Merge pull request #291 from andrestc/query-label-values

api: reorganize API package and add label values endpoint implementation

api/client.go

@@ -0,0 +1,131 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.7
+
+// Package api provides clients for the HTTP APIs.
+package api
+
+import (
+	"context"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+	"time"
+)
+
+// DefaultRoundTripper is used if no RoundTripper is set in Config.
+var DefaultRoundTripper http.RoundTripper = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	Dial: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).Dial,
+	TLSHandshakeTimeout: 10 * time.Second,
+}
+
+// Config defines configuration parameters for a new client.
+type Config struct {
+	// The address of the Prometheus to connect to.
+	Address string
+
+	// RoundTripper is used by the Client to drive HTTP requests. If not
+	// provided, DefaultRoundTripper will be used.
+	RoundTripper http.RoundTripper
+}
+
+func (cfg *Config) roundTripper() http.RoundTripper {
+	if cfg.RoundTripper == nil {
+		return DefaultRoundTripper
+	}
+	return cfg.RoundTripper
+}
+
+// Client is the interface for an API client.
+type Client interface {
+	URL(ep string, args map[string]string) *url.URL
+	Do(context.Context, *http.Request) (*http.Response, []byte, error)
+}
+
+// NewClient returns a new Client.
+//
+// It is safe to use the returned Client from multiple goroutines.
+func NewClient(cfg Config) (Client, error) {
+	u, err := url.Parse(cfg.Address)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = strings.TrimRight(u.Path, "/")
+
+	return &httpClient{
+		endpoint: u,
+		client:   http.Client{Transport: cfg.roundTripper()},
+	}, nil
+}
+
+type httpClient struct {
+	endpoint *url.URL
+	client   http.Client
+}
+
+func (c *httpClient) URL(ep string, args map[string]string) *url.URL {
+	p := path.Join(c.endpoint.Path, ep)
+
+	for arg, val := range args {
+		arg = ":" + arg
+		p = strings.Replace(p, arg, val, -1)
+	}
+
+	u := *c.endpoint
+	u.Path = p
+
+	return &u
+}
+
+func (c *httpClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+	if ctx != nil {
+		req = req.WithContext(ctx)
+	}
+	resp, err := c.client.Do(req)
+	defer func() {
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var body []byte
+	done := make(chan struct{})
+	go func() {
+		body, err = ioutil.ReadAll(resp.Body)
+		close(done)
+	}()
+
+	select {
+	case <-ctx.Done():
+		err = resp.Body.Close()
+		<-done
+		if err == nil {
+			err = ctx.Err()
+		}
+	case <-done:
+	}
+
+	return resp, body, err
+}

api/client_test.go

@@ -0,0 +1,115 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.7
+
+package api
+
+import (
+	"net/http"
+	"net/url"
+	"testing"
+)
+
+func TestConfig(t *testing.T) {
+	c := Config{}
+	if c.roundTripper() != DefaultRoundTripper {
+		t.Fatalf("expected default roundtripper for nil RoundTripper field")
+	}
+}
+
+func TestClientURL(t *testing.T) {
+	tests := []struct {
+		address  string
+		endpoint string
+		args     map[string]string
+		expected string
+	}{
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test",
+			expected: "http://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost",
+			endpoint: "/test",
+			expected: "http://localhost/test",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "test",
+			expected: "http://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost:9090/prefix",
+			endpoint: "/test",
+			expected: "http://localhost:9090/prefix/test",
+		},
+		{
+			address:  "https://localhost:9090/",
+			endpoint: "/test/",
+			expected: "https://localhost:9090/test",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param",
+			args: map[string]string{
+				"param": "content",
+			},
+			expected: "http://localhost:9090/test/content",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param/more/:param",
+			args: map[string]string{
+				"param": "content",
+			},
+			expected: "http://localhost:9090/test/content/more/content",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param/more/:foo",
+			args: map[string]string{
+				"param": "content",
+				"foo":   "bar",
+			},
+			expected: "http://localhost:9090/test/content/more/bar",
+		},
+		{
+			address:  "http://localhost:9090",
+			endpoint: "/test/:param",
+			args: map[string]string{
+				"nonexistant": "content",
+			},
+			expected: "http://localhost:9090/test/:param",
+		},
+	}
+
+	for _, test := range tests {
+		ep, err := url.Parse(test.address)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		hclient := &httpClient{
+			endpoint: ep,
+			client:   http.Client{Transport: DefaultRoundTripper},
+		}
+
+		u := hclient.URL(test.endpoint, test.args)
+		if u.String() != test.expected {
+			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
+			continue
+		}
+	}
+}

