Takahiro Suzuki | d7bf820 | 2020-12-17 20:21:59 +0900 | [diff] [blame] | 1 | // Copyright (c) 2016 Uber Technologies, Inc. |
| 2 | // |
| 3 | // Permission is hereby granted, free of charge, to any person obtaining a copy |
| 4 | // of this software and associated documentation files (the "Software"), to deal |
| 5 | // in the Software without restriction, including without limitation the rights |
| 6 | // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 7 | // copies of the Software, and to permit persons to whom the Software is |
| 8 | // furnished to do so, subject to the following conditions: |
| 9 | // |
| 10 | // The above copyright notice and this permission notice shall be included in |
| 11 | // all copies or substantial portions of the Software. |
| 12 | // |
| 13 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 14 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 15 | // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 16 | // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 17 | // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 18 | // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 19 | // THE SOFTWARE. |
| 20 | |
| 21 | package zap |
| 22 | |
| 23 | import ( |
| 24 | "encoding/json" |
| 25 | "fmt" |
| 26 | "net/http" |
| 27 | |
| 28 | "go.uber.org/zap/zapcore" |
| 29 | ) |
| 30 | |
| 31 | // ServeHTTP is a simple JSON endpoint that can report on or change the current |
| 32 | // logging level. |
| 33 | // |
| 34 | // GET requests return a JSON description of the current logging level. PUT |
| 35 | // requests change the logging level and expect a payload like: |
| 36 | // {"level":"info"} |
| 37 | // |
| 38 | // It's perfectly safe to change the logging level while a program is running. |
| 39 | func (lvl AtomicLevel) ServeHTTP(w http.ResponseWriter, r *http.Request) { |
| 40 | type errorResponse struct { |
| 41 | Error string `json:"error"` |
| 42 | } |
| 43 | type payload struct { |
| 44 | Level *zapcore.Level `json:"level"` |
| 45 | } |
| 46 | |
| 47 | enc := json.NewEncoder(w) |
| 48 | |
| 49 | switch r.Method { |
| 50 | |
| 51 | case http.MethodGet: |
| 52 | current := lvl.Level() |
| 53 | enc.Encode(payload{Level: ¤t}) |
| 54 | |
| 55 | case http.MethodPut: |
| 56 | var req payload |
| 57 | |
| 58 | if errmess := func() string { |
| 59 | if err := json.NewDecoder(r.Body).Decode(&req); err != nil { |
| 60 | return fmt.Sprintf("Request body must be well-formed JSON: %v", err) |
| 61 | } |
| 62 | if req.Level == nil { |
| 63 | return "Must specify a logging level." |
| 64 | } |
| 65 | return "" |
| 66 | }(); errmess != "" { |
| 67 | w.WriteHeader(http.StatusBadRequest) |
| 68 | enc.Encode(errorResponse{Error: errmess}) |
| 69 | return |
| 70 | } |
| 71 | |
| 72 | lvl.SetLevel(*req.Level) |
| 73 | enc.Encode(req) |
| 74 | |
| 75 | default: |
| 76 | w.WriteHeader(http.StatusMethodNotAllowed) |
| 77 | enc.Encode(errorResponse{ |
| 78 | Error: "Only GET and PUT are supported.", |
| 79 | }) |
| 80 | } |
| 81 | } |