HedgeDoc

HedgeDoc is running in a docker container. HedgeDoc is a web editor for markdown notes and contains everything from college notes to personal journal entries and todo lists.

It's available here.

The repository which the container is from is located on the hedgedoc/container repo.

Configuration

All configuration is done through nomad. The configuration is located in the nomad/hedgedoc.hcl file.

Environment variables control the configuration of the container, with the most important one being the domain.

Backup Strategy

HedgeDoc is backed up every 3 hours to /backups/hedgedoc/ on Dionysus. The files are then kept for 14 days before being removed. If the backup fails, a ping is sent to a Discord channel with the filename and date of the backup.

The script which cron runs is shown below. It execs into the hedgedoc-database container and runs pg_dump. This is then sent to the mounted backup folder. The script then removes files older than 14 days and gets the file size of the most recent backup. Finally a notification is sent to Discord if the backup fails, otherwise, the script exits cleanly.

The script that runs the backup task is defined in a nomad "batch" job here

If you just want the bash script that backs up the database, click on the "Bash script" tab below.

Nomad Job

job "hedgedoc-backup" {
  datacenters = ["dc1"]
  type        = "batch"

  periodic {
    cron             = "0 */3 * * * *"
    prohibit_overlap = true
  }

  group "db-backup" {
    task "postgres-backup" {
      driver = "raw_exec"

      config {
        command = "/bin/bash"
        args    = ["local/script.sh"]
      }

      template {
        data = <<EOH
#!/bin/bash

file=/backups/hedgedoc/hedgedoc-$(date +%Y-%m-%d_%H-%M-%S).sql

docker exec $(docker ps -aqf "name=^hedgedoc-db-*") pg_dump hedgedoc -U hedgedoc > "${file}"

find /backups/hedgedoc/hedgedoc* -ctime +14 -exec rm {} \;

file_size=$(find $file -exec du -sh {} \; | cut -f1 | xargs | sed 's/$//')

if test -f "$file"; then
  exit 0
else
  curl -H "Content-Type: application/json" -d '{"content": "`HedgeDoc` backup has just **FAILED**\nFile name: `'"$file"'`\nDate: `'"$(TZ=Europe/Dublin date)"'`"}' {{ key "discord/log/webhook" }}
fi
EOH

        destination = "local/script.sh"
      }

      template {
        data = <<EOH
# as service 'db-task' is registered in Consul
# we wat to grab its 'alloc' tag
{{- range $tag, $services := service "db-task" | byTag -}}
{{if $tag | contains "alloc"}}
{{$allocId := index ($tag | split "=") 1}}
DB_ALLOC_ID="{{ $allocId }}"
{{end}}
{{end}}
        EOH
        destination = "secrets/file.env"
        env         = true
      }
    }
  }
}

Bash script

#!/bin/bash

file=/backups/hedgedoc/hedgedoc-$(date +%Y-%m-%d_%H-%M-%S).sql

docker exec $(docker ps -aqf "name=^hedgedoc-db-*") pg_dump hedgedoc -U hedgedoc > "${file}"

find /backups/hedgedoc/hedgedoc* -ctime +14 -exec rm {} \;

file_size=$(find $file -exec du -sh {} \; | cut -f1 | xargs | sed 's/$//')

if test -f "$file"; then
  exit 0
else
  curl -H "Content-Type: application/json" -d '{"content": "`HedgeDoc` backup has just **FAILED**\nFile name: `'"$file"'`\nDate: `'"$(TZ=Europe/Dublin date)"'`"}' {{ key "discord/log/webhook" }}
  # `{{ key "discord/log/webhook" }}` is the webhook URL for the Discord channel
fi