feat(exporter) export enterprise license info (#110)

Co-authored-by: Guilherme Salazar <gsz@acm.org>

kong-prometheus-plugin-1.0.0-1.rockspec

@@ -23,6 +23,7 @@ build = {
     ["kong.plugins.prometheus.api"] = "kong/plugins/prometheus/api.lua",
     ["kong.plugins.prometheus.status_api"] = "kong/plugins/prometheus/status_api.lua",
     ["kong.plugins.prometheus.exporter"] = "kong/plugins/prometheus/exporter.lua",
+    ["kong.plugins.prometheus.enterprise.exporter"] = "kong/plugins/prometheus/enterprise/exporter.lua",
     ["kong.plugins.prometheus.handler"] = "kong/plugins/prometheus/handler.lua",
     ["kong.plugins.prometheus.prometheus"] = "kong/plugins/prometheus/prometheus.lua",
     ["kong.plugins.prometheus.serve"] = "kong/plugins/prometheus/serve.lua",

kong/plugins/prometheus/enterprise/exporter.lua

@@ -0,0 +1,94 @@
+local kong = kong
+local sub = string.sub
+local split = require('kong.tools.utils').split
+
+local metrics = {}
+
+
+local function init(prometheus)
+  metrics.license_errors = prometheus:counter("enterprise_license_errors",
+                                              "Errors when collecting license info")
+  metrics.license_signature = prometheus:gauge("enterprise_license_signature",
+                                              "Last 32 bytes of the license signautre in number")
+  metrics.license_expiration = prometheus:gauge("enterprise_license_expiration",
+                                                "Unix epoch time when the license expires, " ..
+                                                "the timestamp is substracted by 24 hours "..
+                                                "to avoid difference in timezone")
+  metrics.license_features = prometheus:gauge("enterprise_license_features",
+                                                "License features features",
+                                              { "feature" })
+end
+
+local function license_date_to_unix(yyyy_mm_dd)
+  local date_t = split(yyyy_mm_dd, "-")
+
+  local ok, res = pcall(os.time, {
+    year = tonumber(date_t[1]),
+    month = tonumber(date_t[2]),
+    day = tonumber(date_t[3])
+  })
+  if ok then
+    return res
+  end
+
+  return nil, res
+end
+
+local function metric_data()
+  if not metrics then
+    kong.log.err("prometheus: plugin is not initialized, please make sure ",
+                 " 'prometheus_metrics' shared dict is present in nginx template")
+    return kong.response.exit(500, { message = "An unexpected error occurred" })
+  end
+
+  if not kong.license or not kong.license.license then
+    metrics.license_errors:inc()
+    kong.log.err("cannot read kong.license when collecting license info")
+    return
+  end
+
+  local lic = kong.license.license
+
+  if lic.version ~= 1 then
+    metrics.license_errors:inc()
+    kong.log.err("enterprise license version (" .. (lic.version or "nil") .. ") unsupported")
+    return
+  end
+
+  local sig = lic.signature
+  if not sig then
+    metrics.license_errors:inc()
+    kong.log.err("cannot read license signature when collecting license info")
+    return
+  end
+  -- last 32 bytes as an int32
+  metrics.license_signature:set(tonumber("0x" .. sub(sig, #sig-33, #sig)))
+
+  local expiration = lic.payload and lic.payload.license_expiration_date
+  if not expiration then
+    metrics.license_errors:inc()
+    kong.log.err("cannot read license expiration when collecting license info")
+    return
+  end
+  local tm, err = license_date_to_unix(expiration)
+  if not tm then
+    metrics.license_errors:inc()
+    kong.log.err("cannot parse license expiration when collecting license info ", err)
+    return
+  end
+  -- substract it by 24h so everyone one earth is happy monitoring it
+  metrics.license_expiration:set(tm - 86400)
+
+
+  metrics.license_features:set(kong.licensing:can("ee_plugins") and 1 or 0,
+                              { "ee_plugins" })
+
+  metrics.license_features:set(kong.licensing:can("write_admin_api") and 1 or 0,
+                              { "write_admin_api" })
+end
+
+
+return {
+  init        = init,
+  metric_data = metric_data,
+}

kong/plugins/prometheus/exporter.lua

@@ -18,6 +18,12 @@ local prometheus
 -- use the same counter library shipped with Kong
 package.loaded['prometheus_resty_counter'] = require("resty.counter")
 
+local enterprise
+local pok = pcall(require, "kong.enterprise_edition.licensing")
+if pok then
+  enterprise = require("kong.plugins.prometheus.enterprise.exporter")
+end
+
 
 local function init()
   local shm = "prometheus_metrics"
@@ -73,6 +79,9 @@ local function init()
                                          "Total bandwidth in bytes " ..
                                          "consumed per service/route in Kong",
                                          {"service", "route", "type"})
+  if enterprise then
+    enterprise.init(prometheus)
+  end
 end
 
 local function init_worker()
@@ -295,6 +304,10 @@ local function metric_data()
                                         {res.workers_lua_vms[i].pid})
   end
 
+  if enterprise then
+    enterprise.metric_data()
+  end
+
   return prometheus:metric_data()
 end