v0.0.1 release

.gitignore

@@ -0,0 +1,34 @@
+# Build artifacts
+/qu
+/qu-*
+/dist/
+*.exe
+*.test
+*.out
+
+# Go workspace / module cache (only relevant if vendored)
+/vendor/
+
+# Local node state — never commit anything that looks like a data dir
+/quptime/
+/etc/quptime/
+node.yaml
+cluster.yaml
+trust.yaml
+keys/
+
+# Compose / secrets
+.env
+.env.local
+*.local.yml
+*.local.yaml
+
+# Editor / OS scratch
+*.swp
+*.swo
+*~
+.DS_Store
+
+# Test / coverage
+coverage.out
+coverage.html

CHANGELOG.md

@@ -0,0 +1,86 @@
+# Changelog
+
+All notable changes to this project are documented here. The format
+follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and
+this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [v0.0.1] — 2026-05-15
+
+Initial public release.
+
+### Added
+
+- **Quorum-based uptime monitoring.** Multiple cooperating nodes run
+  the same probes (HTTP, TCP, ICMP) and vote on the cluster-wide
+  truth. A check flips state only after two consecutive aggregate
+  evaluations agree (hysteresis), so single-node flake doesn't page
+  anyone.
+- **Deterministic master election.** Among the live members of the
+  quorum the lexicographically smallest NodeID wins — no negotiation
+  step, no split-brain window.
+- **mTLS inter-node transport** with TLS 1.3 minimum, SSH-style
+  fingerprint pinning, and a pre-shared `cluster_secret` gating the
+  Join RPC.
+- **Replicated `cluster.yaml`** carrying peers, checks, and alerts.
+  Master is the only writer; followers receive monotonic-versioned
+  snapshots and converge on the latest. Hand-edits to the file on any
+  node are picked up by the manual-edit watcher and forwarded through
+  the master.
+- **HTTP, TCP, and ICMP probes** with configurable interval,
+  timeout, expected status, and optional body-substring match. ICMP
+  defaults to unprivileged UDP-mode pings so the daemon can run as a
+  non-root user.
+- **SMTP and Discord alerts** with optional Go `text/template`
+  subject/body overrides per alert, default-attach mode (`default:
+  true`), and per-check opt-outs via `suppress_alert_ids`.
+- **Docker-friendly env-var configuration.** Every field in
+  `node.yaml` can also be supplied via a `QUPTIME_*` environment
+  variable; `qu serve` auto-initialises a fresh data volume from
+  these on first start, so `docker compose up` is enough to launch a
+  node.
+- **Interactive TUI** (`qu tui`) for peers, checks, and alerts with
+  live refresh.
+- **Hardened systemd unit** shipped via `install.sh`: dedicated
+  `quptime` user, `ProtectSystem=strict`, all capabilities dropped by
+  default.
+- **Multi-arch Docker images** (`linux/amd64`, `linux/arm64`)
+  published to `git.cer.sh/axodouble/quptime`.
+- **Static Linux binaries** (`amd64`, `arm64`) published per tag with
+  a `SHA256SUMS` file; the official installer verifies the checksum
+  before placing the binary on disk.
+
+### Security
+
+- Cluster secret is compared in constant time
+  (`crypto/subtle.ConstantTimeCompare`).
+- Self-signed RSA certs minted at `qu init`; SPKI SHA-256
+  fingerprints are what's pinned, matching the canonical OpenSSL
+  representation.
+- Private keys are written with mode `0600`; data and runtime
+  directories with `0700`/`0750`.
+- All `cluster.yaml` writes go through an atomic `tmpfile + rename`.
+- `install.sh` downloads the published `SHA256SUMS` and refuses to
+  install if the downloaded binary doesn't match.
+
+### Known limitations
+
+- **Cluster-wide secret distribution.** SMTP passwords and Discord
+  webhook URLs configured via `qu alert add …` are stored in
+  `cluster.yaml`, which is replicated to every node. Treat every node
+  as having read access to every alert credential. Restrict who can
+  reach the data directory accordingly. See
+  [docs/security.md](docs/security.md) for the threat model.
+- **No automatic key rotation.** Rolling a node's identity means
+  wiping its data directory, running `qu init` again, and re-adding
+  it from another node.
+- **No historical metrics.** Only the current aggregate state is kept
+  in memory. There is no built-in graph store, SLA calculator, or
+  audit log.
+- **Master-flap state.** Aggregator hysteresis state lives in
+  memory on the current master. When leadership changes the new
+  master starts from `StateUnknown` and re-accumulates hysteresis —
+  expect a few seconds of delayed alerting after a master switch.
+- **No release signing beyond SHA256SUMS** (no cosign / GPG).
+  Planned for a future release.
+
+[v0.0.1]: https://git.cer.sh/axodouble/quptime/releases/tag/v0.0.1

