问题
While creating new AWS EC2 instance using EC2 command line API, i am passing some user data to new instance.
Now how i came to know whether that user data executed or not ?
How should i check it ?
回答1:
You can verify using following steps
- SSH on launch EC2 instance
- Check log of your user data script in
/var/log/cloud-init.logand/var/log/cloud-init-output.log
You can see all log's of your user data script and it will also create /etc/cloud folder.
回答2:
Just for reference, you can check if the user data executed by taking a look at the system log from the EC2 console. Right click on your instance - Instance Settings - Get System log
This should open a modal window with the system logs
回答3:
Debugging user data scripts on Amazon EC2 is a bit awkward indeed, as there is usually no way to actively hook into the process, so one ideally would like to gain Real time access to user-data script output as summarized in Eric Hammond's article Logging user-data Script Output on EC2 Instances:
The recent Ubuntu AMIs still send user-data script to the console output, so you can view it remotely, but it is no longer available in syslog on the instance. The console output is only updated a few minutes after the instance boots, reboots, or terminates, which forces you to wait to see the output of the user-data script as well as not capturing output that might come out after the snapshot.
Depending on your setup you might want to ship the logs to a remote logging facility like Loggly right away, but getting this installed early enough can obviously be kind of a chicken/egg problem (though it works great if the AMI happens to be configured like so already).
回答4:
Enable logging for your user data
exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
Take care to put a space between the two > > characters at the beginning of the statement.
Here’s a complete user-data script as an example:
#!/bin/bash -ex
exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
echo BEGIN
date '+%Y-%m-%d %H:%M:%S'
echo END
回答5:
Have your user data create a file in your ec2's /tmp directory to see if it works:
bob.txt:
#!/bin/sh
echo 'Woot!' > /home/ec2-user/user-script-output.txt
Then launch with:
ec2-run-instances -f bob.txt -t t1.micro -g ServerPolicy ami-05cf5c6d -v
来源：https://stackoverflow.com/questions/15904095/how-to-check-whether-my-user-data-passing-to-ec2-instance-working-or-not