Add component discovery.dockerswarm to flow (#5181)

* Add component discovery.dockerswarm to flow

* minor cleanup

* Update docs/sources/flow/reference/components/discovery.dockerswarm.md

Co-authored-by: Robert Fratto <[email protected]>

* improve doc

---------

Co-authored-by: Robert Fratto <[email protected]>

CHANGELOG.md

@@ -32,6 +32,7 @@ Main (unreleased)
   - `discovery.serverset` discovers Serversets stored in Zookeeper. (@thampiotr)
   - `discovery.scaleway` discovers scrape targets from Scaleway virtual
     instances and bare-metal machines. (@rfratto)
+  - `discovery.dockerswarm` discovers scrape targets from Docker Swarm. (@wildum)
   - `otelcol.processor.probabilistic_sampler` samples logs and traces based on configuration options. (@mar4uk)
   - `remote.kubernetes.configmap` loads a configmap's data for use in other components (@captncraig)
   - `remote.kubernetes.secret` loads a secret's data for use in other components (@captncraig)

component/all/all.go

@@ -9,6 +9,7 @@ import (
 	_ "github.com/grafana/agent/component/discovery/digitalocean"                   // Import discovery.digitalocean
 	_ "github.com/grafana/agent/component/discovery/dns"                            // Import discovery.dns
 	_ "github.com/grafana/agent/component/discovery/docker"                         // Import discovery.docker
+	_ "github.com/grafana/agent/component/discovery/dockerswarm"                    // Import discovery.dockerswarm
 	_ "github.com/grafana/agent/component/discovery/eureka"                         // Import discovery.eureka
 	_ "github.com/grafana/agent/component/discovery/file"                           // Import discovery.file
 	_ "github.com/grafana/agent/component/discovery/gce"                            // Import discovery.gce

component/discovery/dockerswarm/dockerswarm.go

@@ -0,0 +1,104 @@
+package dockerswarm
+
+import (
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/grafana/agent/component"
+	"github.com/grafana/agent/component/common/config"
+	"github.com/grafana/agent/component/discovery"
+	"github.com/prometheus/common/model"
+	prom_discovery "github.com/prometheus/prometheus/discovery/moby"
+)
+
+func init() {
+	component.Register(component.Registration{
+		Name:    "discovery.dockerswarm",
+		Args:    Arguments{},
+		Exports: discovery.Exports{},
+
+		Build: func(opts component.Options, args component.Arguments) (component.Component, error) {
+			return New(opts, args.(Arguments))
+		},
+	})
+}
+
+type Arguments struct {
+	Host             string                  `river:"host,attr"`
+	Role             string                  `river:"role,attr"`
+	Port             int                     `river:"port,attr,optional"`
+	Filters          []Filter                `river:"filter,block,optional"`
+	RefreshInterval  time.Duration           `river:"refresh_interval,attr,optional"`
+	HTTPClientConfig config.HTTPClientConfig `river:",squash"`
+}
+
+type Filter struct {
+	Name   string   `river:"name,attr"`
+	Values []string `river:"values,attr"`
+}
+
+var DefaultArguments = Arguments{
+	RefreshInterval:  60 * time.Second,
+	Port:             80,
+	HTTPClientConfig: config.DefaultHTTPClientConfig,
+}
+
+// SetToDefault implements river.Defaulter.
+func (a *Arguments) SetToDefault() {
+	*a = DefaultArguments
+}
+
+// Validate implements river.Validator.
+func (a *Arguments) Validate() error {
+	if _, err := url.Parse(a.Host); err != nil {
+		return err
+	}
+	if a.RefreshInterval <= 0 {
+		return fmt.Errorf("refresh_interval must be greater than 0")
+	}
+	switch a.Role {
+	case "services", "nodes", "tasks":
+	default:
+		return fmt.Errorf("invalid role %s, expected tasks, services, or nodes", a.Role)
+	}
+	return a.HTTPClientConfig.Validate()
+}
+
+// Convert converts Arguments into the SDConfig type.
+func (a *Arguments) Convert() *prom_discovery.DockerSwarmSDConfig {
+	return &prom_discovery.DockerSwarmSDConfig{
+		Host:             a.Host,
+		Role:             a.Role,
+		Port:             a.Port,
+		Filters:          convertFilters(a.Filters),
+		RefreshInterval:  model.Duration(a.RefreshInterval),
+		HTTPClientConfig: *a.HTTPClientConfig.Convert(),
+	}
+}
+
+func convertFilters(filters []Filter) []prom_discovery.Filter {
+	promFilters := make([]prom_discovery.Filter, len(filters))
+	for i, filter := range filters {
+		promFilters[i] = filter.convert()
+	}
+	return promFilters
+}
+
+func (f *Filter) convert() prom_discovery.Filter {
+	values := make([]string, len(f.Values))
+	copy(values, f.Values)
+
+	return prom_discovery.Filter{
+		Name:   f.Name,
+		Values: values,
+	}
+}
+
+// New returns a new instance of discovery.dockerswarm component.
+func New(opts component.Options, args Arguments) (*discovery.Component, error) {
+	return discovery.New(opts, args, func(args component.Arguments) (discovery.Discoverer, error) {
+		newArgs := args.(Arguments)
+		return prom_discovery.NewDiscovery(newArgs.Convert(), opts.Logger)
+	})
+}

