Ruby on Lamdba Tutorial - main struggles

ruby_on_lambda.md

How to deploy Ruby Functions/ Apps with AWS Lambda

I followed this tutorial about getting started with Ruby on Lambda.

Nothing really happened as mentionned in the tutorial because many surprises occurred along the way :)

This tutorial is basically in 3 parts:

1. Creating a Hello World example
2. Including dependencies
3. Migrating a Sinatra application

I had no troubles with the first part. The suprises started from the second.

The main struggles were

1. Creating a user
2. Create a package
3. Deploy

1. Create a user

When creating the bucket with the following command

$ aws s3 mb s3://my-bucket

I had this error.

make_bucket failed: s3://my-bucket An error occurred (InvalidAccessKeyId)
when calling the CreateBucket operation: The AWS Access Key Id you 
provided does not exist in our records.

First of all, the context is that I had another AWS account and had to setup a second user in my config with the related access key and secret key for this second account.

On one side, in the AWS console, I had to create a user and IAM group for this different account. And no to forget to give this user AdministratorAccess. Then I generated keys for this user.

Then, in bash console, I configured the credentials for this user:

$ aws configure --profile new_user

As explained in the link above, the information to fill in are, as follows:

AWS Access Key ID [None]: EXAMPLE
AWS Secret Access Key [None]: EXAMPLEKEY
Default region name [None]: us-east-1
Default output format [None]: text

👆🏻These keys have been generated in the User section, "Create New Access Key"

Then I created the bucket directly in AWS console, in S3. You have to be careful to use the same region as the one you defined for your user.

Create a package

Then I used the AWS SAM CLI to package your application

$ sam package --template-file template.yaml \
--output-template-file packaged-template.yaml \
--s3-bucket <bucketname>

I had this error:

Unable to upload artifact None referenced by CodeUri parameter 
of HelloRubyRecordFunction resource.
An error occurred (InvalidAccessKeyId) when calling the PutObject 
operation: The AWS Access Key Id you provided does not exist in our records.

What I had to do to solve this is to pass the profile in the command, as follow:

$ sam package --template-file template.yaml \
--output-template-file packaged-template.yaml \
--s3-bucket <bucketname>
--profile new_user

and it worked 💃🏻

Successfully packaged artifacts and wrote output template to file 
packaged-template.yaml.
Execute the following command to deploy the packaged template

Deploy

Then I tried to deploy, with the given command:

$ sam deploy --template-file packaged-template.yaml 
--stack-name helloRubyRecord 
--capabilities CAPABILITY_IAM

An error occurred (InvalidClientTokenId) when calling the DescribeStacks 
operation: The security token included in the request is invalid.

Same than before, I had to specify the user in the command:

$ sam deploy --template-file packaged-template.yaml 
--stack-name helloRubyRecord 
--capabilities CAPABILITY_IAM --profile new_user

Waiting for changeset to be created..
Waiting for stack create/update to complete

Failed to create/update the stack. Run the following command
to fetch the list of events leading up to the failure
aws cloudformation describe-stack-events --stack-name helloRubyRecord

It was better, but I still had an error. This was related to the region of my bucket. As I mentionned earlier, it has to be the same.

I could learn about this error with the provided command.

$ aws cloudformation describe-stack-events 
--stack-name helloRubyRecord

This command gives a big json with events that happened during the deploiement.

I found this error for the "ResourceStatus": "CREATE_FAILED"

"ResourceStatusReason": "Error occurred while GetObject. S3 Error Code: 
PermanentRedirect. S3 Error Message: The bucket is in this region: eu-west-3.
Please use this region to retry the request...

So I created a new bucket with a correct region (same than the user has), and tried to deploy again.

aws cloudformation deploy 
--template-file packaged-template.yaml 
--stack-name HelloRubyRecord 
--capabilities CAPABILITY_IAM 
--profile new_user

An error occurred (ValidationError) when calling the CreateChangeSet 
operation: Stack:arn:aws:cloudformation:eu-west-1:blabla 
is in ROLLBACK_COMPLETE state and can not be updated.

I then changed the stack-name from HelloRubyRecord to HelloRubyRecord2.

aws cloudformation deploy 
--template-file packaged-template.yaml 
--stack-name HelloRubyRecord2 
--capabilities CAPABILITY_IAM 
--profile new_user

Waiting for changeset to be created..
Waiting for stack create/update to complete
Successfully created/updated stack - HelloRubyRecord2

and it worked 💃🏻

Here were the main struggles I had to follow the tutorial. I really recommend to do this tuto, just think about these tips if suprises happen.