Add pod healthcheck script.

healthcheck

@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+
+set -u
+
+CHECK_SPACE_APIKEY="<API-KEY>"
+HEALTCHECKSIO_UPTIMEKUMA_UUID="<HEALTCHECKSIO_UPTIMEKUMA_UUID>"
+
+UPTIMEKUMA_URL="https://uptime-kuma.golem.linux.it"
+PUSH_PATH="/api/push/"
+
+UK_PING_TIMEOUT=2
+UK_PING_RETRY=3
+UK_STATUS_UP="up"
+UK_STATUS_DOWN="down"
+
+HC_PING_TIMEOUT=10
+HC_PING_RETRY=5
+HC_FAIL_PATH="/fail"
+
+ROOTFS_USED_THRESHOLD=75
+
+# uptime-kuma ###########################################################
+
+get-push-url() {
+    local apikey="$1"
+    echo "${UPTIMEKUMA_URL}${PUSH_PATH}${apikey}"
+}
+
+ping-url() {
+    local url="${1}"
+    echo "Ping to ${url}: "
+    curl -m "$UK_PING_TIMEOUT" --retry "$UK_PING_RETRY" "${url}"
+    echo
+}
+
+ping-status-msg() {
+    local apikey="${1}"
+    local status="${2}"
+    local msg="${3}"
+    local url
+    url=$(get-push-url "${apikey}")"?status=${status}&msg=${msg}"
+    ping-url "${url}"
+}
+
+urlencode() {
+    echo "${1}" | jq -s -R -r @uri
+}
+
+# healthchecks.io #######################################################
+
+hc-ping() {
+    local url="$1"
+    echo "Ping to ${url}: "
+    curl -m $HC_PING_TIMEOUT --retry $HC_PING_RETRY "${url}"
+    echo
+}
+
+# checks ################################################################
+
+check-site-hc() {
+    local hcurl="$1"
+    local site="$2"
+    local hcpath=""
+    echo "Checking ${site}:"
+    # shellcheck disable=SC2015
+    curl -m 3 -fSs -o /dev/null "${site}"
+    if test $? -ne 0; then
+        hcpath=$HC_FAIL_PATH
+    fi
+    hc-ping "${hcurl}${hcpath}"
+}
+
+check-space() {
+    local apikey=$CHECK_SPACE_APIKEY
+    local status=$UK_STATUS_UP
+    local msg
+
+    local rootfs_used
+    rootfs_used="$(df --output=pcent / | tail -n1 | sed 's/\%//')"
+    if test "$rootfs_used" -ge $ROOTFS_USED_THRESHOLD; then
+        status=$UK_STATUS_DOWN
+        msg="WARN / : ${rootfs_used}%"
+    else
+        msg="OK / : ${rootfs_used}%"
+    fi
+
+    echo "$msg"
+    msg=$(urlencode "$msg")
+    ping-status-msg "$apikey" "$status" "$msg"
+}
+
+#########################################################################
+
+check-space
+check-site-hc "https://hc-ping.com/${HEALTCHECKSIO_UPTIMEKUMA_UUID}" uptime-kuma.golem.linux.it