I am building a AWS Java Lambda function using SAM template and AWS CodePiepline using terraform.

The Build stage fails stating that it cannot find the template file for running sam package command.

Relevant code snippet is as below.

Terraform Code For Building Pipeline:

stage {
      name = "Source" 
      action {
        name = "Source"
        category = "Source"
        owner = "AWS"
        provider = "CodeCommit"
        version = "1"
        input_artifacts = []
        output_artifacts = ["source_output"]
        configuration = {
          RepositoryName       = "add-integers-lambda"
          BranchName           = "master"
          PollForSourceChanges = true
      }
    }
    }
 
  stage {
      name = "BuildStage" 
     
      action {
        name = "BuildAction"
        category = "Build"
        owner = "AWS"
        provider = "CodeBuild"
        version = "1"
        input_artifacts  = ["source_output"]
        output_artifacts = ["build_output"]
        configuration = {
          ProjectName = var.project_name
        }
      }
    }
}

SAM Template File

Resources:
  AddIntegersFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: add-integers-lambda-function
      CodeUri: target/add-integers-lambda-1.0-SNAPSHOT.jar
      Handler: com.csz.lambda.AddIntegersHandler::handleRequest
      Runtime: java17
      Timeout: 20
      Architectures:
        - x86_64
      MemorySize: 1024
      Policies:
        - LambdaInvokePolicy:
            FunctionName: add-integers-lambda-function

buildspec.yml file

version: 0.2
phases:
  install:
    runtime-versions:
      java: corretto17
  pre_build:
    commands:
      - echo Nothing to do in pre_build phase
  build:
    commands:
      - echo Build started on `date`
      - mvn package
      - sam package
        --template-file build_output::template.yml
        --output-template-file package.yml
        --s3-bucket add-integers-lambda-171965071268
artifacts:
  files:
    - package.yml

Thanks much for all your help.