From 14915071d66d3cf2b9ed7101abfc8c6263c39b66 Mon Sep 17 00:00:00 2001
From: Nikolay <nik@victoriametrics.com>
Date: Fri, 25 Dec 2020 12:03:13 +0300
Subject: [PATCH] adds escape for CRLF (#984)

at external.alert.source - \n and \r symbols was url encoded, instead of direct usage.
replace it from "\n" to `\n`  allows to skip url encoding.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890
---
 app/vmalert/README.md                 | 2 +-
 app/vmalert/main.go                   | 2 +-
 app/vmalert/notifier/template_func.go | 4 ++++
 docs/vmalert.md                       | 2 +-
 4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/app/vmalert/README.md b/app/vmalert/README.md
index 6f705db6f..aba8231d6 100644
--- a/app/vmalert/README.md
+++ b/app/vmalert/README.md
@@ -202,7 +202,7 @@ The shortlist of configuration flags is the following:
     	How often to evaluate the rules (default 1m0s)
   -external.alert.source string
     	External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service.
-    	eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used
+    	eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|crlfEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used
   -external.label array
     	Optional label in the form 'name=value' to add to all generated recording rules and alerts. Pass multiple -label flags in order to add multiple label sets.
     	Supports array of values separated by comma or specified via multiple flags.
diff --git a/app/vmalert/main.go b/app/vmalert/main.go
index ea6922d86..d04584eb2 100644
--- a/app/vmalert/main.go
+++ b/app/vmalert/main.go
@@ -41,7 +41,7 @@ Rule files may contain %{ENV_VAR} placeholders, which are substituted by the cor
 	validateExpressions = flag.Bool("rule.validateExpressions", true, "Whether to validate rules expressions via MetricsQL engine")
 	externalURL         = flag.String("external.url", "", "External URL is used as alert's source for sent alerts to the notifier")
 	externalAlertSource = flag.String("external.alert.source", "", `External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service.
-eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used`)
+eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|crlfEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used`)
 	externalLabels = flagutil.NewArray("external.label", "Optional label in the form 'name=value' to add to all generated recording rules and alerts. "+
 		"Pass multiple -label flags in order to add multiple label sets.")
 
diff --git a/app/vmalert/notifier/template_func.go b/app/vmalert/notifier/template_func.go
index e643d5880..043339b87 100644
--- a/app/vmalert/notifier/template_func.go
+++ b/app/vmalert/notifier/template_func.go
@@ -167,6 +167,10 @@ func InitTemplateFunc(externalURL *url.URL) {
 		"queryEscape": func(q string) string {
 			return url.QueryEscape(q)
 		},
+		"crlfEscape": func(q string) string {
+			q = strings.Replace(q, "\n", `\n`, -1)
+			return strings.Replace(q, "\r", `\r`, -1)
+		},
 		"quotesEscape": func(q string) string {
 			return strings.Replace(q, `"`, `\"`, -1)
 		},
diff --git a/docs/vmalert.md b/docs/vmalert.md
index 6f705db6f..aba8231d6 100644
--- a/docs/vmalert.md
+++ b/docs/vmalert.md
@@ -202,7 +202,7 @@ The shortlist of configuration flags is the following:
     	How often to evaluate the rules (default 1m0s)
   -external.alert.source string
     	External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service.
-    	eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used
+    	eg. 'explore?orgId=1&left=[\"now-1h\",\"now\",\"VictoriaMetrics\",{\"expr\": \"{{$expr|quotesEscape|crlfEscape|pathEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/api/v1/:groupID/alertID/status' is used
   -external.label array
     	Optional label in the form 'name=value' to add to all generated recording rules and alerts. Pass multiple -label flags in order to add multiple label sets.
     	Supports array of values separated by comma or specified via multiple flags.