Add filtering options to select plugin at startup

agent.go

@@ -99,8 +99,14 @@ func (a *Agent) Connect() error {
 }
 
 // LoadPlugins loads the agent's plugins
-func (a *Agent) LoadPlugins() ([]string, error) {
+func (a *Agent) LoadPlugins(pluginsFilter string) ([]string, error) {
 	var names []string
+	var filters []string
+
+	pluginsFilter = strings.TrimSpace(pluginsFilter)
+	if pluginsFilter != "" {
+		filters = strings.Split(":"+pluginsFilter+":", ":")
+	}
 
 	for _, name := range a.Config.PluginsDeclared() {
 		creator, ok := plugins.Plugins[name]
@@ -108,15 +114,31 @@ func (a *Agent) LoadPlugins() ([]string, error) {
 			return nil, fmt.Errorf("Undefined but requested plugin: %s", name)
 		}
 
-		plugin := creator()
 
-		config, err := a.Config.ApplyPlugin(name, plugin)
-		if err != nil {
-			return nil, err
+		isPluginEnabled := false
+		if len(filters)>0 {
+			for _, runeValue := range filters {
+				if runeValue != "" && strings.ToLower(runeValue) == strings.ToLower(name) {
+					fmt.Printf("plugin [%s] is enabled (filter options)\n", name)
+					isPluginEnabled = true
+					break
+				}
+			}
+		} else {
+			// if no filter, we ALWAYS accept the plugin
+			isPluginEnabled = true
 		}
 
-		a.plugins = append(a.plugins, &runningPlugin{name, plugin, config})
-		names = append(names, name)
+		if isPluginEnabled {
+			plugin := creator()
+			config, err := a.Config.ApplyPlugin(name, plugin)
+			if err != nil {
+				return nil, err
+			}
+
+			a.plugins = append(a.plugins, &runningPlugin{name, plugin, config})
+			names = append(names, name)
+		}
 	}
 
 	sort.Strings(names)

agent_test.go

@@ -1,5 +1,47 @@
 package telegraf
 
+import (
+	"testing"
+	"github.com/stretchr/testify/assert"
+
+// needing to load the plugins
+	_ "github.com/influxdb/telegraf/plugins/all"
+)
+
+func TestAgent_LoadPlugin(t *testing.T) {
+
+	// load a dedicated configuration file
+	config, _ := LoadConfig("./testdata/telegraf-agent.toml")
+	a, _ := NewAgent(config)
+
+	pluginsEnabled, _ := a.LoadPlugins("mysql")
+	assert.Equal(t, 1, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("foo")
+	assert.Equal(t, 0, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("mysql:foo")
+	assert.Equal(t, 1, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("mysql:redis")
+	assert.Equal(t, 2, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins(":mysql:foo:redis:bar")
+	assert.Equal(t, 2, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("")
+	assert.Equal(t, 24, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins(" ")
+	assert.Equal(t, 24, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("		")
+	assert.Equal(t, 24, len(pluginsEnabled))
+
+	pluginsEnabled, _ = a.LoadPlugins("\n\t")
+	assert.Equal(t, 24, len(pluginsEnabled))
+}
+
 /*
 func TestAgent_DrivesMetrics(t *testing.T) {
 	var (
@@ -58,4 +100,4 @@ func TestAgent_AppliesTags(t *testing.T) {
 	err := a.crank()
 	require.NoError(t, err)
 }
-*/
+*/

cmd/telegraf/telegraf.go

@@ -18,6 +18,7 @@ var fConfig = flag.String("config", "", "configuration file to load")
 var fVersion = flag.Bool("version", false, "display the version")
 var fSampleConfig = flag.Bool("sample-config", false, "print out full sample configuration")
 var fPidfile = flag.String("pidfile", "", "file to write our pid to")
+var fPLuginsFilter = flag.String("filter", "", "filter the plugins to enable, separator is :")
 
 // Telegraf version
 var Version = "unreleased"
@@ -61,7 +62,7 @@ func main() {
 		ag.Debug = true
 	}
 
