Merge pull request #613 from prometheus/beorn7/push

Add Delete method to Pusher

prometheus/push/push.go

@@ -117,14 +117,14 @@ func New(url, job string) *Pusher {
 // Push returns the first error encountered by any method call (including this
 // one) in the lifetime of the Pusher.
 func (p *Pusher) Push() error {
-	return p.push("PUT")
+	return p.push(http.MethodPut)
 }
 
 // Add works like push, but only previously pushed metrics with the same name
 // (and the same job and other grouping labels) will be replaced. (It uses HTTP
 // method “POST” to push to the Pushgateway.)
 func (p *Pusher) Add() error {
-	return p.push("POST")
+	return p.push(http.MethodPost)
 }
 
 // Gatherer adds a Gatherer to the Pusher, from which metrics will be gathered
@@ -204,6 +204,42 @@ func (p *Pusher) Format(format expfmt.Format) *Pusher {
 	return p
 }
 
+// Delete sends a “DELETE” request to the Pushgateway configured while creating
+// this Pusher, using the configured job name and any added grouping labels as
+// grouping key. Any added Gatherers and Collectors added to this Pusher are
+// ignored by this method.
+//
+// Delete returns the first error encountered by any method call (including this
+// one) in the lifetime of the Pusher.
+func (p *Pusher) Delete() error {
+	if p.error != nil {
+		return p.error
+	}
+	urlComponents := []string{url.QueryEscape(p.job)}
+	for ln, lv := range p.grouping {
+		urlComponents = append(urlComponents, ln, lv)
+	}
+	deleteURL := fmt.Sprintf("%s/metrics/job/%s", p.url, strings.Join(urlComponents, "/"))
+
+	req, err := http.NewRequest(http.MethodDelete, deleteURL, nil)
+	if err != nil {
+		return err
+	}
+	if p.useBasicAuth {
+		req.SetBasicAuth(p.username, p.password)
+	}
+	resp, err := p.client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 202 {
+		body, _ := ioutil.ReadAll(resp.Body) // Ignore any further error as this is for an error message only.
+		return fmt.Errorf("unexpected status code %d while deleting %s: %s", resp.StatusCode, deleteURL, body)
+	}
+	return nil
+}
+
 func (p *Pusher) push(method string) error {
 	if p.error != nil {
 		return p.error

prometheus/push/push_test.go

@@ -93,8 +93,8 @@ func TestPush(t *testing.T) {
 		Push(); err != nil {
 		t.Fatal(err)
 	}
-	if lastMethod != "PUT" {
-		t.Error("want method PUT for Push, got", lastMethod)
+	if lastMethod != http.MethodPut {
+		t.Errorf("got method %q for Push, want %q", lastMethod, http.MethodPut)
 	}
 	if !bytes.Equal(lastBody, wantBody) {
 		t.Errorf("got body %v, want %v", lastBody, wantBody)
@@ -110,8 +110,8 @@ func TestPush(t *testing.T) {
 		Add(); err != nil {
 		t.Fatal(err)
 	}
-	if lastMethod != "POST" {
-		t.Error("want method POST for Add, got", lastMethod)
+	if lastMethod != http.MethodPost {
+		t.Errorf("got method %q for Add, want %q", lastMethod, http.MethodPost)
 	}
 	if !bytes.Equal(lastBody, wantBody) {
 		t.Errorf("got body %v, want %v", lastBody, wantBody)
@@ -167,8 +167,8 @@ func TestPush(t *testing.T) {
 		Push(); err != nil {
 		t.Fatal(err)
 	}
-	if lastMethod != "PUT" {
-		t.Error("want method PUT for Push, got", lastMethod)
+	if lastMethod != http.MethodPut {
+		t.Errorf("got method %q for Push, want %q", lastMethod, http.MethodPut)
 	}
 	if !bytes.Equal(lastBody, wantBody) {
 		t.Errorf("got body %v, want %v", lastBody, wantBody)
@@ -182,8 +182,8 @@ func TestPush(t *testing.T) {
 		Add(); err != nil {
 		t.Fatal(err)
 	}
-	if lastMethod != "POST" {
-		t.Error("want method POST for Add, got", lastMethod)
+	if lastMethod != http.MethodPost {
+		t.Errorf("got method %q for Add, want %q", lastMethod, http.MethodPost)
 	}
 	if !bytes.Equal(lastBody, wantBody) {
 		t.Errorf("got body %v, want %v", lastBody, wantBody)
@@ -191,4 +191,22 @@ func TestPush(t *testing.T) {
 	if lastPath != "/metrics/job/testjob/a/x/b/y" && lastPath != "/metrics/job/testjob/b/y/a/x" {
 		t.Error("unexpected path:", lastPath)
 	}
+
+	// Delete, all good.
+	if err := New(pgwOK.URL, "testjob").
+		Grouping("a", "x").
+		Grouping("b", "y").
+		Delete(); err != nil {
+		t.Fatal(err)
+	}
+	if lastMethod != http.MethodDelete {
+		t.Errorf("got method %q for Delete, want %q", lastMethod, http.MethodDelete)
+	}
+	if len(lastBody) != 0 {
+		t.Errorf("got body of length %d, want empty body", len(lastBody))
+	}
+	if lastPath != "/metrics/job/testjob/a/x/b/y" && lastPath != "/metrics/job/testjob/b/y/a/x" {
+		t.Error("unexpected path:", lastPath)
+	}
+
 }