Merge "Add borg-backup roles"

doc/source/sysadmin.rst

@@ -162,12 +162,14 @@ you can inspect any of the clouds with::
 Backups
 =======
 
-Infra uses the `bup <https://bup.github.io>`__ tool for backups.
+Infra uses the `borg <https://borgbackup.readthedocs.io>`__ backup
+tool.
 
-Hosts in the ``backup`` Ansible inventory group will be backed up to
-servers in the ``backup-server`` group with ``bup``.  The
-``playbooks/roles/backup`` and ``playbooks/roles/backup-server`` roles
-implement the required setup.
+Hosts in the ``borg-backup`` Ansible inventory group will be backed up
+to servers in the ``borg-backup-server`` group with ``borg``.  The
+``playbooks/roles/borg-backup`` and
+``playbooks/roles/borg-backup-server`` roles implement the required
+setup.
 
 The backup server has a unique Unix user for each host to be backed
 up.  The roles will setup required users, their home directories in
@@ -181,52 +183,27 @@ key setup just for backup communication (see ``/root/.ssh/config``).
 Restore from Backup
 -------------------
 
-On the server that needs items restored from backup become root, start a
-screen session as restoring can take a while, and create a working
-directory to restore the backups into. This allows us to be selective in
-how we restore content from backups::
+``borg`` has many options for restoring but a basic way to dump a host
+at a particular time is to
 
-  sudo su -
-  screen
-  mkdir /root/backup-restore-$DATE
-  cd /root/backup-restore-$DATE
-
-Root uses a separate ssh key and remote user to communicate with the
-backup server(s); the username and key to use for backup should be
-automatically configured in ``/root/.ssh/config``.  The backup server
-hostname can be taken from there.
-
-At this point we can join the tar that was split by the backup cron::
-
-  bup join -r backup.x.y.opendev.org: root > backup.tar
-
-At this point you may need to wait a while. These backups are stored on
-servers geographically distant from our normal servers resulting in less
-network throughput between servers than we are used to.
-
-Once the ``bup join`` is complete you will have a tar archive of that
-backup. It may be useful to list the files in the backup
-``tar -tf backup.tar`` to get an idea of what things are available. At
-this point you will probably either want to extract the entire backup::
-
-  tar -xvf backup.tar
-  ls -al
-
-Or selectively extract files::
-
-  # path/to/file needs to match the output given by tar -t
-  tar -xvf backup.tar path/to/file
-
-Note if you created your working directory in a path that is not
-excluded by bup you will want to remove that directory when your work is
-done. /root/backup-restore-* is excluded so the path above is safe.
+* log into the backup server
+* sudo ``su -`` to switch to the backup user for the host to be restored
+* you will now be in the home directory of that user
+* run ``/opt/borg/bin/borg list ./backup`` to list the archives available
+* these should look like ``hostname-YYYY-MM-DDTHH:MM:SS``
+* move to working directory
+* extract one of the appropriate archives with ``/opt/borg/bin/borg extract ~/backup <archive-tag>``
 
 Rotating backup storage
 -----------------------
 
-Since ``bup`` only stores differences, it does not have an effective
-way to prune old backups.  The easiest way is to simply periodically
-start the backups fresh.
+We run ``borg`` in append-only mode, so that clients can not remove
+old backups on the server.
+
+TODO(ianw) : Write instructions on how to prune server side.  We
+should monitor growth to see if automatic pruning would be
+appropriate, or periodic manual pruning, or something similar to this
+existing system where we keep a historic archive and start fresh.
 
