commit 532302ae8e88297344e2b2d0e902875286524575
Author: osmarks <osmarks@protonmail.com>
Date:   Thu Jan 28 16:22:33 2021 +0000

    initial commit

diff --git a/.gitignore b/.gitignore
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+++ b/.gitignore
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+onstat
+monitoring.sqlite3*
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diff --git a/nim.cfg b/nim.cfg
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+++ b/nim.cfg
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+-d:ssl
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diff --git a/onstat.nimble b/onstat.nimble
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+++ b/onstat.nimble
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+# Package
+
+version       = "0.1.0"
+author        = "osmarks"
+description   = "Monitor the existence/status of your networked things."
+license       = "MIT"
+srcDir        = "src"
+bin           = @["onstat"]
+
+# Dependencies
+
+requires "nim >= 1.4.2"
+requires "https://github.com/GULPF/tiny_sqlite#8fe760d9"
+requires "karax >= 1.2.1"
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diff --git a/src/db.nim b/src/db.nim
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+import tiny_sqlite
+import options
+import times
+
+let migrations: seq[string] = @[
+    """
+    CREATE TABLE sites (
+        sid INTEGER PRIMARY KEY,
+        url TEXT NOT NULL
+    );
+
+    CREATE TABLE reqs (
+        rid INTEGER PRIMARY KEY,
+        site INTEGER NOT NULL REFERENCES sites(sid),
+        timestamp INTEGER NOT NULL,
+        status INTEGER NOT NULL,
+        latency INTEGER NOT NULL
+    );
+    """,
+    """
+    CREATE INDEX req_ts_idx ON reqs (timestamp);
+    """
+]
+
+proc migrate*(db: DbConn) =
+    let currentVersion = fromDbValue(get db.value("PRAGMA user_version"), int)
+    for mid in (currentVersion + 1) .. migrations.len:
+        db.transaction:
+            echo "Migrating to schema " & $mid
+            db.execScript migrations[mid - 1]
+            # for some reason this pragma does not work using normal parameter binding
+            db.exec("PRAGMA user_version = " & $mid)
+    echo "DB ready"
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diff --git a/src/onstat.nim b/src/onstat.nim
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+++ b/src/onstat.nim
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+import options
+import asyncdispatch
+import asynchttpserver
+import tiny_sqlite
+import macros
+import times
+import karax/[karaxdsl, vdom]
+import httpclient
+import sugar
+import net
+import sequtils
+import strformat
+
+import ./db
+
+macro includeFile(x: string): string = newStrLitNode(readFile(x.strVal))
+
+const css = includeFile("./src/style.css")
+let database = openDatabase("./monitoring.sqlite3")
+migrate(database)
+
+var threadDB {.threadvar.}: Option[DbConn]
+proc getDB(): DbConn =
+    if isNone threadDB:
+        let x = openDatabase("./monitoring.sqlite3")
+        x.exec("PRAGMA journal_mode=WAL")
+        threadDB = some x
+    get threadDB
+
+func timeToTimestamp*(t: Time): int64 = toUnix(t) * 1000000 + (nanosecond(t) div 1000)
+func timestampToTime*(ts: int64): Time = initTime(ts div 1000000, (ts mod 1000000) * 1000)
+
+proc toDbValue(t: Time): DbValue = DbValue(kind: sqliteInteger, intVal: timeToTimestamp(t))
+proc fromDbValue(value: DbValue, T: typedesc[Time]): Time = timestampToTime(value.intVal)
+
+type
+    ResponseType = enum
+        rtOk = 0
+        rtHttpError = 1
+        rtTimeout = 2
+        rtFetchError = 3
+    Response = object
+        rtype: ResponseType
+        latency: int64 # microseconds
+    SiteStatus = object
+        url: string
+        lastPing: Time
+        lastResponse: ResponseType
+        lastLatency: float
+        uptimePercent: float
+
+proc uptimeSince(sid: int, time: Time): float =
+    let okPings = fromDbValue(get getDB().value("SELECT COUNT(*) FROM reqs WHERE site = ? AND status = 0", sid), int)
+    let totalPings = fromDbValue(get getDB().value("SELECT COUNT(*) FROM reqs WHERE site = ?", sid), int)