api/prometheus/v1/api.go

@@ -1,4 +1,4 @@
-// Copyright 2015 The Prometheus Authors
+// Copyright 2017 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -11,35 +11,33 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// Package prometheus provides bindings to the Prometheus HTTP API:
+// +build go1.7
+
+// Package v1 provides bindings to the Prometheus HTTP API v1:
 // http://prometheus.io/docs/querying/api/
-package prometheus
+package v1
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
-	"net"
 	"net/http"
-	"net/url"
-	"path"
 	"strconv"
-	"strings"
 	"time"
 
+	"github.com/prometheus/client_golang/api"
 	"github.com/prometheus/common/model"
-	"golang.org/x/net/context"
-	"golang.org/x/net/context/ctxhttp"
 )
 
 const (
 	statusAPIError = 422
-	apiPrefix      = "/api/v1"
 
-	epQuery       = "/query"
+	apiPrefix = "/api/v1"
-	epQueryRange  = "/query_range"
+
-	epLabelValues = "/label/:name/values"
+	epQuery       = apiPrefix + "/query"
-	epSeries      = "/series"
+	epQueryRange  = apiPrefix + "/query_range"
+	epLabelValues = apiPrefix + "/label/:name/values"
+	epSeries      = apiPrefix + "/series"
 )
 
 // ErrorType models the different API error types.
@@ -64,168 +62,6 @@ func (e *Error) Error() string {
 	return fmt.Sprintf("%s: %s", e.Type, e.Msg)
 }
 
