Feature: adsbexchange-stats: add new package

[billmcilhargey]

⚠️ Depends on #29411 (readsb-wiedehopf: new package).
Filed as a Draft until #29411 merges. CI failures on this PR until then are
expected — +readsb-wiedehopf is unresolved in the feed without it.

ADSBexchange.com statistics uploader for OpenWrt.

Periodically reads aircraft.json from readsb (via readsb-wiedehopf),
aggregates per-aircraft RSSI and counts, and POSTs the result to
https://adsbexchange.com identified by the station UUID stored at
readsb.main.uuid -- shared with readsb's BEAST connectors so a single
readsb-uuid configures both.

📦 Package Details

Maintainer: @billmcilhargey

Description:
New leaf package utils/adsbexchange-stats. Procd-supervised bash
uploader that talks to ADSBexchange.com's per-station ranking endpoint.
Pure shell payload, no compile step. Configuration is UCI-only
(/etc/config/adsbexchange-stats); the station UUID is shared with
readsb-wiedehopf via readsb.main.uuid so a single identity is used
by the BEAST feed connector and this uploader. Logging goes to syslog
under the adsbexchange-stats tag at user-selectable verbosity.

Files added:

Path	Purpose
utils/adsbexchange-stats/Makefile	Package metadata, install rules, postinst/prerm/postrm
utils/adsbexchange-stats/files/adsbexchange-stats.config	UCI defaults (declarative-only, see README)
utils/adsbexchange-stats/files/adsbexchange-stats.init	procd init script (extra actions: showurl, info)
utils/adsbexchange-stats/files/adsbexchange-stats.functions.sh	Shared sh helpers (UUID, JSON path resolution, logging)
utils/adsbexchange-stats/files/adsbexchange-stats.json-status-helpers.sh	curl wrapper + per-cycle/summary metrics
utils/adsbexchange-stats/patches/010-openwrt-paths.patch	Five minimal hooks on upstream json-status (paths, env file, scratch dir, perl-version gate, metrics)
utils/adsbexchange-stats/README.md	Full operator documentation

Upstream: https://github.com/ADSBexchange/adsbexchange-stats pinned at
commit 11647f27de3eef51fb19bcb39f0dc0b8500a6671. Upstream license
preserved as MIT; OpenWrt packaging files are GPL-2.0-only.

Dependency chain

This PR consumes three artifacts shipped by #29411:

• readsb.main.uuid — shared station identity
• readsb-uuid CLI — manages the UUID for both packages
• /usr/lib/readsb/functions.sh — provides readsb_is_uuid (8-4-4-4-12 hex validator)

DEPENDS:=+bash +jq +curl +coreutils-stat +readsb-wiedehopf

---

🧪 Run Testing Details

• OpenWrt Version: OpenWrt 23.05-SNAPSHOT (LuCI openwrt-23.05 branch git-25.163.46318-26086b5, kernel 5.4.164)
• OpenWrt Target/Subtarget: ipq60xx/generic
• OpenWrt Device: GL.iNet GL-AXT1800 (Slate AX) — Qualcomm IPQ6018, ARMv8 rev 4

Build verification (snapshot SDK, aarch64_cortex-a53):

./scripts/feeds update -a
./scripts/feeds install -a -p packages
make package/adsbexchange-stats/{clean,download,prepare,compile} V=s

Runtime verification on the GL-AXT1800:

opkg install adsbexchange-stats_*.ipk
readsb-uuid                                  # set the shared station UUID
service adsbexchange-stats enable
service adsbexchange-stats start
service adsbexchange-stats showurl           # public per-station stats URL
logread -e adsbexchange-stats                # confirm uploads at log_level=1

Tested behavior:

• postinst auto-start path: with readsb.main.uuid already set → service starts; without UUID → banner printed, service stays stopped (verified both).
• service adsbexchange-stats {start,stop,restart,reload,status,enable,disable,showurl,info} — all return expected output.
• Reload trigger fires correctly on uci commit adsbexchange-stats and on uci commit readsb (UUID / write_json changes propagate without manual restart).
• log_level 0 / 1 / 2 / 3 — error-only / +summary / +per-cycle / +curl-v all observed in logread.
• dns_cache=0 (default) and dns_cache=1 with a non-loopback resolver — both function; 127.0.0.0/8 resolver auto-disables the cache as documented.
• json_paths_override empty (derived from readsb.main.write_json=/var/run/readsb) and explicit override both resolve correctly; unsafe-token rejection logs at warn.
• prerm / postrm clean removal: /var/run/adsbexchange-stats cleared, /etc/config/adsbexchange-stats preserved (conffile), readsb.main.uuid untouched.
• Uptime at submission: 1d 0h 29m 55s, load 0.19/0.21/0.27 — uploader stable across the window with no procd respawns.

---

✅ Formalities

• I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

If your PR contains a patch:

• It can be applied using git am
• It has been refreshed to avoid offsets, fuzzes, etc., using

  make package/adsbexchange-stats/refresh V=s

• It is structured in a way that it is potentially upstreamable
  (the patch only adds OpenWrt-specific defaults and an opt-in
  $ADSBX_ENV_FILE source hook; both are no-ops when the env file is
  unset, so the change is upstream-friendly).

[billmcilhargey]

Marked as ready for review, I was waiting for the main one to be reviewed and approved first as I was not sure the process but in case this one was holding the main one up, I marked this as ready for review too

Appreciate it again!