supaspin/README.md

supaspin

Version 1.3.4

Create, list, show and delete throwaway Supabase instances on a single-node microk8s server, from a terminal menu.

Use it for testing and staging copies of an app. Each instance is numbered, has its own hostname, its own database, capped disk and capped memory, and runs beside your other workloads without endangering them. Nothing in it is specific to any one app.

What each instance gets

Web API	https://<slot hostname> (auth, rest, graphql, realtime, storage, functions), with a Let's Encrypt certificate
Postgres	<LAN IP>:544N (instance 1 → 5441, 2 → 5442, …), bound on the LAN address only
Studio (admin UI)	http://<LAN IP>:300N (3001, 3002, …), not on the public hostname
Disk	fixed-size ext4 image files, mounted at boot: db 2 GB, storage 1 GB, every other volume 256 MB
Memory	limits add up to 9 GiB per instance, requests to 1.875 GiB (table below)
Priority	pods run at priority -100 (supaspin-low); when the server runs short of memory they are evicted first and never evict anyone else
Secrets	generated fresh per instance: JWT secret, anon and service keys, Postgres password, Studio password, and the internal keys
Uploads	stored in the instance's own storage image (no MinIO); deleted with the instance

Studio and pg-meta (the admin UI and its schema API) are removed from the public gateway: / and /pg/ return 404 on the public hostname. Studio on port 300N has no login of its own, so keep that port off the internet (do not forward it on your router).

Instance N uses hostname slot N from your settings, so the number of slots is the maximum number of instances at once. Numbers are reused: create picks the lowest free one.

Requirements

• A Debian/Ubuntu server with microk8s (or any Kubernetes with kubectl and helm on the path), with an ingress-nginx ingress class and cert-manager installed.
• DNS A records for every hostname slot pointing at the server, and ports 80 and 443 forwarded to it (Let's Encrypt fetches a test file over port 80 to issue each certificate).
• Root access on that server. python3 and python3-yaml (the installer adds the latter with apt).

Install

curl -fsSL https://git.didgibot.com/public/supaspin/raw/branch/main/install.sh | sudo bash

If your Gitea requires sign-in even for public repositories (the download then fails with "Could not download"), either pass a read-only token (Gitea → Settings → Applications, scope repository: read):

curl -fsSL -H "Authorization: token $TOKEN" https://git.didgibot.com/public/supaspin/raw/branch/main/install.sh | sudo SUPASPIN_TOKEN=$TOKEN bash

or clone the repository and install from the checkout:

git clone ssh://git@git.didgibot.com:2226/public/supaspin.git && sudo bash supaspin/install.sh

Run it again to upgrade. It installs /usr/local/bin/supaspin, its values template and the uninstaller in /usr/share/supaspin/.

Then start the app; the first run asks for your settings and prepares the cluster:

sudo supaspin

Setting	Meaning
Storage root	folder that holds every instance's images and .env (<root>/<N>/…)
Node name	Kubernetes node the volumes are pinned to (detected)
Server LAN IP	address the Postgres and Studio ports are bound to (detected)
Let's Encrypt e-mail	for certificate expiry notices
Ingress class	usually public on microk8s
Hostname slots	comma-separated; the first is instance 1, the second instance 2, …
Public SSH host / port / user	only used to print the tunnel command
Mail settings	default SMTP settings for the auth service (changeable later)

Settings live in /etc/supaspin/config.yaml (readable by root only). The first run also creates, only if missing: the supaspin-local-sc StorageClass, the supaspin-letsencrypt ClusterIssuer, the supaspin-low PriorityClass and the supaspin-certs namespace, and downloads the pinned Supabase Helm chart (0.8.0, Postgres 17.6.1.136) once into /var/lib/supaspin/charts/.

Using it

sudo supaspin opens the menu (arrow keys, Enter, q to go back).