-// CancelableTransport is like net.Transport but provides
-// per-request cancelation functionality.
-type CancelableTransport interface {
-	http.RoundTripper
-	CancelRequest(req *http.Request)
-}
-
-// DefaultTransport is used if no Transport is set in Config.
-var DefaultTransport CancelableTransport = &http.Transport{
-	Proxy: http.ProxyFromEnvironment,
-	Dial: (&net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
-	}).Dial,
-	TLSHandshakeTimeout: 10 * time.Second,
-}
-
-// Config defines configuration parameters for a new client.
-type Config struct {
-	// The address of the Prometheus to connect to.
-	Address string
-
-	// Transport is used by the Client to drive HTTP requests. If not
-	// provided, DefaultTransport will be used.
-	Transport CancelableTransport
-}
-
-func (cfg *Config) transport() CancelableTransport {
-	if cfg.Transport == nil {
-		return DefaultTransport
-	}
-	return cfg.Transport
-}
-
-// Client is the interface for an API client.
-type Client interface {
-	url(ep string, args map[string]string) *url.URL
-	do(context.Context, *http.Request) (*http.Response, []byte, error)
-}
-
-// New returns a new Client.
-//
-// It is safe to use the returned Client from multiple goroutines.
-func New(cfg Config) (Client, error) {
-	u, err := url.Parse(cfg.Address)
-	if err != nil {
-		return nil, err
-	}
-	u.Path = strings.TrimRight(u.Path, "/") + apiPrefix
-
-	return &httpClient{
-		endpoint:  u,
-		transport: cfg.transport(),
-	}, nil
-}
-
-type httpClient struct {
-	endpoint  *url.URL
-	transport CancelableTransport
-}
-
-func (c *httpClient) url(ep string, args map[string]string) *url.URL {
-	p := path.Join(c.endpoint.Path, ep)
-
-	for arg, val := range args {
-		arg = ":" + arg
-		p = strings.Replace(p, arg, val, -1)
-	}
-
-	u := *c.endpoint
-	u.Path = p
-
-	return &u
-}
-
-func (c *httpClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-	resp, err := ctxhttp.Do(ctx, &http.Client{Transport: c.transport}, req)
-
-	defer func() {
-		if resp != nil {
-			resp.Body.Close()
-		}
-	}()
-
-	if err != nil {
-		return nil, nil, err
-	}
-
-	var body []byte
-	done := make(chan struct{})
-	go func() {
-		body, err = ioutil.ReadAll(resp.Body)
-		close(done)
-	}()
-
-	select {
-	case <-ctx.Done():
-		err = resp.Body.Close()
-		<-done
-		if err == nil {
-			err = ctx.Err()
-		}
-	case <-done:
-	}
-
-	return resp, body, err
-}
-
-// apiClient wraps a regular client and processes successful API responses.
-// Successful also includes responses that errored at the API level.
-type apiClient struct {
-	Client
-}
-
-type apiResponse struct {
-	Status    string          `json:"status"`
-	Data      json.RawMessage `json:"data"`
-	ErrorType ErrorType       `json:"errorType"`
-	Error     string          `json:"error"`
-}
-
-func (c apiClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-	resp, body, err := c.Client.do(ctx, req)
-	if err != nil {
-		return resp, body, err
-	}
-
-	code := resp.StatusCode
-
-	if code/100 != 2 && code != statusAPIError {
-		return resp, body, &Error{
-			Type: ErrBadResponse,
-			Msg:  fmt.Sprintf("bad response code %d", resp.StatusCode),
-		}
-	}
-
-	var result apiResponse
-
-	if err = json.Unmarshal(body, &result); err != nil {
-		return resp, body, &Error{
-			Type: ErrBadResponse,
-			Msg:  err.Error(),
-		}
-	}
-
-	if (code == statusAPIError) != (result.Status == "error") {
-		err = &Error{
-			Type: ErrBadResponse,
-			Msg:  "inconsistent body for response code",
-		}
-	}
-
-	if code == statusAPIError && result.Status == "error" {
-		err = &Error{
-			Type: result.ErrorType,
-			Msg:  result.Error,
-		}
-	}
-
-	return resp, []byte(result.Data), err
-}
-
 // Range represents a sliced time range.
 type Range struct {
 	// The boundaries of the time range.
@@ -234,6 +70,16 @@ type Range struct {
 	Step time.Duration
 }
 
+// API provides bindings for Prometheus's v1 API.
+type API interface {
+	// Query performs a query for the given time.
+	Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
+	// QueryRange performs a query for the given range.
+	QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
+	// LabelValues performs a query for the values of the given label.
+	LabelValues(ctx context.Context, label string) (model.LabelValues, error)
+}
+
 // queryResult contains result data for a query.
 type queryResult struct {
 	Type   model.ValueType `json:"resultType"`
@@ -276,27 +122,19 @@ func (qr *queryResult) UnmarshalJSON(b []byte) error {
 	return err
 }
 
-// QueryAPI provides bindings the Prometheus's query API.
+// NewAPI returns a new API for the client.
-type QueryAPI interface {
-	// Query performs a query for the given time.
-	Query(ctx context.Context, query string, ts time.Time) (model.Value, error)
-	// Query performs a query for the given range.
-	QueryRange(ctx context.Context, query string, r Range) (model.Value, error)
-}
-
-// NewQueryAPI returns a new QueryAPI for the client.
 //
-// It is safe to use the returned QueryAPI from multiple goroutines.
+// It is safe to use the returned API from multiple goroutines.
-func NewQueryAPI(c Client) QueryAPI {
+func NewAPI(c api.Client) API {
-	return &httpQueryAPI{client: apiClient{c}}
+	return &httpAPI{client: apiClient{c}}
 }
 
