tests(plugins/prometheus): add unit tests for prometheus plugin (#11157)

Adds tests for #11115 and #11126.

Replaces #11137

spec/03-plugins/26-prometheus/08-unit_spec.lua

@@ -0,0 +1,141 @@
+
+describe("Plugin: prometheus (unit)", function()
+  local prometheus
+
+  local orig_ngx_shared    = ngx.shared
+  local orig_ngx_get_phase = ngx.get_phase
+  local orig_ngx_timer     = ngx.timer
+
+  setup(function()
+    ngx.shared = require("spec.fixtures.shm-stub")
+    ngx.get_phase = function()  -- luacheck: ignore
+      return "init_worker"
+    end
+    ngx.timer = {               -- luacheck: ignore
+      every = function() end,
+    }
+
+    package.loaded['prometheus_resty_counter'] = require("resty.counter")
+    prometheus = require("kong.plugins.prometheus.prometheus")
+  end)
+
+  teardown(function()
+    ngx.shared    = orig_ngx_shared
+    ngx.get_phase = orig_ngx_get_phase  -- luacheck: ignore
+    ngx.timer     = orig_ngx_timer      -- luacheck: ignore
+  end)
+
+  it("check metric names", function()
+    local prom = prometheus.init("prometheus_metrics", "kong_")
+    local m
+
+    m = prom:counter("mem_used")
+    assert.truthy(m)
+
+    m = prom:counter("Mem_Used")
+    assert.truthy(m)
+
+    m = prom:counter(":mem_used")
+    assert.truthy(m)
+
+    m = prom:counter("mem_used:")
+    assert.truthy(m)
+
+    m = prom:counter("_mem_used_")
+    assert.truthy(m)
+
+    m = prom:counter("mem-used")
+    assert.falsy(m)
+
+    m = prom:counter("0name")
+    assert.falsy(m)
+
+    m = prom:counter("name$")
+    assert.falsy(m)
+  end)
+
+  it("check metric label names", function()
+    local prom = prometheus.init("prometheus_metrics", "kong_")
+    local m
+
+    m = prom:counter("mem0", nil, {"LUA"})
+    assert.truthy(m)
+
+    m = prom:counter("mem1", nil, {"lua"})
+    assert.truthy(m)
+
+    m = prom:counter("mem2", nil, {"_lua_"})
+    assert.truthy(m)
+
+    m = prom:counter("mem3", nil, {":lua"})
+    assert.falsy(m)
+
+    m = prom:counter("mem4", nil, {"0lua"})
+    assert.falsy(m)
+
+    m = prom:counter("mem5", nil, {"lua*"})
+    assert.falsy(m)
+
+    m = prom:counter("mem6", nil, {"lua\\5.1"})
+    assert.falsy(m)
+
+    m = prom:counter("mem7", nil, {"lua\"5.1\""})
+    assert.falsy(m)
+
+    m = prom:counter("mem8", nil, {"lua-vm"})
+    assert.falsy(m)
+  end)
+
+  it("check metric full name", function()
+    local prom = prometheus.init("prometheus_metrics", "kong_")
+    local shm = ngx.shared["prometheus_metrics"]
+    local m
+
+    m = prom:counter("mem", nil, {"lua"})
+    assert.truthy(m)
+    m:inc(1, {"2.1"})
+
+    m = prom:counter("file", nil, {"path"})
+    assert.truthy(m)
+    m:inc(1, {"\\root"})
+
+    m = prom:counter("user", nil, {"name"})
+    assert.truthy(m)
+    m:inc(1, {"\"quote"})
+
+    -- sync to shdict
+    prom._counter:sync()
+
+    assert.equal(shm:get([[mem{lua="2.1"}]]), 1)
+    assert.equal(shm:get([[file{path="\\root"}]]), 1)
+    assert.equal(shm:get([[user{name="\"quote"}]]), 1)
+  end)
+
+  it("emit metric data", function()
+    local prom = prometheus.init("metrics", "kong_")
+    local m
+
+    m = prom:counter("mem", nil, {"lua"})
+    assert.truthy(m)
+    m:inc(2, {"2.1"})
+
+    m = prom:counter("file", nil, {"path"})
+    assert.truthy(m)
+    m:inc(3, {"\\root"})
+
+    m = prom:counter("user", nil, {"name"})
+    assert.truthy(m)
+    m:inc(5, {"\"quote"})
+    m:inc(1, {"\"quote"})
+
+    local str = ""
+    prom:metric_data(function(d)
+      str = str .. d
+    end)
+
+    assert.truthy(str:find([[kong_mem{lua="2.1"} 2]], 1, true))
+    assert.truthy(str:find([[kong_file{path="\\root"} 3]], 1, true))
+    assert.truthy(str:find([[kong_user{name="\"quote"} 6]], 1, true))
+  end)
+
+end)

spec/fixtures/shm-stub.lua

@@ -0,0 +1,110 @@
+-- DICT Proxy
+-- https://github.com/bsm/fakengx/blob/master/fakengx.lua
+
+local SharedDict = {}
+
+local function set(data, key, value)
+  data[key] = {
+    value = value,
+    info = {expired = false}
+  }
+end
+
+function SharedDict:new()
+  return setmetatable({data = {}}, {__index = self})
+end
+
+function SharedDict:get(key)
+  return self.data[key] and self.data[key].value, nil
+end
+
+function SharedDict:set(key, value)
+  set(self.data, key, value)
+  return true, nil, false
+end
+
+SharedDict.safe_set = SharedDict.set
+
+function SharedDict:add(key, value)
+  if self.data[key] ~= nil then
+    return false, "exists", false
+  end
+
+  set(self.data, key, value)
+  return true, nil, false
+end
+
+function SharedDict:replace(key, value)
+  if self.data[key] == nil then
+    return false, "not found", false
+  end
+
+  set(self.data, key, value)
+  return true, nil, false
+end
+
+function SharedDict:delete(key)
+  if self.data[key] ~= nil then
+    self.data[key] = nil
+  end
+end
+
+function SharedDict:incr(key, value, init)
+  if not self.data[key] then
+    if not init then
+      return nil, "not found"
+    else
+      set(self.data, key, init)
+    end
+  elseif type(self.data[key]) ~= "table" then
+    return nil, "not a table"
+  end
+
+  self.data[key].value = self.data[key].value + value
+  return self.data[key].value, nil
+end
+
+function SharedDict:flush_all()
+  for _, item in pairs(self.data) do
+    item.info.expired = true
+  end
+end
+
+function SharedDict:flush_expired(n)
+  local data = self.data
+  local flushed = 0
+
+  for key, item in pairs(self.data) do
+    if item.info.expired then
+      data[key] = nil
+      flushed = flushed + 1
+      if n and flushed == n then
+        break
+      end
+    end
+  end
+
+  self.data = data
+
+  return flushed
+end
+
+function SharedDict:get_keys()
+  local keys = {}
+  for k, _ in pairs(self.data) do
+    table.insert(keys, k)
+  end
+
+  return keys
+end
+
+local shared_mt = {
+  __index = function(self, key)
+    if rawget(self, key) == nil then
+      self[key] = SharedDict:new()
+    end
+    return self[key]
+  end
+}
+
+return setmetatable({}, shared_mt)