 The backup server keeps an active volume and the previously rotated
 volume.  Each consists of 3 x 1TiB volumes grouped with LVM.  The

playbooks/roles/borg-backup-server/README.rst

@@ -0,0 +1,15 @@
+Setup backup server
+
+This role configures backup server(s) in the ``borg-backup-server`` group
+to accept backups from remote hosts.
+
+Note that the ``borg-backup`` role must have run on each host in the
+``borg-backup`` group before this role.  That role will create a
+``borg_user`` tuple in the hostvars for for each host consisting of
+the required username and public key.
+
+Each required user gets a separate home directory in ``/opt/backups``.
+Their ``authorized_keys`` file is configured with the public key to
+allow the remote host to log in and only run ``borg`` in server mode.
+
+**Role Variables**

playbooks/roles/borg-backup-server/defaults/main.yaml

@@ -0,0 +1 @@
+borg_users: []

playbooks/roles/borg-backup-server/tasks/main.yaml

@@ -0,0 +1,19 @@
+- name: Create backup directory
+  file:
+    state: directory
+    path: /opt/backups
+
+- name: Install borg
+  include_role:
+    name: install-borg
+
+- name: Build all borg users from backup hosts
+  set_fact:
+    borg_users: '{{ borg_users }} + [ {{ hostvars[item]["borg_user"] }} ]'
+  with_inventory_hostnames: 'borg-backup:!disabled'
+
+- name: Create borg users
+  include_tasks: user.yaml
+  loop: '{{ borg_users }}'
+  loop_control:
+    loop_var: borg_user

playbooks/roles/borg-backup-server/tasks/user.yaml

@@ -0,0 +1,31 @@
+# note borg_user is the parent loop variable name; this works on each
+# element from the borg_users global.
+- name: Set variables
+  set_fact:
+    user_name: '{{ borg_user[0] }}'
+    user_key: '{{ borg_user[1] }}'
+
+- name: Create borg user
+  user:
+    name: '{{ user_name }}'
+    comment: 'Backup user'
+    shell: /bin/bash
+    home: '/opt/backups/{{ user_name }}'
+    create_home: yes
+  register: homedir
+
+- name: Create borg user authorized key
+  authorized_key:
+    user: '{{ user_name }}'
+    state: present
+    key: '{{ user_key }}'
+    key_options: 'command="/opt/borg/bin/borg serve --append-only --restrict-to-path /opt/backups/{{ user_name }}/backup",restrict'
+
+# ansible-lint wants this in a handler, it should be done here and
+# now; this isn't like a service restart where multiple things might
+# call it.
+- name: Initalise borg
+  command:  /opt/borg/bin/borg init --encryption=none /opt/backups/{{ user_name }}/backup
+  become: yes
+  become_user: '{{ user_name }}'
+  when: homedir.changed

playbooks/roles/borg-backup/README.rst

@@ -0,0 +1,36 @@
+Configure a host to be backed up
+
+This role setups a host to use ``borgp`` for backup to any hosts in the
+``borg-backup-server`` group.
+
+A separate ssh key will be generated for root to connect to the backup
+server(s) and the host key for the backup servers will be accepted to
+the host.
+
+The ``borg`` tool is installed and a cron job is setup to run the
+backup periodically.
+
+Note the ``borg-backup-server`` role must run after this to create the user
+correctly on the backup server.  This role sets a tuple ``borg_user``
+with the username and public key; the ``borg-backup-server`` role uses this
+variable for each host in the ``borg-backup`` group to initalise users.
+
+**Role Variables**
+
+.. zuul:rolevar:: borg_username
+
+   The username to connect to the backup server.  If this is left
+   undefined, it will be automatically set to ``borg-$(hostname)``
+
+.. zuul:rolevar:: borg_backup_excludes_extra
+   :default: []
+
+   A list of extra items to pass as ``--exclude`` arguments to borg.
+   Appended to the global default list of excludes set with
+   ``borg_backup_excludes``.
+
+.. zuul:rolevar:: borg_backup_dirs_extra
+   :default: []
+
+   A list of extra directories to backup.  Appended to the global
+   default list of directories set with ``borg_backup_dirs``.