Menu item	What it does
Create instance	picks the lowest free number, asks whether to use the saved mail settings or enter different ones, creates the disks, installs Supabase, waits until every pod is ready, writes <root>/<N>/.env
List instances	number, hostname, pods ready, memory in use, disk use per image, .env path, and for each instance the tunnel command with plain instructions (open it, keep it in the background, close it)
Show instance (and suspend or resume it)	the .env (secrets hidden unless you ask), the tunnel command, pod status and recent events - and the one line that stops this instance or starts it again, worded for whichever state it is in
Delete instance	asks you to type the number; removes everything (see below)
Copy instance values into another .env file	puts an instance's .env values into your app's .env, on this server or on another computer (see below)
Apply current memory caps and log retention to running instances	puts this version's memory limits and the log-retention job on instances that already exist, replacing their pods one service at a time; databases, uploads and .env files are not touched
Mail settings	view and change the saved default mail settings
Settings	change any first-run setting

The same actions are available without the menu:

sudo supaspin create [--ask-mail]     # --ask-mail: choose saved or different mail settings
sudo supaspin list
sudo supaspin show N                  # .env with secrets hidden, plus tunnel help
sudo supaspin env N                   # the full .env (contains secrets)
sudo supaspin tunnel N                # the tunnel commands, step by step
sudo supaspin push-env N TARGET [--port P] [--key FILE] [--dry-run]   # see "Copying an instance's values"
sudo supaspin delete N [--yes]
sudo supaspin upgrade [N]             # apply this version's memory caps to running instances
sudo supaspin suspend N               # stop an instance, keep its data (see "Suspending an instance")
sudo supaspin resume N                # start it again
sudo supaspin mail                    # change the saved default mail settings
sudo supaspin setup                   # change settings
supaspin --version                    # prints "supaspin 1.3.1"

Connecting your app

Each instance writes <root>/<N>/.env (mode 600, owned by root) with the usual Supabase variable names: SUPABASE_URL, PUBLIC_SUPABASE_URL, API_EXTERNAL_URL, ANON_KEY, PUBLIC_SUPABASE_ANON_KEY, JWT_ANON_KEY, SERVICE_ROLE_KEY, JWT_SERVICE_KEY, JWT_SECRET, JWT_EXPIRY, POSTGRES_*, DATABASE_URL, DASHBOARD_USERNAME, DASHBOARD_PASSWORD and GOTRUE_SMTP_*. Read it with sudo supaspin env N and copy what your app needs.

The web API is public, so the URL and keys work from anywhere. Postgres and Studio are not public. To reach them from your own computer you open a tunnel: a private connection from your computer to the server that makes the instance's database and Studio (its admin screen) appear on your own computer, at localhost:544N (database) and http://localhost:300N (Studio), for as long as the tunnel is open. sudo supaspin list prints the exact commands for every instance (sudo supaspin tunnel N prints them with a few more hints). Run them in a terminal on your computer, not on the server.

Which computer you use matters. The commands for keeping the tunnel in the background and for closing it work on Mac and Linux only. They do not work on Windows, because the ssh program that comes with Windows does not support the "control file" they need. On Windows use the first command (keep the tunnel open in its own PowerShell window) and close it with Ctrl+C or by closing the window.

• If you want to open the tunnel and keep it open in your terminal window (Mac, Linux, Windows), run the ssh -N ... command. The window looks stuck and prints nothing: that is normal, it means the tunnel is open. Press Ctrl+C to close it.
• If you want the tunnel to run in the background so your terminal stays free (Mac and Linux only), run the ssh -f -N -M -S /tmp/supaspin-N.sock ... command. It asks for your password if needed, then gives you your terminal back.
• If you no longer need the background tunnel and want to close it (Mac and Linux only), run ssh -S /tmp/supaspin-N.sock -O exit you@your.server. It answers "Exit request sent."
• If you want to check whether the background tunnel is running (Mac and Linux only), run ssh -S /tmp/supaspin-N.sock -O check you@your.server. It answers "Master running" if it is.
• If closing says "No such file or directory" but the tunnel still works, or starting a tunnel says "address already in use" and the check does not say "Master running", a leftover tunnel is in the way: run pkill -f "[s]upaspin-N.sock" (Mac and Linux only; the [s] is on purpose, it stops the command from stopping itself) and start the tunnel again.

While the tunnel is open, put DATABASE_URL=postgresql://postgres:<password>@localhost:5441/postgres in your app's .env (the password is POSTGRES_PASSWORD in the instance's .env) and open Studio at http://localhost:3001. On the server's own LAN you do not need a tunnel: use <LAN IP>:5441 and http://<LAN IP>:3001.

