httpjson: support configurable response_timeout (#1651)

* httpjson: support configurable response_timeout

* make default ResponseTimeout in init

* Update CHANGELOG.md

CHANGELOG.md

@@ -101,6 +101,7 @@ consistent with the behavior of `collection_jitter`.
 - [#1278](https://github.com/influxdata/telegraf/pull/1278) & [#1288](https://github.com/influxdata/telegraf/pull/1288) & [#1295](https://github.com/influxdata/telegraf/pull/1295): RabbitMQ/Apache/InfluxDB inputs: made url(s) parameter optional by using reasonable input defaults if not specified
 - [#1296](https://github.com/influxdata/telegraf/issues/1296): Refactor of flush_jitter argument.
 - [#1213](https://github.com/influxdata/telegraf/issues/1213): Add inactive & active memory to mem plugin.
+- [#1650](https://github.com/influxdata/telegraf/issues/1650): Ability to configure response_timeout in httpjson input.
 - [#1543](https://github.com/influxdata/telegraf/pull/1543): Official Windows service.
 - [#1414](https://github.com/influxdata/telegraf/pull/1414): Forking sensors command to remove C package dependency.
 - [#1389](https://github.com/influxdata/telegraf/pull/1389): Add a new SNMP plugin.

plugins/inputs/httpjson/README.md

@@ -2,8 +2,7 @@
 
 The httpjson plugin can collect data from remote URLs which respond with JSON. Then it flattens JSON and finds all numeric values, treating them as floats.
 
-For example, if you have a service called _mycollector_, which has HTTP endpoint for gathering stats at http://my.service.com/_stats, you would configure the HTTP JSON
+For example, if you have a service called _mycollector_, which has HTTP endpoint for gathering stats at http://my.service.com/_stats, you would configure the HTTP JSON plugin like this:
-plugin like this:
 
 ```
 [[inputs.httpjson]]
@@ -15,12 +14,17 @@ plugin like this:
 
   # HTTP method to use (case-sensitive)
   method = "GET"
+
+  # Set response_timeout (default 5 seconds)
+  response_timeout = "5s"
 ```
 
 `name` is used as a prefix for the measurements.
 
 `method` specifies HTTP method to use for requests.
 
+`response_timeout` specifies timeout to wait to get the response
+
 You can also specify which keys from server response should be considered tags:
 
 ```
@@ -94,8 +98,7 @@ httpjson_mycollector_b_e,service='service01',server='http://my.service.com/_stat
 
 # Example 2, Multiple Services:
 
-There is also the option to collect JSON from multiple services, here is an
+There is also the option to collect JSON from multiple services, here is an example doing that.
-example doing that.
 
 ```
 [[inputs.httpjson]]

plugins/inputs/httpjson/httpjson.go

@@ -16,11 +16,13 @@ import (
 	"github.com/influxdata/telegraf/plugins/parsers"
 )
 
+// HttpJson struct
 type HttpJson struct {
 	Name            string
 	Servers         []string
 	Method          string
 	TagKeys         []string
+	ResponseTimeout internal.Duration
 	Parameters      map[string]string
 	Headers         map[string]string
 
@@ -79,6 +81,8 @@ var sampleConfig = `
     "http://localhost:9999/stats/",
     "http://localhost:9998/stats/",
   ]
+  ## Set response_timeout (default 5 seconds)
+  response_timeout = "5s"
 
   ## HTTP method to use: GET or POST (case-sensitive)
   method = "GET"
@@ -126,12 +130,12 @@ func (h *HttpJson) Gather(acc telegraf.Accumulator) error {
 			return err
 		}
 		tr := &http.Transport{
-			ResponseHeaderTimeout: time.Duration(3 * time.Second),
+			ResponseHeaderTimeout: h.ResponseTimeout.Duration,
 			TLSClientConfig:       tlsCfg,
 		}
 		client := &http.Client{
 			Transport: tr,
-			Timeout:   time.Duration(4 * time.Second),
+			Timeout:   h.ResponseTimeout.Duration,
 		}
 		h.client.SetHTTPClient(client)
 	}
@@ -291,6 +295,9 @@ func init() {
 	inputs.Add("httpjson", func() telegraf.Input {
 		return &HttpJson{
 			client: &RealHTTPClient{},
+			ResponseTimeout: internal.Duration{
+				Duration: 5 * time.Second,
+			},
 		}
 	})
 }