README.md

@@ -88,7 +88,7 @@ go build -o qu ./cmd/qu
 To stamp the version into the binary:
 
 ```sh
-go build -ldflags "-X main.version=v0.1.0" -o qu ./cmd/qu
+go build -ldflags "-X main.version=v0.0.1" -o qu ./cmd/qu
 qu --version
 ```
 
@@ -100,7 +100,7 @@ amd64 and arm64, and publishes them as a Gitea release with a
 `SHA256SUMS` file alongside.
 
 ```sh
-git tag v0.1.0
+git tag v0.0.1
 git push --tags
 ```
 
@@ -166,6 +166,15 @@ c0d4...  charlie.example.com:9901  true  2026-05-12T15:01:32Z
 
 ## Adding checks and alerts
 
+> ⚠️ **Alert credentials are replicated cluster-wide.** SMTP passwords
+> and Discord webhook URLs live in `cluster.yaml`, which is mirrored to
+> every node. Any node that can read its own data directory can read
+> every alert secret. Treat compromising one node as compromising every
+> alert credential, and restrict who can reach `$QUPTIME_DIR` on each
+> host (the hardened systemd unit and the Docker image both default to
+> `0700`/`0750`). See [docs/security.md](docs/security.md) for the full
+> threat model.
+
 ```sh
 # alerts first so checks can reference them
 qu alert add discord oncall --webhook https://discord.com/api/webhooks/...

docs/deployment/docker.md

@@ -9,8 +9,9 @@ daemon can bind privileged ports and open ICMP sockets; override with
 
 ```
 git.cer.sh/axodouble/quptime:master          # tip of main, multi-arch
-git.cer.sh/axodouble/quptime:v0.1.0          # tagged release
+git.cer.sh/axodouble/quptime:latest          # latest tagged release
-git.cer.sh/axodouble/quptime:v0.1.0-amd64    # single-arch (if you must pin)
+git.cer.sh/axodouble/quptime:v0.0.1          # specific tagged release
+git.cer.sh/axodouble/quptime:latest-amd64    # single-arch (if you must pin)
 ```
 
 The image embeds `QUPTIME_DIR=/etc/quptime` and declares it a volume —
@@ -24,7 +25,7 @@ For a development cluster or a single-node smoke test:
 # compose.yaml
 services:
   quptime:
-    image: git.cer.sh/axodouble/quptime:v0.1.0
+    image: git.cer.sh/axodouble/quptime:latest
     container_name: quptime
     restart: unless-stopped
     environment:
@@ -76,7 +77,7 @@ For local testing of the full quorum machinery without three machines:
 ```yaml
 # compose.yaml
 x-quptime: &quptime
-  image: git.cer.sh/axodouble/quptime:v0.1.0
+  image: git.cer.sh/axodouble/quptime:latest
   restart: unless-stopped
   cap_add:
     - NET_RAW
@@ -146,7 +147,7 @@ The natural unit is one compose file per host, each running one
 # /etc/qu-stack/compose.yaml
 services:
   quptime:
-    image: git.cer.sh/axodouble/quptime:v0.1.0
+    image: git.cer.sh/axodouble/quptime:latest
     container_name: quptime
     restart: unless-stopped
     environment:

