When you use a custom Linux image, we recommend that you install cloud-init in your servers to guarantee successful initialization of the instances running that image.

What is cloud-init?

cloud-init is an open source software used by cloud-based platforms to configure system initialization of Linux instances. It is supported by major platforms such as Alibaba Cloud, AWS, Azure, and OpenStack. For more information, see cloud-init documentation.

Alibaba Cloud cloud-init initializes the configurations of instances during their startup, including the network, NTP, software source, host name, and SSH key pair. It also executes the user data script.

Scenarios

Cloud-init is installed by default for all public images of Alibaba Cloud. If you use custom images in the following scenarios, we recommend that you install Alibaba Cloud cloud-init for your Linux servers so as to ensure the system configurations of created instances can be automatically initialized:

  • Linux servers that will be migrated to Alibaba Cloud, but have not installed cloud-init.
  • Linux servers that have installed cloud-init whose version is earlier than 0.7.9.
  • Alibaba Cloud ECS instances that have not installed cloud-init.

Check the cloud-init version

Different cloud platforms may use different versions of cloud-init. Please select the appropriate version and configure the appropriate datasource. Alibaba Cloud uses cloud-init 0.7.6a and the data source is Aliyun.

After cloud-init is installed, its option of self-start upon instance startup is enabled by default. If the selected cloud-init version or data source is not suitable, cloud-init may run abnormally and the instance may start slowly (or fail to start) the next time you restart your instance. As a result, we recommend that you back up your data before you install it. Exercise caution when you install it if you are not fully ready to migrate your servers onto Alibaba Cloud.

  • Check if cloud-init is installed: which cloud-init
    Note No output indicates that it is not installed and you need to install the Alibaba Cloud cloud-init.
  • Check the cloud-init version: cloud-init --version
    Note If the version is earlier than the community version 0.7.9 (except 0.7.6a), you need to install the Alibaba Cloud cloud-init.

(Recommended) Install the Alibaba Cloud cloud-init

  1. Check and install the python-pip dependency.
  2. Download the Alibaba Cloud cloud-init and decompress it to the current directory: 
    wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ali-cloud-init-latest.tgz
  3. Enter the tools directory of cloud-init, and then run the cloud-init installation script deploy.sh: 
    bash ./deploy.sh <issue> <major_version>

    • The parameters are described as follows:

      • issue: The operating system platform. The value range is: centos | redhat |rhel | debian | ubuntu | opensuse | sles. The parameter values are case sensitive. sles represents SUSE/SLES.
      • major_version: The major version of an operating system platform. For example, the major version of CentOS 6.5 is 6.

    • The following are command examples:

      • Install cloud-init in CentOS 6.5: 
        bash ./deploy.sh centos 6
      • Install cloud-init in Ubuntu 14.04: 
        bash ./deploy.sh ubuntu 14
  4. Confirm that the installation is successful. If "description": "success" is returned, the installation is successful.

Install the Alibaba Cloud cloud-init in different platforms

Installation commands for different platforms are shown as follows:

  • CentOS 6/7 
    # Check and install python-pip
if ! python -c 'import setuptools' >& /dev/null; then
  yum -y install python-pip
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$( cat /etc/redhat-release | awk '{printf $3}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh centos "$issue_major"
  • RHEL 6/7 
    # Check and install python-pip
if ! python -c 'import setuptools' >& /dev/null; then
  yum -y install python-pip
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$(cat /etc/os-release | grep VERSION_ID | awk -F'"' '{printf $2}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh rhel "$issue_major"
  • Ubuntu 14/16/18 
    # Check and install python-pip
if ! python -c 'import setuptools' >& /dev/null; then
  apt-get install python-pip -y
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$(cat /etc/os-release | grep VERSION_ID | awk -F'"' '{printf $2}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh ubuntu "$issue_major"
  • Debian 8/9 
    # Check and install python-pip
if ! python -c 'import setuptools' >& /dev/null; then
  apt-get -y install python-pip
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$(cat /etc/os-release | grep VERSION_ID | awk -F'"' '{printf $2}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh debian "$issue_major"
  • SUSE 11/12 
    # Check and install python-pip
if ! python -c 'import setuptools'>& /dev/null; then
  zypper -n install python-pip
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud/etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$(cat /etc/os-release | grep VERSION_ID | awk -F'"' '{printf $2}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh sles "$issue_major"
  • OpenSUSE 13/42 
    # Check and install python-pip
if ! python -c 'import setuptools'>& /dev/null; then
  zypper -n install python-pip
fi
# Back up the legacy cloud-init configuration
test -d /etc/cloud && mv /etc/cloud/etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init
wget http://ecs-image-utils.oss-cn-hangzhou.aliyuncs.com/cloudinit/ali-cloud-init-latest.tgz
tar -zxvf ./ali-cloud-init-latest.tgz
# Install cloud-init
issue_major=$(cat /etc/os-release | grep VERSION_ID | awk -F'"' '{printf $2}' | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh opensuse"$issue_major"

