app/vmalert/templates: properly escape all the special chars in quotesEscape function

Previously the `quotesEscape` function was escaping only double quotes. This wasn't enough, since the input string could contain other special chars, which must be escaped when put inside JSON string. For example, carriage return and line feed chars (\n\r), backslash char, etc. This led to the following issues, which were improperly fixed: - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890 - this issue was "fixed" by introducing the `crlfEscape` function, which led to unnecessary complications in user templates, while not fixing various corner cases such as backslash chars in the input string. See 1de15ad490 - https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3139 - this issue was "fixed" by urlencoding the whole string passed to -external.alert.source command-line flag. This led to invalid urls, which couldn't be parsed by Grafana. See 00c838353d and 4bd0244599 This commit properly encodes the input string passed to `quotesEscape`, so it can be safely embedded inside JSON strings. This commit deprecates crlfEscape template function and adds the following new template functions: - strvalue and stripDomain - these functions are supported by Prometheus, so they were added for compatibility purposes. - jsonEscape and htmlEscape for converting the input string to valid quoted JSON string and for html-escaping the input string, so it could be safely embedded as a plaintext into html. This commit also documents all supported template functions at https://docs.victoriametrics.com/vmalert.html#template-functions The deprecated crlfEscape function isn't documented on purpose, since its usefulness is negative in general case.
2024-11-21 14:44:00 +00:00 · 2022-10-27 23:38:19 +03:00 · 2022-10-27 23:38:19 +03:00 · ae64be4f2c
commit ae64be4f2c
parent c32d3695e7
10 changed files with 281 additions and 56 deletions
--- a/app/vmalert/README.md
+++ b/app/vmalert/README.md
@ -675,8 +675,8 @@ The shortlist of configuration flags is the following:
  -evaluationInterval duration
     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\": \"{{$expr|quotesEscape|crlfEscape|queryEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/vmalert/api/v1/alert?group_id=&alert_id=' is used
+     External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service. Supports templating - see https://docs.victoriametrics.com/vmalert.html#templating . For example, link to Grafana: -external.alert.source='explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":{{$expr|jsonEscape|queryEscape}} },{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]' . If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' is used
+     If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' 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 an array of values separated by comma or specified via multiple flags.
--- a/app/vmalert/main.go
+++ b/app/vmalert/main.go
@ -58,8 +58,11 @@ absolute path to all .tpl files in root.`)
 	resendDelay = flag.Duration("rule.resendDelay", 0, "Minimum amount of time to wait before resending an alert to notifier")

 	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\": \"{{$expr|quotesEscape|crlfEscape|queryEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/vmalert/api/v1/alert?group_id=&alert_id=' is used`)
+	externalAlertSource = flag.String("external.alert.source", "", `External Alert Source allows to override the Source link for alerts sent to AlertManager `+
+		`for cases where you want to build a custom link to Grafana, Prometheus or any other service. `+
+		`Supports templating - see https://docs.victoriametrics.com/vmalert.html#templating . `+
+		`For example, link to Grafana: -external.alert.source='explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":{{$expr|jsonEscape|queryEscape}} },{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]' . `+
+		`If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' 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.")

