feat: added capability to extract metrics from the logs

helm/Chart.yaml

@@ -6,7 +6,7 @@ version: 2.1.1
 appVersion: 2.1.1
 dependencies:
   - name: nginx
-    version: 2.3.1
+    version: 2.4.0
     repository: oci://acrarolibotnonprod.azurecr.io/helm/common
   - name: mclabels
     version: 1.0.1

helm/config/custom.lua

@@ -0,0 +1,128 @@
+-------------------------------------------------------------------------------
+-- Helper Functions
+-------------------------------------------------------------------------------
+
+local function url_decode(str)
+    if not str then return "" end
+    local decoded = str:gsub("+", " "):gsub("%%(%x%x)", function(h)
+        return string.char(tonumber(h, 16))
+    end)
+    return decoded
+end
+
+local function parse_query_string(query)
+    local params = {}
+    if not query or query == "" then return params end
+    for k, v in query:gmatch("([^&]+)=([^&]+)") do
+        params[string.lower(k)] = url_decode(v)
+    end
+    return params
+end
+
+local function normalize_format(format_str)
+    if not format_str then return nil end
+    return string.lower(format_str):gsub("^image/", "")
+end
+
+-------------------------------------------------------------------------------
+-- Parsers (KVP and RESTful)
+-------------------------------------------------------------------------------
+
+local function parse_kvp(params)
+    local service   = params["service"] and string.upper(params["service"])
+    local operation = params["request"] and string.upper(params["request"])
+    local layer     = params["layers"] or params["layer"]
+    local format    = normalize_format(params["format"])
+    local zoom      = nil
+
+    if params["tilematrix"] then
+        zoom = params["tilematrix"]:match(":(%d+)$") or
+              params["tilematrix"]:match("^(%d+)$") or
+              params["tilematrix"]
+    end
+
+    if not service and operation then
+        if operation == "GETMAP" or operation == "GETFEATUREINFO" then
+            service = "WMS"
+        elseif operation == "GETTILE" then
+            service = "WMTS"
+        end
+    end
+
+    return service, operation, layer, zoom, format
+end
+
+local function parse_restful(path)
+    local lower_path = string.lower(path)
+
+    if lower_path:find("/wmts/") then
+        local pattern = "/wmts/([^/]+)/([^/]+)/(%d+)/(%d+)/(%d+)%.(%w+)"
+        local layer, grid, zoom, x, y, format = path:match(pattern)
+
+        if layer then
+            return "WMTS", "GETTILE", layer, zoom, normalize_format(format)
+        elseif lower_path:find("wmtscapabilities%.xml$") then
+            return "WMTS", "GETCAPABILITIES", nil, nil, "xml"
+        end
+    end
+
+    return nil, nil, nil, nil, nil
+end
+
+-- Bucket a raw zoom level so the WMTS counter's cardinality doesn't scale with
+-- every individual zoom on top of layer count: 0-14 (overview/regional),
+-- 15-18 (street level), 19+ (max detail).
+local function zoom_group(zoom)
+    local z = tonumber(zoom)
+    if z == nil then return "none" end
+    if z <= 14 then return "0-14" end
+    if z <= 18 then return "15-18" end
+    return "19+"
+end
+
+-------------------------------------------------------------------------------
+-- Main Fluent Bit Entrypoint
+-------------------------------------------------------------------------------
+
+function parse_mapproxy_request(tag, timestamp, record)
+    -- The URL lives at Attributes["url.path"] / Attributes["url.query"] -
+    -- Fluent Bit's json parser never produces a top-level "request_uri".
+    local attrs = record["Attributes"] or {}
+    local path         = attrs["url.path"] or ""
+    local query_string = attrs["url.query"] or ""
+
+    local params = parse_query_string(query_string)
+
+    local service, operation, layer, zoom, format
+
+    if query_string ~= "" then
+        service, operation, layer, zoom, format = parse_kvp(params)
+    end
+
+    if not service then
+        service, operation, layer, zoom, format = parse_restful(path)
+    end
+
+    if not service or not operation then
+        return 0, 0, 0
+    end
+
+    record["ogc_service"]   = service
+    record["ogc_operation"] = operation
+    record["ogc_layer"]     = layer  or "none"
+    record["ogc_zoom"]      = zoom   or "none"
+    record["ogc_format"]    = format or "none"
+    record["ogc_zoom_group"] = zoom_group(zoom)
+
+    -- result (ok/error) + a numeric request_time, for the latency histograms
+    -- below. Both come off nginx as strings ("200", "0.043").
+    local status = tonumber(attrs["http.response.status_code"])
+    record["result"] = (status ~= nil and status >= 400) and "error" or "ok"
+
+    local request_time = tonumber(attrs["mapcolonies.request_time"])
+    if request_time ~= nil then
+        record["request_time_seconds"] = request_time
+    end
+
+    return 1, timestamp, record
+end

helm/templates/nginx/nginx-configmap.yaml

@@ -12,10 +12,10 @@ metadata:
     environment: {{ .Values.environment }}
     release: {{ $releaseName }}
 data:
-  log_format.conf: {{ tpl (.Files.Get "config/log_format.conf") . | quote }}
   nginx.mapproxy.conf: {{ tpl (.Files.Get "config/nginx.mapproxy.conf") . | quote }}
   nginx.mapproxy.wmts.conf: {{ tpl (.Files.Get "config/nginx.mapproxy.wmts.conf") . | quote }}
   mapproxy-http.conf: {{ tpl (.Files.Get "config/mapproxy-http.conf") . | quote }}
   mapproxy-server.conf: {{ tpl (.Files.Get "config/mapproxy-server.conf") . | quote }}
   mapproxy-location.conf: {{ tpl (.Files.Get "config/mapproxy-location.conf") . | quote }}
+  custom.lua: {{ tpl (.Files.Get "config/custom.lua") . | quote }}
 {{- end }}