fix: change name of snmp translator setting (#10872)

CHANGELOG.md

@@ -2,6 +2,21 @@
 
 # Changelog
 
+## v1.22.0
+
+This version introduces an agent setting to select the method of
+translating SNMP objects. The agent setting "snmp_translator" can be
+"netsnmp" which translates by calling external programs snmptranslate
+and snmptable, or "gosmi" which translates using the built-in gosmi
+library.
+
+Before version 1.21.0, Telegraf only used the netsnmp method. Versions
+1.21.0 through 1.21.4 only used the gosmi method. Since the
+translation method is now configurable and "netsnmp" is the default,
+users who wish to continue using "gosmi" must add `snmp_translator =
+"gosmi"` in the agent section of their config file. See
+[#10802](https://github.com/influxdata/telegraf/pull/10802).
+
 ## v1.21.4 [2022-02-16]
 
 ### Bugfixes

agent/agent.go

@@ -189,7 +189,7 @@ func (a *Agent) initPlugins() error {
 	for _, input := range a.Config.Inputs {
 		// Share the snmp translator setting with plugins that need it.
 		if tp, ok := input.Input.(snmp.TranslatorPlugin); ok {
-			tp.SetTranslator(a.Config.Agent.Translator)
+			tp.SetTranslator(a.Config.Agent.SnmpTranslator)
 		}
 		err := input.Init()
 		if err != nil {

config/config.go

@@ -226,7 +226,9 @@ type AgentConfig struct {
 	Hostname     string
 	OmitHostname bool
 
-	Translator string `toml:"translator"`
+	// Method for translating SNMP objects. 'netsnmp' to call external programs,
+	// 'gosmi' to use the built-in library.
+	SnmpTranslator string `toml:"snmp_translator"`
 }
 
 // InputNames returns a list of strings of the configured inputs.
@@ -421,10 +423,10 @@ var agentConfig = `
   ## If set to true, do no set the "host" tag in the telegraf agent.
   omit_hostname = false
 
-  ## Translator for SNMP OIDs
+  ## Method of translating SNMP objects. Can be "netsnmp" which
-  ## Valid values are "netsnmp" which runs snmptranslate and snmptable,
+  ## translates by calling external programs snmptranslate and snmptable,
-  ## and "gosmi" which uses the gosmi library.
+  ## or "gosmi" which translates using the built-in gosmi library.
-  # translator = "netsnmp"
+  # snmp_translator = "netsnmp"
 `
 
 var outputHeader = `
@@ -863,8 +865,8 @@ func (c *Config) LoadConfigData(data []byte) error {
 	}
 
 	// Set snmp agent translator default
-	if c.Agent.Translator == "" {
+	if c.Agent.SnmpTranslator == "" {
-		c.Agent.Translator = "netsnmp"
+		c.Agent.SnmpTranslator = "netsnmp"
 	}
 
 	if len(c.UnusedFields) > 0 {

docs/CONFIGURATION.md

@@ -242,9 +242,15 @@ The agent table configures Telegraf and the defaults used across all plugins.
 
 - **hostname**:
   Override default hostname, if empty use os.Hostname()
+
 - **omit_hostname**:
   If set to true, do no set the "host" tag in the telegraf agent.
 
+- **snmp_translator**:
+  Method of translating SNMP objects. Can be "netsnmp" which
+  translates by calling external programs snmptranslate and snmptable,
+  or "gosmi" which translates using the built-in gosmi library.
+
 ## Plugins
 
 Telegraf plugins are divided into 4 types: [inputs][], [outputs][],