jrd / capp-hooks

Scripts to execute while deploying/undeploying an application using capp

CAPP-HOOKS

Goal

These scripts will be executed while deploying/undeploying an application using capp infrastructure.

Structure

Script files should be put in any of the following directories:

• pre_deploy
• post_deploy
• pre_undeploy
• post_undeploy

Script files should have the executive bit set.

Backup format

Backup configurations are described in a x-backups section in the docker-compose.yml file.

In this x-backups section, describe each named volume that needs a backup and indicates a number of rentention_days for the backup repository.

Example:

volumes:
    pgdata:
x-backups:
    pgdata:
        retention_days: 3

Monitoring

The monitoring hooks allows an automatic configuration of monitoring dashboards.

Three hooks are used :

• pre_deploy/monitoring for labelling the containers (the labels are later needed by the monitoring solution),
• post_deploy/monitoring for setting up the monitoring dashboards,
• post_undeploy/monitoring for tearing down the monitoring dashboards.

These hooks need the configuration elements located in confs/monitoring. This directory contains :

• templates directory: json templates for the dashboards, that will be adapted to the service and environment and injected in Grafana, for the monitoring solution,
• blacklist: a blacklist of services that do not need monitoring panels,
• locking.py: a helper module that provides functions for locking files and avoid race conditions,
• post_deploy: a python script executed for setting up the dashboards,
• post_undeploy: a python script used for tearing down the dashboards.

These hooks rely on the fact that Grafana's dashboard configuration is located in a docker volume. The monitoring hook will read and write configurations on this volume in order to update Grafana's dashboards.

Hub

The hub hooks are maintaining a json file up to date with currently deployed application and their frontend urls.

Two hooks are used:

• post_deploy/hub for adding the app/env and its url to the json,
• pre_undeploy/hub for removing the app/env from the json.

The json file is kept in a hub_data docker volume at /data/apps.json location.

The hub application should be deployed to read that volume/file.