-type httpQueryAPI struct {
+type httpAPI struct {
-	client Client
+	client api.Client
 }
 
-func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
+func (h *httpAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) {
-	u := h.client.url(epQuery, nil)
+	u := h.client.URL(epQuery, nil)
 	q := u.Query()
 
 	q.Set("query", query)
@@ -304,9 +142,12 @@ func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (m
 
 	u.RawQuery = q.Encode()
 
-	req, _ := http.NewRequest("GET", u.String(), nil)
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
 
-	_, body, err := h.client.do(ctx, req)
+	_, body, err := h.client.Do(ctx, req)
 	if err != nil {
 		return nil, err
 	}
@@ -317,8 +158,8 @@ func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (m
 	return model.Value(qres.v), err
 }
 
-func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
+func (h *httpAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) {
-	u := h.client.url(epQueryRange, nil)
+	u := h.client.URL(epQueryRange, nil)
 	q := u.Query()
 
 	var (
@@ -334,9 +175,12 @@ func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (m
 
 	u.RawQuery = q.Encode()
 
-	req, _ := http.NewRequest("GET", u.String(), nil)
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
 
-	_, body, err := h.client.do(ctx, req)
+	_, body, err := h.client.Do(ctx, req)
 	if err != nil {
 		return nil, err
 	}
@@ -346,3 +190,72 @@ func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (m
 
 	return model.Value(qres.v), err
 }
+
+func (h *httpAPI) LabelValues(ctx context.Context, label string) (model.LabelValues, error) {
+	u := h.client.URL(epLabelValues, map[string]string{"name": label})
+	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	_, body, err := h.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	var labelValues model.LabelValues
+	err = json.Unmarshal(body, &labelValues)
+	return labelValues, err
+}
+
+// apiClient wraps a regular client and processes successful API responses.
+// Successful also includes responses that errored at the API level.
+type apiClient struct {
+	api.Client
+}
+
+type apiResponse struct {
+	Status    string          `json:"status"`
+	Data      json.RawMessage `json:"data"`
+	ErrorType ErrorType       `json:"errorType"`
+	Error     string          `json:"error"`
+}
+
+func (c apiClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+	resp, body, err := c.Client.Do(ctx, req)
+	if err != nil {
+		return resp, body, err
+	}
+
+	code := resp.StatusCode
+
+	if code/100 != 2 && code != statusAPIError {
+		return resp, body, &Error{
+			Type: ErrBadResponse,
+			Msg:  fmt.Sprintf("bad response code %d", resp.StatusCode),
+		}
+	}
+
+	var result apiResponse
+
+	if err = json.Unmarshal(body, &result); err != nil {
+		return resp, body, &Error{
+			Type: ErrBadResponse,
+			Msg:  err.Error(),
+		}
+	}
+
+	if (code == statusAPIError) != (result.Status == "error") {
+		err = &Error{
+			Type: ErrBadResponse,
+			Msg:  "inconsistent body for response code",
+		}
+	}
+
+	if code == statusAPIError && result.Status == "error" {
+		err = &Error{
+			Type: result.ErrorType,
+			Msg:  result.Error,
+		}
+	}
+
+	return resp, []byte(result.Data), err
+}

api/prometheus/v1/api_test.go

@@ -1,4 +1,4 @@
-// Copyright 2015 The Prometheus Authors
+// Copyright 2017 The Prometheus Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
@@ -11,118 +11,203 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package prometheus
+// +build go1.7
+
+package v1
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/url"
 	"reflect"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/prometheus/common/model"
-	"golang.org/x/net/context"
 )
 
-func TestConfig(t *testing.T) {
+type apiTest struct {
-	c := Config{}
+	do    func() (interface{}, error)
-	if c.transport() != DefaultTransport {
+	inErr error
-		t.Fatalf("expected default transport for nil Transport field")
+	inRes interface{}
-	}
+
+	reqPath   string
+	reqParam  url.Values
+	reqMethod string
+	res       interface{}
+	err       error
 }
 