docs/deployment/tailscale.md

@@ -51,7 +51,7 @@ services:
     restart: unless-stopped
 
   quptime:
-    image: git.cer.sh/axodouble/quptime:v0.1.0
+    image: git.cer.sh/axodouble/quptime:latest
     container_name: quptime
     environment:
       # host:port other QUptime nodes use to reach this one. Should be

docs/installation.md

@@ -79,7 +79,8 @@ registry on every tag and every push to `master`:
 
 ```
 git.cer.sh/axodouble/quptime:master   # tip of main
-git.cer.sh/axodouble/quptime:v0.1.0   # tagged release
+git.cer.sh/axodouble/quptime:latest   # latest tagged release
+git.cer.sh/axodouble/quptime:v0.0.1   # pinned release
 ```
 
 See the [Docker deployment guide](deployment/docker.md) for compose

install.sh

@@ -1,21 +1,28 @@
 #!/bin/bash
+# QUptime installer.
+#
+# Downloads the latest released `qu` binary from the Gitea release
+# page, verifies it against the published SHA256SUMS, installs it to
+# /usr/local/bin, and (on systemd hosts) drops in a hardened
+# quptime.service that matches the unit documented in
+# docs/deployment/systemd.md. Idempotent — re-running upgrades the
+# binary and refreshes the unit without touching the data directory.
 set -euo pipefail
 
 INSTALL_BIN="/usr/local/bin/qu"
-SERVICE_FILE="/etc/systemd/system/qu-serve.service"
+SERVICE_FILE="/etc/systemd/system/quptime.service"
-SERVICE_USER="${SUDO_USER:-$(whoami)}"
+SERVICE_NAME="$(basename "$SERVICE_FILE")"
-SERVICE_GROUP="$(id -gn "$SERVICE_USER" 2>/dev/null || echo root)"
+SERVICE_USER="quptime"
+SERVICE_GROUP="quptime"
+DATA_DIR="/etc/quptime"
+REPO_API="https://git.cer.sh/api/v1/repos/axodouble/quptime/releases/latest"
+RELEASE_BASE="https://git.cer.sh/axodouble/quptime/releases/download"
 
 fail() {
     echo "Error: $*" >&2
     exit 1
 }
 
-echo_cmd() {
-    echo -e "\033[90m> $1\033[0m"
-    eval "$1"
-}
-
 require_command() {
     command -v "$1" >/dev/null 2>&1 || fail "$1 is not installed. Please install $1 and try again."
 }
@@ -31,52 +38,182 @@ write_completion() {
     return 1
 }
 
-require_command jq
 require_command curl
+require_command jq
+require_command sha256sum
+require_command install
+require_command mktemp
+
+# --- target architecture ------------------------------------------------
+case "$(uname -m)" in
+    x86_64)         ARCH=amd64 ;;
+    aarch64|arm64)  ARCH=arm64 ;;
+    *)              fail "unsupported architecture: $(uname -m). Pre-built binaries are published for amd64 and arm64 only — build from source for other platforms." ;;
+esac
 
 if [ ! -w "$(dirname "$INSTALL_BIN")" ]; then
-    fail "You are not allowed to write to $(dirname "$INSTALL_BIN"). Run this script with sudo or install qu manually."
+    fail "Cannot write to $(dirname "$INSTALL_BIN"). Run this script with sudo, or set INSTALL_BIN to a writable location."
 fi
 
-RELEASE=$(curl -s https://git.cer.sh/api/v1/repos/axodouble/quptime/releases/latest | jq -r '.tag_name')
+# --- latest release tag -------------------------------------------------
+RELEASE=$(curl -fsSL "$REPO_API" | jq -r '.tag_name')
+[ -n "$RELEASE" ] && [ "$RELEASE" != "null" ] \
+    || fail "could not determine the latest release tag from $REPO_API"
 