Copying an instance's values into your app's .env

If you want your app's .env to point at an instance, run:

sudo supaspin push-env 1 igor@192.168.10.50:/Users/igor/app/.env      # a Mac or Linux computer
sudo supaspin push-env 1 "igor@192.168.10.50:C:/Users/igor/app/.env"  # a Windows computer
sudo supaspin push-env 1 /home/igor/app/.env                          # a file on this server
sudo supaspin push-env 1 --dry-run igor@192.168.10.50:/Users/igor/app/.env   # only show what would change

or choose "Copy instance values into another .env file" in the menu, which asks for everything (instance, file, SSH user, port and key file). Options: --port (SSH port, default 22), --key (key file), --dry-run (write nothing). If the SSH server needs a password, SSH asks for it in your terminal, once.

What it does with the target file:

• Every KEY=VALUE line of the instance's .env is put in. If the key is already in the file (also as export KEY=...), its value is replaced. If it is not, the line is added at the end.
• Lines that start with # are ignored completely. # ANON_KEY=old is left as it is, and ANON_KEY counts as missing, so a new ANON_KEY=... line is added.
• Every other line (other keys, comments, blank lines, their order, line endings, the file's owner and permissions) stays exactly as it was. The file must already exist; it is never created.
• It never prints values, only key names: replaced, added, already correct, and how many other lines stayed untouched. It ends with SUCCESS or FAILED and the reason, and its exit status is 0 or 1.

Safety net: before the file is changed, an untouched copy is kept in a private temporary folder (in memory, in /run). After writing, the file is read back and compared with that copy: nothing but the instance's keys may differ, and each of them must have the instance's value. If anything is off, the copy is written back and checked. The copy is deleted at the end. Only if even the write-back fails is it kept, and its path is printed so that you can restore the file by hand.

The other computer can be a Mac, a Linux computer or a Windows computer. It only needs an SSH server with file copying (SFTP) switched on and this server must be able to reach it. Files are copied with scp, so nothing has to be installed there. The SSH connection is made as the person who typed sudo, so your own keys and known computers apply. If the connection fails, supaspin says why and what to do: for example how to switch SSH on (Mac: System Settings > General > Sharing > Remote Login; Linux: sudo apt install openssh-server; Windows: the optional feature "OpenSSH Server"), how to install this server's key (ssh-copy-id), or how to trust a new computer.

Deleting

Delete works on a half-created instance too and can be run again safely. It:

1. saves the instance's TLS certificate into namespace supaspin-certs,
2. uninstalls the Helm release, then deletes the namespace and the volumes' Kubernetes objects,
3. unmounts every image, removes its /etc/fstab line and deletes <root>/<N>/.

Creating that instance again restores the saved certificate, so repeated create/delete cycles do not hit Let's Encrypt's limit of 5 certificates per hostname per week. If a create fails midway, run supaspin delete N to clean up.

Suspending an instance

An instance you are not using right now does not have to be deleted. It can be stopped and started again with its data, from the menu:

sudo supaspin  ->  Show instance (and suspend or resume it)  ->  pick the instance
                                                             ->  Suspend it (stop it, keep its data)

The picker names every instance with its state next to it, so you can see at a glance which ones are awake. Inside an instance the same line reads Resume it when the instance is asleep, so there is one line to look for either way and nothing to remember. Stopping takes about half a minute; starting takes a minute or two, because the database answers first and the rest wait for it.

The same two actions without the menu, if you prefer typing:

sudo supaspin suspend 2
sudo supaspin resume 2

What the server gets back while an instance sleeps:

• the memory it had reserved (1.875 GiB) and everything it was actually using (1.5 to 2.5 GiB),
• its twelve pod slots, out of the 110 a node allows,
• its two ports on the server: Postgres on 544N and Studio on 300N are free for something else.

What is kept, untouched:

• the database and the uploaded files - the disk images stay mounted and keep their contents,
• the .env file with its passwords and keys, so your app needs no change when the instance is back,
• the HTTPS certificate, which goes on renewing itself while the instance sleeps,
• the hostname and every Kubernetes object. Until you resume it, the hostname answers "service unavailable" instead of not answering at all.

Disk space is not given back: that is the data you are keeping. sudo supaspin list shows the state of every instance, and a suspended one is listed as suspended with no tunnel commands, because nothing is listening on its ports. Asking for the tunnel command of a sleeping instance says so instead of handing you a command that cannot work.