+    okPings / totalPings
+
+proc fetchLatest(row: ResultRow): Option[SiteStatus] =
+    let weekAgo = getTime() + initTimeInterval(weeks= -1)
+    let (site, url) = row.unpack((int, string))
+    let row = getDB().one("SELECT timestamp, status, latency FROM reqs WHERE site = ? ORDER BY timestamp DESC LIMIT 1", site)
+    if isNone row: return none(SiteStatus)
+    let (ts, status, latency) = (get row).unpack((Time, int, int))
+    some SiteStatus(url: url, lastPing: ts, lastResponse: ResponseType(status), lastLatency: float64(latency) / 1e3, uptimePercent: uptimeSince(site, weekAgo))
+
+proc mainPage(): string =
+    let sites = getDB().all("SELECT * FROM sites ORDER BY sid").map(fetchLatest).filter(x => isSome x).map(x => get x)
+    let up = sites.filter(x => x.lastResponse == rtOk).len()
+    let vnode = buildHtml(html()):
+        head:
+            meta(charset="utf8")
+            title: text &"{up}/{sites.len} up - OnStat"
+            style: text css
+        body:
+            h1(class="title"): text "OnStat"
+            h2(class="title"): text &"{up}/{sites.len} up"
+            for site in sites:
+                tdiv(class="card " & $site.lastResponse):
+                    h2:
+                        case site.lastResponse
+                        of rtOk: text "✓ "
+                        of rtHttpError: text "⚠ "
+                        of rtTimeout: text "✕ "
+                        of rtFetchError: text "✕ "
+                        text site.url
+                    tdiv: text("Last pinged " & format(site.lastPing, "HH:mm:ss dd-MM-yyyy"))
+                    tdiv:
+                        case site.lastResponse
+                        of rtOk: text &"Latency {site.lastLatency}ms"
+                        of rtHttpError: text "HTTP error"
+                        of rtTimeout: text "Timed out"
+                        of rtFetchError: text "Fetch failed"
+                    tdiv: text &"{site.uptimePercent * 100}% up in last week"
+    $vnode
+
+proc onRequest(req: Request) {.async.} =
+    if req.reqMethod == HttpGet:
+        case req.url.path
+        of "/": await req.respond(Http200, mainPage(), headers=newHttpHeaders([("Content-Type", "text/html")]))
+        else: await req.respond(Http404, "not found")
+    else:
+        await req.respond(Http404, "not found")
+
+proc pollTarget(s: string): Future[Response] {.async.} =
+    var client = newAsyncHttpClient()
+    var x = Response(rtype: rtTimeout, latency: 0)
+    proc doFetch() {.async.} =
+        let ts = now().utc
+        let res = await client.get(s)
+        let latency = (now().utc - ts).inMicroseconds
+        if res.code.is4xx or res.code.is5xx: x = Response(rtype: rtHttpError, latency: latency)
+        else: x = Response(rtype: rtOk, latency: latency)
+    try:
+        discard await withTimeout(doFetch(), 10000)
+    except:
+        x = Response(rtype: rtFetchError, latency: 0)
+    return x
+
+proc pollTargets() {.async.} =
+    for row in getDB().all("SELECT * FROM sites"):
+        let (id, url) = row.unpack((int64, string))
+        let res = await pollTarget(url)
+        getDB().exec("INSERT INTO reqs (site, timestamp, status, latency) VALUES (?, ?, ?, ?)", id, getTime(), int(res.rtype), res.latency)
+
+proc timerCallback(fd: AsyncFD): bool =
+    asyncCheck pollTargets()
+    false
+
+echo "Starting up"
+asyncCheck pollTargets()
+addTimer(5000, false, timerCallback)
+var server = newAsyncHttpServer()
+waitFor server.serve(Port(7800), onRequest)
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diff --git a/src/style.css b/src/style.css
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+body {
+    max-width: 40em;
+    font-family: sans-serif;
+}
+
+.title {
+    margin-bottom: 0.5em;
+}
+
+h1, h2 {
+    font-weight: normal;
+    margin: 0;
+}
+
+h1 {
+    border-bottom: 1px solid black;
+}
+
+.card {
+    margin-bottom: 1em;
+}
+
+.card.rtOk h2 {
+    color: green;
+}
+.card.rtHttpError h2 {
+    color: orange;
+}
+.card.rtFetchError h2 {
+    color: red;
+}
+.card.rtTimeout h2 {
+    color: red;
+}
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