playbooks/roles/borg-backup/defaults/main.yaml

@@ -0,0 +1,13 @@
+borg_backup_excludes:
+  - '/home/*.cache/*'
+  - '/var/cache/*'
+  - '/var/tmp/*'
+borg_backup_excludes_extra: []
+
+borg_backup_dirs:
+  - /etc
+  - /home
+  - /root
+  - /var
+borg_backup_dirs_extra: []
+

playbooks/roles/borg-backup/tasks/main.yaml

@@ -0,0 +1,63 @@
+- name: Generate borg username for this host
+  set_fact:
+    borg_username: 'borg-{{ inventory_hostname.split(".", 1)[0] }}'
+  when: borg_username is not defined
+
+- debug:
+    var: borg_username
+
+- name: Install borg
+  include_role:
+    name: install-borg
+
+- name: Install backup script
+  template:
+    src: borg-backup.j2
+    dest: /usr/local/bin/borg-backup
+    mode: 0755
+
+- name: Generate keypair for backups
+  openssh_keypair:
+    path: /root/.ssh/id_borg_backup_ed25519
+    type: ed25519
+  register: borg_keypair
+
+- name: Configure ssh for backup server
+  blockinfile:
+    path: /root/.ssh/config
+    create: true
+    block: |
+      # {{ item }} backup server
+      Host {{ item }}
+      HostName {{ item }}
+      IdentityFile /root/.ssh/id_borg_backup_ed25519
+      User {{ borg_username }}
+    mode: 0600
+  with_inventory_hostnames: borg-backup-server
+
+- name: Generate borg_user info tuple
+  set_fact:
+    borg_user: '{{ [ borg_username, borg_keypair["public_key"] ] }}'
+
+- name: Accept hostkey of backup server
+  known_hosts:
+    state: present
+    key: '{{ item }} ssh-ed25519 {{ hostvars[item]["ansible_ssh_host_key_ed25519_public"] }}'
+    name: '{{ item }}'
+  with_inventory_hostnames: borg-backup-server
+
+- name: Install backup cron job
+  cron:
+    name: "Run borg backup"
+    job: "/usr/local/bin/borg-backup {{ item }} 2>> /var/log/borg-backup-{{ item }}.log"
+    user: root
+    hour: '5'
+    minute: '{{ 59|random(seed=item) }}'
+  with_inventory_hostnames: borg-backup-server
+
+- name: Install logrotate rules
+  include_role:
+    name: logrotate
+  vars:
+    logrotate_file_name: '/var/log/borg-backup-{{ item }}.txt'
+  with_inventory_hostnames: borg-backup-server

playbooks/roles/borg-backup/templates/borg-backup.j2

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Flags based on
+#  https://borgbackup.readthedocs.io/en/stable/quickstart.html
+
+if [ -z "$1" ]; then
+    echo "Must specify backup host"
+    exit 1
+fi
+
+BORG="/opt/borg/bin/borg"
+
+# Setting this, so the repo does not need to be given on the commandline:
+export BORG_REPO="ssh://{{ borg_username}}@${1}/opt/backups/{{ borg_username }}/backup"
+
+# some helpers and error handling:
+info() { printf "\n%s %s\n\n" "$( date )" "$*" >&2; }
+trap 'echo $( date ) Backup interrupted >&2; exit 2' INT TERM
+
+info "Starting backup"
+
+# This avoids UI prompts when first accessing the remote repository
+export BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK=1
+
+# Backup the most important directories into an archive named after
+# the machine this script is currently running on:
+${BORG} create                      \
+    --verbose                       \
+    --filter AME                    \
+    --list                          \
+    --stats                         \
+    --show-rc                       \
+    --compression lz4               \
+    --exclude-caches                \
+{% for item in borg_backup_excludes + borg_backup_excludes_extra -%}
+    --exclude '{{ item }}'          \
+{% endfor -%}
+                                    \
+    ::'{hostname}-{now}'            \
+{% for item in borg_backup_dirs + borg_backup_dirs_extra -%}
+    {{ item }} {{ '\\' if not loop.last }}
+{% endfor -%}
+
+backup_exit=$?
+
+if [ ${backup_exit} -eq 0 ]; then
+    info "Backup finished successfully"
+else
+    info "Backup finished with errors"
+fi
+
+exit ${backup_exit}
+

