LambdaStack backup design document with details

Affected version: 0.7.x

Goals

This document is extension of high level design doc: LambdaStack backup design document and describes more detailed, operational point-of-view of this case. Document does not include Kubernetes and Kafka stack

Components

lsbackup application

Example use:

lambdastack backup -b build_dir -t target_path

Where -b is path to build folder that contains Ansible inventory and -t contains target path to store backup.

backup runs tasks from ansible backup role

build_dir contains cluster's ansible inventory

target_path location to store backup, see Storage section below.

Consider to add disclaimer for user to check whether backup location has enough space to store whole backup.

Storage

Location created on master node to keep backup files. This location might be used to mount external storage, like:

• Amazon S3
• Azure blob
• NFS
• Any external disk mounted by administrator

In cloud configuration blob or S3 storage might be mounted directly on every machine in cluster and can be configured by LambdaStack. For on-prem installation it's up to administrator to attach external disk to backup location on master node. This location should be shared with other machines in cluster as NFS.

Backup scripts structure:

Role backup

Main role for backup contains ansible tasks to run backups on cluster components.

Tasks:

1. Elasticsearch & Kibana

   1.1. Create local location where snapshot will be stored: /tmp/snapshots 1.2. Update elasticsearch.yml file with backup location

    ```bash
    path.repo: ["/tmp/backup/elastic"]
    ```
   

   1.3. Reload configuration 1.4. Register repository:

   curl -X PUT "https://host_ip:9200/_snapshot/my_backup?pretty" \n
   -H 'Content-Type: application/json' -d '
   {
       "type": "fs",
       "settings": {
       "location": "/tmp/backup/elastic"
       }
   }
   '
   

   1.5. Take snapshot:

   curl -X GET "https://host_ip:9200/_snapshot/my_repository/1" \n 
   -H 'Content-Type: application/json'
   

   This command will create snapshot in location sent in step 1.2

   1.5. Backup restoration:

   curl -X POST "https://host_ip:9200/_snapshot/my_repository/2/_restore" -H 'Content-Type: application/json'
   

   Consider options described in opendistro documentation

   1.6. Backup configuration files:

   /etc/elasticsearch/elasticsearch.yml
   /etc/kibana/kibana.yml
   

2. Monitoring

   2.1.1 Prometheus data

   Prometheus delivers solution to create data snapshot. Admin access is required to connect to application api with admin privileges. By default admin access is disabled, and needs to be enabled before snapshot creation. To enable admin access --web.enable-admin-api needs to be set up while starting service:

   service configuration:
   /etc/systemd/system/prometheus.service
   
   systemctl daemon-reload
   systemctl restart prometheus
   

   Snapshot creation:

   curl -XPOST http://localhost:9090/api/v1/admin/tsdb/snapshot
   

   By default snapshot is saved in data directory, which is configured in Prometheus service configuration file as flag:

   --storage.tsdb.path=/var/lib/prometheus
   

   Which means that snapshot directory is creted under:

   /var/lib/prometheus/snapshots/yyyymmddThhmmssZ-*
   

   After snapshot admin access throuh API should be reverted.

   Snapshot restoration process is just pointing --storage.tsdb.path parameter to snaphot location and restart Prometheus.

   2.1.2. Prometheus configuration

   Prometheus configurations are located in:

   /etc/prometheus
   

   2.2. Grafana backup and restore

   Copy files from grafana home folder do desired location and set up correct permissions:

   location: /var/lib/grafana
   content:
   - dashboards
   - grafana.db
   - plugins
   - png (contains renederes png images - not necessary to back up)
   

   2.3 Alert manager

   Configuration files are located in:

   /etc/prometheus
   

   File alertmanager.yml should be copied in step 2.1.2 if exists

3. PostgreSQL

   3.1. Basically PostgreSQL delivers two main tools for backup creation: pg_dump and pg_dumpall

   pg_dump create dump of selected database:

   pg_dump dbname > dbname.bak
   

   pg_dumpall - create dump of all databases of a cluster into one script. This dumps also global objects that are common to all databases like: users, groups, tablespaces and properties such as access permissions (pg_dump does not save these objects)

   pg_dumpall > pg_backup.bak
   

   3.2. Database resotre: psql or pg_restore:

   psql < pg_backup.bak
   pgrestore -d dbname db_name.bak
   

   3.3. Copy configuration files:

   /etc/postgresql/10/main/* - configuration files
   .pgpass - authentication credentials
   
   

4. RabbitMQ

   4.1. RabbitMQ definicions might be exported using API (rabbitmq_management plugins need to be enabled):

   rabbitmq-plugins enable rabbitmq_management
   curl -v -X GET http://localhost:15672/api/definitions -u guest:guest -H "content-type:application/json" -o json
   

   Import backed up definitions:

   curl -v -X POST http://localhost:15672/api/definitions -u guest:guest -H "content-type:application/json" --data backup.json
   

   or add backup location to configuration file and restart rabbitmq:

   management.load_definitions = /path/to/backup.json
   

   4.2 Backing up RabbitMQ messages To back up messages RabbitMQ must be stopped. Copy content of rabbitmq mnesia directory:

   RABBITMQ_MNESIA_BASE
   
   ubuntu:
   /var/lib/rabbitmq/mnesia
   

   Restoration: place these files to similar location

   4.3 Backing up configuration:

   Copy /etc/rabbitmq/rabbitmq.conf file

5. HAProxy

Copy /etc/haproxy/ to backup location

Copy certificates stored in /etc/ssl/haproxy/ location.