Station hooks - 3to1go

Hooks run a shell command at two points while Station stores an upload. Use them to trigger an offsite sync, write to a log, or ping a monitoring service.

Pre command: after the upload passes its checksum, before Station stores it. Station waits for it to finish.
Post command: after storing, with THREETOONEGO_STATUS set to ok or error. Retrying an upload that already finished doesn’t rerun hooks.

Set up

Open Custom Scripts

In Station, click Custom Scripts.

Upload a script (optional)

Under Uploaded Items, upload up to 3 files. Only .sh scripts and .txt helper files are allowed, and they must be UTF-8 text. .sh files are made executable, and Windows line endings are converted.

Set the commands

Enter a Pre Command and/or Post Command. Either:

the name of an uploaded script, such as after-upload.sh, or
any shell command, such as curl -fsS https://hc-ping.com/your-id.

Commands run with sh -c inside the Station container, from the hook scripts folder (/hook-scripts). Each command has a 5-minute timeout. Output and non-zero exit codes are written to Station’s logs. A failing hook doesn’t stop the upload.

Environment variables

Every hook gets these variables:

Variable	Value
`THREETOONEGO_APP`	`station`
`THREETOONEGO_HOOK_PHASE`	`pre` or `post`
`THREETOONEGO_HOOK_SCRIPTS_DIR`	The hook scripts folder
`THREETOONEGO_SCOUT_ID`	Sending Scout’s ID
`THREETOONEGO_SCOUT_INSTANCE_ID`	Sending Scout’s instance ID
`THREETOONEGO_JOB_NAME`	Backup job name
`THREETOONEGO_UPLOAD_ID`	Upload session ID
`THREETOONEGO_NAMESPACE`	Storage path, `scout_id/instance_id/job_name`
`THREETOONEGO_FILENAME`	Uploaded filename
`THREETOONEGO_FINGERPRINT`	Snapshot fingerprint
`THREETOONEGO_TIMESTAMP`	Snapshot timestamp
`THREETOONEGO_ARCHIVE_SHA256`	SHA-256 of the encrypted archive
`THREETOONEGO_ARCHIVE_SIZE_BYTES`	Archive size
`THREETOONEGO_SOURCE_ADDRESS`	IP the upload came from
`THREETOONEGO_ADVERTISED_URL`	URL the Scout advertises, if set
`THREETOONEGO_STAGED_PATH`	Where the upload is staged before storing

The post command also gets:

Variable	Value
`THREETOONEGO_STATUS`	`ok` or `error`
`THREETOONEGO_STORED_AS`	Final stored filename
`THREETOONEGO_PRUNED`	Number of old snapshots removed by retention
`THREETOONEGO_DUPLICATE`	`true` if Station already had this snapshot
`THREETOONEGO_UNUSUAL`	Why the archive’s size looks unusual, or empty. See Unusual sizes.

Example: log each stored snapshot

after-upload.sh

#!/bin/sh
[ "$THREETOONEGO_STATUS" = "ok" ] || exit 0
echo "stored $THREETOONEGO_NAMESPACE/$THREETOONEGO_STORED_AS"

Set Post Command to after-upload.sh.

The Station image is a minimal Alpine image with sh and curl. Tools like rclone aren’t included. Run those on the host or in another container that reads the same backup folder.

​Set up

​Environment variables

​Example: log each stored snapshot

Set up

Environment variables

Example: log each stored snapshot