playbooks/roles/install-borg/README.rst

@@ -0,0 +1,11 @@
+Install borg backup tool to /opt/borg
+
+Install borg to a virtualenv; the binary will be available at
+``/opt/borg/bin/borg``.
+
+**Role Variables**
+
+.. zuul:rolevar:: borg_version
+
+   The version of ``borg`` to install.  This should likely be pinned
+   to be the same between server and client.

playbooks/roles/install-borg/defaults/main.yaml

@@ -0,0 +1 @@
+borg_version: 1.1.13

playbooks/roles/install-borg/tasks/main.yaml

@@ -0,0 +1,24 @@
+# We install into a virtualenv here for two reasons; we want a
+# specific version pinned between server and client -- borg has had
+# updates that required transitions so we don't want to use system
+# packages where thing might get out of sync.  Secondly we want to
+# keep as few things as possible to go wrong when running backups.
+- name: Install build deps
+  package:
+    name:
+      - python3-dev
+      - libssl-dev
+      - openssl
+      - libacl1-dev
+      - libacl1
+      - build-essential
+
+- name: Install borg
+  pip:
+    # borg build deps are a little ... interesting, it needs cython
+    # but the requirements don't bring it in.
+    name:
+      - cython
+      - 'borgbackup=={{ borg_version }}'
+    virtualenv: /opt/borg
+    virtualenv_command: /usr/bin/python3 -m venv

playbooks/service-borg-backup.yaml

@@ -0,0 +1,12 @@
+# This needs to happen in order.  Backup hosts export their username/key
+# combos which are installed onto the backup server
+- hosts: "borg-backup:!disabled"
+  name: "Base: Generate borg backup users and keys"
+  roles:
+    - iptables
+    - borg-backup
+- hosts: "borg-backup-server:!disabled"
+  name: "Generate borg configuration"
+  roles:
+    - iptables
+    - borg-backup-server

playbooks/zuul/templates/gate-groups.yaml.j2

@@ -20,3 +20,10 @@ groups:
   backup:
     - backup-test01.opendev.org
     - backup-test02.opendev.org
+
+  borg-backup-server:
+    - borg-backup01.region.provider.opendev.org
+
+  borg-backup:
+    - borg-backup-test01.opendev.org
+    - borg-backup-test02.opendev.org

testinfra/test_borg_backups.py

@@ -0,0 +1,77 @@
+# Copyright 2019 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import os.path
+import pytest
+
+testinfra_hosts = ['borg-backup01.region.provider.opendev.org',
+                   'borg-backup-test01.opendev.org',
+                   'borg-backup-test02.opendev.org']
+
+
+def test_borg_installed(host):
+    f = host.file('/opt/borg/bin/borg')
+    assert f.exists
+
+    cmd = host.run('/opt/borg/bin/borg --version')
+    assert cmd.succeeded
+    # NOTE(ianw): deliberately pinned; we want to be careful if we
+    # update that the new version is compatible with old repos.
+    assert '1.1.13' in cmd.stdout
+
+def test_borg_server_users(host):
+    hostname = host.backend.get_hostname()
+    if hostname.startswith('borg-backup-test'):
+        pytest.skip()
+
+    for username in 'borg-borg-backup-test01', 'borg-borg-backup-test02':
+        homedir = os.path.join('/opt/backups/', username)
+        borg_repo = os.path.join(homedir, 'backup')
+        authorized_keys = os.path.join(homedir, '.ssh', 'authorized_keys')
+
+        user = host.user(username)
+        assert user.exists
+        assert user.home == homedir
+
+        f = host.file(authorized_keys)
+        assert f.exists
+        assert f.contains("ssh-ed25519")
+
+        f = host.file(borg_repo)
+        assert f.exists
+
+def test_borg_backup_host_config(host):
+    hostname = host.backend.get_hostname()
+    if hostname == 'borg-backup01.region.provider.opendev.org':
+        pytest.skip()
+
+    f = host.file('/usr/local/bin/borg-backup')
+    assert f.exists
+
+    f = host.file('/root/.ssh/id_borg_backup_ed25519')
+    assert f.exists
+
+    f = host.file('/root/.ssh/config')
+    assert f.exists
+    assert f.contains('Host borg-backup01.region.provider.opendev.org')
+
+def test_borg_backup(host):
+    hostname = host.backend.get_hostname()
+    if hostname == 'borg-backup01.region.provider.opendev.org':
+        pytest.skip()
+
+    cmd = host.run(
+        '/usr/local/bin/borg-backup borg-backup01.region.provider.opendev.org 2>> '
+        '/var/log/borg-backup-borg-backup01.region.provider.opendev.org.log')
+    assert cmd.succeeded