component/discovery/dockerswarm/dockerswarm_test.go

@@ -0,0 +1,107 @@
+package dockerswarm
+
+import (
+	"testing"
+	"time"
+
+	"github.com/grafana/agent/component/common/config"
+	"github.com/grafana/river"
+	"github.com/grafana/river/rivertypes"
+	promConfig "github.com/prometheus/common/config"
+	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
+	"gotest.tools/assert"
+)
+
+func TestRiverUnmarshal(t *testing.T) {
+	riverCfg := `
+		host = "unix:///var/run/docker.sock"
+		role = "nodes"
+		port = 81
+		filter {
+			name = "n1"
+			values = ["v11", "v12"]
+		}
+		filter {
+			name = "n2"
+			values = ["v21"]
+		}
+		refresh_interval = "12s"
+		basic_auth {
+			username = "username"
+			password = "pass"
+		}
+		`
+
+	var args Arguments
+	err := river.Unmarshal([]byte(riverCfg), &args)
+	require.NoError(t, err)
+	require.ElementsMatch(t, []Filter{{"n1", []string{"v11", "v12"}}, {"n2", []string{"v21"}}}, args.Filters)
+	assert.Equal(t, "unix:///var/run/docker.sock", args.Host)
+	assert.Equal(t, "nodes", args.Role)
+	assert.Equal(t, 81, args.Port)
+	assert.Equal(t, 12*time.Second, args.RefreshInterval)
+	assert.Equal(t, "username", args.HTTPClientConfig.BasicAuth.Username)
+	assert.Equal(t, rivertypes.Secret("pass"), args.HTTPClientConfig.BasicAuth.Password)
+}
+
+func TestConvert(t *testing.T) {
+	riverArgs := Arguments{
+		Host:            "host",
+		Role:            "nodes",
+		Port:            81,
+		Filters:         []Filter{{"n1", []string{"v11", "v12"}}, {"n2", []string{"v21"}}},
+		RefreshInterval: time.Minute,
+		HTTPClientConfig: config.HTTPClientConfig{
+			BasicAuth: &config.BasicAuth{
+				Username: "username",
+				Password: "pass",
+			},
+		},
+	}
+
+	promArgs := riverArgs.Convert()
+	assert.Equal(t, 2, len(promArgs.Filters))
+	assert.Equal(t, "n1", promArgs.Filters[0].Name)
+	require.ElementsMatch(t, []string{"v11", "v12"}, promArgs.Filters[0].Values)
+	assert.Equal(t, "n2", promArgs.Filters[1].Name)
+	require.ElementsMatch(t, []string{"v21"}, promArgs.Filters[1].Values)
+	assert.Equal(t, "host", promArgs.Host)
+	assert.Equal(t, "nodes", promArgs.Role)
+	assert.Equal(t, 81, promArgs.Port)
+	assert.Equal(t, model.Duration(time.Minute), promArgs.RefreshInterval)
+	assert.Equal(t, "username", promArgs.HTTPClientConfig.BasicAuth.Username)
+	assert.Equal(t, promConfig.Secret("pass"), promArgs.HTTPClientConfig.BasicAuth.Password)
+}
+
+func TestValidateRole(t *testing.T) {
+	riverArgs := Arguments{
+		Host:            "host",
+		Role:            "nodes",
+		RefreshInterval: time.Second,
+	}
+	err := riverArgs.Validate()
+	require.NoError(t, err)
+
+	riverArgs.Role = "services"
+	err = riverArgs.Validate()
+	require.NoError(t, err)
+
+	riverArgs.Role = "tasks"
+	err = riverArgs.Validate()
+	require.NoError(t, err)
+
+	riverArgs.Role = "wrong"
+	err = riverArgs.Validate()
+	assert.Error(t, err, "invalid role wrong, expected tasks, services, or nodes")
+}
+
+func TestValidateUrl(t *testing.T) {
+	riverArgs := Arguments{
+		Host:            "::",
+		Role:            "nodes",
+		RefreshInterval: time.Second,
+	}
+	err := riverArgs.Validate()
+	assert.Error(t, err, "parse \"::\": missing protocol scheme")
+}

