diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/api/prometheus/api.go')
-rw-r--r-- | vendor/github.com/prometheus/client_golang/api/prometheus/api.go | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/client_golang/api/prometheus/api.go b/vendor/github.com/prometheus/client_golang/api/prometheus/api.go new file mode 100644 index 000000000..3028d741d --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/api/prometheus/api.go @@ -0,0 +1,345 @@ +// 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. + +// Package prometheus provides bindings to the Prometheus HTTP API: +// http://prometheus.io/docs/querying/api/ +package prometheus + +import ( + "encoding/json" + "fmt" + "io/ioutil" + "net" + "net/http" + "net/url" + "path" + "strconv" + "strings" + "time" + + "github.com/prometheus/common/model" + "golang.org/x/net/context" + "golang.org/x/net/context/ctxhttp" +) + +const ( + statusAPIError = 422 + apiPrefix = "/api/v1" + + epQuery = "/query" + epQueryRange = "/query_range" + epLabelValues = "/label/:name/values" + epSeries = "/series" +) + +type ErrorType string + +const ( + // The different API error types. + ErrBadData ErrorType = "bad_data" + ErrTimeout = "timeout" + ErrCanceled = "canceled" + ErrExec = "execution" + ErrBadResponse = "bad_response" +) + +// Error is an error returned by the API. +type Error struct { + Type ErrorType + Msg string +} + +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) +} + +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 +} + +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. + Start, End time.Time + // The maximum time between two slices within the boundaries. + Step time.Duration +} + +// queryResult contains result data for a query. +type queryResult struct { + Type model.ValueType `json:"resultType"` + Result interface{} `json:"result"` + + // The decoded value. + v model.Value +} + +func (qr *queryResult) UnmarshalJSON(b []byte) error { + v := struct { + Type model.ValueType `json:"resultType"` + Result json.RawMessage `json:"result"` + }{} + + err := json.Unmarshal(b, &v) + if err != nil { + return err + } + + switch v.Type { + case model.ValScalar: + var sv model.Scalar + err = json.Unmarshal(v.Result, &sv) + qr.v = &sv + + case model.ValVector: + var vv model.Vector + err = json.Unmarshal(v.Result, &vv) + qr.v = vv + + case model.ValMatrix: + var mv model.Matrix + err = json.Unmarshal(v.Result, &mv) + qr.v = mv + + default: + err = fmt.Errorf("unexpected value type %q", v.Type) + } + return err +} + +// QueryAPI provides bindings the Prometheus's query API. +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. +func NewQueryAPI(c Client) QueryAPI { + return &httpQueryAPI{client: apiClient{c}} +} + +type httpQueryAPI struct { + client Client +} + +func (h *httpQueryAPI) Query(ctx context.Context, query string, ts time.Time) (model.Value, error) { + u := h.client.url(epQuery, nil) + q := u.Query() + + q.Set("query", query) + q.Set("time", ts.Format(time.RFC3339Nano)) + + u.RawQuery = q.Encode() + + req, _ := http.NewRequest("GET", u.String(), nil) + + _, body, err := h.client.do(ctx, req) + if err != nil { + return nil, err + } + + var qres queryResult + err = json.Unmarshal(body, &qres) + + return model.Value(qres.v), err +} + +func (h *httpQueryAPI) QueryRange(ctx context.Context, query string, r Range) (model.Value, error) { + u := h.client.url(epQueryRange, nil) + q := u.Query() + + var ( + start = r.Start.Format(time.RFC3339Nano) + end = r.End.Format(time.RFC3339Nano) + step = strconv.FormatFloat(r.Step.Seconds(), 'f', 3, 64) + ) + + q.Set("query", query) + q.Set("start", start) + q.Set("end", end) + q.Set("step", step) + + u.RawQuery = q.Encode() + + req, _ := http.NewRequest("GET", u.String(), nil) + + _, body, err := h.client.do(ctx, req) + if err != nil { + return nil, err + } + + var qres queryResult + err = json.Unmarshal(body, &qres) + + return model.Value(qres.v), err +} |