Elastic Compute Service:Install cloud-init

See the official cloud-init documentation.

Step 1: Check the cloud-init version

1. Log on to the source server.

2. Check whether cloud-init is installed.

   CentOS series

   rpm -qa | grep -i cloud-init 
   pip list | grep -i cloud-init

   Ubuntu series

   dpkg -l | grep -i cloud-init 
   pip list | grep -i cloud-init

   • If no output is returned or the version is earlier than 0.7.9, see Step 2: Install cloud-init.

     Important

     Version 0.7.9 is an early community version not suitable for ECS initialization. Upgrade to a later version.

   • If the version is 18 or later, no installation is needed. To customize the default network configuration, see Disable automatic network initialization by Alibaba Cloud.

   • If the version is 19.1.21, upgrade to Alibaba Cloud cloud-init 23.2.2. Key improvements over 19.1.21:

     • Supports metadata access in security hardening mode. See Instance metadata.

     • Other changes include feature enhancements, performance improvements, and bug fixes. See the ChangeLog file.

   • Other versions: no installation needed. See Next steps.

3. To prevent data loss, back up your source server data before installation. For example, create a snapshot.

Step 2: Install cloud-init

• (Recommended) Alibaba Cloud cloud-init 23.2.2: Requires Python 3.6 or later. Data source: Aliyun.

• Alibaba Cloud cloud-init 19.1.21: Requires Python 3.6 or later. Data source: Aliyun.

• Alibaba Cloud cloud-init 0.7.6a18: This version is required for some earlier operating systems, such as CentOS 6, Debian 9, and SUSE Linux Enterprise Server 12. It requires Python 2.7 and uses the Aliyun data source.

  Important

  The Python community no longer supports Python 2.7. Use a later version of cloud-init to avoid potential dependency library issues.

• Community version of cloud-init: Maintained by the cloud-init community. The latest Alibaba Cloud version is 23.2.2. For a later version, install the community version from the official cloud-init website.

The Alibaba Cloud version is optimized for Alibaba Cloud services. Use the Alibaba Cloud version unless you need a later community release.

# Check and install python3-pip.
if ! python3 -c 'import setuptools' >& /dev/null; then
  yum -y install python3-pip
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/redhat-release | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh centos "$issue_major"

# Check and install python3-pip.
if ! python3 -c 'import setuptools' >& /dev/null; then
  yum -y install python3-pip
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/os-release | grep VERSION_ID | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh rhel "$issue_major"

# Check and install python3-pip.
if ! python3 -c 'import setuptools' >& /dev/null; then
  apt-get install python36 python3-pip -y
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/os-release | grep VERSION_ID | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh ubuntu "$issue_major"

# Check and install python3-pip.
if ! python3 -c 'import setuptools' >& /dev/null; then
  apt-get -y install python3-pip
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/os-release | grep VERSION_ID | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh debian "$issue_major"

# Check and install python3-pip.
if ! python3 -c 'import setuptools'>& /dev/null; then
  zypper -n install python3-pip
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/os-release | grep VERSION_ID | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh sles "$issue_major"

# Check and install python3-pip.
if ! python3 -c 'import setuptools'>& /dev/null; then
  zypper -n install python3-pip
fi
# Back up the old version of cloud-init.
test -d /etc/cloud && mv /etc/cloud /etc/cloud-old
# Download and decompress the Alibaba Cloud cloud-init package.
wget https://ecs-image-tools.oss-cn-hangzhou.aliyuncs.com/cloudinit/cloud-init-19.1.21.tgz
tar -zxvf ./cloud-init-19.1.21.tgz
# Install cloud-init.
issue_major=$( cat /etc/os-release | grep VERSION_ID | grep -Eo '[0-9]+\.?[0-9]+' | head -1 | awk -F'.' '{printf $1}')
bash ./cloud-init-*/tools/deploy.sh opensuse "$issue_major"

(Optional) Step 3: Configure cloud-init

FAQ

• What should I do if dependency libraries are missing when I install cloud-init using Python 3?

  The missing libraries vary by image. Install them using pip, then install cloud-init again.

• What should I do if cloud-init runs abnormally and returns an error message?

  If the default package manager (such as yum) and pip installed different versions of the same dependency library, version conflicts may cause cloud-init to run abnormally. Download the required dependency libraries based on the error message.

  Error message	Cause	Troubleshooting command
  no setuptools module in python	The python setuptools module is missing.	For Python 3.6: CentOS/Red Hat: yum -y install python3-pip Ubuntu/Debian: apt-get -y install python3-pip OpenSUSE/SUSE: zypper -n install python3-pip
  File "/home/testuser/cloud-init/cloudinit/log.py", line 19, in <module> import six ImportError: No module named six )	The six dependency library is missing.	pip3 install six
  File "/home/testuser/cloud-init/cloudinit/url_helper.py", line 20, in <module> import oauthlib.oauth1 as oauth1 ImportError: No module named oauthlib.oauth1 )	The oauthlib dependency library is missing.	pip3 install oauthlib
  The error message does not specify a missing dependency library.	The related error message is not mapped.	Based on the libraries listed in the requirements.txt file, install all dependency libraries: pip3 install -r requirements.txt

• What should I do if cloud-init runs abnormally after a new version of Python 3 is installed on the instance?

