Concierge Scheduler

This part of the Concierge Paradigm concerns how we coordinate the scaling of our services.

The Concierge acting in the role of concierge_scheduler.sh is taking a request from its client to manage their business schedule. As such when some particular resource gets low, order some more; and when something is no longer being used, get rid of it.

Environment Variables

Set the following environment variables in the docker-compose.yml file for the Zabbix server service:

ZBX_API_HOST: The Zabbix web frontend endpoint
ZBX_API_USER: A Zabbix username to access the web API
ZBX_API_PASS: Password for the above Zabbix username, or absolute path to password file
ZBX_CONFIG_DIR: The source path for the Zabbix backup/export files
ZBX_TLS_VERIFY: 'true' to enable ssl verification (default), 'false' to disable
ZBX_FORCE_TEMPLATES: Will delete all templates in destination zabbix server before importing configuration. Setting to anything other than 'false' will enable this. Can also use the --force-templates flag
GCP_CREDENTIAL_FILE: Credential file of GCP service account for cloud storage
STORAGE_LOCATION: Remote storage location to store configuration files in. E.g. Cloud Storage bucket name or Azure Container
STORAGE_FOLDER: Folder within bucket/container to upload files to

Example:

ZBX_API_HOST: "zbxweb.svc.eb49da3d-7240-6e94-8e93-b65f3954c652.us-east-1.triton.zone"
ZBX_USER: "Admin"
ZBX_PASS: "zabbix"
ZBX_CONFIG_DIR: "/usr/lib/zabbix/app_config"

Set the following environment variables in the docker_env.py file:

DOCKER_CERT_PATH: The path where the certificates will be generated
DOCKER_HOST: The Docker service API endpoint
COMPOSE_HTTP_TIMEOUT: The time a request to the Docker daemon is allowed to hang before Compose considers it failed

Example:

DOCKER_CERT_PATH = "/tmp/certs"
DOCKER_HOST = "tcp://us-east-1.docker.joyent.com:2376"
DOCKER_CLIENT_TIMEOUT = 800
COMPOSE_HTTP_TIMEOUT = 800

Actions

Actions known to the scheduler include the following:

1. list: this action will run docker-compose ps and provide a list of what containers are currently running.

   It takes two arguments: list + <component>

   Example: concierge_scheduler list consul

   Logic insight:

   Given a component (e.g: consul), functions pre_pem_file and generate_pem_file construct certificates from the inventory of a component dummy host containing the relevant data and call function list to provide the list of running containers. Once the result is provided the certificates will be deleted.

2. backup_config: this action will make an export of the below components existing in Zabbix.

   List of components: templates, hostgroups, hosts, mediatypes, auto-registration actions and triggers actions.

   It only takes one argument: backup_config

   Example: concierge_scheduler backup_config

   Logic insight:

   Different Zabbix API methods are used to export components.

   • Function export_templates exports all templates configuration data to file templates.json using the configuration.export method.
   • Function export_host_groups exports all hostgroups configuration data to file hostgroups.json using the configuration.export method.
   • Function export_hosts exports all hosts configuration data to file hostgroups.json using the configuration.export method.
   • Function export_media_types exports all mediatypes configuration data to file mediatypes.json using the get method.
   • Function export_auto_registration_actions exports all auto-registration actions configuration data to file reg_actions.json using the get method.
   • Function export_trigger_actions exports all trigger actions configuration data to file trigger_actions.json using the get method.
   • Function export_actions_data export all templates and hostgroups names and IDs to file actions_data_orig.json using get methods. This file can later be used to import auto-registration actions.

3. restore_config: this action will make an import of the below components using a set of backup files as source from the assigned configuration directory.

   List of components: hostgroups, templates, hosts, auto-registration actions, triggers actions, mediatypes.

   It only takes one argument: restore_config

   Example: concierge_scheduler restore_config

   It also takes the flag: --force-templates which will force all templates on destination server to be deleted before importing the template configuration

   Logic insight:

   Different Zabbix API methods are used to import components.

