ec2 user data script is only partialy excecuted - amazon-web-services

Question

I am using ec2 instances with ubuntu 18 ami,
with user data script as follows:
#!/bin/bash
sudo apt-get update -y
sudo apt-get install python-pip -y
sudo apt-get install awscli -y
mkdir /home/ubuntu/dir
aws s3 sync s3://art-meta-data ./art-meta-data
the script it only partially executed, It installed pip, performs apt-get update, installed the awscli, but does not sync the bucket and does not create the directory.
I don't get any errors (maybe I don't look the right place?) and when I try to create the dir and sync the bucker via ssh, it works perfectly, meaning the s3 permissions and os permissions are fine.
What can be the issue here? What else should I check?
edit:
I found this - explaining how to make your script run each time you stop and start the instance, but without explanation why the added meta coding changes anything. can anyone point me to some reference for why this script works differently than just regular bash script?

Answer 1

It would be better to describe the full path on the sync command to avoid being created in the wrong place.
#!/bin/bash
sudo apt-get update -y
sudo apt-get install python-pip -y
sudo apt-get install awscli -y
mkdir /home/ubuntu/dir
aws s3 sync s3://art-meta-data /home/ubuntu/dir/art-meta-data

Answer 2

You can check the EC2 system logs to see the output of the failed command. That is really the only way for you to debug your an issue within your user data script.
Double check your instance profile has access to the bucket and that you are using the correct arn to reference the bucket

Answer 3

If you run sudo cat /var/log/cloud-init-output.log you can see the log output of everything that happened while the ec2 user-data you supplied was run. Here's what you'd likely see if you did that:
mkdir: cannot create directory '/home/ubuntu/dir': No such file or directory
Jul 16 18:57:21 cloud-init[2471]: util.py[WARNING]: Failed running /var/lib/cloud/instance/scripts/part-001 [1]
Jul 16 18:57:21 cloud-init[2471]: cc_scripts_user.py[WARNING]: Failed to run module scripts-user (scripts in /var/lib/cloud/instance/scripts)
Jul 16 18:57:21 cloud-init[2471]: util.py[WARNING]: Running module scripts-user (<module 'cloudinit.config.cc_scripts_user' from '/usr/lib/python2.7/site-packages/cloudinit/config/cc_scripts_user.pyc'>) failed
ci-info: no authorized ssh keys fingerprints found for user ec2-user.
Cloud-init v. 19.3-45.amzn2 finished at Sat, 16 Jul 2022 18:57:21 +0000. Datasource DataSourceEc2. Up 121.29 seconds
It appears that mkdir fails because /home/ubuntu doesn't yet exist at the time the ec2 user data script runs. One way to solve this would be to move the creation of the folder to /etc/profile.d.
To do this, you could modify your user data script as follows:
echo "mkdir -p /home/ubuntu/dir && aws s3 sync s3://art-meta-data /home/ubuntu/dir/art-meta-data" >> /etc/profile.d/sync_bucket.sh
Files in /etc/profile.d/ are run when a user logs in so you're guaranteed the existence of /home/ubuntu folder and the sync will occur on each login.