-func TestClientURL(t *testing.T) {
+type apiTestClient struct {
-	tests := []struct {
+	*testing.T
-		address  string
+	curTest apiTest
-		endpoint string
+}
-		args     map[string]string
+
-		expected string
+func (c *apiTestClient) URL(ep string, args map[string]string) *url.URL {
-	}{
+	path := ep
+	for k, v := range args {
+		path = strings.Replace(path, ":"+k, v, -1)
+	}
+	u := &url.URL{
+		Host: "test:9090",
+		Path: path,
+	}
+	return u
+}
+
+func (c *apiTestClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+
+	test := c.curTest
+
+	if req.URL.Path != test.reqPath {
+		c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
+	}
+	if req.Method != test.reqMethod {
+		c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
+	}
+
+	b, err := json.Marshal(test.inRes)
+	if err != nil {
+		c.Fatal(err)
+	}
+
+	resp := &http.Response{}
+	if test.inErr != nil {
+		resp.StatusCode = statusAPIError
+	} else {
+		resp.StatusCode = http.StatusOK
+	}
+
+	return resp, b, test.inErr
+}
+
+func TestAPIs(t *testing.T) {
+
+	testTime := time.Now()
+
+	client := &apiTestClient{T: t}
+
+	queryAPI := &httpAPI{
+		client: client,
+	}
+
+	doQuery := func(q string, ts time.Time) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.Query(context.Background(), q, ts)
+		}
+	}
+
+	doQueryRange := func(q string, rng Range) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.QueryRange(context.Background(), q, rng)
+		}
+	}
+
+	doLabelValues := func(label string) func() (interface{}, error) {
+		return func() (interface{}, error) {
+			return queryAPI.LabelValues(context.Background(), label)
+		}
+	}
+
+	queryTests := []apiTest{
 		{
-			address:  "http://localhost:9090",
+			do: doQuery("2", testTime),
-			endpoint: "/test",
+			inRes: &queryResult{
-			expected: "http://localhost:9090/test",
+				Type: model.ValScalar,
-		},
+				Result: &model.Scalar{
-		{
+					Value:     2,
-			address:  "http://localhost",
+					Timestamp: model.TimeFromUnix(testTime.Unix()),
-			endpoint: "/test",
+				},
-			expected: "http://localhost/test",
+			},
-		},
+
-		{
+			reqMethod: "GET",
-			address:  "http://localhost:9090",
+			reqPath:   "/api/v1/query",
-			endpoint: "test",
+			reqParam: url.Values{
-			expected: "http://localhost:9090/test",
+				"query": []string{"2"},
-		},
+				"time":  []string{testTime.Format(time.RFC3339Nano)},
-		{
+			},
-			address:  "http://localhost:9090/prefix",
+			res: &model.Scalar{
-			endpoint: "/test",
+				Value:     2,
-			expected: "http://localhost:9090/prefix/test",
+				Timestamp: model.TimeFromUnix(testTime.Unix()),
-		},
-		{
-			address:  "https://localhost:9090/",
-			endpoint: "/test/",
-			expected: "https://localhost:9090/test",
-		},
-		{
-			address:  "http://localhost:9090",
-			endpoint: "/test/:param",
-			args: map[string]string{
-				"param": "content",
 			},
-			expected: "http://localhost:9090/test/content",
 		},
 		{
-			address:  "http://localhost:9090",
+			do:    doQuery("2", testTime),
-			endpoint: "/test/:param/more/:param",
+			inErr: fmt.Errorf("some error"),
-			args: map[string]string{
+
-				"param": "content",
+			reqMethod: "GET",
+			reqPath:   "/api/v1/query",
+			reqParam: url.Values{
+				"query": []string{"2"},
+				"time":  []string{testTime.Format(time.RFC3339Nano)},
 			},
-			expected: "http://localhost:9090/test/content/more/content",
+			err: fmt.Errorf("some error"),
 		},
+
 		{
-			address:  "http://localhost:9090",
+			do: doQueryRange("2", Range{
-			endpoint: "/test/:param/more/:foo",
+				Start: testTime.Add(-time.Minute),
-			args: map[string]string{
+				End:   testTime,
-				"param": "content",
+				Step:  time.Minute,
-				"foo":   "bar",
+			}),
+			inErr: fmt.Errorf("some error"),
+
+			reqMethod: "GET",
+			reqPath:   "/api/v1/query_range",
+			reqParam: url.Values{
+				"query": []string{"2"},
+				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
+				"end":   []string{testTime.Format(time.RFC3339Nano)},
+				"step":  []string{time.Minute.String()},
 			},
-			expected: "http://localhost:9090/test/content/more/bar",
+			err: fmt.Errorf("some error"),
 		},
+
 		{
-			address:  "http://localhost:9090",
+			do:        doLabelValues("mylabel"),
-			endpoint: "/test/:param",
+			inRes:     []string{"val1", "val2"},
-			args: map[string]string{
+			reqMethod: "GET",
-				"nonexistant": "content",
+			reqPath:   "/api/v1/label/mylabel/values",
-			},
+			res:       model.LabelValues{"val1", "val2"},
-			expected: "http://localhost:9090/test/:param",
+		},
+
+		{
+			do:        doLabelValues("mylabel"),
+			inErr:     fmt.Errorf("some error"),
+			reqMethod: "GET",
+			reqPath:   "/api/v1/label/mylabel/values",
+			err:       fmt.Errorf("some error"),
 		},
 	}
 
