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Merged
merged 4 commits into from
Dec 1, 2025
Merged

feature(metrics): enable scrape targets #10

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4f5ec18
feature(metrics): enable scrape targets
tschaefer Nov 6, 2025
d70d158
feat(metrics): adapt tests
tschaefer Nov 6, 2025
3633d9d
feat(metrics): validate target url
tschaefer Nov 6, 2025
11bf226
feat(metrics): fix migration
tschaefer Nov 7, 2025
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103 changes: 82 additions & 21 deletions internal/controller/agent.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -29,8 +29,17 @@ var (
ErrAgentAlreadyExists = errors.New("agent already exists")
)

type Agent struct {
Hostname string `json:"hostname"`
Tags []string `json:"tags"`
LogSources []string `json:"log_sources"`
Metrics bool `json:"metrics"`
MetricsTargets []string `json:"metrics_targets"`
Profiles bool `json:"profiles"`
}

type ControllerAgent interface {
RegisterAgent(hostname string, tags, logSources []string, metrics bool, profiles bool) (string, error)
RegisterAgent(agent *Agent) (string, error)
DeregisterAgent(rid string) error
CreateAgentConfig(rid string) ([]byte, error)
ListAgents() ([]map[string]string, error)
Expand Down Expand Up @@ -186,6 +195,19 @@ prometheus.receive_http "default" {
}
forward_to = [prometheus.remote_write.default.receiver]
}

{{ if .MetricsTargets }}
{{ range $index, $source := .MetricsTargets }}
prometheus.scrape "custom_{{ $index }}" {
targets = [{"__address__" = "{{ $source.Address }}"}]
forward_to = [prometheus.remote_write.default.receiver]
scrape_interval = "15s"
{{ if $source.MetricsPath }}
metrics_path = "{{ $source.MetricsPath }}"
{{- end }}
}
{{ end -}}
{{ end -}}
{{ end -}}

{{ if .Profiles }}
Expand Down Expand Up @@ -233,15 +255,15 @@ http:
{{- end }}
`

func (c *controller) RegisterAgent(hostname string, tags, logSources []string, Metrics bool, Profiles bool) (string, error) {
slog.Debug("Register Agent", "hostname", hostname, "tags", tags, "logSources", logSources, "metrics", Metrics, "profiles", Profiles)
func (c *controller) RegisterAgent(data *Agent) (string, error) {
slog.Debug("Register Agent", "data", fmt.Sprintf("%+v", data))

agent, err := c.marshalAgent(hostname, tags, logSources, Metrics, Profiles)
agent, err := c.marshalAgent(data)
if err != nil {
return "", err
}

exists, err := c.model.GetAgent(&model.Agent{Hostname: hostname})
exists, err := c.model.GetAgent(&model.Agent{Hostname: data.Hostname})
if err != nil && !errors.Is(err, model.ErrAgentNotFound) {
return "", err
}
Expand Down Expand Up @@ -319,7 +341,11 @@ func (c *controller) CreateAgentConfig(rid string) ([]byte, error) {
Docker bool
Files []string
}
Metrics bool
Metrics bool
MetricsTargets []struct {
Address string
MetricsPath string
}
Profiles bool
}{
Hostname: agent.Hostname,
Expand All @@ -336,7 +362,11 @@ func (c *controller) CreateAgentConfig(rid string) ([]byte, error) {
Docker: false,
Files: make([]string, 0),
},
Metrics: agent.Metrics,
Metrics: agent.Metrics,
MetricsTargets: make([]struct {
Address string
MetricsPath string
}, 0),
Profiles: agent.Profiles,
}

Expand All @@ -353,12 +383,27 @@ func (c *controller) CreateAgentConfig(rid string) ([]byte, error) {
data.LogSources.Docker = true
case "file":
files = append(files, fmt.Sprintf("{__path__ = \"%s\"}", uri.Path))
data.LogSources.Files = files // fmt.Sprintf("[%s,]", strings.Join(files, ", "))
data.LogSources.Files = files
default:
continue
}
}

for _, source := range agent.MetricsTargets {
uri, err := url.Parse(source)
if err != nil {
continue
}
entry := struct {
Address string
MetricsPath string
}{
Address: uri.Host,
MetricsPath: uri.Path,
}
data.MetricsTargets = append(data.MetricsTargets, entry)
}