-echo_cmd "curl -L -o '$INSTALL_BIN' 'https://git.cer.sh/axodouble/quptime/releases/download/${RELEASE}/qu-${RELEASE}-linux-amd64'"
+BINARY_NAME="qu-${RELEASE}-linux-${ARCH}"
-echo_cmd "chmod +x '$INSTALL_BIN'"
+BINARY_URL="${RELEASE_BASE}/${RELEASE}/${BINARY_NAME}"
-echo "> qu has been installed to $INSTALL_BIN"
+SUMS_URL="${RELEASE_BASE}/${RELEASE}/SHA256SUMS"
 
+# --- download + verify --------------------------------------------------
+# Stage in a temp dir so a failed verification never leaves a partial
+# or unverified binary on disk.
+TMPDIR=$(mktemp -d)
+trap 'rm -rf "$TMPDIR"' EXIT
+
+echo "> downloading $BINARY_NAME"
+curl -fsSL --proto '=https' --tlsv1.2 -o "$TMPDIR/$BINARY_NAME" "$BINARY_URL"
+echo "> downloading SHA256SUMS"
+curl -fsSL --proto '=https' --tlsv1.2 -o "$TMPDIR/SHA256SUMS" "$SUMS_URL"
+
+echo "> verifying checksum"
+# Pull just our binary's entry so sha256sum -c doesn't fail on the
+# arches we didn't download.
+(
+    cd "$TMPDIR"
+    if ! grep -E "[[:space:]]\\*?${BINARY_NAME}\$" SHA256SUMS > expected.sum; then
+        fail "no entry for $BINARY_NAME in published SHA256SUMS — refusing to install"
+    fi
+    if ! sha256sum -c expected.sum >/dev/null 2>&1; then
+        echo "expected: $(awk '{print $1}' expected.sum)"
+        echo "actual:   $(sha256sum "$BINARY_NAME" | awk '{print $1}')"
+        fail "checksum mismatch for $BINARY_NAME — refusing to install"
+    fi
+)
+echo "> checksum OK"
+
+install -m 0755 "$TMPDIR/$BINARY_NAME" "$INSTALL_BIN"
+echo "> qu ${RELEASE} installed to $INSTALL_BIN"
+
+# --- shell completions --------------------------------------------------
 if "$INSTALL_BIN" --help 2>/dev/null | grep -q "completion"; then
     write_completion bash /usr/share/bash-completion/completions/qu \
-    || write_completion bash /etc/bash_completion.d/qu || true
+        || write_completion bash /etc/bash_completion.d/qu \
+        || true
     write_completion zsh  /usr/share/zsh/site-functions/_qu                 || true
     write_completion fish /usr/share/fish/vendor_completions.d/qu.fish      || true
 else
     echo "> qu does not expose completion support; skipping shell completion installation."
 fi
 
+# --- systemd unit -------------------------------------------------------
 if ! command -v systemctl >/dev/null 2>&1; then
-    echo "> Warning: systemd is not available on this system. qu serve will not be automatically started on boot."
+    echo
-    echo "Installation complete, before starting qu serve, make sure to run qu init and read the documentation."
+    echo "> systemd is not available on this system. Installation stops here."
+    echo "> Run \`qu serve\` manually (or wire it into the supervisor of your choice)."
     exit 0
 fi
 
-echo "> Creating systemd service file for qu serve..."
+# Dedicated service user. Hardened unit drops all capabilities and
-cat > "$SERVICE_FILE" <<EOL
+# locks the daemon down with ProtectSystem=strict, so it must run as
+# its own unprivileged account rather than the invoking sudo user.
+if ! id "$SERVICE_USER" >/dev/null 2>&1; then
+    echo "> creating system user $SERVICE_USER"
+    useradd --system --no-create-home --shell /usr/sbin/nologin "$SERVICE_USER"
+fi
+
+install -d -o "$SERVICE_USER" -g "$SERVICE_GROUP" -m 0750 "$DATA_DIR"
+
+echo "> writing $SERVICE_FILE"
+cat > "$SERVICE_FILE" <<'EOF'
 [Unit]
-Description=QUptime Serve
+Description=QUptime distributed uptime monitor
-After=network.target
+Documentation=https://git.cer.sh/axodouble/quptime
+Wants=network-online.target
+After=network-online.target
 
