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Using the AWS console, I’m launching an instance using a custom AMI. A few XML files need to be updated as part of the system initialization. Although I entered the user data, it doesn’t appear to be working.

Upon checking ds-idenify.log and cloud-init-generator.log, I can see that cloud-init is unable to obtain the data source.

**cat ds-identify.log**
[up 1.17s] ds-identify
policy loaded: mode=search report=false found=all maybe=all notfound=disabled
no datasource_list found, using default: MAAS ConfigDrive NoCloud AltCloud Azure Bigstep CloudSigma CloudStack DigitalOcean AliYun Ec2 GCE OpenNebula OpenStack OVF SmartOS Scaleway Hetzner IBMCloud Oracle Exoscale RbxCloud
DMI_PRODUCT_NAME=t3.small
DMI_SYS_VENDOR=Amazon EC2
DMI_PRODUCT_SERIAL=ec2972df-81d1-c72e-f54d-0da7741efa46
DMI_PRODUCT_UUID=DF7229EC-D181-2EC7-F54D-0DA7741EFA46
PID_1_PRODUCT_NAME=unavailable
DMI_CHASSIS_ASSET_TAG=Amazon EC2
FS_LABELS=any:scandir,any:scandir,any:scandir,any:scandir,var,config,deferred,logs,wk,boot,opt,root,notused,rescue
ISO9660_DEVS=
KERNEL_CMDLINE=BOOT_IMAGE=/vmlinuz-x.x.xx-x.xx..0.x86_64 ro root=LABEL=root quiet nmi_watchdog=2 fsck.repair=yes fips=1 elevator=noop rootdelay=300 console=ttyS0,115200n8 aws nvme_core.io_timeout=255 rootfstype=ext4
VIRT=kvm
UNAME_KERNEL_NAME=Linux
UNAME_KERNEL_RELEASE=x.x.xx-x.xx..0.x86_64
UNAME_KERNEL_VERSION=#1 SMP Thu Mar 21 13:43:44 UTC 2024
UNAME_MACHINE=x86_64
UNAME_NODENAME=mlos-tiny
UNAME_OPERATING_SYSTEM=GNU/Linux
DSNAME=
DSLIST=MAAS ConfigDrive NoCloud AltCloud Azure Bigstep CloudSigma CloudStack DigitalOcean AliYun Ec2 GCE OpenNebula OpenStack OVF SmartOS Scaleway Hetzner IBMCloud Oracle Exoscale RbxCloud
MODE=search
ON_FOUND=all
ON_MAYBE=all
ON_NOTFOUND=disabled
pid=734 ppid=722
is_container=false
is_ds_enabled(IBMCloud) = true.
ec2 platform is 'Unknown'.
is_ds_enabled(IBMCloud) = true.
No ds found [mode=search, notfound=disabled]. Disabled cloud-init [1]
[up 1.44s] returning 1

**cat cloud-init-generator.log**
/usr/lib/systemd/system-generators/cloud-init-generator normal=/run/systemd/generator early=/run/systemd/generator.early late=/run/systemd/generator.late
kernel command line (/proc/cmdline): BOOT_IMAGE=/vmlinuz-x.x.xx-x.xx.xx.x.x86_64 ro root=LABEL=root quiet nmi_watchdog=2 fsck.repair=yes fips=1 elevator=noop rootdelay=300 console=ttyS0,115200n8 aws nvme_core.io_timeout=255 rootfstype=ext4
kernel_cmdline found unset
etc_file found unset
default found enabled
checking for datasource
ds-identify rc=1
ds-identify _RET=notfound
**cloud-init is enabled but no datasource found, disabling**
already disabled: no change needed [no /run/systemd/generator.early/multi-user.target.wants/cloud-init.target]
[root@ip-xx-xx-xx-xx cloud-init]#
 