zuul.d/infra-prod.yaml

@@ -287,6 +287,19 @@
       - playbooks/roles/backup-server/
       - playbooks/roles/iptables/
 
+- job:
+    name: infra-prod-service-borg-backup
+    parent: infra-prod-service-base
+    description: Run service-borg-backup.yaml playbook.
+    vars:
+      playbook_name: service-borg-backup.yaml
+    files:
+      - inventory/
+      - playbooks/service-borg-backup.yaml
+      - playbooks/roles/borg-backup/
+      - playbooks/roles/borg-backup-server/
+      - playbooks/roles/iptables/
+
 - job:
     name: infra-prod-service-registry
     parent: infra-prod-service-base

zuul.d/project.yaml

@@ -13,6 +13,7 @@
         - system-config-run-base-ansible-devel:
             voting: false
         - system-config-run-backup
+        - system-config-run-borg-backup
         - system-config-run-dns
         - system-config-run-eavesdrop:
             dependencies:
@@ -235,6 +236,7 @@
         - infra-prod-service-mirror
         - infra-prod-service-static
         - infra-prod-service-backup
+        - infra-prod-service-borg-backup
         - infra-prod-service-registry
         - infra-prod-service-zookeeper
         - infra-prod-service-zuul
@@ -276,6 +278,7 @@
         - infra-prod-service-mirror-update
         - infra-prod-service-mirror
         - infra-prod-service-static
+        - infra-prod-service-borg-backup
         - infra-prod-service-backup
         - infra-prod-service-zookeeper
         - infra-prod-service-review

zuul.d/system-config-run.yaml

@@ -356,6 +356,38 @@
       - playbooks/zuul/templates/host_vars/backup
       - testinfra/test_backups.py
 
+- job:
+    name: system-config-run-borg-backup
+    parent: system-config-run
+    description: |
+      Run the playbook for borg backup configuration
+    nodeset:
+      nodes:
+        - name: bridge.openstack.org
+          label: ubuntu-bionic
+        - name: borg-backup01.region.provider.opendev.org
+          label: ubuntu-focal
+        - name: borg-backup-test01.opendev.org
+          label: ubuntu-focal
+        - name: borg-backup-test02.opendev.org
+          label: ubuntu-bionic
+    vars:
+      run_playbooks:
+        - playbooks/service-borg-backup.yaml
+    files:
+      - playbooks/install-ansible.yaml
+      - playbooks/roles/borg-backup
+      - playbooks/zuul/templates/host_vars/borg-backup
+      - testinfra/test_borg_backups.py
+    host-vars:
+      borg-backup-test01.opendev.org:
+        host_copy_output:
+          '/var/log/borg-backup-borg-backup01.region.provider.opendev.org.log': logs
+      borg-backup-test02.opendev.org:
+        host_copy_output:
+          '/var/log/borg-backup-borg-backup01.region.provider.opendev.org.log': logs
+
+
 - job:
     name: system-config-run-mirror-base
     parent: system-config-run