Create Invoice Handler"
labels:
app: "payments"
annotations:
celerity.handler.http: true
celerity.handler.http.method: "POST"
celerity.handler.http.path: "/invoices"
spec:
handler: "billing.create_invoice"
linkSelector:
byLabel:
handlerGroup: "billing"
billingHandlerConfig:
type: celerity/handlerConfig
metadata:
displayName: Billing Handlers Configuration
labels:
handlerGroup: billing
spec:
codeLocation: ./handlers
runtime: python3.12.x
memory: 256
timeout: 60
tracingEnabled: true
environmentVariables:
DB_HOST: "${variables.dbHost}"
DB_PORT: "${variables.dbPort}"
ordersHandlerConfig:
type: celerity/handlerConfig
metadata:
displayName: Order Handlers Configuration
labels:
handlerGroup: orders
spec:
codeLocation: ./handlers
runtime: python3.12.x
memory: 512
timeout: 120
tracingEnabled: false
environmentVariables:
DB_HOST: "${variables.dbHost}"
DB_PORT: "${variables.dbPort}"
Footnotes
-
Function-as-a-Service such as AWS Lambda, Google Cloud Functions, and Azure Functions. ↩