converter/internal/prometheusconvert/dockerswarm.go

@@ -0,0 +1,56 @@
+package prometheusconvert
+
+import (
+	"time"
+
+	"github.com/grafana/agent/component/discovery"
+	"github.com/grafana/agent/component/discovery/dockerswarm"
+	"github.com/grafana/agent/converter/diag"
+	"github.com/grafana/agent/converter/internal/common"
+	prom_moby "github.com/prometheus/prometheus/discovery/moby"
+)
+
+func appendDiscoveryDockerswarm(pb *prometheusBlocks, label string, sdConfig *prom_moby.DockerSwarmSDConfig) discovery.Exports {
+	discoveryDockerswarmArgs := toDiscoveryDockerswarm(sdConfig)
+	name := []string{"discovery", "dockerswarm"}
+	block := common.NewBlockWithOverride(name, label, discoveryDockerswarmArgs)
+	pb.discoveryBlocks = append(pb.discoveryBlocks, newPrometheusBlock(block, name, label, "", ""))
+	return NewDiscoveryExports("discovery.dockerswarm." + label + ".targets")
+}
+
+func validateDiscoveryDockerswarm(sdConfig *prom_moby.DockerSwarmSDConfig) diag.Diagnostics {
+	return ValidateHttpClientConfig(&sdConfig.HTTPClientConfig)
+}
+
+func toDiscoveryDockerswarm(sdConfig *prom_moby.DockerSwarmSDConfig) *dockerswarm.Arguments {
+	if sdConfig == nil {
+		return nil
+	}
+
+	return &dockerswarm.Arguments{
+		Host:             sdConfig.Host,
+		Role:             sdConfig.Role,
+		Port:             sdConfig.Port,
+		Filters:          convertFilters(sdConfig.Filters),
+		RefreshInterval:  time.Duration(sdConfig.RefreshInterval),
+		HTTPClientConfig: *ToHttpClientConfig(&sdConfig.HTTPClientConfig),
+	}
+}
+
+func convertFilters(mobyFilters []prom_moby.Filter) []dockerswarm.Filter {
+	riverFilters := make([]dockerswarm.Filter, len(mobyFilters))
+	for i, mobyFilter := range mobyFilters {
+		riverFilters[i] = convertFilter(&mobyFilter)
+	}
+	return riverFilters
+}
+
+func convertFilter(mobyFilter *prom_moby.Filter) dockerswarm.Filter {
+	values := make([]string, len(mobyFilter.Values))
+	copy(values, mobyFilter.Values)
+
+	return dockerswarm.Filter{
+		Name:   mobyFilter.Name,
+		Values: values,
+	}
+}

