Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/common/shim/config.go

@@ -0,0 +1,170 @@
+package shim
+
+import (
+	"errors"
+	"fmt"
+	"log" //nolint:depguard // Allow exceptional but valid use of log here.
+	"os"
+
+	"github.com/BurntSushi/toml"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/influxdata/telegraf/plugins/outputs"
+	"github.com/influxdata/telegraf/plugins/processors"
+)
+
+type config struct {
+	Inputs     map[string][]toml.Primitive
+	Processors map[string][]toml.Primitive
+	Outputs    map[string][]toml.Primitive
+}
+
+type loadedConfig struct {
+	Input     telegraf.Input
+	Processor telegraf.StreamingProcessor
+	Output    telegraf.Output
+}
+
+// LoadConfig Adds plugins to the shim
+func (s *Shim) LoadConfig(filePath *string) error {
+	conf, err := LoadConfig(filePath)
+	if err != nil {
+		return err
+	}
+	if conf.Input != nil {
+		if err = s.AddInput(conf.Input); err != nil {
+			return fmt.Errorf("failed to add Input: %w", err)
+		}
+	} else if conf.Processor != nil {
+		if err = s.AddStreamingProcessor(conf.Processor); err != nil {
+			return fmt.Errorf("failed to add Processor: %w", err)
+		}
+	} else if conf.Output != nil {
+		if err = s.AddOutput(conf.Output); err != nil {
+			return fmt.Errorf("failed to add Output: %w", err)
+		}
+	}
+	return nil
+}
+
+// LoadConfig loads the config and returns inputs that later need to be loaded.
+func LoadConfig(filePath *string) (loaded loadedConfig, err error) {
+	var data string
+	conf := config{}
+	if filePath != nil && *filePath != "" {
+		b, err := os.ReadFile(*filePath)
+		if err != nil {
+			return loadedConfig{}, err
+		}
+
+		data = expandEnvVars(b)
+	} else {
+		conf = DefaultImportedPlugins()
+	}
+
+	md, err := toml.Decode(data, &conf)
+	if err != nil {
+		return loadedConfig{}, err
+	}
+
+	return createPluginsWithTomlConfig(md, conf)
+}
+
+func expandEnvVars(contents []byte) string {
+	return os.Expand(string(contents), getEnv)
+}
+
+func getEnv(key string) string {
+	v := os.Getenv(key)
+
+	return envVarEscaper.Replace(v)
+}
+
+func createPluginsWithTomlConfig(md toml.MetaData, conf config) (loadedConfig, error) {
+	loadedConf := loadedConfig{}
+
+	for name, primitives := range conf.Inputs {
+		creator, ok := inputs.Inputs[name]
+		if !ok {
+			return loadedConf, errors.New("unknown input " + name)
+		}
+
+		plugin := creator()
+		if len(primitives) > 0 {
+			primitive := primitives[0]
+			if err := md.PrimitiveDecode(primitive, plugin); err != nil {
+				return loadedConf, err
+			}
+		}
+
+		loadedConf.Input = plugin
+		break
+	}
+
+	for name, primitives := range conf.Processors {
+		creator, ok := processors.Processors[name]
+		if !ok {
+			return loadedConf, errors.New("unknown processor " + name)
+		}
+
+		plugin := creator()
+		if len(primitives) > 0 {
+			primitive := primitives[0]
+			var p telegraf.PluginDescriber = plugin
+			if processor, ok := plugin.(processors.HasUnwrap); ok {
+				p = processor.Unwrap()
+			}
+			if err := md.PrimitiveDecode(primitive, p); err != nil {
+				return loadedConf, err
+			}
+		}
+		loadedConf.Processor = plugin
+		break
+	}
+
+	for name, primitives := range conf.Outputs {
+		creator, ok := outputs.Outputs[name]
+		if !ok {
+			return loadedConf, errors.New("unknown output " + name)
+		}
+
+		plugin := creator()
+		if len(primitives) > 0 {
+			primitive := primitives[0]
+			if err := md.PrimitiveDecode(primitive, plugin); err != nil {
+				return loadedConf, err
+			}
+		}
+		loadedConf.Output = plugin
+		break
+	}
+	return loadedConf, nil
+}
+
+// DefaultImportedPlugins defaults to whatever plugins happen to be loaded and
+// have registered themselves with the registry. This makes loading plugins
+// without having to define a config dead easy.
+func DefaultImportedPlugins() config {
+	conf := config{
+		Inputs:     make(map[string][]toml.Primitive, len(inputs.Inputs)),
+		Processors: make(map[string][]toml.Primitive, len(processors.Processors)),
+		Outputs:    make(map[string][]toml.Primitive, len(outputs.Outputs)),
+	}
+	for name := range inputs.Inputs {
+		log.Println("No config found. Loading default config for plugin", name)
+		conf.Inputs[name] = make([]toml.Primitive, 0)
+		return conf
+	}
+	for name := range processors.Processors {
+		log.Println("No config found. Loading default config for plugin", name)
+		conf.Processors[name] = make([]toml.Primitive, 0)
+		return conf
+	}
+	for name := range outputs.Outputs {
+		log.Println("No config found. Loading default config for plugin", name)
+		conf.Outputs[name] = make([]toml.Primitive, 0)
+		return conf
+	}
+	return conf
+}