buf := new(bytes.Buffer)
if err := tmpl.Execute(buf, data); err != nil {
return nil, err
Expand Down Expand Up @@ -408,17 +453,17 @@ func (c *controller) GetAgent(rid string) (*model.Agent, error) {
return agent, nil
}

func (c *controller) marshalAgent(hostname string, tags, logSources []string, metrics bool, profiles bool) (*model.Agent, error) {
if hostname == "" {
func (c *controller) marshalAgent(data *Agent) (*model.Agent, error) {
if data.Hostname == "" {
return nil, fmt.Errorf("hostname must not be empty")
}

if len(logSources) == 0 {
if len(data.LogSources) == 0 {
return nil, fmt.Errorf("at least one log source must be specified")
}

var effectiveLogSources []string
for _, logSource := range logSources {
for _, logSource := range data.LogSources {
uri, err := url.Parse(logSource)
if err != nil {
continue
Expand All @@ -434,6 +479,21 @@ func (c *controller) marshalAgent(hostname string, tags, logSources []string, me
return nil, fmt.Errorf("no valid log source specified")
}

var effectiveMetricsTargets []string
for _, metricsTarget := range data.MetricsTargets {
uri, err := url.Parse(metricsTarget)
if err != nil {
continue
}
if !slices.Contains([]string{"http", "https"}, uri.Scheme) {
continue
}
if uri.Host == "" {
continue
}
effectiveMetricsTargets = append(effectiveMetricsTargets, uri.String())
}

password := rand.Text()
hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
Expand All @@ -445,15 +505,16 @@ func (c *controller) marshalAgent(hostname string, tags, logSources []string, me
}

agent := &model.Agent{
Hostname: hostname,
LogSources: effectiveLogSources,
Metrics: metrics,
Profiles: profiles,
Tags: tags,
ResourceId: fmt.Sprintf("rid:finch:%s:agent:%s", c.config.Id(), uuid.New().String()),
Username: rand.Text(),
Password: password,
PasswordHash: string(hash),
Hostname: data.Hostname,
LogSources: effectiveLogSources,
Metrics: data.Metrics,
MetricsTargets: effectiveMetricsTargets,
Profiles: data.Profiles,
Tags: data.Tags,
ResourceId: fmt.Sprintf("rid:finch:%s:agent:%s", c.config.Id(), uuid.New().String()),
Username: rand.Text(),
Password: password,
PasswordHash: string(hash),
}

return agent, nil
Expand Down
94 changes: 84 additions & 10 deletions internal/controller/agent_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,15 +71,26 @@ func Test_RegisterAgentReturnsError_BadParameters(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

_, err := ctrl.RegisterAgent("", nil, nil, false, false)
data := Agent{
Hostname: "",
Tags: nil,
LogSources: nil,
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

_, err := ctrl.RegisterAgent(&data)
expected := "hostname must not be empty"
assert.EqualError(t, err, expected, "register agent with empty hostname")

_, err = ctrl.RegisterAgent("test-host", nil, nil, false, false)
data.Hostname = "test-host"
_, err = ctrl.RegisterAgent(&data)
expected = "at least one log source must be specified"
assert.EqualError(t, err, expected, "register agent with no log sources")

_, err = ctrl.RegisterAgent("test-host", nil, []string{"invalid://source"}, false, false)
data.LogSources = []string{"invalid://source"}
_, err = ctrl.RegisterAgent(&data)
expected = "no valid log source specified"
assert.EqualError(t, err, expected, "register agent with invalid log source")
}
Expand All @@ -92,7 +103,16 @@ func Test_RegisterAgentReturnsError_InvalidSecret(t *testing.T) {
ctrl := New(model, &config)
assert.NotNil(t, ctrl, "create controller")

_, err := ctrl.RegisterAgent("test-host", []string{"tag1"}, []string{"journal://"}, false, false)
data := Agent{
Hostname: "test-host",
Tags: []string{"tag1"},
LogSources: []string{"journal://"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

_, err := ctrl.RegisterAgent(&data)
assert.Error(t, err, "register agent with invalid config secret")
}

