package sinks import ( "encoding/json" "fmt" "log" cclog "github.com/ClusterCockpit/cc-metric-collector/pkg/ccLogger" lp "github.com/ClusterCockpit/cc-metric-collector/pkg/ccMetric" ) type SampleSinkConfig struct { // defines JSON tags for 'type' and 'meta_as_tags' (string list) // See: metricSink.go defaultSinkConfig // Additional config options, for SampleSink } type SampleSink struct { // declares elements 'name' and 'meta_as_tags' (string to bool map!) sink config SampleSinkConfig // entry point to the SampleSinkConfig } // Implement functions required for Sink interface // Write(...), Flush(), Close() // See: metricSink.go // Code to submit a single CCMetric to the sink func (s *SampleSink) Write(point lp.CCMetric) error { // based on s.meta_as_tags use meta infos as tags log.Print(point) return nil } // If the sink uses batched sends internally, you can tell to flush its buffers func (s *SampleSink) Flush() error { return nil } // Close sink: close network connection, close files, close libraries, ... func (s *SampleSink) Close() { cclog.ComponentDebug(s.name, "CLOSE") } // New function to create a new instance of the sink // Initialize the sink by giving it a name and reading in the config JSON func NewSampleSink(name string, config json.RawMessage) (Sink, error) { s := new(SampleSink) // Set name of sampleSink // The name should be chosen in such a way that different instances of SampleSink can be distinguished s.name = fmt.Sprintf("SampleSink(%s)", name) // Always specify a name here // Set defaults in s.config // Allow overwriting these defaults by reading config JSON // Read in the config JSON if len(config) > 0 { err := json.Unmarshal(config, &s.config) if err != nil { return nil, err } } // Create lookup map to use meta infos as tags in the output metric s.meta_as_tags = make(map[string]bool) for _, k := range s.config.MetaAsTags { s.meta_as_tags[k] = true } // Check if all required fields in the config are set // E.g. use 'len(s.config.Option) > 0' for string settings // Establish connection to the server, library, ... // Check required files exist and lookup path(s) of executable(s) // Return (nil, meaningful error message) in case of errors return s, nil }