minor: Ballista showplan helper script

[milenkovicm]

Ballista plan print CLI helper

What

Adds dev/bin/showplan.sh, a bash CLI utility for quickly inspecting query plans of Ballista jobs directly from the terminal, using the Ballista REST API.

Why

Inspecting a job's logical, physical, or stage plans currently requires manually assembling curl + jq pipelines and knowing which endpoint to hit. This script wraps that into a single ergonomic command, making debugging and plan analysis faster during development.

ballista-cli displays this information but copying and pasting the generated plan is difficult. Furthermore, inspecting the last job plans during development is common and offers a quick way to access this information.

How it works

The script queries the Ballista scheduler REST API (default: http://localhost:50050/) and prints the requested plan for a given job.

Usage:

showplan.sh [job_id] [-a ADDR] [-p] [-l] [-e] [-s [STAGE_ID]] [-w] [-t]

Options:

Flag	Description
job_id	Optional. Defaults to the most recently started job (resolved via max_by(.start_time) from /api/jobs)
-a ADDR	Override the API base URL (default: http://localhost:50050/)
-p	Display physical_plan from job info (default)
-l	Display logical_plan from job info
-e	Display stage_plan (execution plan) from job info
-s [STAGE_ID]	Display the physical plan for a specific stage, or all stages if no ID given (from /api/job/{id}/stages)
-w	Pipe output through less -S (no line-wrap, horizontal scroll — useful for wide plans)
-t	Request tree-rendered plans (?render_tree=true query parameter)

Other details:

• The separator line dynamically fills the full terminal width (tput cols, falls back to 80)
• API base URL is normalised to always have exactly one trailing slash
• Uses set -euo pipefail for safe error handling

[martin-g]

Suggested change

	COLS=$(tput cols 2>/dev/tty || echo 80)
	COLS=$(tput cols 2>/dev/null || echo 80)

[milenkovicm]

this does not work, it will return 80 every time

[martin-g]

$ COLS=$(tput cols 2>/dev/null || echo 80)
$ echo $COLS
238

You want errors to be ignored, right ?
The normal way is to write them to /dev/null. It will return 80 only if /dev/null is not existing or your OS user does not have permissions to read that file.

$ ls -la /dev/null 
crw-rw-rw- 1 root root 1, 3 May 12 14:08 /dev/null
$ COLS=$(tput cols 2>/dev/null || echo 80) && echo $COLS
238
$ COLS=$(tput cols 2>/dev/nulllll || echo 80) && echo $COLS
bash: /dev/nulllll: Permission denied
80

[milenkovicm]

Yes, but for some reason it return 80 all the time on my own machine

[milenkovicm]

Will try later

[milenkovicm]

$ COLS=$(tput cols 2>/dev/null || echo 80)
$ echo $COLS
80
$  tput cols
215

for some reason

[milenkovicm]

minor thing we can fix it later if needed

[martin-g]

$ COLS=$(tput cols 2>/dev/null || echo 80)
$ echo $COLS
238

You want errors to be ignored, right ?
The normal way is to write them to /dev/null. It will return 80 only if /dev/null is not existing or your OS user does not have permissions to read that file.

$ ls -la /dev/null 
crw-rw-rw- 1 root root 1, 3 May 12 14:08 /dev/null
$ COLS=$(tput cols 2>/dev/null || echo 80) && echo $COLS
238
$ COLS=$(tput cols 2>/dev/nulllll || echo 80) && echo $COLS
bash: /dev/nulllll: Permission denied
80

[milenkovicm]

$ COLS=$(tput cols 2>/dev/null || echo 80)
$ echo $COLS
80
$  tput cols
215