escape metric help and label values

prometheus.formats.text.asd

@@ -9,5 +9,6 @@
                 :serial t
                 :components
                 ((:file "package")
+                 (:file "escape")
                  (:file "text"))))
   :description "Prometheus.io Client Text format")

src/formats/text/escape.lisp

@@ -0,0 +1,30 @@
+(in-package #:prometheus.formats.text)
+
+;; http://cl-cookbook.sourceforge.net/strings.html#manip
+(defun replace-all (string part replacement &key (test #'char=))
+  "Returns a new string in which all the occurences of the part 
+is replaced with replacement."
+  (with-output-to-string (out)
+    (loop with part-length = (length part)
+          for old-pos = 0 then (+ pos part-length)
+          for pos = (search part string
+                            :start2 old-pos
+                            :test test)
+          do (write-string string out
+                           :start old-pos
+                           :end (or pos (length string)))
+          when pos do (write-string replacement out)
+          while pos)))
+
+(defun escape-metric-help (help)
+  (replace-all (replace-all help "\\" "\\\\")
+               #.(string #\Newline) "\\n"))
+
+(defun escape-label-value (help)
+  (replace-all
+   (replace-all
+    (replace-all
+     help
+     "\\" "\\\\")
+    #.(string #\Newline) "\\n")
+   "\"" "\\\""))

src/formats/text/text.lisp

@@ -13,7 +13,10 @@
 
 (defun print-sample-line (stream name lables lvalues value)
   (let ((*read-default-float-format* 'double-float))
-    (format stream "~a~@[{~{~{~(~A~)=\"~A\"~}~^, ~}}~] ~a~%" name (mapcar #'list lables lvalues) (if (floatp value) (coerce value 'double-float) value))))
+    (format stream "~a~@[{~{~{~(~A~)=\"~A\"~}~^, ~}}~] ~a~%" name (mapcar (lambda (lname lvalue)
+                                                                            (list lname (if (stringp lvalue)
+                                                                                            (escape-label-value lvalue)
+                                                                                            lvalue))) lables lvalues) (if (floatp value) (coerce value 'double-float) value))))
 
 (defgeneric metric-to-text (metric name family-lables stream)
   (:method ((metric prom:simple-metric) name family-lables stream)
@@ -48,13 +51,12 @@
                        (prom:metric-labels metric)
                        (prom:metric-value metric))))
 
-
 (defgeneric metric-family-to-text (mf stream)
   (:method ((mf prom::metric-family) stream)
     (let ((name (prom::metric-family-name mf))
           (labels (prom:metric-family-labels mf)))
       (format stream "# TYPE ~a ~a~%" name (prom:metric-family-type mf))
-      (format stream "# HELP ~a ~a~%" name (prom:metric-family-help mf))
+      (format stream "# HELP ~a ~a~%" name (escape-metric-help (prom:metric-family-help mf)))
       (loop for metric in (prom::get-metrics mf) do
             (metric-to-text metric name labels stream)))))
 

t/formats/text/basic.lisp

@@ -4,13 +4,15 @@
 
 (subtest "Basic test"
   (with-fresh-registry
-    (let ((rc (prom:make-counter :name "requests_counter" :help "Hunchentoot requests counter" :labels '("type")))
+    (let ((rc (prom:make-counter :name "requests_counter" :help "Hunch\\entoot
+requests counter" :labels '("type")))
           (ic (prom:make-int-counter :name "irequests_counter" :help "Hunchentoot requests counter" :labels '("type")))
           (tmg (prom:make-gauge :name "total_memory" :help "SBCL total memory"))
           (h (prom:make-histogram :name "render_time" :help "qwe" :labels '("type") :buckets '(2 4 6)))
           (s (prom:make-summary :name "traffic_summary" :help "traffic summary" :value 12)))
-      (prom:counter.inc rc :value 5 :labels '("get"))
-      (prom:counter.inc rc :value 12 :labels '("post"))
+      (prom:counter.inc rc :value 5 :labels '("ge\"t"))
+      (prom:counter.inc rc :value 12 :labels '("p\\os
+t"))
       (prom:counter.inc ic :value 5 :labels '("get"))
       (prom:counter.inc ic :value 12 :labels '("post"))
       (prom:gauge.set tmg 566)
@@ -20,9 +22,9 @@
       (prom:histogram.observe h 4.5 :labels '("pdf"))
       (prom:summary.observe s 43.3d0)
       (is (prom.text:marshal) "# TYPE requests_counter counter
-# HELP requests_counter Hunchentoot requests counter
-requests_counter{type=\"post\"} 12
-requests_counter{type=\"get\"} 5
+# HELP requests_counter Hunch\\\\entoot\\nrequests counter
+requests_counter{type=\"p\\\\os\\nt\"} 12
+requests_counter{type=\"ge\\\"t\"} 5
 # TYPE irequests_counter counter
 # HELP irequests_counter Hunchentoot requests counter
 irequests_counter{type=\"post\"} 12