# subscription-manager register --username=<user_name> --password=<password>
The PATH for the root user on each host must contain the following directories:
/bin
/sbin
/usr/bin
/usr/sbin
These should all be included by default in a fresh RHEL 7.x installation.
A base installation of RHEL 7.3 or 7.4 (with the latest packages from the Extras channel) or RHEL Atomic Host 7.4.2 or later is required for master and node hosts. See the following documentation for the respective installation instructions, if required:
Each host must be registered using Red Hat Subscription Manager (RHSM) and have an active OpenShift Container Platform subscription attached to access the required packages.
On each host, register with RHSM:
# subscription-manager register --username=<user_name> --password=<password>
Pull the latest subscription data from RHSM:
# subscription-manager refresh
List the available subscriptions:
# subscription-manager list --available --matches '*OpenShift*'
In the output for the previous command, find the pool ID for an OpenShift Container Platform subscription and attach it:
# subscription-manager attach --pool=<pool_id>
Disable all yum repositories:
Disable all the enabled RHSM repositories:
# subscription-manager repos --disable="*"
List the remaining yum repositories and note their names under repo id, if any:
# yum repolist
Use yum-config-manager to disable the remaining yum repositories:
# yum-config-manager --disable <repo_id>
Alternatively, disable all repositories:
yum-config-manager --disable \*
Note that this could take a few minutes if you have a large number of available repositories
Enable only the repositories required by OpenShift Container Platform 3.9:
# subscription-manager repos \
--enable="rhel-7-server-rpms" \
--enable="rhel-7-server-extras-rpms" \
--enable="rhel-7-server-ose-3.9-rpms" \
--enable="rhel-7-fast-datapath-rpms" \
--enable="rhel-7-server-ansible-2.4-rpms"
|
The addition of the rhel-7-server-ansible-2.4-rpms repository is a new requirement as of OpenShift Container Platform 3.9. |
For RHEL 7 systems:
Install the following base packages:
# yum install wget git net-tools bind-utils iptables-services bridge-utils bash-completion kexec-tools sos psacct
Update the system to the latest packages:
# yum update
If you plan to use the RPM-based installer to run an advanced installation, you can skip this step. However, if you plan to use the containerized installer:
Install the atomic package:
# yum install atomic
Skip to Installing Docker.
Install the following package, which provides RPM-based OpenShift Container Platform installer utilities and pulls in other tools required by the quick and advanced installation methods, such as Ansible and related configuration files:
# yum install atomic-openshift-utils
For RHEL Atomic Host 7 systems:
Ensure the host is up to date by upgrading to the latest Atomic tree if one is available:
# atomic host upgrade
After the upgrade is completed and prepared for the next boot, reboot the host:
# systemctl reboot
At this point, you should install Docker on all master and node hosts. This allows you to configure your Docker storage options before installing OpenShift Container Platform.
For RHEL 7 systems, install Docker 1.13:
|
On RHEL Atomic Host 7 systems, Docker should already be installed, configured, and running by default. |
# yum install docker-1.13.1
After the package installation is complete, verify that version 1.13 was installed:
# rpm -V docker-1.13.1 # docker version
|
The Advanced Installation method automatically changes /etc/sysconfig/docker. |
The --insecure-registry option instructs the Docker daemon to trust any Docker
registry on the indicated subnet, rather than
requiring a certificate.
|
172.30.0.0/16 is the default value of the |
|
After the initial OpenShift Container Platform installation is complete, you can choose to
secure the integrated Docker
registry, which involves adjusting the |
Containers and the images they are created from are stored in Docker’s storage back end. This storage is ephemeral and separate from any persistent storage allocated to meet the needs of your applications.
The default storage back end for Docker on RHEL Atomic Host is a thin pool logical volume, which is supported for production environments. You must ensure that enough space is allocated for this volume per the Docker storage requirements mentioned in System Requirements.
If you do not have enough allocated, see Managing Storage with Docker Formatted Containers for details on using docker-storage-setup and basic instructions on storage management in RHEL Atomic Host.
The default storage back end for Docker on RHEL 7 is a thin pool on loopback devices, which is not supported for production use and only appropriate for proof of concept environments. For production environments, you must create a thin pool logical volume and re-configure Docker to use that volume.
You can use the docker-storage-setup script included with Docker to create a thin pool device and configure Docker’s storage driver. This can be done after installing Docker and should be done before creating images or containers. The script reads configuration options from the /etc/sysconfig/docker-storage-setup file and supports three options for creating the logical volume:
Option A) Use an additional block device.
Option B) Use an existing, specified volume group.
Option C) Use the remaining free space from the volume group where your root file system is located.