--- a/app/vmalert/notifier/alert_test.go
+++ b/app/vmalert/notifier/alert_test.go
@ -66,15 +66,21 @@ func TestAlert_ExecTemplate(t *testing.T) {
 		{
 			name: "expression-template",
 			alert: &Alert{
-				Expr: `vm_rows{"label"="bar"}>0`,
+				Expr: `vm_rows{"label"="bar"}<0`,
 			},
 			annotations: map[string]string{
-				"exprEscapedQuery": "{{ $expr|quotesEscape|queryEscape }}",
-				"exprEscapedPath":  "{{ $expr|quotesEscape|pathEscape }}",
+				"exprEscapedQuery":  "{{ $expr|queryEscape }}",
+				"exprEscapedPath":   "{{ $expr|pathEscape }}",
+				"exprEscapedJSON":   "{{ $expr|jsonEscape }}",
+				"exprEscapedQuotes": "{{ $expr|quotesEscape }}",
+				"exprEscapedHTML":   "{{ $expr|htmlEscape }}",
 			},
 			expTpl: map[string]string{
-				"exprEscapedQuery": "vm_rows%7B%5C%22label%5C%22%3D%5C%22bar%5C%22%7D%3E0",
-				"exprEscapedPath":  "vm_rows%7B%5C%22label%5C%22=%5C%22bar%5C%22%7D%3E0",
+				"exprEscapedQuery":  "vm_rows%7B%22label%22%3D%22bar%22%7D%3C0",
+				"exprEscapedPath":   "vm_rows%7B%22label%22=%22bar%22%7D%3C0",
+				"exprEscapedJSON":   `"vm_rows{\"label\"=\"bar\"}\u003c0"`,
+				"exprEscapedQuotes": `vm_rows{\"label\"=\"bar\"}\u003c0`,
+				"exprEscapedHTML":   "vm_rows{&quot;label&quot;=&quot;bar&quot;}&lt;0",
 			},
 		},
 		{
--- a/app/vmalert/templates/funcs.qtpl
+++ b/app/vmalert/templates/funcs.qtpl
@ -0,0 +1,15 @@
+{% stripspace %}
+
+{% func quotesEscape(s string) %}
+	{%j= s %}
+{% endfunc %}
+
+{% func jsonEscape(s string) %}
+	{%q= s %}
+{% endfunc %}
+
+{% func htmlEscape(s string) %}
+	{%s s %}
+{% endfunc %}
+
+{% endstripspace %}
--- a/app/vmalert/templates/funcs.qtpl.go
+++ b/app/vmalert/templates/funcs.qtpl.go
@ -0,0 +1,117 @@
+// Code generated by qtc from "funcs.qtpl". DO NOT EDIT.
+// See https://github.com/valyala/quicktemplate for details.
+
+//line app/vmalert/templates/funcs.qtpl:3
+package templates
+
+//line app/vmalert/templates/funcs.qtpl:3
+import (
+	qtio422016 "io"
+
+	qt422016 "github.com/valyala/quicktemplate"
+)
+
+//line app/vmalert/templates/funcs.qtpl:3
+var (
+	_ = qtio422016.Copy
+	_ = qt422016.AcquireByteBuffer
+)
+
+//line app/vmalert/templates/funcs.qtpl:3
+func streamquotesEscape(qw422016 *qt422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:4
+	qw422016.N().J(s)
+//line app/vmalert/templates/funcs.qtpl:5
+}
+
+//line app/vmalert/templates/funcs.qtpl:5
+func writequotesEscape(qq422016 qtio422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:5
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmalert/templates/funcs.qtpl:5
+	streamquotesEscape(qw422016, s)
+//line app/vmalert/templates/funcs.qtpl:5
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmalert/templates/funcs.qtpl:5
+}
+
+//line app/vmalert/templates/funcs.qtpl:5
+func quotesEscape(s string) string {
+//line app/vmalert/templates/funcs.qtpl:5
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmalert/templates/funcs.qtpl:5
+	writequotesEscape(qb422016, s)
+//line app/vmalert/templates/funcs.qtpl:5
+	qs422016 := string(qb422016.B)
+//line app/vmalert/templates/funcs.qtpl:5
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmalert/templates/funcs.qtpl:5
+	return qs422016
+//line app/vmalert/templates/funcs.qtpl:5
+}
+
+//line app/vmalert/templates/funcs.qtpl:7
+func streamjsonEscape(qw422016 *qt422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:8
+	qw422016.N().Q(s)
+//line app/vmalert/templates/funcs.qtpl:9
+}
+
+//line app/vmalert/templates/funcs.qtpl:9
+func writejsonEscape(qq422016 qtio422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:9
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmalert/templates/funcs.qtpl:9
+	streamjsonEscape(qw422016, s)
+//line app/vmalert/templates/funcs.qtpl:9
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmalert/templates/funcs.qtpl:9
+}
+
+//line app/vmalert/templates/funcs.qtpl:9
+func jsonEscape(s string) string {
+//line app/vmalert/templates/funcs.qtpl:9
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmalert/templates/funcs.qtpl:9
+	writejsonEscape(qb422016, s)
+//line app/vmalert/templates/funcs.qtpl:9
+	qs422016 := string(qb422016.B)
+//line app/vmalert/templates/funcs.qtpl:9
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmalert/templates/funcs.qtpl:9
+	return qs422016
+//line app/vmalert/templates/funcs.qtpl:9
+}
+
+//line app/vmalert/templates/funcs.qtpl:11
+func streamhtmlEscape(qw422016 *qt422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:12
+	qw422016.E().S(s)
+//line app/vmalert/templates/funcs.qtpl:13
+}
+
+//line app/vmalert/templates/funcs.qtpl:13
+func writehtmlEscape(qq422016 qtio422016.Writer, s string) {
+//line app/vmalert/templates/funcs.qtpl:13
+	qw422016 := qt422016.AcquireWriter(qq422016)
+//line app/vmalert/templates/funcs.qtpl:13
+	streamhtmlEscape(qw422016, s)
+//line app/vmalert/templates/funcs.qtpl:13
+	qt422016.ReleaseWriter(qw422016)
+//line app/vmalert/templates/funcs.qtpl:13
+}
+
+//line app/vmalert/templates/funcs.qtpl:13
+func htmlEscape(s string) string {
+//line app/vmalert/templates/funcs.qtpl:13
+	qb422016 := qt422016.AcquireByteBuffer()
+//line app/vmalert/templates/funcs.qtpl:13
+	writehtmlEscape(qb422016, s)
+//line app/vmalert/templates/funcs.qtpl:13
+	qs422016 := string(qb422016.B)
+//line app/vmalert/templates/funcs.qtpl:13
+	qt422016.ReleaseByteBuffer(qb422016)
+//line app/vmalert/templates/funcs.qtpl:13
+	return qs422016
+//line app/vmalert/templates/funcs.qtpl:13
+}
--- a/app/vmalert/templates/template.go
+++ b/app/vmalert/templates/template.go
@ -207,23 +207,10 @@ func FuncsWithExternalURL(externalURL *url.URL) textTpl.FuncMap {
 // templateFuncs initiates template helper functions
 func templateFuncs() textTpl.FuncMap {
 	// See https://prometheus.io/docs/prometheus/latest/configuration/template_reference/
+	// and https://github.com/prometheus/prometheus/blob/fa6e05903fd3ce52e374a6e1bf4eb98c9f1f45a7/template/template.go#L150
 	return textTpl.FuncMap{
 		/* Strings */

