Add missing backend.{name}.* variables

__generator__/predefined.yml

@@ -182,6 +182,21 @@ backend.socket.tcpi_total_retrans:
   on: [FETCH]
   get: INTEGER
 
+backend.%any%.connections_open:
+  reference: "https://www.fastly.com/documentation/reference/vcl/variables/backend-connection/backend-connections-open/"
+  on: [RECV, HASH, HIT, MISS, PASS, FETCH, ERROR, DELIVER, LOG]
+  get: INTEGER
+
+backend.%any%.connections_used:
+  reference: "https://www.fastly.com/documentation/reference/vcl/variables/backend-connection/backend-connections-used/"
+  on: [RECV, HASH, HIT, MISS, PASS, FETCH, ERROR, DELIVER, LOG]
+  get: INTEGER
+
+backend.%any%.healthy:
+  reference: "https://developer.fastly.com/reference/vcl/variables/backend-connection/backend-healthy/"
+  on: [RECV, HASH, HIT, MISS, PASS, FETCH, ERROR, DELIVER, LOG]
+  get: INTEGER
+
 bereq.between_bytes_timeout:
   reference: "https://developer.fastly.com/reference/vcl/variables/backend-connection/bereq-between-bytes-timeout/"
   on: [PASS, MISS]

docs/variables.md

@@ -97,6 +97,9 @@ Will be updated when we find or implement a way to get accurate values.
 | backend.socket.tcpi_snd_mss                | 0                                  |
 | backend.socket.tcpi_snd_ssthresh           | 0                                  |
 | backend.socket.tcpi_total_retrans          | 0                                  |
+| backend.{name}.connections_open            | 0                                  |
+| backend.{name}.connections_used            | 0                                  |
+| backend.{name}.healthy                     | true                               |
 | beresp.backend.alternate_ips               | (empty string)                     |
 | beresp.backend.ip                          | 0                                  |
 | beresp.backend.requests                    | 1                                  |

interpreter/variable/all.go

@@ -664,6 +664,19 @@ func (v *AllScopeVariables) getFromRegex(name string) value.Value {
 			Value: val,
 		}
 	}
+
+	if match := backendConnectionsOpenRegex.FindStringSubmatch(name); match != nil {
+		return &value.Integer{}
+	}
+
+	if match := backendConnectionsUsedRegex.FindStringSubmatch(name); match != nil {
+		return &value.Integer{}
+	}
+
+	if match := backendHealthyRegex.FindStringSubmatch(name); match != nil {
+		return &value.Boolean{Value: true}
+	}
+
 	return nil
 }
 

interpreter/variable/variable.go

@@ -23,6 +23,9 @@ var (
 	objectHttpHeaderRegex          = regexp.MustCompile(`^obj\.http\.(.+)`)
 	rateCounterRegex               = regexp.MustCompile(`ratecounter\.([^\.]+)\.(.+)`)
 	regexMatchedRegex              = regexp.MustCompile(`re\.group\.([0-9]+)`)
+	backendConnectionsOpenRegex    = regexp.MustCompile(`backend\.([^\.]+)\.connections_open`)
+	backendConnectionsUsedRegex    = regexp.MustCompile(`backend\.([^\.]+)\.connections_used`)
+	backendHealthyRegex            = regexp.MustCompile(`backend\.([^\.]+)\.healthy`)
 )
 
 func doAssign(left value.Value, operator string, right value.Value) error {