Ubuntu 20.04 LTS (Focal Fossa)edit

The following instructions show you how to prepare your hosts on 20.04 LTS (Focal Fossa).

Install Dockeredit

Install Docker LTS version 20.10 for Ubuntu 20.04

  1. Install the Docker repository dependencies:

    sudo apt-get install ca-certificates curl gnupg lsb-release
  2. Add Docker’s official GPG key:

    sudo mkdir -m 0755 -p /etc/apt/keyrings
    curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
  3. Add the stable docker repository:

    echo \
      "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
      $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
  4. Install the correct version of the docker-ce package, for Ubuntu 20.04 LTS (Focal Fossa):

    sudo apt install -y docker-ce=5:20.10.* docker-ce-cli=5:20.10.* containerd.io
Set up XFS quotasedit

XFS is required to support disk space quotas for Elasticsearch data directories. Some Linux distributions such as RHEL and CentOS already provide XFS as the default file system. On Ubuntu, you need to set up an XFS file system and have quotas enabled.

Disk space quotas set a limit on the amount of disk space an Elasticsearch cluster node can use. Currently, quotas are calculated by a static ratio of 1:32, which means that for every 1 GB of RAM a cluster is given, a cluster node is allowed to consume 32 GB of disk space.

Using LVM, mdadm, or a combination of the two for block device management is possible, but the configuration is not covered here, and it is not supported by Elastic Cloud Enterprise.

You must use XFS and have quotas enabled on all allocators, otherwise disk usage won’t display correctly.

Example: Set up XFS on a single, pre-partitioned block device named /dev/xvdg1.

  1. Format the partition:

    sudo mkfs.xfs /dev/xvdg1
  2. Create the /mnt/data/ directory as a mount point:

    sudo install -o $USER -g $USER -d -m 700 /mnt/data
  3. Add an entry to the /etc/fstab file for the new XFS volume. The default filesystem path used by Elastic Cloud Enterprise is /mnt/data.

    /dev/xvdg1	/mnt/data	xfs	defaults,nofail,x-systemd.automount,prjquota,pquota  0 2
  4. Regenerate the mount files:

    sudo systemctl daemon-reload
    sudo systemctl restart local-fs.target
Update the configurations settingsedit
  1. Stop the Docker service:

    sudo systemctl stop docker
  2. Enable cgroup accounting for memory and swap space.

    1. In the /etc/default/grub file, ensure that the GRUB_CMDLINE_LINUX= variable includes these values:

      cgroup_enable=memory swapaccount=1 cgroup.memory=nokmem
    2. Update your Grub configuration:

      sudo update-grub
  3. Configure kernel parameters

    cat <<EOF | sudo tee -a /etc/sysctl.conf
    # Required by Elasticsearch 5.0 and later
    vm.max_map_count=262144
    # enable forwarding so the Docker networking works as expected
    net.ipv4.ip_forward=1
    # Decrease the maximum number of TCP retransmissions to 5 as recommended for Elasticsearch TCP retransmission timeout.
    # See https://www.elastic.co/guide/en/elasticsearch/reference/current/system-config-tcpretries.html
    net.ipv4.tcp_retries2=5
    # Make sure the host doesn't swap too early
    vm.swappiness=1
    EOF

    The net.ipv4.tcp_retries2 setting applies to all TCP connections and affects the reliability of communication with systems other than Elasticsearch clusters too. If your clusters communicate with external systems over a low quality network then you may need to select a higher value for net.ipv4.tcp_retries2.

    1. Apply the settings:

      sudo sysctl -p
  4. Adjust the system limits.

    Add the following configuration values to the /etc/security/limits.conf file. These values are derived from our experience with the Elastic Cloud hosted offering and should be used for Elastic Cloud Enterprise as well.

    If you are using a user name other than elastic, adjust the configuration values accordingly.

