docker-volume-backup/docs/how-tos/set-up-notifications.md

title	layout	nav_order	parent
Receive notifications	default	4	How Tos

Receive notifications

Send email notifications on failed backup runs

To send out email notifications on failed backup runs, provide SMTP credentials, a sender and a recipient:

version: '3'

services:
  backup:
    image: offen/docker-volume-backup:v2
    environment:
      # ... other configuration values go here
      NOTIFICATION_URLS=smtp://me:secret@smtp.example.com:587/?fromAddress=no-reply@example.com&toAddresses=you@example.com

Notification backends other than email are also supported. Refer to the documentation of shoutrrr to find out about options and configuration.

{: .note } If you also want notifications on successful executions, set NOTIFICATION_LEVEL to info.

Customize notifications

The title and body of the notifications can be tailored to your needs using Go templates. Template sources must be mounted inside the container in /etc/dockervolumebackup/notifications.d/: any file inside this directory will be parsed.

services:
  backup:
    image: offen/docker-volume-backup:v2
    volumes:
      - ./customized.template:/etc/dockervolumebackup/notifications.d/01.template

The files have to define nested templates in order to override the original values. An example:

{% raw %}

{{ define "title_success" -}}
✅ Successfully ran backup {{ .Config.BackupStopContainerLabel }}
{{- end }}

{{ define "body_success" -}}
▶️ Start time: {{ .Stats.StartTime | formatTime }}
⏹️ End time: {{ .Stats.EndTime | formatTime }}
⌛ Took time: {{ .Stats.TookTime }}
🛑 Stopped containers: {{ .Stats.Containers.Stopped }}/{{ .Stats.Containers.All }} ({{ .Stats.Containers.StopErrors }} errors)
⚖️ Backup size: {{ .Stats.BackupFile.Size | formatBytesBin }} / {{ .Stats.BackupFile.Size | formatBytesDec }}
🗑️ Pruned backups: {{ .Stats.Storages.Local.Pruned }}/{{ .Stats.Storages.Local.Total }} ({{ .Stats.Storages.Local.PruneErrors }} errors)
{{- end }}

{% endraw %}

Template names that can be overridden are:

• title_success (the title used for a successful execution)
• body_success (the body used for a successful execution)
• title_failure (the title used for a failed execution)
• body_failure (the body used for a failed execution)

Notification templates reference

Configuration, data about the backup run and helper functions will be passed to these templates, this page documents them fully.

Data

Here is a list of all data passed to the template:

• Config: this object holds the configuration that has been passed to the script. The field names are the name of the recognized environment variables converted in PascalCase. (e.g. BACKUP_STOP_CONTAINER_LABEL becomes BackupStopContainerLabel)
• Error: the error that made the backup fail. Only available in the title_failure and body_failure templates
• Stats: objects that holds stats regarding script execution. In case of an unsuccessful run, some information may not be available.
  • StartTime: time when the script started execution
  • EndTime: time when the backup has completed successfully (after pruning)
  • TookTime: amount of time it took for the backup to run. (equal to EndTime - StartTime)
  • LockedTime: amount of time it took for the backup to acquire the exclusive lock
  • LogOutput: full log of the application
  • Containers: object containing stats about the docker containers
    • All: total number of containers
    • ToStop: number of containers matched by the stop rule
    • Stopped: number of containers successfully stopped
    • StopErrors: number of containers that were unable to be stopped (equal to ToStop - Stopped)
  • BackupFile: object containing information about the backup file
    • Name: name of the backup file (e.g. backup-2022-02-11T01-00-00.tar.gz)
    • FullPath: full path of the backup file (e.g. /archive/backup-2022-02-11T01-00-00.tar.gz)
    • Size: size in bytes of the backup file
  • Storages: object that holds stats about each storage
    • Local, S3, WebDAV, Azure, Dropbox or SSH:
      • Total: total number of backup files
      • Pruned: number of backup files that were deleted due to pruning rule
      • PruneErrors: number of backup files that were unable to be pruned

Functions

Some formatting and helper functions are also available:

• formatTime: formats a time object using RFC3339 format (e.g. 2022-02-11T01:00:00Z)
• formatBytesBin: formats an amount of bytes using powers of 1024 (e.g. 7055258 bytes will be 6.7 MiB)
• formatBytesDec: formats an amount of bytes using powers of 1000 (e.g. 7055258 bytes will be 7.1 MB)
• env: returns the value of the environment variable of the given key if set
• toJson: converting object to JSON
• toPrettyJson: converting object to pretty JSON

Special characters in notification URLs

The value given to NOTIFICATION_URLS is a comma separated list of URLs. If such a URL contains special characters (e.g. commas) these need to be URL encoded. To obtain an encoded version of your URL, you can use the CLI tool provided by shoutrrr (which is the library used for sending notifications):

docker run --rm -ti containrrr/shoutrrr generate [service]

where service is any of the supported services, e.g. for SMTP:

docker run --rm -ti containrrr/shoutrrr generate smtp