-		// reReplaceAll ReplaceAllString returns a copy of src, replacing matches of the Regexp with
-		// the replacement string repl. Inside repl, $ signs are interpreted as in Expand,
-		// so for instance $1 represents the text of the first submatch.
-		// alias for https://golang.org/pkg/regexp/#Regexp.ReplaceAllString
-		"reReplaceAll": func(pattern, repl, text string) string {
-			re := regexp.MustCompile(pattern)
-			return re.ReplaceAllString(text, repl)
-		},
-
-		// match reports whether the string s
-		// contains any match of the regular expression pattern.
-		// alias for https://golang.org/pkg/regexp/#MatchString
-		"match": regexp.MatchString,
-
 		// title returns a copy of the string s with all Unicode letters
 		// that begin words mapped to their Unicode title case.
 		// alias for https://golang.org/pkg/strings/#Title
@ -237,6 +224,31 @@ func templateFuncs() textTpl.FuncMap {
 		// alias for https://golang.org/pkg/strings/#ToLower
 		"toLower": strings.ToLower,

+		// crlfEscape replaces '\n' and '\r' chars with `\\n` and `\\r`.
+		// This funcion is deprectated.
+		//
+		// It is better to use quotesEscape, jsonEscape, queryEscape or pathEscape instead -
+		// these functions properly escape `\n` and `\r` chars according to their purpose.
+		"crlfEscape": func(q string) string {
+			q = strings.Replace(q, "\n", `\n`, -1)
+			return strings.Replace(q, "\r", `\r`, -1)
+		},
+
+		// quotesEscape escapes the string, so it can be safely put inside JSON string.
+		//
+		// See also jsonEscape.
+		"quotesEscape": quotesEscape,
+
+		// jsonEscape converts the string to properly encoded JSON string.
+		//
+		// See also quotesEscape.
+		"jsonEscape": jsonEscape,
+
+		// htmlEscape applies html-escaping to q, so it can be safely embedded as plaintext into html.
+		//
+		// See also safeHtml.
+		"htmlEscape": htmlEscape,
+
 		// stripPort splits string into host and port, then returns only host.
 		"stripPort": func(hostPort string) string {
 			host, _, err := net.SplitHostPort(hostPort)
@ -246,6 +258,37 @@ func templateFuncs() textTpl.FuncMap {
 			return host
 		},

+		// stripDomain removes the domain part of a FQDN. Leaves port untouched.
+		"stripDomain": func(hostPort string) string {
+			host, port, err := net.SplitHostPort(hostPort)
+			if err != nil {
+				host = hostPort
+			}
+			ip := net.ParseIP(host)
+			if ip != nil {
+				return hostPort
+			}
+			host = strings.Split(host, ".")[0]
+			if port != "" {
+				return net.JoinHostPort(host, port)
+			}
+			return host
+		},
+
+		// match reports whether the string s
+		// contains any match of the regular expression pattern.
+		// alias for https://golang.org/pkg/regexp/#MatchString
+		"match": regexp.MatchString,
+
+		// reReplaceAll ReplaceAllString returns a copy of src, replacing matches of the Regexp with
+		// the replacement string repl. Inside repl, $ signs are interpreted as in Expand,
+		// so for instance $1 represents the text of the first submatch.
+		// alias for https://golang.org/pkg/regexp/#Regexp.ReplaceAllString
+		"reReplaceAll": func(pattern, repl, text string) string {
+			re := regexp.MustCompile(pattern)
+			return re.ReplaceAllString(text, repl)
+		},
+
 		// parseDuration parses a duration string such as "1h" into the number of seconds it represents
 		"parseDuration": func(s string) (float64, error) {
 			d, err := promutils.ParseDuration(s)
@ -399,31 +442,15 @@ func templateFuncs() textTpl.FuncMap {
 			return ""
 		},