-	plugins, err := ag.LoadPlugins()
+	plugins, err := ag.LoadPlugins(*fPLuginsFilter)
 	if err != nil {
 		log.Fatal(err)
 	}

testdata/telegraf-agent.toml

@@ -0,0 +1,269 @@
+# Telegraf configuration
+
+# If this file is missing an [agent] section, you must first generate a
+# valid config with 'telegraf -sample-config > telegraf.toml'
+
+# Telegraf is entirely plugin driven. All metrics are gathered from the
+# declared plugins.
+
+# Even if a plugin has no configuration, it must be declared in here
+# to be active. Declaring a plugin means just specifying the name
+# as a section with no variables. To deactivate a plugin, comment
+# out the name and any variables.
+
+# Use 'telegraf -config telegraf.toml -test' to see what metrics a config
+# file would generate.
+
+# One rule that plugins conform to is wherever a connection string
+# can be passed, the values '' and 'localhost' are treated specially.
+# They indicate to the plugin to use their own builtin configuration to
+# connect to the local system.
+
+# NOTE: The configuration has a few required parameters. They are marked
+# with 'required'. Be sure to edit those to make this configuration work.
+
+# Configuration for influxdb server to send metrics to
+[influxdb]
+# The full HTTP endpoint URL for your InfluxDB instance
+url = "http://localhost:8086" # required.
+
+# The target database for metrics. This database must already exist
+database = "telegraf" # required.
+
+# Connection timeout (for the connection with InfluxDB), formatted as a string.
+# Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
+# If not provided, will default to 0 (no timeout)
+# timeout = "5s"
+
+# username = "telegraf"
+# password = "metricsmetricsmetricsmetrics"
+
+# Set the user agent for the POSTs (can be useful for log differentiation)
+# user_agent = "telegraf"
+# tags = { "dc": "us-east-1" }
+
+# Tags can also be specified via a normal map, but only one form at a time:
+
+# [influxdb.tags]
+# dc = "us-east-1"
+
+# Configuration for telegraf itself
+# [agent]
+# interval = "10s"
+# debug = false
+# hostname = "prod3241"
+
+# PLUGINS
+
+# Read metrics about cpu usage
+[cpu]
+  # no configuration
+
+# Read metrics about disk usage by mount point
+[disk]
+  # no configuration
+
+# Read metrics from one or many disque servers
+[disque]
+
+# An array of URI to gather stats about. Specify an ip or hostname
+# with optional port and password. ie disque://localhost, disque://10.10.3.33:18832,
+# 10.0.0.1:10000, etc.
+#
+# If no servers are specified, then localhost is used as the host.
+servers = ["localhost"]
+
+# Read metrics about docker containers
+[docker]
+  # no configuration
+
+# Read stats from one or more Elasticsearch servers or clusters
+[elasticsearch]
+
+# specify a list of one or more Elasticsearch servers
+servers = ["http://localhost:9200"]
+
+# set local to false when you want to read the indices stats from all nodes
+# within the cluster
+local = true
+
+# Read flattened metrics from one or more commands that output JSON to stdout
+[exec]
+
+# specify commands via an array of tables
+[[exec.commands]]
+# the command to run
+command = "/usr/bin/mycollector --foo=bar"
+
+# name of the command (used as a prefix for measurements)
+name = "mycollector"
+
+# Read metrics of haproxy, via socket or csv stats page
+[haproxy]
+
+# An array of address to gather stats about. Specify an ip on hostname
+# with optional port. ie localhost, 10.10.3.33:1936, etc.
+#
+# If no servers are specified, then default to 127.0.0.1:1936
+servers = ["http://myhaproxy.com:1936", "http://anotherhaproxy.com:1936"]
+# Or you can also use local socket(not work yet)
+# servers = ["socket:/run/haproxy/admin.sock"]
+
+# Read metrics about disk IO by device
+[io]
+  # no configuration
+
+# read metrics from a Kafka topic
+[kafka]
+
+# topic to consume
+topic = "topic_with_metrics"
+
+# the name of the consumer group
+consumerGroupName = "telegraf_metrics_consumers"
+
+# an array of Zookeeper connection strings
+zookeeperPeers = ["localhost:2181"]
+
+# Batch size of points sent to InfluxDB
+batchSize = 1000
+
+# Read metrics from a LeoFS Server via SNMP
+[leofs]
+
+# An array of URI to gather stats about LeoFS.
