Overview

 =================

 ```cloud-init``` is a multi-distribution package that handles early initialization of a cloud instance.

 In-depth documentation for cloud-init is available here:
 
 [https://cloudinit.readthedocs.org/en/latest/](https://cloudinit.readthedocs.org/en/latest/)

 
 Supported installations
 =================

 Both the full version of and the minimal version of Photon OS support cloud-init. 

 
 Supported capabilities
 =================

 
 Photon OS supports the following cloud-init capabilities:
 
 
 * run commands: execute a list of commands with output to console.
 * configure ssh keys: add an entry to ~/.ssh/authorized_keys for the configured user.
 * install package: install additional packages on first boot.
 * configure networking: update /etc/hosts, hostname, etc.
 * write files: write arbitrary files to disk.
 * add yum repository: add a yum repository to /etc/yum.repos.d.
 * create groups and users: add groups and users to the system and set properties for them. 
 * run yum upgrade: upgrade all packages.
 * reboot: reboot or power off when done with cloud-init.
 

 
 Getting Started
 =================

 The Amazon Machine Image of Photon OS has an ```ec2 datasource``` turned on by default so an ```ec2``` configuration is accepted.
 However, for testing, the following methods provide ways to do ```cloud-init``` with a standalone instance of Photon OS.

 Using a Seed ISO

 ----------------

 This will be using the ```nocloud``` data source. In order to initialize the system in this way, an ISO file needs to be created with a meta-data file and an user-data file as shown below:

 ```

 $ { echo instance-id: iid-local01; echo local-hostname: cloudimg; } > meta-data
 $ printf "#cloud-config\nhostname: testhost\n" > user-data
 $ genisoimage  -output seed.iso -volid cidata -joliet -rock user-data meta-data

 ```

 Attach the `seed.iso` generated above to your machine and reboot for the init to take effect.
 In this case, the hostname is set to ```testhost```.

 Using a Seed Disk File

 ----------------

 To init using local disk files, do the following:

 ```

 mkdir /var/lib/cloud/seed/nocloud
 cd /var/lib/cloud/seed/nocloud
 $ { echo instance-id: iid-local01; echo local-hostname: cloudimg; } > meta-data
 $ printf "#cloud-config\nhostname: testhost\n" > user-data

 ```

 Reboot the machine and the hostname will be set to `testhost`.

 
 Frequencies
 -----------

 Cloud-init modules have predetermined frequencies. Based on the frequency setting, multiple runs will yield different results. For the scripts to always run, remove the `instances` directory before rebooting.

 ```

 rm -rf /var/lib/cloud/instances

 ```

 Module Frequency Info

 ------------------------------------
 Name                  |  Frequency
 ----------------------|-------------

 disable_ec2_metadata  | Always

 users_groups          | Instance
 write_files           | Instance
 update_hostname       | Always
 final_message         | Always
 resolv_conf           | Instance
 growpart              | Always
 update_etc_hosts      | Always
 power_state_change    | Instance
 phone_home            | Instance