-		// pathEscape escapes the string so it can be safely placed inside a URL path segment,
-		// replacing special characters (including /) with %XX sequences as needed.
-		// alias for https://golang.org/pkg/net/url/#PathEscape
-		"pathEscape": func(u string) string {
-			return url.PathEscape(u)
-		},
+		// pathEscape escapes the string so it can be safely placed inside a URL path segment.
+		//
+		// See also queryEscape.
+		"pathEscape": url.PathEscape,

-		// queryEscape escapes the string so it can be safely placed
-		// inside a URL query.
-		// alias for https://golang.org/pkg/net/url/#QueryEscape
-		"queryEscape": func(q string) string {
-			return url.QueryEscape(q)
-		},
-
-		// crlfEscape replaces new line chars to skip URL encoding.
-		// see https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890
-		"crlfEscape": func(q string) string {
-			q = strings.Replace(q, "\n", `\n`, -1)
-			return strings.Replace(q, "\r", `\r`, -1)
-		},
-
-		// quotesEscape escapes quote char
-		"quotesEscape": func(q string) string {
-			return strings.Replace(q, `"`, `\"`, -1)
-		},
+		// queryEscape escapes the string so it can be safely placed inside a query arg in URL.
+		//
+		// See also queryEscape.
+		"queryEscape": url.QueryEscape,

 		// query executes the MetricsQL/PromQL query against
 		// configured `datasource.url` address.
@ -455,6 +482,17 @@ func templateFuncs() textTpl.FuncMap {
 			return m.Labels[label]
 		},

+		// value returns the value of the given metric.
+		// usually used alongside with `query` template function.
+		"value": func(m metric) float64 {
+			return m.Value
+		},
+
+		// strvalue returns metric name.
+		"strvalue": func(m metric) string {
+			return m.Labels["__name__"]
+		},
+
 		// sortByLabel sorts the given metrics by provided label key
 		"sortByLabel": func(label string, metrics []metric) []metric {
 			sort.SliceStable(metrics, func(i, j int) bool {
@ -463,12 +501,6 @@ func templateFuncs() textTpl.FuncMap {
 			return metrics
 		},

-		// value returns the value of the given metric.
-		// usually used alongside with `query` template function.
-		"value": func(m metric) float64 {
-			return m.Value
-		},
-
 		/* Helpers */

 		// Converts a list of objects to a map with keys arg0, arg1 etc.
@ -482,6 +514,8 @@ func templateFuncs() textTpl.FuncMap {
 		},

 		// safeHtml marks string as HTML not requiring auto-escaping.
+		//
+		// See also htmlEscape.
 		"safeHtml": func(text string) htmlTpl.HTML {
 			return htmlTpl.HTML(text)
 		},
--- a/app/vmalert/templates/template_test.go
+++ b/app/vmalert/templates/template_test.go
@ -6,6 +6,52 @@ import (
 	textTpl "text/template"
 )

