Chapter 2. Restoring a containerized undercloud

Procedure

1. Log into your undercloud as the root user.

2. Register your system with the Content Delivery Network, entering your Customer Portal user name and password when prompted:

   [root@director ~]# subscription-manager register

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3. Attach the Red Hat OpenStack Platform entitlement:

   [root@director ~]# subscription-manager attach --pool=Valid-Pool-Number-123456

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4. Disable all default repositories, and then enable the required Red Hat Enterprise Linux repositories:

   [root@director ~]# subscription-manager repos --disable=*
   [root@director ~]# subscription-manager repos --enable=rhel-8-for-x86_64-baseos-rpms --enable=rhel-8-for-x86_64-appstream-rpms --enable=rhel-8-for-x86_64-highavailability-rpms --enable=ansible-2.8-for-rhel-8-x86_64-rpms --enable=openstack-15-for-rhel-8-x86_64-rpms --enable=fast-datapath-for-rhel-8-x86_64-rpms

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5. Perform an update on your system to make sure you have the latest base system packages:

   [root@director ~]# dnf update -y
   [root@director ~]# reboot

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6. Ensure the time on your undercloud is synchronized. For example:

   [root@director ~]# dnf install -y chrony
   [root@director ~]# systemctl start chronyd
   [root@director ~]# systemctl enable chronyd

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7. Copy the undercloud backup archive to the undercloud’s root directory. The following steps use undercloud-backup-$TIMESTAMP.tar as the filename, where $TIMESTAMP is a Bash variable for the timestamp on the archive.

8. Install the database server and client tools:

   [root@director ~]# dnf install -y mariadb mariadb-server

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9. Start the database:

   [root@director ~]# systemctl start mariadb

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10. Increase the allowed packets to accommodate the size of our database backup:

    [root@director ~]# mysql -uroot -e"set global max_allowed_packet = 1073741824;"

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11. Extract the database and database configuration from the archive:

    [root@director ~]# tar -xvC / -f undercloud-backup-$TIMESTAMP.tar var/lib/config-data/mysql/etc/my.cnf.d/galera.cnf
    [root@director ~]# tar -xvC / -f undercloud-backup-$TIMESTAMP.tar root/undercloud-all-databases.sql

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12. Restore the database backup:

    [root@director ~]# mysql -u root < /root/undercloud-all-databases.sql

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13. Extract a temporary version of the root configuration file:

    [root@director ~]# tar -xvf undercloud-backup-$TIMESTAMP.tar root/.my.cnf

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14. Get the old root database password:

    [root@director ~]# OLDPASSWORD=$(sudo cat root/.my.cnf | grep -m1 password | cut -d'=' -f2 | tr -d "'")

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15. Reset the root database password:

    [root@director ~]# mysqladmin -u root password "$OLDPASSWORD"

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16. Copy the root configuration file from the temporary location:

    [root@director ~]# mv root/.my.cnf .
    [root@director ~]# rmdir root

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17. Get a list of old user permissions:

    [root@director ~]# mysql -e 'select host, user, password from mysql.user;'

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18. Remove the old user permissions for each host listed. For example:

    [root@director ~]# HOST="192.0.2.1"
    [root@director ~]# USERS=$(mysql -Nse "select user from mysql.user WHERE user != \"root\" and host = \"$HOST\";" | uniq | xargs)
    [root@director ~]# for USER in $USERS ; do mysql -e "drop user \"$USER\"@\"$HOST\"" || true ;done
    [root@director ~]# mysql -e 'flush privileges'

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    Perform this for all users accessing through the host IP and any host ("%").

1. Stop the database:

   [root@director ~]# systemctl stop mariadb

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2. Create the stack user:

   [root@director ~]# useradd stack

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3. Set a password for the user:

   [root@director ~]# passwd stack

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4. Disable password requirements when using sudo:

   [root@director ~]# echo "stack ALL=(root) NOPASSWD:ALL" | tee -a /etc/sudoers.d/stack
   [root@director ~]# chmod 0440 /etc/sudoers.d/stack

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5. Restore the stack user home directory:

   # tar -xvC / -f undercloud-backup-$TIMESTAMP.tar home/stack

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6. Install the python3-policycoreutils package:

   [root@director ~]# dnf -y install python3-policycoreutils

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7. Restore the glance data:

   [root@director ~]# tar --xattrs -xvC / -f undercloud-backup-$TIMESTAMP.tar var/lib/glance

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8. Restore the swift data:

   [root@director ~]# tar --xattrs -xvC / -f undercloud-backup-$TIMESTAMP.tar srv/node

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9. If using SSL in the undercloud, refresh the CA certificates:

   [root@director ~]# tar -xvC / -f undercloud-backup-$TIMESTAMP.tar etc/pki/instack-certs/undercloud.pem
   [root@director ~]# tar -xvC / -f undercloud-backup-$TIMESTAMP.tar etc/pki/ca-trust/source/anchors/*
   [root@director ~]# restorecon -R /etc/pki
   [root@director ~]# semanage fcontext -a -t etc_t "/etc/pki/instack-certs(/.*)?"
   [root@director ~]# restorecon -R /etc/pki/instack-certs
   [root@director ~]# update-ca-trust extract

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10. Switch to the stack user:

    [root@director ~]# su - stack
    [stack@director ~]$

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11. Install the python3-tripleoclient package:

    $ sudo dnf install -y python3-tripleoclient

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12. Run the undercloud installation command. Ensure to run it in the stack user’s home directory:

    [stack@director ~]$ openstack undercloud install

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13. Wait until the install completes. The undercloud automatically restores its connection to the overcloud. The nodes will continue to poll OpenStack Orchestration (heat) for pending tasks.