4.8. Creating a customized instance

Procedure

1. Create a file with instructions for cloud-init. For example, create a bash script that installs and enables a web server on the instance:

   $ vim /home/scripts/install_httpd
   #!/bin/bash
   
   yum -y install httpd python-psycopg2
   systemctl enable httpd --now

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2. Launch an instance with the --user-data option to pass the bash script:

   $ openstack server create \
   --image rhel8 \
   --flavor default \
   --nic net-id=web-server-network \
   --security-group default \
   --key-name web-server-keypair \
   --user-data /home/scripts/install_httpd \
   --wait web-server-instance

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3. When the instance state is active, attach a floating IP address:

   $ openstack floating ip create web-server-network
   $ openstack server add floating ip web-server-instance 172.25.250.123

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4. Log in to the instance with SSH:

   $ ssh -i ~/.ssh/web-server-keypair cloud-user@172.25.250.123

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5. Check that the customization was successfully performed. For example, to check that the web server has been installed and enabled, enter the following command:

   $ curl http://localhost | grep Test
   <title>Test Page for the Apache HTTP Server on Red Hat Enterprise Linux</title>
   <h1>Red Hat Enterprise Linux <strong>Test Page</strong></h1>

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6. Review the /var/log/cloud-init.log file for relevant messages, such as whether or not the cloud-init executed:

   $ sudo less /var/log/cloud-init.log
   ...output omitted...
   ...util.py[DEBUG]: Cloud-init v. 0.7.9 finished at Sat, 23 Jun 2018 02:26:02 +0000. Datasource DataSourceOpenStack [net,ver=2].  Up 21.25 seconds

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