79f1732a14
The first executable form of our host requirements. Until now a machine
was qualified by a human reading a table of hard requirements — and a
requirement that nothing can check is one that is silently optional.
It also replaces a form. Everything we wanted from a prospective host is
measurable, and most of it **cannot be answered honestly by a human
anyway**: almost nobody knows their real upstream, and essentially
nobody has ever seen their own bufferbloat figure. What's left for the
questions is only what a machine cannot know — intent, and what someone
already pays.
## What it does
```
nesdoctor
```
- **Checks every hard requirement**: `/dev/kvm`, an AMD or Intel GPU
with a DRM render node, `VK_KHR_video_encode_queue` plus a codec,
`virglrenderer`, the two stores, the `io` cgroup controller,
`virtiofsd`. Pass / fail / **unknown**, and unknown is never collapsed
into fail — a machine we could not ask is not a machine that failed, and
losing a capable host to a missing `lspci` is the failure mode that
matters.
- **Measures upstream and, the point of the whole thing, added latency
under load.** Grade bands come from the frame budget rather than
convention: the network allowance is ~40 ms because render, encode,
decode, display and jitter buffer have already spent ~58 ms.
- **Reads Steam, only with an explicit yes**, for library size and shape
plus an hour-of-day histogram of launches — one sample per title, which
is a real distribution obtained without asking anybody anything.
- **Asks at most five questions**, branched on what was found, all
skippable.
## No server
Nothing is uploaded and no telemetry endpoint exists. The network test
talks to Cloudflare's public speed-test sink and to `1.1.1.1`, neither
of which is ours. The output is a line on the terminal that the person
may choose to paste.
The shareable line carries **no hostname, IP, username, game title or
path** — a size band rather than a size, hours rather than dates. The
long version, which does include titles and paths, stays in a local JSON
file the person is told the path of.
That is a property of the design and not a promise about our intentions:
there is nothing to switch on later.
```
nesdoctor 0.1.0 | linux/x86_64 | gpu=AMD Barcelo | cpu=12t ram=13G |
kvm=y venc=y zfs=n boxfs=n io=y | up=28Mbps rtt=179ms bloat=+19ms grade=B |
disk=91G | edge=KE/JNB | steam=1 titles/<100G | plays=20-03h n=74 |
role=- share=- pays=- | HOST-READY-LOCAL
```
## Five bugs found by running it, every one of which would have produced
wrong data
- **`vulkaninfo --summary` lists ZERO `VK_KHR_video` entries** where
full `vulkaninfo` lists five on the same machine. Preferring the summary
reported "not advertised" on a card that advertises it — a false
negative on the check most likely to disqualify a host.
- **btrfs subvolumes counted as separate disks**: `/`, `/home` and
`/srv` each reporting 91 GiB of one 91 GiB device. Now deduped by
backing device, which the two-stores check needs anyway since it wants
*separate devices*.
- **Proton and the Steam Linux Runtimes are installed like games and are
not games.** Five of eight entries on the test machine, so the title
count was 5× too high and the library-shape question was corrupted.
- **`--quiet` printed the whole questionnaire** before its summary line,
breaking the one thing `--quiet` promises. Prompts are now skipped when
output is quiet or stdin is not a terminal — and a pipe is explicitly
*not* treated as consent to read a Steam library, unlike `--yes`.
- Boot history was reporting `13.2 h/day` off **two days** of history.
Under a three-day span it now reports the span and no rate.
## One finding, now encoded as a verdict
The development connection measures **179 ms idle RTT, served from
Johannesburg**. That machine passes every other check and cannot host
for a European player, because it is distance and no upgrade shortens
it.
`HOST-READY-LOCAL` exists for exactly that case, and the wording is
deliberate:
> Every requirement passes and your uplink queues cleanly. But the idle
round trip to the nearest major network is already most of the latency
budget, and that is distance rather than a fault: no upgrade shortens
it. So this machine is a good host for people on your side of the world
and cannot be one for anybody else. **If you are somewhere without a
cloud gaming edge, that is not a consolation prize — it is the only way
anyone there gets a playable stream.**
## CI
- **`ci.yml` gains a `nesdoctor` job** — fmt, `clippy -D warnings`,
test, one real run. Scoped to this member deliberately: the rest of the
Rust half has never been under CI, so `--workspace` would turn every PR
red for unrelated reasons. Widen it one member at a time.
- **`release-nesdoctor.yml`** builds four targets on tag `nesdoctor-v*`
— x86_64 linux-musl, x86_64 windows-msvc, aarch64 and x86_64 macOS —
with `SHA256SUMS`. musl rather than glibc so one Linux binary runs on
every distro.