Suspending is written into the instance's stored settings, not done by hand to the running pods, so it survives anything that re-applies the chart. sudo supaspin upgrade on a suspended instance stores the new memory limits and leaves it asleep; they take effect when you resume it.

Memory per instance

Service	Request	Limit	Highest use measured
db	512 MiB	2048 MiB	273 MiB
analytics	128 MiB	1536 MiB	694 MiB
vector	128 MiB	512 MiB	290 MiB
kong	128 MiB	768 MiB	269 MiB
realtime	128 MiB	768 MiB	300 MiB
auth, functions, imgproxy, meta, rest, storage, studio	128 MiB each	512 MiB each	203 MiB (studio)
Total	1.875 GiB	9 GiB

The request is what the scheduler sets aside for a service and can never be given to anything else. The limit is the ceiling the kernel kills the container at. They do different jobs here.

The requests are deliberately small: the server is one machine shared with the production workloads, and reserving what three instances really use would leave production nothing to start in. The limits are roughly twice the highest use measured across three running instances on 2026-09-22 (right-hand column above).

The earlier limits sat right on top of normal use and the kernel kept killing the two logging services. Analytics (Logflare, which stores the logs Studio shows) used 612, 694 and 662 MiB of a 768 MiB ceiling and was killed 36 times on one instance. Vector, the log collector that ships the instance's pod logs to analytics, was killed 297 times on that same instance, where a backlog it could not deliver kept growing in its memory. The two feed each other: analytics dies, vector cannot deliver, vector fills up and dies, and on restart it replays the backlog into analytics. Realtime at 300 MiB of 384 and studio at 203 MiB of 256 were the next in line. Image resizing (imgproxy) reads the uploads from the storage volume, so it has no image of its own.

On 2026-10-06 instance 3 died of the same pipeline in a different place: Logflare stores the logs it receives in the _supabase database and never deletes them, so the 2 GB db image filled to 100% over eight days, Postgres crashed and could not even start its recovery, analytics answered every delivery with an error, and vector was killed against its 1024 MiB ceiling every few minutes with the undeliverable backlog. The fix is log retention: every instance gets a pg_cron job (set up on create, upgrade and resume) that deletes analytics logs older than 2 days every night. pg_cron in this image only runs jobs from the postgres database, so the job lives there and reaches the log tables in _supabase over a local dblink connection. That bounds both the db image and vector's backlog, so vector is back to the 512 MiB ceiling the production supabase charts carry.

Changing the numbers in this table only affects instances created afterwards. To put them on instances that already run, use sudo supaspin upgrade: it reads back the values Helm stored when the instance was installed, replaces the memory block in them and applies the chart again, so the pods are replaced service by service and nothing else about the instance changes.

Troubleshooting

• Pods not ready. sudo supaspin → Show instance → Pods and events, or kubectl get pods -n supaspin-N and kubectl describe pod …. OOMKilled means a pod hit its memory limit.
• Certificate stays pending. The hostname's DNS record must point at the server and port 80 must reach the ingress: kubectl get certificate,order,challenge -n supaspin-N.
• "no free hostname slot". Delete an instance or add a slot in Settings (and its DNS record).
• Create failed. sudo supaspin delete N, then create again.
• Port already in use. Postgres and Studio ports are fixed per number (5440+N, 3000+N); another program is using it. Free the port or use another instance number.
• After a reboot. Images are mounted from /etc/fstab (nofail, after the storage root is available) and the pods restart on their own. Check the mounts with findmnt | grep supabase. Kubernetes can start a pod a moment before its image is mounted, so supaspin makes every empty mount-point folder read-only (chattr +i) until the image is mounted over it: an early pod fails and retries instead of setting up a fresh database on the bare folder.

Uninstall

sudo bash /usr/share/supaspin/uninstall.sh

It asks before deleting the instances (their data is gone for good) and before removing the shared cluster objects, then removes the app, its settings and its cache.

Development

The tests use Python's built-in unittest and need no extra packages:

python3 -m unittest discover -s tests

Versions

The version is written in three places that must always show the same number: the file VERSION, the VERSION constant at the top of supaspin, and the line "Version x.y.z" at the top of this README. A test fails if they differ. Every release is a git tag vX.Y.Z (for example v1.1.0) on the commit that has that number in VERSION.

License

MIT, see LICENSE.