   • Function import_hostgroups imports all hostgroups configuration data from file hostgroups.json using the configuration.import method.
   • Function import_templates imports all templates configuration data from file templates.json using the configuration.import method.
   • Function import_hosts imports all hosts configuration data from file hosts.json using the configuration.import method.
   • Function import_reg_actions imports all auto-registration actions configuration data from file reg_actions_import.json using the create method. As we don't know beforehand which IDs will have the templates and hostgroups created by the above imports and these are necessary to create the auto-registration actions we use the following approach:
     • Generate the json file actions_data_dest.json with hostgroups and templates info from the destination Zabbix server (where the import is happening) using the __exp_act_data_dest function. We already have the json file actions_data_orig.json with hostgroups and templates info from the origin Zabbix server (where the backup/export was done).
     • Loop through the reg_actions.json backup file using function __get_autoreg_action_dict to replace the origin hostgroup and template IDs with the destination IDs using the above generated files and constructing the file reg_actions_import.json with the result. Some unnecessary keys are also removed while looping through the file.
     • Import the auto-registration actions making a request to the action.create method using the newly generated reg_actions_import.json file.
   • Function import_trig_actions imports all trigger actions configuration data from file trigger_actions_import.json using the create method. Some unnecessary keys are removed from the backup file trigger_actions.json using function __get_trigger_action_dict which generates the desired file trigger_actions_import.json.
   • Function import_mediatypes imports all mediatypes configuration data from file mediatypes.json using the configuration.import method.
   • Function import_services imports all services configuration data from file services.json using the create method.
   • Function import_proxies imports all proxy configuration data from file proxies.json using the create method.

4. scale_up: this action will increment the number of containers on a selected component.

   It takes four arguments: scale_up + <component> + <current_scale> + <increment>

   Example: concierge_scheduler scale_up consul 1 1

   Logic insight:

   Given a component (e.g: consul) which needs to be scaled up, functions pre_pem_file and generate_pem_file construct certificates from the inventory of a component dummy host containing the relevant data and call function scale_up with the current number of containers for the component (current_scale) and the number we want to add (increment). Once the component is incremented to the desired scale the certificates will be deleted.

5. scale_down: this action will decrease the number of containers on a selected component.

   It takes four arguments: scale_up + <component> + <current_scale> + <decrement>

   Example: concierge_scheduler scale_down consul 2 1

   Logic insight:

   Given a component (e.g: consul) which needs to be scaled down, functions pre_pem_file and generate_pem_file construct certificates from the inventory of a component dummy host containing the relevant data and call function scale_down with the current number of containers for the component (current_scale) and the number we want to reduce (decrement). Once the component is decremented to the desired scale the certificates will be deleted.

6. upload: this action will upload files in specified config directory to a cloud storage location. Defaults to using GCP Cloud Storage.

Image Use

To perform actions using the concierge_scheduler image, the required environment variables must be set, and actions performed using command below. Note: Actions will be performed in order b->r->u->d regardless of command combination order (e.g. -bud will be performed in same order as -dub)

• -b: run backup_config
• -r: run restore_config
• -u: run upload
• -d: delete ZBX_CONFIG_DIR (after running other commands)

Examples

Using docker run to perform restore_config:

docker create -e ZBX_CONFIG_DIR=/config-dir --env-file .env-file mesoform/concierge_scheduler -r

Using docker-compose.yml to perform backup_config, then upload to cloud :

service:
  concierge_scheduler:
    image: mesoform/concierge_scheduler
    env-file: 
       - .env-file
    environment:
       - ZBX_CONFIG_DIR=/config-dir
    command: ["-bu"]

Individual Use

The scheduler can be used outside the concierge paradigm to perform Zabbix configuration import/exports. Some external libraries are required performing actions:

• pyzabbix: Required for Zabbix API usage
• (Optional) google-auth: Required for authentication with GCP
• (Optional) google-cloud-storage: Required for uploading files to GCS

Backing up existing zabbix configuration:

export ZBX_CONFIG_DIR=/zbx-config/
export ZBX_API_USER="Admin"
export ZBX_API_HOST="http://company-zabbix-frontend.com/"
export ZBX_API_PASS="zabbix"
export ZBX_TLS_VERIFY='false'

##Backup existing configuration
python concierge_scheduler.py event backup_config

##Restore configuration from configuration files
python concierge_scheduler.py event restore_config

##Upload ZBX_CONFIG_DIR to GCS bucket 
export GCP_CREDENTIAL_FILE=/credentials-file.json
export STORAGE_LOCATION=gcs-bucket-name
export STORAGE_FOLDER=subfolder-for-config-folders

python concierge_scheduler.py cloud upload

Notes

• With container infrastructures, like Joyent's Triton, that manage placement of containers and allow containers to be first-class citizen's on the host and network, simply running docker-compose will be fine. However, when running containers on other infrastructures you may need to perform a little extra work to set up Docker Engine in Swarm Mode and scale services using docker service.
• If using scheduler for importing zabbix configuration, do not use in a server where existing configuration is needed. Importing configuration will remove the existing configuration.