I can't read from the environment variable (aws-lambda in Go) - amazon-web-services

Question

I want to test AWS Lambda in local environment using DynamoDB Local and SAM CLI.
I create a simple user db table(id, name) and I'm trying to get the data.
I run "sam local start-api --env-vars test/env.json". When I access "http://localhost:3000/users/1", an error occured. Error message is below. I can't understand what this error message means. How do I fix this error?
{
"errorMessage": "InvalidParameter: 1 validation error(s) found.\n- minimum field size of 3, GetItemInput.TableName.\n",
"errorType": "ErrInvalidParams"
}
This is my code.
func handler(request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
// Environment variables
endpoint := os.Getenv("DYNAMODB_ENDPOINT")
tableName := os.Getenv("DYNAMODB_TABLE_NAME")
// Request
id, _ := request.PathParameters["id"]
// DynamoDB
sess := session.Must(session.NewSession())
config := aws.NewConfig().WithRegion("ap-northeast-1")
if len(endpoint) > 0 {
config = config.WithEndpoint(endpoint)
}
db := dynamodb.New(sess, config)
response, err := db.GetItem(&dynamodb.GetItemInput{
TableName: aws.String(tableName),
Key: map[string]*dynamodb.AttributeValue{
"Id": {
N: aws.String(string(id)),
},
},
AttributesToGet: []*string{
aws.String("Id"),
aws.String("Name"),
},
ConsistentRead: aws.Bool(true),
ReturnConsumedCapacity: aws.String("NONE"),
})
if err != nil {
return events.APIGatewayProxyResponse{}, err
}
user := User{}
err = dynamodbattribute.Unmarshal(&dynamodb.AttributeValue{M: response.Item}, &user)
if err != nil {
return events.APIGatewayProxyResponse{}, err
}
// Json
bytes, err := json.Marshal(user)
if err != nil {
return events.APIGatewayProxyResponse{}, err
}
return events.APIGatewayProxyResponse{
Body: string(bytes),
StatusCode: 200,
}, nil
}
error message

Answer 1

That's been resolved.
First Problem: can't read from the environment variable
This was because the indent size deviation of template.yaml. Category "Events" and Category "Environment" had to be in line.
Second Problem: error with "Function 'UserGetFunction' timed out after 5 seconds"
This was because "localhost" expression. Rewriting "localhost" in env.json to "xxx.xxx.xxx.xxx" worked fine.("xxx.xxx.xxx.xxx" is ip address of your laptop)