+func TestTemplateFuncs(t *testing.T) {
+	funcs := templateFuncs()
+	f := func(funcName, s, resultExpected string) {
+		t.Helper()
+		v := funcs[funcName]
+		fLocal := v.(func(s string) string)
+		result := fLocal(s)
+		if result != resultExpected {
+			t.Fatalf("unexpected result for %s(%q); got\n%s\nwant\n%s", funcName, s, result, resultExpected)
+		}
+	}
+	f("title", "foo bar", "Foo Bar")
+	f("toUpper", "foo", "FOO")
+	f("toLower", "FOO", "foo")
+	f("pathEscape", "foo/bar\n+baz", "foo%2Fbar%0A+baz")
+	f("queryEscape", "foo+bar\n+baz", "foo%2Bbar%0A%2Bbaz")
+	f("jsonEscape", `foo{bar="baz"}`+"\n + 1", `"foo{bar=\"baz\"}\n + 1"`)
+	f("quotesEscape", `foo{bar="baz"}`+"\n + 1", `foo{bar=\"baz\"}\n + 1`)
+	f("htmlEscape", "foo < 10\nabc", "foo &lt; 10\nabc")
+	f("crlfEscape", "foo\nbar\rx", `foo\nbar\rx`)
+	f("stripPort", "foo", "foo")
+	f("stripPort", "foo:1234", "foo")
+	f("stripDomain", "foo.bar.baz", "foo")
+	f("stripDomain", "foo.bar:123", "foo:123")
+
+	// check "match" func
+	matchFunc := funcs["match"].(func(pattern, s string) (bool, error))
+	if _, err := matchFunc("invalid[regexp", "abc"); err == nil {
+		t.Fatalf("expecting non-nil error on invalid regexp")
+	}
+	ok, err := matchFunc("abc", "def")
+	if err != nil {
+		t.Fatalf("unexpected error")
+	}
+	if ok {
+		t.Fatalf("unexpected match")
+	}
+	ok, err = matchFunc("a.+b", "acsdb")
+	if err != nil {
+		t.Fatalf("unexpected error")
+	}
+	if !ok {
+		t.Fatalf("unexpected mismatch")
+	}
+}
+
 func mkTemplate(current, replacement interface{}) textTemplate {
 	tmpl := textTemplate{}
 	if current != nil {
--- a/deployment/docker/docker-compose.yml
+++ b/deployment/docker/docker-compose.yml
@ -72,7 +72,8 @@ services:
      - "--rule=/etc/alerts/*.yml"
      # display source of alerts in grafana
      - "--external.url=http://127.0.0.1:3000" #grafana outside container
-      - '--external.alert.source=explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":"{{$$expr|quotesEscape|crlfEscape|queryEscape}}"},{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]' ## when copypaste the line be aware of '$$' for escaping in '$expr'
+      # when copypaste the line be aware of '$$' for escaping in '$expr'
+      - '--external.alert.source=explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":{{$$expr|jsonEscape|queryEscape}} },{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]'
    networks:
      - vm_net
    restart: always
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@ -15,9 +15,12 @@ The following tip changes can be tested by building VictoriaMetrics components f

 ## v1.79.x long-time support release (LTS)

+**Update note 1:** [vmalert](https://docs.victoriametrics.com/vmalert.html): the `crlfEscape` [template function](https://docs.victoriametrics.com/vmalert.html#template-functions) becames obsolete starting from this release. It can be safely removed from alerting templates, since `\n` chars are properly escaped with other `*Escape` functions now. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3139) and [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890) issue for details.
+
 * SECURITY: update Go builder to v1.19.3. This fixes [CVE-2022 security issue](https://github.com/golang/go/issues/56328). See [the changelog](https://github.com/golang/go/issues?q=milestone%3AGo1.19.3+label%3ACherryPickApproved).

 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): change severity level for log messages about failed attempts for sending data to remote storage from `error` to `warn`. The message for about all failed send attempts remains at `error` severity level.
+* BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): properly escape string passed to `quotesEscape` [template function](https://docs.victoriametrics.com/vmalert.html#template-functions), so it can be safely embedded into JSON string. This makes obsolete the `crlfEscape` function. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3139) and [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/890) issue.
 * BUGFIX: `vmselect`: expose missing metric `vm_cache_size_max_bytes{type="promql/rollupResult"}` . This metric is used for monitoring rollup cache usage with the query `vm_cache_size_bytes{type="promql/rollupResult"} / vm_cache_size_max_bytes{type="promql/rollupResult"}` in the same way as this is done for other cache types.


--- a/docs/vmalert.md
+++ b/docs/vmalert.md
@ -679,8 +679,8 @@ The shortlist of configuration flags is the following:
  -evaluationInterval duration
     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\": \"{{$expr|quotesEscape|crlfEscape|queryEscape}}\"},{\"mode\":\"Metrics\"},{\"ui\":[true,true,true,\"none\"]}]'.If empty '/vmalert/api/v1/alert?group_id=&alert_id=' is used
+     External Alert Source allows to override the Source link for alerts sent to AlertManager for cases where you want to build a custom link to Grafana, Prometheus or any other service. Supports templating - see https://docs.victoriametrics.com/vmalert.html#templating . For example, link to Grafana: -external.alert.source='explore?orgId=1&left=["now-1h","now","VictoriaMetrics",{"expr":{{$expr|jsonEscape|queryEscape}} },{"mode":"Metrics"},{"ui":[true,true,true,"none"]}]' . If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' is used
+     If empty 'vmalert/alert?group_id={{.GroupID}}&alert_id={{.AlertID}}' 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 an array of values separated by comma or specified via multiple flags.