    *                soft    nofile         1024000
    *                hard    nofile         1024000
    *                soft    memlock        unlimited
    *                hard    memlock        unlimited
    elastic          soft    nofile         1024000
    elastic          hard    nofile         1024000
    elastic          soft    memlock        unlimited
    elastic          hard    memlock        unlimited
    elastic          soft    nproc          unlimited
    elastic          hard    nproc          unlimited
    root             soft    nofile         1024000
    root             hard    nofile         1024000
    root             soft    memlock        unlimited
  5. NOTE: This step is optional if the docker registry doesn’t require authentication.

    Authenticate the elastic user to pull images from the docker registry you use, by creating the file /home/elastic/.docker/config.json. This file needs to be owned by the elastic user. If you are using a user name other than elastic, adjust the path accordingly.

    Example: In case you use docker.elastic.co, the file content looks like as follows:

    {
     "auths": {
       "docker.elastic.co": {
         "auth": "<auth-token>"
       }
     }
    }
  6. If you did not create the mount point earlier (if you did not set up XFS), create the /mnt/data/ directory as a mount point:

    sudo install -o $USER -g $USER -d -m 700 /mnt/data
  7. If you set up a new device with XFS earlier:

    1. Mount the block device (change the device name if you use a different device than /dev/xvdg1):

      sudo mount /dev/xvdg1 /mnt/data
    2. Set the permissions on the newly mounted device:

      sudo chown $USER:$USER /mnt/data
  8. Create the /mnt/data/docker directory for the Docker service storage:

    sudo install -o $USER -g $USER -d -m 700 /mnt/data/docker
Configure the Docker daemon optionsedit

Docker creates a bridge IP address that can conflict with IP addresses on your internal network. To avoid an IP address conflict, change the --bip=172.17.42.1/16 parameter in our examples to something that you know will work. If there is no conflict, you can omit the --bip parameter. The --bip parameter is internal to the host and can be set to the same IP for each host in the cluster. More information on Docker daemon options can be found in the dockerd command line reference.

You can specify --log-opt max-size and --log-opt max-file to define the Docker daemon containers log rotation.

  1. Update /etc/systemd/system/docker.service.d/docker.conf. If the file path and file do not exist, create them first.

    [Unit]
    Description=Docker Service
    After=multi-user.target
    
    [Service]
    Environment="DOCKER_OPTS=-H unix:///run/docker.sock --data-root /mnt/data/docker --storage-driver=overlay2 --bip=172.17.42.1/16 --raw-logs --log-opt max-size=500m --log-opt max-file=10 --icc=false"
    ExecStart=
    ExecStart=/usr/bin/dockerd $DOCKER_OPTS
  2. Apply the updated Docker daemon configuration:

    Reload the Docker daemon configuration:

    sudo systemctl daemon-reload

    Restart the Docker service:

    sudo systemctl restart docker

    Enable Docker to start on boot:

    sudo systemctl enable docker
  3. Enable your user to communicate with the Docker subsystem by adding it to the docker group:

    sudo usermod -aG docker $USER
  4. Recommended: Tune your network settings.

    Create a 70-cloudenterprise.conf file in the /etc/sysctl.d/ file path that includes these network settings:

    cat << SETTINGS | sudo tee /etc/sysctl.d/70-cloudenterprise.conf
    net.ipv4.tcp_max_syn_backlog=65536
    net.core.somaxconn=32768
    net.core.netdev_max_backlog=32768
    SETTINGS
  5. Pin the Docker version to ensure that the package does not get upgraded:

    echo "docker-ce hold" | sudo dpkg --set-selections
    echo "docker-ce-cli hold" | sudo dpkg --set-selections
    echo "containerd.io hold" | sudo dpkg --set-selections
  6. Reboot your system to ensure that all configuration changes take effect:

    sudo reboot
  7. After rebooting, verify that your Docker settings persist as expected:

    sudo docker info | grep Root

    If the command returns Docker Root Dir: /mnt/data/docker, then your changes were applied successfully and persist as expected.

    If the command returns Docker Root Dir: /var/lib/docker, then you need to troubleshoot the previous configuration steps until the Docker settings are applied successfully before continuing with the installation process. For more information, check Custom Docker daemon options in the Docker documentation.

  8. Repeat these steps on other hosts that you want to use with Elastic Cloud Enterprise or follow the steps in the next section to start installing Elastic Cloud Enterprise.