The step that justifies the workflow **runs the binary it just built,
network included**. `ring` under rustls resolves root certificates
through the host trust store, so a static musl build can compile cleanly
and then fail TLS on the machine it ships to — breaking the network
test, silently, and only for other people. The step fails the build if
the summary line comes back `net=unmeasured`.
## Dependencies
Four: `anyhow`, `clap`, `serde`, `ureq`. The VDF parser, every platform
probe and the text wrapping are in-tree. A binary handed to strangers
has a dependency tree that is part of its interface, so anything that
could be done with `std` is.
4 MB release binary.
## What it deliberately does not claim
- **A pass is not a promise.** Every check is a *necessary* condition,
and nothing here runs under load — a machine that passes can still fail
on block I/O.
- **The encode extension being advertised is not proof the path works.**
We have had a correct extension list over a broken path before, so that
row says so.
- **Whether `libvirglrenderer` carries the native-context patches cannot
be determined from outside**, so that row reports presence only and
stays `unknown` rather than `pass`.
<!-- greptile_comment -->
<h3>Greptile Summary</h3>
The PR adds the nesdoctor host-readiness executable, local Steam
analysis, network measurement, installers, CI validation, and
multi-platform release packaging. Two attempted correctness fixes remain
incomplete:
- physical disk deduplication does not resolve common device-mapper
source names before comparing backing devices
- unknown historical Steam appids can still be counted as game launches
without passing runtime filtering
<h3>Confidence Score: 3/5</h3>
The PR is not yet safe to merge because shared LVM-backed stores can be
reported as physically independent and unknown Steam tools can still be
reported as game launches.
The new disk resolver fails open for common device-mapper names,
preserving a false host-readiness verdict, while Steam history still
counts absent appids without determining whether they are games or
runtime tools.
**Files Needing Attention:** apps/nesdoctor/src/sys.rs,
apps/nesdoctor/src/hostreq.rs, apps/nesdoctor/src/steam.rs
<h3>Important Files Changed</h3>
| Filename | Overview |
|----------|----------|
| apps/nesdoctor/src/sys.rs | Adds system and disk discovery, but
unresolved device-mapper names undermine physical-backing comparisons. |
| apps/nesdoctor/src/hostreq.rs | Implements host requirement verdicts
and uses physical-device sets that can falsely classify shared LVM
backing as independent. |
| apps/nesdoctor/src/steam.rs | Adds manifest and launch-history
analysis, but unknown appids bypass runtime classification and
contaminate launch metrics. |
| apps/nesdoctor/src/net.rs | Adds bounded upload-based upstream and
bufferbloat measurement; the previously reported unbounded request path
is addressed. |
| .github/workflows/release-nesdoctor.yml | Builds, smoke-tests,
packages, checksums, and publishes the four release targets. |
| .github/workflows/ci.yml | Adds focused formatting, linting, testing,
and offline execution checks for nesdoctor. |
<h3>Flowchart</h3>
```mermaid
%%{init: {'theme': 'neutral'}}%%
flowchart LR
Run[nesdoctor] --> Host[Host requirement probes]
Run --> Net[Upload and latency measurement]
Run --> Consent{Steam consent}
Consent -->|yes| Steam[Installed manifests and LastPlayed records]
Host --> Physical[Resolve filesystem sources to physical devices]
Physical --> Verdict[Host readiness verdict]
Net --> Report[Detailed JSON and shareable summary]
Steam --> Report
Verdict --> Report
```
<details><summary>Prompt To Fix All With AI</summary>
`````markdown
### Issue 1
apps/nesdoctor/src/sys.rs:369-374
**Mapper devices remain unresolved**
When root and box-store filesystems are separate LVM or dm-crypt mappings on the same physical disk, `df` supplies `/dev/mapper/...` names that do not exist under `/sys/class/block`. This branch returns those unrelated logical names unchanged, so the overlap check passes stores that still share one physical I/O queue.
### Issue 2
apps/nesdoctor/src/steam.rs:247-250
**Unknown appids bypass runtime filtering**
If `localconfig.vdf` retains `LastPlayed` data for an uninstalled Proton build, Steam runtime, or other non-game tool, its appid is absent from the installed-manifest map and this branch treats it as an uninstalled game. The tool activity then changes the launch histogram, peak window, and shareable `n` value.
---
For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.
`````
</details>
<sub>Reviews (5): Last reviewed commit: ["fix(nesdoctor): three valid P1
findings
..."](7afc8929a6)
| [Re-trigger
Greptile](https://app.greptile.com/api/retrigger?id=59231233)</sub>
> Greptile also left **2 inline comments** on this PR.
<!-- /greptile_comment -->
5.7 KiB
nesdoctor
Is this machine any good — as a Nestri host, or as a client?