Expand All @@ -102,7 +122,16 @@ func Test_RegisterAgentReturnsResourceId(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

rid, err := ctrl.RegisterAgent("test-host", []string{"tag1", "tag2"}, []string{"file:///var/log/syslog"}, false, false)
data := Agent{
Hostname: "test-host",
Tags: []string{"tag1", "tag2"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

rid, err := ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register agent with valid parameters")

assert.NotEmpty(t, rid, "resource ID not empty")
Expand Down Expand Up @@ -133,7 +162,16 @@ func Test_DeregisterAgentReturnsNil(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

rid, err := ctrl.RegisterAgent("test-host", []string{"tag1"}, []string{"file:///var/log/syslog"}, false, false)
data := Agent{
Hostname: "test-host",
Tags: []string{"tag1"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

rid, err := ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register agent with valid parameters")

err = ctrl.DeregisterAgent(rid)
Expand All @@ -157,7 +195,16 @@ func Test_CreateAgentConfigReturnsConfig(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

rid, err := ctrl.RegisterAgent("test-host", []string{"tag1"}, []string{"file:///var/log/syslog"}, false, false)
data := Agent{
Hostname: "test-host",
Tags: []string{"tag1"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

rid, err := ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register agent with valid parameters")

config, err := ctrl.CreateAgentConfig(rid)
Expand All @@ -182,7 +229,16 @@ func Test_GetAgentReturnsAgent(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

rid, err := ctrl.RegisterAgent("test-host", []string{"tag1"}, []string{"file:///var/log/syslog"}, false, false)
data := Agent{
Hostname: "test-host",
Tags: []string{"tag1"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

rid, err := ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register agent with valid parameters")

agent, err := ctrl.GetAgent(rid)
Expand All @@ -207,10 +263,28 @@ func Test_ListAgentsReturnsAgents(t *testing.T) {
ctrl := New(model, &mockedConfig)
assert.NotNil(t, ctrl, "create controller")

_, err := ctrl.RegisterAgent("test-host-1", []string{"tag1"}, []string{"file:///var/log/syslog"}, false, false)
data := Agent{
Hostname: "test-host-1",
Tags: []string{"tag1"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

_, err := ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register first agent")

_, err = ctrl.RegisterAgent("test-host-2", []string{"tag2"}, []string{"file:///var/log/syslog"}, false, false)
data = Agent{
Hostname: "test-host-2",
Tags: []string{"tag2"},
LogSources: []string{"file:///var/log/syslog"},
Metrics: false,
MetricsTargets: nil,
Profiles: false,
}

_, err = ctrl.RegisterAgent(&data)
assert.NoError(t, err, "register second agent")

agents, err := ctrl.ListAgents()
Expand Down
11 changes: 2 additions & 9 deletions internal/handler/agent.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -26,22 +26,15 @@ func (h *handler) registerAgentHandlers() {
}

func (h *handler) CreateAgent(w http.ResponseWriter, r *http.Request) {
type payload struct {
Hostname string `json:"hostname"`
Tags []string `json:"tags"`
LogSources []string `json:"log_sources"`
Metrics bool `json:"metrics"`
Profiles bool `json:"profiles"`
}
var p payload
var p controller.Agent

if err := json.NewDecoder(r.Body).Decode(&p); err != nil {
go h.makeLog(r, http.StatusBadRequest, slog.LevelError, "invalid request body")
h.makeError(w, http.StatusBadRequest, "invalid request body")
return
}

rid, err := h.controller.RegisterAgent(p.Hostname, p.Tags, p.LogSources, p.Metrics, p.Profiles)
rid, err := h.controller.RegisterAgent(&p)
if err != nil {
status := http.StatusInternalServerError
if errors.Is(err, controller.ErrAgentAlreadyExists) {
Expand Down
2 changes: 1 addition & 1 deletion internal/handler/agent_test.go
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@ var mockedConfig = mockConfig{

type mockController struct{}

func (m *mockController) RegisterAgent(hostname string, tags, logSources []string, metrics bool, profiles bool) (string, error) {
func (m *mockController) RegisterAgent(data *controller.Agent) (string, error) {
return "rid:12345", nil
}
func (m *mockController) DeregisterAgent(rid string) error {
Expand Down
5 changes: 5 additions & 0 deletions internal/handler/openapi.yaml
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,11 @@ components:
metrics:
type: boolean
example: true
metrics_targets:
type: array
items:
type: string
example: ["http://localhost:9100/metrics"]
profiles:
type: boolean
example: true
Expand Down
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