add output prometheus-sd (service discovery)

cmd/config_test.go

@@ -27,7 +27,7 @@ func TestReadConfig(t *testing.T) {
 	assert.Contains(config.Respondd.Sites["ffhb"].Domains, "city")
 
 	// Test output plugins
-	assert.Len(config.Nodes.Output, 5)
+	assert.Len(config.Nodes.Output, 6)
 	outputs := config.Nodes.Output["meshviewer"].([]map[string]interface{})
 	assert.Len(outputs, 1)
 	meshviewer := outputs[0]

config_example.toml

@@ -158,6 +158,16 @@ path = "/var/www/html/meshviewer/data/nodelist.json"
 # WARNING: if it is not set, it will publish contact information of other persons
 no_owner = true
 
+# definition for prometheus-sd.json
+[[nodes.output.prometheus-sd]]
+enable  = true
+path    = "/var/www/html/meshviewer/data/prometheus-sd.json"
+# ip = lates recieved ip, node_id = node id from host
+target_address = "ip"
+
+[nodes.output.prometheus-sd.labels]
+hosts   = "ffhb"
+service = "yanic"
 
 # definition for raw.json
 [[nodes.output.raw]]

output/all/main.go

@@ -5,6 +5,7 @@ import (
 	_ "yanic/output/meshviewer"
 	_ "yanic/output/meshviewer-ffrgb"
 	_ "yanic/output/nodelist"
+	_ "yanic/output/prometheus-sd"
 	_ "yanic/output/raw"
 	_ "yanic/output/raw-jsonl"
 )

output/prometheus-sd/output.go

@@ -0,0 +1,93 @@
+package prometheus_sd
+
+import (
+	"errors"
+
+	"yanic/output"
+	"yanic/runtime"
+)
+
+type Output struct {
+	output.Output
+	path       string
+	targetType TargetAddressType
+	labels     map[string]interface{}
+}
+
+type Config map[string]interface{}
+
+func (c Config) Path() string {
+	if path, ok := c["path"]; ok {
+		return path.(string)
+	}
+	return ""
+}
+
+type TargetAddressType string
+
+const (
+	TargetAddressIP     TargetAddressType = "ip"
+	TargetAddressNodeID TargetAddressType = "node_id"
+)
+
+func (c Config) TargetAddress() TargetAddressType {
+	if v, ok := c["target_address"]; ok {
+		return TargetAddressType(v.(string))
+	}
+	return TargetAddressIP
+}
+
+func (c Config) Labels() map[string]interface{} {
+	if v, ok := c["labels"]; ok {
+		return v.(map[string]interface{})
+	}
+	return nil
+}
+
+func init() {
+	output.RegisterAdapter("prometheus-sd", Register)
+}
+
+func Register(configuration map[string]interface{}) (output.Output, error) {
+	config := Config(configuration)
+
+	if path := config.Path(); path != "" {
+		return &Output{
+			path:       path,
+			targetType: config.TargetAddress(),
+			labels:     config.Labels(),
+		}, nil
+	}
+	return nil, errors.New("no path given")
+
+}
+
+type Targets struct {
+	Targets []string               `json:"targets"`
+	Labels  map[string]interface{} `json:"labels,omitempty"`
+}
+
+func (o *Output) Save(nodes *runtime.Nodes) {
+	nodes.RLock()
+	defer nodes.RUnlock()
+
+	targets := &Targets{
+		Targets: []string{},
+		Labels:  o.labels,
+	}
+	if o.targetType == TargetAddressNodeID {
+		for _, n := range nodes.List {
+			if ni := n.Nodeinfo; ni != nil {
+				targets.Targets = append(targets.Targets, ni.NodeID)
+			}
+		}
+	} else {
+		for _, n := range nodes.List {
+			if addr := n.Address; addr != nil {
+				targets.Targets = append(targets.Targets, addr.IP.String())
+			}
+		}
+	}
+
+	runtime.SaveJSON([]interface{}{targets}, o.path)
+}

output/prometheus-sd/output_test.go

@@ -0,0 +1,28 @@
+package prometheus_sd
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"yanic/runtime"
+)
+
+func TestOutput(t *testing.T) {
+	assert := assert.New(t)
+
+	out, err := Register(map[string]interface{}{})
+	assert.Error(err)
+	assert.Nil(out)
+
+	out, err = Register(map[string]interface{}{
+		"path": "/tmp/prometheus_sd.json",
+	})
+	os.Remove("/tmp/prometheus_sd.json")
+	assert.NoError(err)
+	assert.NotNil(out)
+
+	out.Save(&runtime.Nodes{})
+	_, err = os.Stat("/tmp/prometheus_sd.json")
+	assert.NoError(err)
+}