# macOS and Linux
curl -fsSL https://doctor.nestri.io/install.sh | sh
# Windows
powershell -c "irm https://doctor.nestri.io/install.ps1 | iex"
Both download one binary, verify its checksum, run it, and delete it. They
install nothing, need no administrator rights, and touch no system directory.
The scripts those URLs serve are the files in install/ — the
worker fetches them from this repository, so you can read exactly what you are
about to run before you run it.
Or build it yourself:
cargo run --release -p nesdoctor
Checks every hard requirement for running a Nestri box, measures what your connection actually does when it is busy, and asks at most five questions.
Nothing is uploaded
There is no server. No telemetry endpoint exists, and there is no build of this
program that reports home — the network test talks to Cloudflare's public
speed-test sink and to 1.1.1.1, neither of which is ours.
The output is a line on your terminal. If you want us to have it, you paste it somewhere. If you do not, we never had it. That is a property of the design rather than a promise about our intentions: there is nothing to switch on later.
The shareable line carries no hostname, no IP, no username, no game titles and no file paths — a size band rather than a size, and an hour histogram rather than timestamps. It is put on your clipboard at the end so pasting it is one keystroke.
The long version lands in nesdoctor.json: every check with its reason, the
full latency series, and your installed titles with sizes and launch times if
you said yes to Steam. That file is considerably more useful to us than the
line — it is what lets us size a game library and see which requirement
actually stops people — so do have a read through it and send it along if
nothing in there bothers you. Plain JSON, entirely optional, and the one-line
version is already plenty.
Reading your Steam library needs an explicit yes, and the question is asked last, after you have seen what this program does.
The number worth running it for
Everybody knows their download speed. Almost nobody has seen how much latency their connection adds when it is busy, and for anything interactive that is the figure that decides it:
upstream 28 Mbps
latency, idle 179 ms
latency, loaded 198 ms
added under load +19 ms grade B
A 500 Mbps uplink that queues for 300 ms under load cannot carry a game. A
25 Mbps one with fq_codel or CAKE can. If your grade is C or F it is almost
always a router setting rather than a line you need to upgrade.
Options
--no-net |
Skip the network test (it uploads ~100 MB) |
--no-steam |
Never look at Steam, and do not ask |
--yes |
Take the defaults — for a second run, not a first |
--json <PATH> |
Where to write the full report |
--quiet |
Only the summary line, for scripting |
--no-open |
Do not offer to open a browser; just print the link |
--submit-url |
Where the submit link points (default https://doctor.nestri.io) |
Verdicts
HOST-READY |
Passes everything, and close enough to the network to serve others |
HOST-READY-LOCAL |
Passes everything, but far enough out that it can only serve players nearby |
HOST-NET |
Good machine; the connection is in the way |
HOST-FIXABLE |
Nothing is a hardware limit — what is missing can be installed |
CLIENT |
Not a host. A complete answer, and what most machines are |
UNKNOWN |
A blocking check could not be run. An unknown is not a no |
Sending it back
At the end it prints a link, lists in plain English what the link contains, and opens it when you press Enter. That is the whole submission — no account, no form, no email client.
One thing worth knowing if you are reading install/install.sh: it reopens
stdin on /dev/tty before handing over. Piped into a shell the documented way,
the script's stdin is the pipe and the pipe is at end of file, so without
that line nesdoctor correctly sees a non-terminal stdin and skips every
question — a run that completes, looks fine, and answers nothing. Running the
script from a file works perfectly, which is what makes it worth a comment.
The link is built from readable query parameters rather than an encoded blob. A blob would be shorter and would let us send more; it would also mean you cannot read what you are sending, which is the one thing this program has going for it.
If you would rather not click a link we wrote, the short line is printed too and put on your clipboard.
What it deliberately does not tell you
- A pass is not a promise. Every check is a necessary condition. Nothing here runs under load, so a machine that passes can still fail on block I/O.
vulkaninforeporting the encode extension is not proof the path works. We have had a correct extension list over a broken path before.- The host's
virglrendererand Mesa are not checked at all, on purpose. The box carries its own inside the image it runs in, so the host's copies are not on the path — and a row that could only ever say "present, patch state unknown" told prospective hosts their machine was wrong when it was not.
Building
cargo build --release -p nesdoctor
Four dependencies, three of them serde/clap/anyhow. Everything that could
be done with std is: the VDF parser, the platform probes and the text wrapping
are all in-tree, because a binary handed to strangers has a dependency tree that
is part of its interface.
A static build, for a release someone downloads rather than compiles:
cargo build --release -p nesdoctor --target x86_64-unknown-linux-musl