+# Specify an ip or hostname with port. ie 127.0.0.1:4020
+#
+# If no servers are specified, then 127.0.0.1 is used as the host and 4020 as the port.
+servers = ["127.0.0.1:4021"]
+
+# Read metrics from local Lustre service on OST, MDS
+[lustre2]
+
+# An array of /proc globs to search for Lustre stats
+# If not specified, the default will work on Lustre 2.5.x
+#
+# ost_procfiles = ["/proc/fs/lustre/obdfilter/*/stats", "/proc/fs/lustre/osd-ldiskfs/*/stats"]
+# mds_procfiles = ["/proc/fs/lustre/mdt/*/md_stats"]
+
+# Read metrics about memory usage
+[mem]
+  # no configuration
+
+# Read metrics from one or many memcached servers
+[memcached]
+
+# An array of address to gather stats about. Specify an ip on hostname
+# with optional port. ie localhost, 10.0.0.1:11211, etc.
+#
+# If no servers are specified, then localhost is used as the host.
+servers = ["localhost"]
+
+# Read metrics from one or many MongoDB servers
+[mongodb]
+
+# An array of URI to gather stats about. Specify an ip or hostname
+# with optional port add password. ie mongodb://user:auth_key@10.10.3.30:27017,
+# mongodb://10.10.3.33:18832, 10.0.0.1:10000, etc.
+#
+# If no servers are specified, then 127.0.0.1 is used as the host and 27107 as the port.
+servers = ["127.0.0.1:27017"]
+
+# Read metrics from one or many mysql servers
+[mysql]
+
+# specify servers via a url matching:
+#  [username[:password]@][protocol[(address)]]/[?tls=[true|false|skip-verify]]
+#  e.g. root:root@http://10.0.0.18/?tls=false
+#
+# If no servers are specified, then localhost is used as the host.
+servers = ["localhost"]
+
+# Read metrics about network interface usage
+[net]
+
+# By default, telegraf gathers stats from any up interface (excluding loopback)
+# Setting interfaces will tell it to gather these explicit interfaces,
+# regardless of status.
+#
+# interfaces = ["eth0", ... ]
+
+# Read Nginx's basic status information (ngx_http_stub_status_module)
+[nginx]
+
+# An array of Nginx stub_status URI to gather stats.
+urls = ["localhost/status"]
+
+# Read metrics from one or many postgresql servers
+[postgresql]
+
+# specify servers via an array of tables
+[[postgresql.servers]]
+
+# specify address via a url matching:
+#   postgres://[pqgotest[:password]]@localhost?sslmode=[disable|verify-ca|verify-full]
+# or a simple string:
+#   host=localhost user=pqotest password=... sslmode=...
+# 
+# All connection parameters are optional. By default, the host is localhost
+# and the user is the currently running user. For localhost, we default
+# to sslmode=disable as well.
+# 
+
+address = "sslmode=disable"
+
+# A list of databases to pull metrics about. If not specified, metrics for all
+# databases are gathered.
+
+# databases = ["app_production", "blah_testing"]
+
+# [[postgresql.servers]]
+# address = "influx@remoteserver"
+
+# Read metrics from one or many prometheus clients
+[prometheus]
+
+# An array of urls to scrape metrics from.
+urls = ["http://localhost:9100/metrics"]
+
+# Read metrics from one or many RabbitMQ servers via the management API
+[rabbitmq]
+
+# Specify servers via an array of tables
+[[rabbitmq.servers]]
+# url = "http://localhost:15672"
+# username = "guest"
+# password = "guest"
+
+# A list of nodes to pull metrics about. If not specified, metrics for
+# all nodes are gathered.
+# nodes = ["rabbit@node1", "rabbit@node2"]
+
+# Read metrics from one or many redis servers
+[redis]
+
+# An array of URI to gather stats about. Specify an ip or hostname
+# with optional port add password. ie redis://localhost, redis://10.10.3.33:18832,
+# 10.0.0.1:10000, etc.
+#
+# If no servers are specified, then localhost is used as the host.
+servers = ["localhost"]
+
+# Read metrics from one or many RethinkDB servers
+[rethinkdb]
+
+# An array of URI to gather stats about. Specify an ip or hostname
+# with optional port add password. ie rethinkdb://user:auth_key@10.10.3.30:28105,
+# rethinkdb://10.10.3.33:18832, 10.0.0.1:10000, etc.
+#
+# If no servers are specified, then 127.0.0.1 is used as the host and 28015 as the port.
+servers = ["127.0.0.1:28015"]
+
+# Read metrics about swap memory usage
+[swap]
+  # no configuration
+
+# Read metrics about system load
+[system]
+  # no configuration
+