+	var tests []apiTest
+	tests = append(tests, queryTests...)
+
 	for _, test := range tests {
-		ep, err := url.Parse(test.address)
+		client.curTest = test
+
+		res, err := test.do()
+
+		if test.err != nil {
+			if err == nil {
+				t.Errorf("expected error %q but got none", test.err)
+				continue
+			}
+			if err.Error() != test.err.Error() {
+				t.Errorf("unexpected error: want %s, got %s", test.err, err)
+			}
+			continue
+		}
 		if err != nil {
-			t.Fatal(err)
+			t.Errorf("unexpected error: %s", err)
-		}
-
-		hclient := &httpClient{
-			endpoint:  ep,
-			transport: DefaultTransport,
-		}
-
-		u := hclient.url(test.endpoint, test.args)
-		if u.String() != test.expected {
-			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
 			continue
 		}
 
-		// The apiClient must return exactly the same result as the httpClient.
+		if !reflect.DeepEqual(res, test.res) {
-		aclient := &apiClient{hclient}
+			t.Errorf("unexpected result: want %v, got %v", test.res, res)
-
-		u = aclient.url(test.endpoint, test.args)
-		if u.String() != test.expected {
-			t.Errorf("unexpected result: got %s, want %s", u, test.expected)
 		}
 	}
 }
@@ -141,11 +226,11 @@ type apiClientTest struct {
 	err      *Error
 }
 
-func (c *testClient) url(ep string, args map[string]string) *url.URL {
+func (c *testClient) URL(ep string, args map[string]string) *url.URL {
 	return nil
 }
 
-func (c *testClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
+func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
 	if ctx == nil {
 		c.Fatalf("context was not passed down")
 	}
@@ -271,7 +356,7 @@ func TestAPIClientDo(t *testing.T) {
 
 		tc.ch <- test
 
-		_, body, err := client.do(context.Background(), tc.req)
+		_, body, err := client.Do(context.Background(), tc.req)
 
