From 25575a69f33778134d7db42b090ab12bbb58479d Mon Sep 17 00:00:00 2001
From: yukkop <hectic.yukkop@gmail.com>
Date: Sat, 23 Aug 2025 15:16:15 +0000
Subject: [PATCH] feat(package): `server-health`: created

---
 package/default.nix                    |  1 +
 package/server-health/default.nix      |  4 ++
 package/server-health/server-health.sh | 73 ++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 package/server-health/default.nix
 create mode 100644 package/server-health/server-health.sh

diff --git a/package/default.nix b/package/default.nix
index 80ff22b..5262117 100644
--- a/package/default.nix
+++ b/package/default.nix
@@ -273,4 +273,5 @@ in {
   watch = pkgs.callPackage ./c/watch/default.nix {};
   support-bot = pkgs.callPackage ./support-bot {};
   nix-derivation-hash = pkgs.callPackage ./nix-derivation-hash {};
+  server-health = pkgs.callPackage ./server-health {};
 }
diff --git a/package/server-health/default.nix b/package/server-health/default.nix
new file mode 100644
index 0000000..58134ad
--- /dev/null
+++ b/package/server-health/default.nix
@@ -0,0 +1,4 @@
+{ writeShellScriptBin, socat, bash }:
+writeShellScriptBin "server-health" ''
+  ${socat}/bin/socat -T5 -t5 TCP-LISTEN:''${PORT:-5988},reuseaddr,fork EXEC:"${bash}/bin/sh ${./server-health.sh}"
+''
diff --git a/package/server-health/server-health.sh b/package/server-health/server-health.sh
new file mode 100644
index 0000000..5edf290
--- /dev/null
+++ b/package/server-health/server-health.sh
@@ -0,0 +1,73 @@
+#!/bin/sh
+# router.sh — POSIX sh HTTP backend (for socat)
+# usage: socat -T5 -t5 TCP-LISTEN:${port},reuseaddr,fork EXEC:"sh ${currentfile}"
+# Routes:
+#   GET /status  -> check $URLS (0/0 if unset)
+#   GET /disk    -> check $VOLUMES (all if unset)
+# Env:
+#   URLS="http://..."     # default: none
+#   VOLUMES="/ /home"     # default: all from df -P
+#   TIMEOUT=5
+
+TIMEOUT=${TIMEOUT:-5}
+[ -n "$VOLUMES" ] || VOLUMES=$(df -P | awk 'NR>1{print $6}')
+
+route_status() {
+    if [ -z "$URLS" ]; then
+        printf '{\n  "checks": [],\n  "summary":{"total":0,"ok":0}\n}\n'
+        return
+    fi
+    {
+        printf '{\n  "checks": [\n'
+        first=1 okcnt=0 tot=0
+        for u in $URLS; do
+            tot=$((tot+1))
+            res=$(curl -sS -m "$TIMEOUT" -o /dev/null -w '%{http_code} %{time_total}' "$u" 2>/dev/null) || res="000 0"
+            code=${res%% *}; ttot=${res#* }
+            case $code in 2*|3*) ok=true; okcnt=$((okcnt+1));; *) ok=false;; esac
+            [ $first -eq 0 ] && printf ',\n'; first=0
+            printf '    {"url":"%s","code":%s,"time_s":%s,"ok":%s}' "$u" "$code" "$ttot" "$ok"
+        done
+        printf '\n  ],\n  "summary":{"total":%s,"ok":%s}\n}\n' "$tot" "$okcnt"
+    }
+}
+
+route_disk() {
+    {
+        printf '{\n  "volumes": [\n'
+        first=1
+        for v in $VOLUMES; do
+	    # POSIX df -P: Filesystem 1K-blocks Used Available Capacity Mounted on
+	    # shellcheck disable=SC2046
+            set -- $(df -P "$v" 2>/dev/null | awk 'NR==2{print $2, $3, $4, $5, $6}')
+            size=$1 used=$2 avail=$3 usep=$4 mnt=$5
+            [ -z "$size" ] && continue
+            [ $first -eq 0 ] && printf ',\n'; first=0
+            printf '    {"mount":"%s","size_blocks":%s,"used":%s,"avail":%s,"use_percent":"%s"}' \
+              "$mnt" "$size" "$used" "$avail" "$usep"
+        done
+        printf '\n  ]\n}\n'
+    }
+}
+
+# --- read request & headers ---
+IFS= read -r req || exit 0
+cr=$(printf '\r')
+while IFS= read -r line; do
+  [ -z "$line" ] && break
+  [ "$line" = "$cr" ] && break
+done
+
+tmp=$(mktemp) || exit 1
+trap 'rm -f "$tmp"' EXIT INT HUP
+
+case "$req" in
+  "GET /status "*) route_status >"$tmp"; status='200 OK'; ctype='application/json' ;;
+  "GET /disk "*)   route_disk   >"$tmp"; status='200 OK'; ctype='application/json' ;;
+  *)               printf 'Not found\n' >"$tmp"; status='404 Not Found'; ctype='text/plain' ;;
+esac
+
+len=$(wc -c <"$tmp" | awk '{print $1}')
+printf 'HTTP/1.1 %s\r\nContent-Type: %s\r\nContent-Length: %s\r\nConnection: close\r\n\r\n' "$status" "$ctype" "$len"
+cat "$tmp"
+