(Optional) Install the community cloud-init

Prerequisites

Before installing cloud-init, you must install the git, python 2.7, and python-pip dependencies. The installation commands are as follows:

  • CentOS/RedHat: 
    yum -y install git python python-pip
  • Ubuntu/Debian: 
    apt-get -y install git python python-pip
  • OpenSUSE/SUSE: 
    zypper -n install git python python-pip

Procedure

  1. Log on to the source server.
  2. Download the cloud-init package through git and enter the cloud-init directory: 
    git clone https://git.launchpad.net/cloud-init
cd ./cloud-init
  3. Install all the dependencies: 
    pip install -r ./requirements.txt
  4. Install cloud-init: 
    python setup.py install
  5. Run vi /etc/cloud/cloud.cfg to modify the configuration file cloud.cfg.

    Modify the configurations of cloud_init_modules: as follows: 

    # Example datasource config
# The top level settings are used as module
# and system configuration.
# A set of users which may be applied and/or used by various modules
# when a 'default' entry is found it will reference the 'default_user'
# from the distro configuration specified below
users:
   - default
user:
    name: root
    lock_passwd: False
# If this is set, 'root' will not be able to ssh in and they 
# will get a message to login instead as the above $user
disable_root: false
# This will cause the set+update hostname module to not operate (if true)
preserve_hostname: false
syslog_fix_perms: root:root
datasource_list: [ AliYun ]
# Example datasource config
datasource:
    AliYun:
        support_xen: false
        timeout: 5 # (defaults to 50 seconds)
        max_wait: 60 # (defaults to 120 seconds)
#      metadata_urls: [ 'blah.com' ]
# The modules that run in the 'init' stage
cloud_init_modules:

What to do next

  • For Linux servers that are ready for migration to the cloud, you can migrate them to Alibaba Cloud by using the Cloud Migration tool or import custom images.
  • For ECS instances with custom Linux images that are already running on Alibaba Cloud, you can restart the system for verification. If the system is automatically configured with the host name, software source, and NTP, cloud-init is successfully installed.

Troubleshooting

Note
  • The libraries that are missing may vary according to the images. To resolve this issue, you can install them through pip, and then install cloud-init again.
  • If the default package manager (for example yum) and the pip manager have installed different versions of libraries, library version conflicts may occur and lead to cloud-init running abnormally. We recommend that you download the dependency libraries according to the reported errors.

Error: no setuptools module in python

The error prompt no setuptools module in python means you need to install python setuptools. You can fix it in the following ways:
  • CentOS/RedHat: yum -y install python-pip
  • Ubuntu/Debian: apt-get -y install python-pip
  • OpenSUSE/SUSE: zypper -n install python-pip

Error: No module named six

Run pip install six to resolve the following error. 

File "/root/cloud-init/cloudinit/log.py", line 19, in <module>
      import six
  ImportError: No module named six  )

Error: No module named oauthlib.oauth1

Run pip install oauthlib to resolve the following error. 

File "/root/cloud-init/cloudinit/url_helper.py", line 20, in <module>
      import oauthlib.oauth1 as oauth1
  ImportError: No module named oauthlib.oauth1  )

Error messages do not indicate the missing libraries

If error messages do not indicate the missing libraries during installation, you can install all the dependency libraries displayed in the file requirements.txt of cloud-init. 
pip install -r requirements.txt

References

cloud-init website - Alibaba Cloud (AliYun)