Option A is the most robust option, however it requires adding an additional block device to your host before configuring Docker storage. Options B and C both require leaving free space available when provisioning your host. Option C is known to cause issues with some applications, for example Red Hat Mobile Application Platform (RHMAP).
Create the docker-pool volume using one of the following three options:
Option A) Use an additional block device.
In /etc/sysconfig/docker-storage-setup, set DEVS to the path of the block device you wish to use. Set VG to the volume group name you wish to create; docker-vg is a reasonable choice. For example:
# cat <<EOF > /etc/sysconfig/docker-storage-setup DEVS=/dev/vdc VG=docker-vg EOF
Then run docker-storage-setup and review the output to ensure the docker-pool volume was created:
# docker-storage-setup [5/1868] 0 Checking that no-one is using this disk right now ... OK Disk /dev/vdc: 31207 cylinders, 16 heads, 63 sectors/track sfdisk: /dev/vdc: unrecognized partition table type Old situation: sfdisk: No partitions found New situation: Units: sectors of 512 bytes, counting from 0 Device Boot Start End #sectors Id System /dev/vdc1 2048 31457279 31455232 8e Linux LVM /dev/vdc2 0 - 0 0 Empty /dev/vdc3 0 - 0 0 Empty /dev/vdc4 0 - 0 0 Empty Warning: partition 1 does not start at a cylinder boundary Warning: partition 1 does not end at a cylinder boundary Warning: no primary partition is marked bootable (active) This does not matter for LILO, but the DOS MBR will not boot this disk. Successfully wrote the new partition table Re-reading the partition table ... If you created or changed a DOS partition, /dev/foo7, say, then use dd(1) to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1 (See fdisk(8).) Physical volume "/dev/vdc1" successfully created Volume group "docker-vg" successfully created Rounding up size to full physical extent 16.00 MiB Logical volume "docker-poolmeta" created. Logical volume "docker-pool" created. WARNING: Converting logical volume docker-vg/docker-pool and docker-vg/docker-poolmeta to pool's data and metadata volumes. THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.) Converted docker-vg/docker-pool to thin pool. Logical volume "docker-pool" changed.
Option B) Use an existing, specified volume group.
In /etc/sysconfig/docker-storage-setup, set VG to the desired volume group. For example:
# cat <<EOF > /etc/sysconfig/docker-storage-setup VG=docker-vg EOF
Then run docker-storage-setup and review the output to ensure the docker-pool volume was created:
# docker-storage-setup Rounding up size to full physical extent 16.00 MiB Logical volume "docker-poolmeta" created. Logical volume "docker-pool" created. WARNING: Converting logical volume docker-vg/docker-pool and docker-vg/docker-poolmeta to pool's data and metadata volumes. THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.) Converted docker-vg/docker-pool to thin pool. Logical volume "docker-pool" changed.
Option C) Use the remaining free space from the volume group where your root file system is located.
Verify that the volume group where your root file system resides has the desired free space, then run docker-storage-setup and review the output to ensure the docker-pool volume was created:
# docker-storage-setup Rounding up size to full physical extent 32.00 MiB Logical volume "docker-poolmeta" created. Logical volume "docker-pool" created. WARNING: Converting logical volume rhel/docker-pool and rhel/docker-poolmeta to pool's data and metadata volumes. THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.) Converted rhel/docker-pool to thin pool. Logical volume "docker-pool" changed.
Verify your configuration. You should have a dm.thinpooldev value in the /etc/sysconfig/docker-storage file and a docker-pool logical volume:
# cat /etc/sysconfig/docker-storage DOCKER_STORAGE_OPTIONS="--storage-driver devicemapper --storage-opt dm.fs=xfs --storage-opt dm.thinpooldev=/dev/mapper/rhel-docker--pool --storage-opt dm.use_deferred_removal=true --storage-opt dm.use_deferred_deletion=true " # lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert docker-pool rhel twi-a-t--- 9.29g 0.00 0.12
|
Before using Docker or OpenShift Container Platform, verify that the docker-pool logical volume is large enough to meet your needs. The docker-pool volume should be 60% of the available volume group and will grow to fill the volume group via LVM monitoring. |
If Docker has not yet been started on the host, enable and start the service, then verify it is running:
# systemctl enable docker # systemctl start docker # systemctl is-active docker
If Docker is already running, re-initialize Docker:
|
This will destroy any containers or images currently on the host. |
# systemctl stop docker # rm -rf /var/lib/docker/* # systemctl restart docker
If there is any content in /var/lib/docker/, it must be deleted. Files will be present if Docker has been used prior to the installation of OpenShift Container Platform.
Should you need to reconfigure Docker storage after having created the docker-pool, you should first remove the docker-pool logical volume. If you are using a dedicated volume group, you should also remove the volume group and any associated physical volumes before reconfiguring docker-storage-setup according to the instructions above.