 [Service]
-ExecStart=$INSTALL_BIN serve
+Type=simple
+ExecStart=/usr/local/bin/qu serve
 Restart=always
-User=$SERVICE_USER
+RestartSec=5s
-Group=$SERVICE_GROUP
+
+User=quptime
+Group=quptime
+
+# Where state lives. RuntimeDirectory creates /var/run/quptime/ each
+# boot owned by User:Group with mode 0750.
+Environment=QUPTIME_DIR=/etc/quptime
+RuntimeDirectory=quptime
+RuntimeDirectoryMode=0750
+ReadWritePaths=/etc/quptime /var/run/quptime
+
+# Hardening. Comment out individual directives if a probe needs
+# something we've revoked.
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+PrivateTmp=true
+PrivateDevices=true
+ProtectKernelTunables=true
+ProtectKernelModules=true
+ProtectControlGroups=true
+ProtectClock=true
+ProtectHostname=true
+RestrictNamespaces=true
+RestrictRealtime=true
+RestrictSUIDSGID=true
+LockPersonality=true
+MemoryDenyWriteExecute=true
+
+# Network access is required (we're a network monitor). Keep address
+# families minimal — AF_NETLINK is needed for some libc lookups.
+RestrictAddressFamilies=AF_UNIX AF_INET AF_INET6 AF_NETLINK
+
+# If you need raw ICMP, *also* uncomment:
+# AmbientCapabilities=CAP_NET_RAW
+# CapabilityBoundingSet=CAP_NET_RAW
+# Otherwise drop all capabilities:
+CapabilityBoundingSet=
 
 [Install]
 WantedBy=multi-user.target
-EOL
+EOF
 
-echo_cmd "systemctl daemon-reload"
+systemctl daemon-reload
-echo_cmd "systemctl enable $(basename "$SERVICE_FILE")"
+systemctl enable "$SERVICE_NAME" >/dev/null
-echo "> qu serve service has been created and enabled. You can start it with 'systemctl start $(basename "$SERVICE_FILE")'"
+echo "> ${SERVICE_NAME} installed and enabled (not yet started)"
 
-echo "Installation complete, before starting qu serve, make sure to run qu init and read the documentation."
+cat <<EOF
+
+Installation complete.
+
+Next steps:
+
+  1. Initialise the node identity. Either:
+
+       a) Let \`qu serve\` auto-init from environment variables.
+          Drop a systemd override like:
+
+            sudo systemctl edit ${SERVICE_NAME}
+              [Service]
+              Environment=QUPTIME_ADVERTISE=<this-host>:9901
+              # On follower nodes, also set the shared join secret:
+              # Environment=QUPTIME_CLUSTER_SECRET=<paste from first node>
+
+       b) Or run \`qu init\` once explicitly:
+
+            sudo -u ${SERVICE_USER} QUPTIME_DIR=${DATA_DIR} \\
+              qu init --advertise <this-host>:9901
+
+  2. Start the service:
+
+       sudo systemctl start ${SERVICE_NAME}
+       sudo -u ${SERVICE_USER} qu status
+
+  3. For ICMP checks, the daemon defaults to unprivileged UDP-mode
+     pings — those need the ping_group_range sysctl widened to include
+     the ${SERVICE_USER} GID, or grant CAP_NET_RAW in the unit. See
+     docs/deployment/systemd.md for the recipes.
+
+Full documentation: https://git.cer.sh/axodouble/quptime/src/branch/master/docs
+EOF