I have a AMI which is used to launch instances automatically though Amazon Launch configuration.
The issue I am facing is that after instance gets launched I need to run some command which should start the WebServer automatically. how can I do that using user data option from launch configuration.
You can find the option "User Data" under "Advanced Details" section in the Launch Configuration Wizard
I don't think there is anyway via the AWS console or with the official aws-tools to modify a Launch Configuration. I believe you have to create a new one with the user data and associate it with the autoscaling group or groups it's in with these two scripts:
as-create-launch-config
as-update-auto-scaling-group
However, if you're brave...
I did find this: https://github.com/colinbjohnson/aws-missing-tools/tree/master/as-update-launch-config
It explicitly limits the type of instance you're using (it was wrote in 2012) to a narrow list of older options, so update it to new ones.
Outside this, I've not tested the script, so good luck!
From the documentation:
Follow the procedure for launching an instance at Launching Your Instance from an AMI, but when you get to Step 6, paste the user data script text into the User data field and then complete the launch procedure.
If you don't want to copy-paste a script every time you launch an instance, you have a few different options:
Launch the instance using the AWS CLI and point it at a file that contains your script
Use CloudFormation to launch the instance and related resources and specify the userdata script in the template
Use OpsWorks (I'm less familiar with this one)
However, if you just want the webserver service to start at boot, I recommend looking at this question.
copy paste
#!/bin/sh
curl -L https://s3.amazonaws.com/romuloaddressbook/addressbook.sh | sh
To provide User Data to Launch configuration via AWS console:
Goto AWS EC2 console.
Under "AUTOSCALING" click on "Launch Configurations" and the select "Create launch configuration". Create Launch Configuration wizard will open.
Select the required AMI.
In the next window, select the Instance Type and click "Next: Configure details".
Under "Configure details" -> "Advanced Details" -> Enter your USERDATA in the "User data" text box.
Proceed further and complete the wizard.
Related
I would like to perform domain join on any servers provisioned in my AWS environment.
For ASG and EKS, can launch template be used to run custom scripts as soon as new nodes are launched?
Yes, with ASG you can run custom scripts. You need to modify your User data in your launch template or launch configuration. You can retrive scripts saved in s3 or pass any commands or script directly. If it's just a join to freeipa for example. You can do it with a simple one line command(don't foget to add #!/bin/bash in the begining of user data) instead of a script.
More information can be found here and here.
I would like to find out if there is an easy way to find out whether given launch configuration is created using AWS Console or Programmatically?
Usecase:
We are planning to avoid copying/creating launch configuration using AWS-Console, so we would like to implement some alert system if there is any launch configuration created using AWS-Console.
So is there any way we can look at a flag on the launch configuration and differentiate if the launch configuration is created using AWS Console or not?
Quick thought
Approach 1
Revoke permissions to launch configuration from all users with the console access.
Use separate user for the program, who has permission to launch configuration.
Approach 2
Write a program which is monitoring CloutTrail logs. because all the things we do whether via console or API are/can_be logged in CloudTrail
My suggestion would be: Use only CloudFormation to create the LaunchConfigs and then check for the existence of relevant CF-tags.
Added bonus: you can create a specific role for CF to launch EC2 instances and then revoke all permissions for your users.
I've just created a new Launch Configuration to use with an Auto Scaling group. When a new EC2 instance is launched, I would like the script to be executed.
In details:
I have a script deploy.sh that updates my application code using git...
When a new instance is launched by Auto Scaling, it should execute the script that I've provided via User Data in the Launch Configuration (attached on autoscaling group).
My user data is:
#!/bin/bash
/home/ec2-user/deploy.sh
This doesn't work.
Can you check the permission of your deploy script?
You can login to the instance and check the logs of User Data execution. Logs are at /var/log/cloud-init-output.log
I've checked cloud-init-output.log and seems everything is okay.
I've done another test now and the new instance has the right code.
Probably there was a syntax error in launch configuration user data.
So, the right user data is
#!/bin/bash
/home/ec2-user/deploy.sh
Now I should add yum update before my custom script.
We use AWS cloudformation service to initialize our stack, and set up the auto scaling service to bring up new app servers when load is rising.
My understanding is that Auto Scaling can only start predefined AMI as new instances. These instances could be different from other running instances, because we may have updated packages/source code deployed on those instances.
How can I bring the new instances up-to-date?
Should I update the AMIs everytime I deploy something new to the running instances? Or is there anyway to trigger auto-deployment on new instances (Opsworks) when auto scaling?
I am new to AWS, so pardon me if my question is rudimentary.
There are multiple ways of doing this. My preferred approach is never to touch the servers directly, but instead create a new AMI whenever I deploy a new version of the software.
To do this, use the AutoScalingRollingUpdate property for the auto-scaling group. When you then change ImageId for the launch configuration, AWS will automatically replace your old servers with new ones as a rolling upgrade.
I have a simple deploy script that creates a new AMI, replaces ImageId in the template, and then does a stack update - AWS takes care of the rest.
When creating EC2 instances from Beanstalk, it automatically creates a AutoScaling Group and Launch Configuration based on the specified environment selections. Creating the instance from base AMI is done using a custom code call user data which includes the shell script to create folders and install relevant software.
You can add a new shell scripts or commands there to do your custom work before starting a new instance. This way it is much simpler. e.g. you can run yum update before starting a instance
To find user data section
Go to EC2 Console -> Go to launch configurations section (on left) -> Select the correct launch configuration and copy it -> Click view user data -> Add your scripts and commands as required -> Modify the relevant Auto Scaling group to point to the new launch configuration
I am using AWS SEK for java. I create and run an EC2 instance with a user data script which gets a .jar from a S3 bucket and runs it. When I run the instance it shows me that it is running but nothing happens. The .jar should create a SimpleDB table and a SQS queue. How do see whats wrong whithout connecting through ssh to the instance or is it the only what to see the logs?
Kind regards,
Snafu
Some of the user-data output may be found in the system log (on EC2 dashboard, right-click on the instance and choose System logs)
you could put a piece of java code \ shell script and\or cron job to upload your logs to S3, but it's best to SSH to see what's in there at least at the first time you run your code.
You can use mind-term java applet to connect directly from EC2 dashboard (there's a button labeled 'connect' at the top, it's easy and you don't need to download ssh client). I would highly recommend getting used to work with SSH because it's the easiest way to see what's inside.