converter/internal/prometheusconvert/prometheusconvert.go

@@ -24,6 +24,7 @@ import (
 	prom_linode "github.com/prometheus/prometheus/discovery/linode"
 	prom_marathon "github.com/prometheus/prometheus/discovery/marathon"
 	prom_docker "github.com/prometheus/prometheus/discovery/moby"
+	prom_moby "github.com/prometheus/prometheus/discovery/moby"
 	prom_scaleway "github.com/prometheus/prometheus/discovery/scaleway"
 	prom_triton "github.com/prometheus/prometheus/discovery/triton"
 	prom_xds "github.com/prometheus/prometheus/discovery/xds"
@@ -188,6 +189,9 @@ func AppendServiceDiscoveryConfigs(pb *prometheusBlocks, serviceDiscoveryConfig
 		case *prom_nerve.NerveSDConfig:
 			labelCounts["nerve"]++
 			exports = appendDiscoveryNerve(pb, common.LabelWithIndex(labelCounts["nerve"]-1, label), sdc)
+		case *prom_moby.DockerSwarmSDConfig:
+			labelCounts["dockerswarm"]++
+			exports = appendDiscoveryDockerswarm(pb, common.LabelWithIndex(labelCounts["dockerswarm"]-1, label), sdc)
 		}
 
 		targets = append(targets, exports.Targets...)

converter/internal/prometheusconvert/testdata/dockerswarm.river

@@ -0,0 +1,54 @@
+discovery.dockerswarm "prometheus1" {
+	host = "http://localhost:8081"
+	role = "nodes"
+	port = 81
+
+	filter {
+		name   = "n1"
+		values = ["v1", "v2"]
+	}
+
+	filter {
+		name   = "n2"
+		values = ["v3"]
+	}
+	refresh_interval = "5m0s"
+
+	basic_auth {
+		username = "username"
+		password = "password"
+	}
+}
+
+discovery.dockerswarm "prometheus2" {
+	host = "http://localhost:8080"
+	role = "services"
+}
+
+prometheus.scrape "prometheus1" {
+	targets = concat(
+		discovery.dockerswarm.prometheus1.targets,
+		[{
+			__address__ = "localhost:9090",
+		}],
+	)
+	forward_to = [prometheus.remote_write.default.receiver]
+	job_name   = "prometheus1"
+}
+
+prometheus.scrape "prometheus2" {
+	targets    = discovery.dockerswarm.prometheus2.targets
+	forward_to = [prometheus.remote_write.default.receiver]
+	job_name   = "prometheus2"
+}
+
+prometheus.remote_write "default" {
+	endpoint {
+		name = "remote1"
+		url  = "http://remote-write-url1"
+
+		queue_config { }
+
+		metadata_config { }
+	}
+}

converter/internal/prometheusconvert/testdata/dockerswarm.yaml

@@ -0,0 +1,29 @@
+scrape_configs:
+  - job_name: "prometheus1"
+    static_configs:
+      - targets: ["localhost:9090"]
+    dockerswarm_sd_configs:
+      - host : "http://localhost:8081"
+        role: "nodes"
+        port: 81
+        filters:
+          - name: "n1"
+            values:
+            - "v1"
+            - "v2"
+          - name: "n2"
+            values:
+            - "v3"
+        refresh_interval: 5m
+        basic_auth:
+          username: "username"
+          password: "password"
+
+  - job_name: "prometheus2"
+    dockerswarm_sd_configs:
+      - host : "http://localhost:8080"
+        role: "services"
+
+remote_write:
+  - name: "remote1"
+    url: "http://remote-write-url1"