 		if test.err != nil {
 			if err == nil {
@@ -294,160 +379,3 @@ func TestAPIClientDo(t *testing.T) {
 		}
 	}
 }
-
-type apiTestClient struct {
-	*testing.T
-	curTest apiTest
-}
-
-type apiTest struct {
-	do    func() (interface{}, error)
-	inErr error
-	inRes interface{}
-
-	reqPath   string
-	reqParam  url.Values
-	reqMethod string
-	res       interface{}
-	err       error
-}
-
-func (c *apiTestClient) url(ep string, args map[string]string) *url.URL {
-	u := &url.URL{
-		Host: "test:9090",
-		Path: apiPrefix + ep,
-	}
-	return u
-}
-
-func (c *apiTestClient) do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-
-	test := c.curTest
-
-	if req.URL.Path != test.reqPath {
-		c.Errorf("unexpected request path: want %s, got %s", test.reqPath, req.URL.Path)
-	}
-	if req.Method != test.reqMethod {
-		c.Errorf("unexpected request method: want %s, got %s", test.reqMethod, req.Method)
-	}
-
-	b, err := json.Marshal(test.inRes)
-	if err != nil {
-		c.Fatal(err)
-	}
-
-	resp := &http.Response{}
-	if test.inErr != nil {
-		resp.StatusCode = statusAPIError
-	} else {
-		resp.StatusCode = http.StatusOK
-	}
-
-	return resp, b, test.inErr
-}
-
-func TestAPIs(t *testing.T) {
-
-	testTime := time.Now()
-
-	client := &apiTestClient{T: t}
-
-	queryAPI := &httpQueryAPI{
-		client: client,
-	}
-
-	doQuery := func(q string, ts time.Time) func() (interface{}, error) {
-		return func() (interface{}, error) {
-			return queryAPI.Query(context.Background(), q, ts)
-		}
-	}
-
-	doQueryRange := func(q string, rng Range) func() (interface{}, error) {
-		return func() (interface{}, error) {
-			return queryAPI.QueryRange(context.Background(), q, rng)
-		}
-	}
-
-	queryTests := []apiTest{
-		{
-			do: doQuery("2", testTime),
-			inRes: &queryResult{
-				Type: model.ValScalar,
-				Result: &model.Scalar{
-					Value:     2,
-					Timestamp: model.TimeFromUnix(testTime.Unix()),
-				},
-			},
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"time":  []string{testTime.Format(time.RFC3339Nano)},
-			},
-			res: &model.Scalar{
-				Value:     2,
-				Timestamp: model.TimeFromUnix(testTime.Unix()),
-			},
-		},
-		{
-			do:    doQuery("2", testTime),
-			inErr: fmt.Errorf("some error"),
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"time":  []string{testTime.Format(time.RFC3339Nano)},
-			},
-			err: fmt.Errorf("some error"),
-		},
-
-		{
-			do: doQueryRange("2", Range{
-				Start: testTime.Add(-time.Minute),
-				End:   testTime,
-				Step:  time.Minute,
-			}),
-			inErr: fmt.Errorf("some error"),
-
-			reqMethod: "GET",
-			reqPath:   "/api/v1/query_range",
-			reqParam: url.Values{
-				"query": []string{"2"},
-				"start": []string{testTime.Add(-time.Minute).Format(time.RFC3339Nano)},
-				"end":   []string{testTime.Format(time.RFC3339Nano)},
-				"step":  []string{time.Minute.String()},
-			},
-			err: fmt.Errorf("some error"),
-		},
-	}
-
-	var tests []apiTest
-	tests = append(tests, queryTests...)
-
-	for _, test := range tests {
-		client.curTest = test
-
-		res, err := test.do()
-
-		if test.err != nil {
-			if err == nil {
-				t.Errorf("expected error %q but got none", test.err)
-				continue
-			}
-			if err.Error() != test.err.Error() {
-				t.Errorf("unexpected error: want %s, got %s", test.err, err)
-			}
-			continue
-		}
-		if err != nil {
-			t.Errorf("unexpected error: %s", err)
-			continue
-		}
-
-		if !reflect.DeepEqual(res, test.res) {
-			t.Errorf("unexpected result: want %v, got %v", test.res, res)
-		}
-	}
-}