Editing a running stack by hand is where homelabs quietly break. You tweak a port, run docker compose up -d, and suddenly three unrelated containers restart — or worse, the file no longer parses and nothing comes back up. Stashboard v7.6 and v7.7 fix that with a safe Docker Compose edit diff apply workflow: you see exactly what changed against disk, validate the file before it touches Docker, apply only the services you actually edited, and roll back instantly if anything looks wrong.
This is a deep how-to for the whole loop. If Compose itself is still new to you, start with Docker for beginners and the visual Docker Compose editor pillar first. Here we assume you already edit stacks inside Stashboard and want the mechanics behind the safe save. This guide is the safe Docker Compose edit diff apply workflow, start to finish.
Why a safe Docker Compose edit diff apply workflow matters
The classic failure mode is invisible. A text editor happily saves a compose.yaml with a duplicated port, a typo’d indentation, or a depends_on that points at a service you just renamed. You only find out after up -d half-applies the change. The point of a safe Docker Compose edit diff apply pipeline is to make every one of those mistakes visible and reversible before the runtime ever sees them.
Stashboard does that in three guarantees: show me what changed, prove it’s valid, and let me undo it. Everything below maps to one of those three.
Review & save: the unified diff and the dry-run
When you hit Save in the editor, Stashboard does not write straight to disk. It first opens a Review & save panel built from two checks — the heart of the safe Docker Compose edit diff apply flow.
1. A unified diff against disk. Your in-browser buffer is compared line-by-line with the compose.yaml currently on the host. You get a standard green/red unified diff, so you can confirm you’re only changing what you meant to. No “trust me, it’s fine” — you read the actual hunks.
2. A real dry-run validation. Stashboard writes your edited content to a temporary candidate file next to the stack and runs docker compose -f <candidate> config -q against it. The -q flag means it stays quiet on success and prints only errors. This is the same parser Docker itself uses, so anchors, extends, env interpolation, and merge keys are all resolved exactly as they will be at runtime. If config -q exits non-zero, the error is shown inline and Save is blocked. The candidate file is deleted either way — your real compose.yaml is never touched by a file that doesn’t parse.
The panel also tells you which services change. Stashboard parses both the old and new files into service maps and diffs them, so you see a short list like “jellyfin modified, caddy modified, whoami added” before you commit. That list is what powers the apply step.
⚠️ Critical moment: the dry-run validates syntax and schema, not intent. config -q will happily accept a valid file that exposes the wrong port. The unified diff is there precisely so you catch intent mistakes the parser can’t. Read both.
Save only vs Save & apply changed
Once validation passes you get two buttons, and the distinction is the whole safety story behind the safe Docker Compose edit diff apply flow.
- Save only writes the new
compose.yamlto disk and stops. Nothing is restarted. Use this when you’re staging several edits, or editing a stack you’ll bring up later. - Save & apply changed writes the file and runs a compose-aware
docker compose up -dscoped to only the services the diff flagged as changed. Untouched services keep running undisturbed — no needless restart of your database because you edited the reverse proxy.
That scoping is the part hand-editing can’t give you. A plain docker compose up -d reconciles the entire project; Stashboard passes the changed service names explicitly so the blast radius matches the diff you just approved. This is the same compose-aware targeting behind one-click container updates.
Revision history you can actually trust
Every successful save is snapshotted to a .stashboard/history folder beside the stack. Stashboard keeps the last 20 revisions per stack, pruning the oldest automatically, so history never grows without bound.
Open the History tab and you get a timestamped list of revisions. Picking one and choosing Restore does not blindly overwrite your file. Restore:
- Shows you the diff between the chosen revision and what’s on disk now, so you preview exactly what rolling back will change.
- Re-validates that revision with the same
config -qdry-run — because a config that was valid last week might reference an image tag or network that no longer exists. - Only then writes it, going through the same Save-only / Save & apply path.
And the best part: a restore is itself a normal save, so it’s snapshotted too. That means a restore is undoable — if you roll back and decide you were wrong, the version you rolled away from is still sitting in history one revision up. There is no dead end.
The metadata-only Compose-changes audit tab
Separate from per-stack history, Stashboard keeps a global Compose-changes audit tab. This is deliberately metadata only — it records that a change happened, not the file contents. Each entry captures the stack, the timestamp, the action (save, apply, restore), and which services were affected.
Why metadata only? Your compose.yaml can contain secrets, internal hostnames, and tokens. The audit log is a “who changed what, when” trail you can keep open or share without leaking the payload. The full content already lives, safely, in .stashboard/history.
The Graph tab: see your whole stack at a glance
Version 7.7 adds a Graph tab that renders the parsed stack as an SVG dependency map instead of a wall of YAML:
- Services are nodes, each badged with its live container state (running, exited, restarting) pulled from the Docker API — the same state badges used across Stashboard.
depends_onrelationships are edges, drawn as arrows so you can trace start-up order at a glance.- Shared networks become group boxes — services attached to the same network are visually enclosed together, which instantly reveals isolation mistakes (the service you thought was on the internal network but isn’t).
- Volumes appear in a legend, mapping named volumes to the services that mount them.
- Click any node to jump straight to that service in the editor.
For anything beyond a two-service stack, this is the fastest way to understand a Compose project you haven’t touched in months — far faster than re-reading the file, and a natural companion to the safe Docker Compose edit diff apply workflow.
The inline linter and the Health badge
The Graph tab ships with a linter that runs on every parse and surfaces issues inline, next to the offending node, split into errors (which you should fix before applying) and warnings (which you should at least look at):
- Port collisions → error. Two services publishing the same host port can’t both start.
depends_oncycles → error. A depends on B depends on A will never converge.- Missing healthcheck for
condition: service_healthy→ error. You can’t wait on a health state that’s never defined. - Bind mounts escaping the project root → warning. A
../../etcmount is usually a mistake and a security smell. - Deprecated keys → warning. Legacy fields (like the old top-level
version:) still parse but won’t forever. :latestimage tags → warning.:latestmakes your stack non-reproducible — pin a version. This pairs well with Stashboard’s update monitoring, which tracks pinned tags for you.
All of it rolls up into a single Health badge on the stack: green when clean, yellow with warnings, red when there’s an error. It’s the one-glance answer to “is this stack safe to apply right now?”
Putting the safe Docker Compose edit diff apply loop together
In practice the rhythm becomes second nature: edit in the browser, hit Save, read the unified diff, let config -q prove it parses, glance at the Health badge and Graph, then choose Save only or Save & apply changed. If something feels off afterward, History → Restore walks you back with a preview and a re-validation — and that restore is undoable too.
That’s the entire promise of a safe Docker Compose edit diff apply workflow: you never write an unparseable file, you never restart a service you didn’t touch, and you can always get back to a known-good state. For homelabbers who’ve been bitten by a bad up -d at 1 a.m., the safe Docker Compose edit diff apply loop in v7.6 and v7.7 is the upgrade that makes editing stacks boring again — in the best possible way.
Stashboard is open source — you can find the full source code on GitHub and pull the ready-to-run image directly from Docker Hub. Issues, PRs, and stars are always welcome. 🙌