changeConfig changes the current config (rawCfg) according to the method, traversed via the given path, and uses the given input as the new value (if applicable; i.e. "DELETE" doesn't have an input). If the resulting config is the same as the previous, no reload will occur unless forceReload is true
(method, path string, input []byte, ifMatchHeader string, forceReload bool)
| 156 | // the config at that path. If the hash in the ifMatchHeader doesn't match |
| 157 | // the hash of the config, then an APIError with status 412 will be returned. |
| 158 | func changeConfig(method, path string, input []byte, ifMatchHeader string, forceReload bool) error { |
| 159 | switch method { |
| 160 | case http.MethodGet, |
| 161 | http.MethodHead, |
| 162 | http.MethodOptions, |
| 163 | http.MethodConnect, |
| 164 | http.MethodTrace: |
| 165 | return fmt.Errorf("method not allowed") |
| 166 | } |
| 167 | |
| 168 | rawCfgMu.Lock() |
| 169 | defer rawCfgMu.Unlock() |
| 170 | |
| 171 | if ifMatchHeader != "" { |
| 172 | // expect the first and last character to be quotes |
| 173 | if len(ifMatchHeader) < 2 || ifMatchHeader[0] != '"' || ifMatchHeader[len(ifMatchHeader)-1] != '"' { |
| 174 | return APIError{ |
| 175 | HTTPStatus: http.StatusBadRequest, |
| 176 | Err: fmt.Errorf("malformed If-Match header; expect quoted string"), |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | // read out the parts |
| 181 | parts := strings.Fields(ifMatchHeader[1 : len(ifMatchHeader)-1]) |
| 182 | if len(parts) != 2 { |
| 183 | return APIError{ |
| 184 | HTTPStatus: http.StatusBadRequest, |
| 185 | Err: fmt.Errorf("malformed If-Match header; expect format \"<path> <hash>\""), |
| 186 | } |
| 187 | } |
| 188 | |
| 189 | // get the current hash of the config |
| 190 | // at the given path |
| 191 | hash := etagHasher() |
| 192 | err := unsyncedConfigAccess(http.MethodGet, parts[0], nil, hash) |
| 193 | if err != nil { |
| 194 | return err |
| 195 | } |
| 196 | |
| 197 | if hex.EncodeToString(hash.Sum(nil)) != parts[1] { |
| 198 | return APIError{ |
| 199 | HTTPStatus: http.StatusPreconditionFailed, |
| 200 | Err: fmt.Errorf("If-Match header did not match current config hash"), |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | err := unsyncedConfigAccess(method, path, input, nil) |
| 206 | if err != nil { |
| 207 | return err |
| 208 | } |
| 209 | |
| 210 | // the mutation is complete, so encode the entire config as JSON |
| 211 | newCfg, err := json.Marshal(rawCfg[rawConfigKey]) |
| 212 | if err != nil { |
| 213 | return APIError{ |
| 214 | HTTPStatus: http.StatusBadRequest, |
| 215 | Err: fmt.Errorf("encoding new config: %v", err), |