Nim on AWS Lambda
Write your Lambda functions in nim using the custom runtime and get tiny binaries (250kb) and single-digit millisecond cold starts!
Function Example
Create a bootstrap.nim with the following:
import awslambda, json, times
proc handler(event: JsonNode, context: LambdaContext): JsonNode =
echo "Hi from nim! Invocation will timeout at: ", context.deadline.format("yyyy-MM-dd'T'HH:mm:ss'.'fff")
event["newKey"] = %*"newVal"
event
when isMainModule:
startLambda(handler)Compiling
# if you're using Linux, you probably don't need to compile in docker, but assuming you're not:
docker run --rm -v "$PWD":/app -w /app nimlang/nim \
sh -c 'nimble install -y https://github.com/lambci/awslambda.nim && nim c -d:release bootstrap.nim'
zip -yr lambda.zip bootstrap # and anything else your binary needsThen upload lambda.zip as the function code for your (custom runtime) Lambda.
Documentation
startLambda
proc startLambda*(handler: proc(event: JsonNode, context: LambdaContext): JsonNode)This processes the event processing loop and takes a handler proc that should take the form:
proc handler(event: JsonNode, context: LambdaContext): JsonNodeLambdaContext
Each invocation will also have the following context object populated:
type
LambdaContext* = tuple
functionName: string
functionVersion: string
memoryLimitInMb: int
logGroupName: string
logStreamName: string
awsRequestId: string
invokedFunctionArn: string
deadline: Time
identity: JsonNode
clientContext: JsonNode