Version of the cloud init used : cloud-init-19.4-12

I have added the datasource_list in /etc/cloud/cloud.cfg

[root@ip-xx-xx-xx-xx ~]# cat /etc/cloud/cloud.cfg
users:
 - default

disable_root: 0
ssh_pwauth:   0

mount_default_fields: [~, ~, 'auto', 'defaults,nofail,x-systemd.requires=cloud-init.service', '0', '2']
resize_rootfs_tmp: /dev
ssh_deletekeys:   1
ssh_genkeytypes:  ~
syslog_fix_perms: null
disable_vmware_customization: false

datasource_list: [Ec2]
datasource:
 Ec2:
  metadata_urls: ["http://169.254.169.254:80"]
  max_wait: 120
  timeout: 50
  strict_id: false

#/etc/hosts file will be replaced with the one in /etc/cloud/templates.
manage_etc_hosts: true

cloud_init_modules:
 - disk_setup
 - migrator
 - bootcmd
 - write-files
 - growpart
 - resizefs
 - set_hostname
 - update_hostname
 - update_etc_hosts
 - rsyslog
 - users-groups
 - ssh

cloud_config_modules:
 - mounts
 - locale
 - set-passwords
 - rh_subscription
 - yum-add-repo
 - package-update-upgrade-install
 - timezone
 - puppet
 - chef
 - salt-minion
 - mcollective
 - runcmd

cloud_final_modules:
 - rightscale_userdata
 - scripts-per-once
 - scripts-per-boot
 - scripts-per-instance
 - scripts-user
 - ssh-authkey-fingerprints
 - keys-to-console
 - phone-home
 - final-message
 - power-state-change

system_info:
  default_user:
    name: centos
    lock_passwd: true
    gecos: Cloud User
    groups: [adm, systemd-journal]
    sudo: ["ALL=(ALL) NOPASSWD:ALL"]
    shell: /bin/bash
  distro: rhel
  paths:
    cloud_dir: /var/lib/cloud
    templates_dir: /etc/cloud/templates
  ssh_svcname: sshd

# vim:syntax=yaml

I’m using the following user data to test the same.

Content-Type: multipart/mixed; boundary="//"
MIME-Version: 1.0

--//
Content-Type: text/cloud-config; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="cloud-config.txt"

#cloud-config
cloud_final_modules:
- [scripts-user, always]
runcmd:
 - [ mkdir, /test-cloudinit ]
write_files:
 - path: /test-cloudinit/cloud-init.txt
   content: Created by cloud-init

--//
Content-Type: text/x-shellscript; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="userdata.txt"

#!/bin/bash
  mkdir test-userscript
  touch /test-userscript/userscript.txt
  echo "Created by bash shell script" >> /test-userscript/userscript.txt
--//--

I am new to AWS. Kindly inform me if there is something I am overlooking. Thanks for any assistance.

2

Answers


  1. Chosen as BEST ANSWER

    Got the issues, Line number 102 (uuid = util.read_dmi_data('system-uuid')) in the cloudinit/sources/DataSourceEc2.py file's exception section was returning a value that did not begin with ec2.

    I used the following patch to rebuild the cloud-init source rpm:. I made an AMI using the altered ISO. Following that, it began operating without issue, and the logs showed no errors.

    --- cloud-init-19.4.org/cloudinit/sources/DataSourceEc2.py    2024-04-05 05:05:27.872614814 +0000
    +++ cloud-init-19.4/cloudinit/sources/DataSourceEc2.py   2024-04-05 05:05:58.262552203 +0000
    @@ -653,7 +653,7 @@
             uuid = util.load_file("/sys/hypervisor/uuid").strip()
             data['uuid_source'] = 'hypervisor'
         except Exception:
    -        uuid = util.read_dmi_data('system-uuid')
    +        uuid = util.read_dmi_data('system-serial-number')
             data['uuid_source'] = 'dmi'
    
         if uuid is None:
    

  2. This is was caused by a bug in cloud-init that affects only EC2. The UUID was reported in a different bytorder, which is technically a supported way for ec2 to identify itself. I just filed a PR to fix it.

    Note: The patch you posted doesn’t match the documented way to identify ec2 instances, so I wouldn’t recommend doing it that way.

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