private getWebSocketConnectFunction()

in infrastructure/cdk/lib/layer/websocketLayer.ts [57:110]
47 lines of code
3 McCabe index (conditional complexity)

    private getWebSocketConnectFunction() {
    /**
     * This function requires access to
     * SystemsManager
     *      process.env.SESSION_PARAMETER = /<getAppRefName>/session
     * DynamoDB Tables
     *      process.env.SESSION_CONTROL_TABLENAME = getAppRefName+'SessionControl' 
     */
        let sessionParameter = { name: '/'+this.properties.getApplicationName().toLocaleLowerCase()+'/session' };
        let sessionControlTable : Table = <Table> this.properties.getParameter('table.sessioncontrol');
        if (sessionParameter && sessionControlTable) {
            let createdFunction: Lambda.Function = 
                new Lambda.Function(this, this.properties.getApplicationName() + 'WebSocketConnect', {
                    runtime:Lambda.Runtime.NODEJS_14_X,
                    handler: 'index.handler',
                    code: Lambda.Code.fromAsset(path.join(lambdasLocation, 'websocketConnect')),
                    environment: {
                        'SESSION_CONTROL_TABLENAME': sessionControlTable.tableName,
                        'SESSION_PARAMETER': sessionParameter.name
                    },
                    functionName: this.properties.getApplicationName() + 'WebSocketConnect',
                    description: 'This function stores the connectionID to DynamoDB',
                    memorySize: 128,
                    timeout: Duration.seconds(60),
                    role: new IAM.Role(this, this.properties.getApplicationName() + 'WebSocketConnectFn_Role', {
                        roleName: this.properties.getApplicationName() + 'WebSocketConnectFn_Role',
                        assumedBy: new IAM.ServicePrincipal('lambda.amazonaws.com'),
                        managedPolicies : [ ManagedPolicy.fromAwsManagedPolicyName('service-role/AWSLambdaBasicExecutionRole') ],
                        inlinePolicies: {
                            'DynamoDBPermissions':
                                new IAM.PolicyDocument({
                                    statements : [
                                        new IAM.PolicyStatement({
                                            resources: [ sessionControlTable.tableArn ],
                                            actions : [ 'dynamodb:UpdateItem' ]
                                        })
                                    ]
                                }),
                            'SystemsManagerPermissions':
                                new IAM.PolicyDocument({
                                    statements: [
                                        new IAM.PolicyStatement({
                                            resources : ['arn:aws:ssm:'+this.properties.region+':'+this.properties.accountId+':parameter'+sessionParameter.name ] ,
                                            actions : ['ssm:GetParameter' , 'ssm:GetParameters' ]
                                        })
                                    ]
                                })
                        }  
                    })
                });
            return createdFunction;
        }
        else return undefined;
    }