See Logical Volume Manager Administration for more detailed information on LVM management.
OpenShift Container Platform is capable of cryptographically verifying images are from trusted sources. The Container Security Guide provides a high-level description of how image signing works.
You can configure image signature verification using the atomic command line
interface (CLI), version 1.12.5 or greater.
The atomic CLI is pre-installed on RHEL Atomic Host systems.
|
For more on the |
Install the atomic package if it is not installed on the host system:
$ yum install atomic
The atomic trust sub-command manages trust configuration. The default configuration is to whitelist all registries. This means no signature verification is configured.
$ atomic trust show * (default) accept
A reasonable configuration might be to whitelist a particular registry or namespace, blacklist (reject) untrusted registries, and require signature verification on a vendor registry. The following set of commands performs this example configuration:
$ atomic trust add --type insecureAcceptAnything 172.30.1.1:5000 $ atomic trust add --sigstoretype atomic \ --pubkeys pub@example.com \ 172.30.1.1:5000/production $ atomic trust add --sigstoretype atomic \ --pubkeys /etc/pki/example.com.pub \ 172.30.1.1:5000/production $ atomic trust add --sigstoretype web \ --sigstore https://access.redhat.com/webassets/docker/content/sigstore \ --pubkeys /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release \ registry.access.redhat.com $ sudo atomic trust show * (default) accept 172.30.1.1:5000 accept 172.30.1.1:5000/production signed security@example.com registry.access.redhat.com signed security@redhat.com,security@redhat.com
When all the signed sources are verified, nodes may be further hardened with a
global reject default:
$ atomic trust default reject $ atomic trust show * (default) reject 172.30.1.1:5000 accept 172.30.1.1:5000/production signed security@example.com registry.access.redhat.com signed security@redhat.com,security@redhat.com
Use the atomic man page man atomic-trust for additional examples.
The following files and directories comprise the trust configuration of a host:
/etc/containers/registries.d/*
/etc/containers/policy.json
The trust configuration may be managed directly on each node or the generated files managed on a separate host and distributed to the appropriate nodes using Ansible, for example. See the Container Image Signing Integration Guide for an example of automating file distribution with Ansible.
Sometimes a container’s log file (the
/var/lib/docker/containers/<hash>/<hash>-json.log file on the node where the
container is running) can increase to a problematic size. You can manage this by
configuring Docker’s json-file logging driver to restrict the size and number
of log files.
| Option | Purpose |
|---|---|
|
Sets the size at which a new log file is created. |
|
Sets the maximum number of log files to be kept per host. |
For example, to set the maximum file size to 1MB and always keep the last three
log files, edit the /etc/sysconfig/docker file to configure max-size=1M
and max-file=3:
OPTIONS='--insecure-registry=172.30.0.0/16 --selinux-enabled --log-opt max-size=1M --log-opt max-file=3'
Next, restart the Docker service:
# systemctl restart docker
Container logs are stored in the /var/lib/docker/containers/<hash>/ directory on the node where the container is running. For example:
# ls -lh /var/lib/docker/containers/f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8/ total 2.6M -rw-r--r--. 1 root root 5.6K Nov 24 00:12 config.json -rw-r--r--. 1 root root 649K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log -rw-r--r--. 1 root root 977K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log.1 -rw-r--r--. 1 root root 977K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log.2 -rw-r--r--. 1 root root 1.3K Nov 24 00:12 hostconfig.json drwx------. 2 root root 6 Nov 24 00:12 secrets
See Docker’s documentation for additional information on how to Configure Logging Drivers.
The quick and advanced installation methods require a user that has access to all hosts. If you want to run the installer as a non-root user, passwordless sudo rights must be configured on each destination host.
For example, you can generate an SSH key on the host where you will invoke the installation process:
# ssh-keygen
Do not use a password.
An easy way to distribute your SSH keys is by using a bash loop:
# for host in master.example.com \
node1.example.com \
node2.example.com; \
do ssh-copy-id -i ~/.ssh/id_rsa.pub $host; \
done
Modify the host names in the above command according to your configuration.
If you are interested in installing OpenShift Container Platform using the containerized method (optional for RHEL but required for RHEL Atomic Host), see Installing on Containerized Hosts to prepare your hosts.
When you are ready to proceed, you can install OpenShift Container Platform using the quick installation or advanced installation method.
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As of OpenShift Container Platform 3.9, the quick installation method is deprecated. In a future release, it will be removed completely. In addition, using the quick installer to upgrade from version 3.7 to 3.9 is not supported. |
If you are installing a stand-alone registry, continue with Installing a Stand-alone Registry.