  If you install a new version of Python 3, such as Python 3.9, and set it as the default version by creating a symbolic link (for example, ln -s /usr/bin/python3.9 /usr/bin/python3), the installed cloud-init may run abnormally. For example, running cloud-init --version returns an error:

  $cloud-init --version
  Traceback (most recent call last):
    File "/usr/local/bin/cloud-init", line 33, in <module>
      sys.exit(load_entry_point('cloud-init==19.1.9', 'console_scripts', 'cloud-init')())
    File "/usr/local/bin/cloud-init", line 22, in importlib_load_entry_point
      for entry_point in distribution(dist_name).entry_points
    File "/usr/lib64/python3.9/importlib/metadata.py", line 524, in distribution
      return Distribution.from_name(distribution_name)
    File "/usr/lib64/python3.9/importlib/metadata.py", line 187, in from_name
      raise PackageNotFoundError(name)
  importlib.metadata.PackageNotFoundError: cloud-init

  Use one of the following methods to resolve this issue:

  • Method 1: Reinstall cloud-init using the new version of Python 3.

  • Method 2: Modify the cloud-init executable file to change the Python interpreter path to the previous Python 3 version. The following example changes the interpreter to Python 3.6:

    1. Open the cloud-init file.

       vim   /usr/local/bin/cloud-init

    2. Press i to enter edit mode. At the beginning of the file, change the content after #! to the Python 3.6 path.

       After modification, the line starting with #! reads:

       #!/usr/bin/python3.6

    3. Press the Esc key to exit edit mode. Enter :wq and press Enter to save and close the file.

• After I install cloud-init, why does the instance user data that I set during instance creation fail to run?

  1. Check whether user data exists in the instance metadata.

     curl http://100.100.100.200/latest/user-data

     Result:

     • If user data is returned, proceed to the next step to troubleshoot.

     • If no data is returned, user data was not set.

  2. Use one of the following methods to identify the cause.

     • Check whether the user data format is correct.

       User data is executed by cloud-init and must be in the correct format. For example, the first line must start with #!. See Customize instance initialization configurations.

     • Check the /var/log/cloud-init.log log file for errors and troubleshoot based on the error message.

       Example log entry:

        util.py[DEBUG]: Running command ['/var/lib/cloud/instance/scripts/part-001'] with allowed return codes [0] (shell=False, capture=False)

     • View the standard output and standard error output of the user data execution.

       In systemd, user data runs through the cloud-final.service. View its standard output and error output to troubleshoot:

       journalctl -u cloud-final.service

     • If the preceding methods do not identify the issue, copy the user data to a local host for debugging.

• After I install cloud-init, why don't the system initialization configurations and instance user data script run as expected?

  1. Check whether the four cloud-init services are enabled at boot.

     systemctl is-enabled cloud-init-local.service
     systemctl is-enabled cloud-init.service
     systemctl is-enabled cloud-config.service
     systemctl is-enabled cloud-final.service

     If an error or disabled is returned, cloud-init is not enabled at boot.

  2. Enable cloud-init at boot.

     systemctl enable cloud-init-local.service
     systemctl enable cloud-init.service
     systemctl enable cloud-config.service
     systemctl enable cloud-final.service

• I resized the system disk when I created an instance, but the root partition was not automatically resized. What should I do?

  Automatic partition resizing for Linux instances requires cloud-init. Ensure growpart is installed and the cloud.cfg file is correctly configured.

  1. Check whether growpart is installed.

     which growpart

  2. (Required if applicable) If not installed, install it.

     • For RHEL series:

       sudo yum -y install cloud-utils-growpart

     • For Debian series:

       sudo apt -y install cloud-guest-utils

  3. Check whether the /etc/cloud/cloud.cfg file contains the content shown below.

     cat /etc/cloud/cloud.cfg

     

  4. (Required if applicable) If the content is missing, add it to the /etc/cloud/cloud.cfg file.

• For an ECS instance with cloud-init 0.7.6a16 or earlier, the hostname is not updated after I change it in the console and restart the instance. What should I do?

  • Problem description

    After you update the hostname in the ECS console and restart the instance, the new hostname does not take effect. The cloud-init --version command shows version 0.7.6a16 or earlier.

  • Cause

    When cloud-init uses the update_hostname module to update the hostname, it runs the hostname command to get the current system hostname and reads /var/lib/cloud/data/previous-hostname for the cached hostname. It compares the two: if they match, it updates the hostname; if they differ, it assumes the hostname was manually changed and skips the update.

    In Red Hat-based operating systems, the content read from /var/lib/cloud/data/previous-hostname contains a line feed, but the hostname command output does not. This mismatch prevents the hostname from being updated.

  • Solution

    Use one of the following solutions:

    • Upgrade the cloud-init version. See Step 2: Install cloud-init.

      • For CentOS 6 and earlier, use cloud-init 0.7.6a18.

      • For CentOS 7, use cloud-init 19.1.21.

      • For CentOS 8 or later, use cloud-init 23.2.2 or a later version.

    • Manually handle the line feed.

      Manually fix the defective file cloudinit/distros/rhel.py in cloud-init (use find / -name rhel.py to locate the file). Refer to distros/rhel.py: _read_hostname() missing strip on "hostname" to process the line feed in the hostname command output:

      diff --git a/cloudinit/distros/rhel.py b/cloudinit/distros/rhel.py
      index 0b68414e..65176e99 100644
      --- a/cloudinit/distros/rhel.py
      +++ b/cloudinit/distros/rhel.py
      @@ -143,6 +143,7 @@ class Distro(distros.Distro):
                   return util.load_file(filename).strip()
               elif self.uses_systemd():
                   (out, _err) = util.subp(['hostname'])
      +            out = out.strip()
                   if len(out):
                       return out
                   else: