├── go.mod ├── .gitignore ├── go.sum ├── handler.go ├── email.go ├── json.go └── LICENSE /go.mod: -------------------------------------------------------------------------------- 1 | module github.com/czcorpus/uniresp 2 | 3 | go 1.18 4 | 5 | require github.com/rs/zerolog v1.27.0 6 | 7 | require ( 8 | github.com/mattn/go-colorable v0.1.12 // indirect 9 | github.com/mattn/go-isatty v0.0.14 // indirect 10 | golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6 // indirect 11 | ) 12 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # Binaries for programs and plugins 2 | *.exe 3 | *.exe~ 4 | *.dll 5 | *.so 6 | *.dylib 7 | 8 | # Test binary, built with `go test -c` 9 | *.test 10 | 11 | # Output of the go coverage tool, specifically when used with LiteIDE 12 | *.out 13 | 14 | # Dependency directories (remove the comment below to include it) 15 | # vendor/ 16 | -------------------------------------------------------------------------------- /go.sum: -------------------------------------------------------------------------------- 1 | github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc= 2 | github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA= 3 | github.com/mattn/go-colorable v0.1.12 h1:jF+Du6AlPIjs2BiUiQlKOX0rt3SujHxPnksPKZbaA40= 4 | github.com/mattn/go-colorable v0.1.12/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4= 5 | github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y= 6 | github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94= 7 | github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0= 8 | github.com/rs/xid v1.3.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg= 9 | github.com/rs/zerolog v1.27.0 h1:1T7qCieN22GVc8S4Q2yuexzBb1EqjbgjSH9RohbMjKs= 10 | github.com/rs/zerolog v1.27.0/go.mod h1:7frBqO0oezxmnO7GF86FY++uy8I0Tk/If5ni1G9Qc0U= 11 | golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= 12 | golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6 h1:foEbQz/B0Oz6YIqu/69kfXPYeFQAuuMYFkjaqXzl5Wo= 13 | golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg= 14 | -------------------------------------------------------------------------------- /handler.go: -------------------------------------------------------------------------------- 1 | // Copyright 2022 Tomas Machalek 2 | // Copyright 2022 Martin Zimandl 3 | // Copyright 2022 Institute of the Czech National Corpus, 4 | // Faculty of Arts, Charles University 5 | // 6 | // Licensed under the Apache License, Version 2.0 (the "License"); 7 | // you may not use this file except in compliance with the License. 8 | // You may obtain a copy of the License at 9 | // 10 | // http://www.apache.org/licenses/LICENSE-2.0 11 | // 12 | // Unless required by applicable law or agreed to in writing, software 13 | // distributed under the License is distributed on an "AS IS" BASIS, 14 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 | // See the License for the specific language governing permissions and 16 | // limitations under the License. 17 | 18 | package uniresp 19 | 20 | import "net/http" 21 | 22 | type NotFoundHandler struct { 23 | } 24 | 25 | func (handler NotFoundHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { 26 | WriteJSONErrorResponse( 27 | w, NewActionError("action not found"), http.StatusNotFound) 28 | } 29 | 30 | type NotAllowedHandler struct { 31 | } 32 | 33 | func (handler NotAllowedHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { 34 | WriteJSONErrorResponse( 35 | w, NewActionError("method not allowed"), http.StatusMethodNotAllowed) 36 | } 37 | -------------------------------------------------------------------------------- /email.go: -------------------------------------------------------------------------------- 1 | // Copyright 2022 Tomas Machalek 2 | // Copyright 2022 Martin Zimandl 3 | // Copyright 2022 Institute of the Czech National Corpus, 4 | // Faculty of Arts, Charles University 5 | // 6 | // Licensed under the Apache License, Version 2.0 (the "License"); 7 | // you may not use this file except in compliance with the License. 8 | // You may obtain a copy of the License at 9 | // 10 | // http://www.apache.org/licenses/LICENSE-2.0 11 | // 12 | // Unless required by applicable law or agreed to in writing, software 13 | // distributed under the License is distributed on an "AS IS" BASIS, 14 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 | // See the License for the specific language governing permissions and 16 | // limitations under the License. 17 | 18 | package uniresp 19 | 20 | import ( 21 | "crypto/tls" 22 | "fmt" 23 | "net" 24 | "net/smtp" 25 | ) 26 | 27 | // DialSmtpServer dials an SMTP server and returns a configured client. 28 | // It supports both insecure and TLS access. In case the port in 29 | // the "server" value is 25 (e.g. "localhost:25") then the insecure 30 | // variant is used. For other port values, the function tries to handle 31 | // TLS connection. 32 | func DialSmtpServer(server, username, password string) (*smtp.Client, error) { 33 | host, port, err := net.SplitHostPort(server) 34 | if err != nil { 35 | return nil, fmt.Errorf("failed to parse SMTP server info: %w", err) 36 | } 37 | if port == "25" { 38 | ans, err := smtp.Dial(server) 39 | if err != nil { 40 | return nil, fmt.Errorf("failed to dial: %w", err) 41 | } 42 | return ans, err 43 | } 44 | auth := smtp.PlainAuth("", username, password, host) 45 | client, err := smtp.Dial(server) 46 | if err != nil { 47 | return nil, fmt.Errorf("failed to dial: %w", err) 48 | } 49 | client.StartTLS(&tls.Config{ 50 | InsecureSkipVerify: true, 51 | ServerName: host, 52 | }) 53 | if err != nil { 54 | return nil, fmt.Errorf("failed to StartTLS: %w", err) 55 | } 56 | err = client.Auth(auth) 57 | if err != nil { 58 | return nil, fmt.Errorf("failed to authenticate client: %w", err) 59 | } 60 | return client, nil 61 | } 62 | -------------------------------------------------------------------------------- /json.go: -------------------------------------------------------------------------------- 1 | // Copyright 2022 Tomas Machalek 2 | // Copyright 2022 Martin Zimandl 3 | // Copyright 2022 Institute of the Czech National Corpus, 4 | // Faculty of Arts, Charles University 5 | // 6 | // Licensed under the Apache License, Version 2.0 (the "License"); 7 | // you may not use this file except in compliance with the License. 8 | // You may obtain a copy of the License at 9 | // 10 | // http://www.apache.org/licenses/LICENSE-2.0 11 | // 12 | // Unless required by applicable law or agreed to in writing, software 13 | // distributed under the License is distributed on an "AS IS" BASIS, 14 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 | // See the License for the specific language governing permissions and 16 | // limitations under the License. 17 | 18 | package uniresp 19 | 20 | import ( 21 | "encoding/json" 22 | "fmt" 23 | "hash/crc32" 24 | "net/http" 25 | "strings" 26 | 27 | "github.com/rs/zerolog/log" 28 | ) 29 | 30 | // ActionError represents a basic user action error (e.g. a wrong parameter, 31 | // non-existing record etc.) 32 | type ActionError struct { 33 | error 34 | } 35 | 36 | // MarshalJSON serializes the error to JSON 37 | func (me ActionError) MarshalJSON() ([]byte, error) { 38 | return json.Marshal(me.Error()) 39 | } 40 | 41 | func NewActionErrorFrom(err error) ActionError { 42 | return ActionError{err} 43 | } 44 | 45 | // NewActionError creates an Action error from provided message using 46 | // a newly defined general error as the original error 47 | func NewActionError(msg string, args ...any) ActionError { 48 | return ActionError{fmt.Errorf(msg, args...)} 49 | } 50 | 51 | // ErrorResponse describes a wrapping object for all error HTTP responses 52 | type ErrorResponse struct { 53 | Error *ActionError `json:"error"` 54 | Details []string `json:"details"` 55 | Code int `json:"code"` 56 | } 57 | 58 | // WriteJSONResponse writes 'value' to an HTTP response encoded as JSON 59 | func WriteJSONResponse(w http.ResponseWriter, value any) { 60 | jsonAns, err := json.Marshal(value) 61 | if err != nil { 62 | log.Err(err).Msg("failed to encode a result to JSON") 63 | http.Error(w, err.Error(), http.StatusInternalServerError) 64 | return 65 | } 66 | w.Write(jsonAns) 67 | } 68 | 69 | // WriteJSONResponseWithStatus writes 'value' to an HTTP response encoded as JSON 70 | func WriteJSONResponseWithStatus(w http.ResponseWriter, status int, value any) { 71 | jsonAns, err := json.Marshal(value) 72 | if err != nil { 73 | http.Error(w, err.Error(), http.StatusInternalServerError) 74 | return 75 | } 76 | w.WriteHeader(status) 77 | w.Write(jsonAns) 78 | } 79 | 80 | func testEtagValues(headerValue, testValue string) bool { 81 | if headerValue == "" { 82 | return false 83 | } 84 | for _, item := range strings.Split(headerValue, ", ") { 85 | if strings.HasPrefix(item, "\"") && strings.HasSuffix(item, "\"") { 86 | val := item[1 : len(item)-1] 87 | if val == testValue { 88 | return true 89 | } 90 | 91 | } else { 92 | log.Warn().Msgf("Invalid ETag value: %s", item) 93 | } 94 | } 95 | return false 96 | } 97 | 98 | // WriteCacheableJSONResponse writes 'value' to an HTTP response encoded as JSON 99 | // but before doing that it calculates a checksum of the JSON and in case it is 100 | // equal to provided 'If-Match' header, 304 is returned. Otherwise a value with 101 | // ETag header is returned. 102 | func WriteCacheableJSONResponse(w http.ResponseWriter, req *http.Request, value any) { 103 | jsonAns, err := json.Marshal(value) 104 | if err != nil { 105 | http.Error(w, err.Error(), http.StatusInternalServerError) 106 | 107 | } else { 108 | w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%d", 3600*24*30)) 109 | crc := crc32.ChecksumIEEE(jsonAns) 110 | newEtag := fmt.Sprintf("chksm-%d", crc) 111 | reqEtagString := req.Header.Get("If-Match") 112 | if testEtagValues(reqEtagString, newEtag) { 113 | http.Error(w, http.StatusText(http.StatusNotModified), http.StatusNotModified) 114 | 115 | } else { 116 | w.Header().Set("Etag", newEtag) 117 | w.Write(jsonAns) 118 | } 119 | } 120 | } 121 | 122 | // WriteJSONErrorResponse writes 'aerr' to an HTTP error response as JSON 123 | func WriteJSONErrorResponse(w http.ResponseWriter, aerr ActionError, status int, details ...string) { 124 | ans := &ErrorResponse{ 125 | Code: status, 126 | Error: &aerr, 127 | Details: details, 128 | } 129 | jsonAns, err := json.Marshal(ans) 130 | if err != nil { 131 | http.Error(w, err.Error(), http.StatusInternalServerError) 132 | } 133 | w.WriteHeader(status) 134 | w.Write(jsonAns) 135 | } 136 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. Definitions. 8 | 9 | "License" shall mean the terms and conditions for use, reproduction, 10 | and distribution as defined by Sections 1 through 9 of this document. 11 | 12 | "Licensor" shall mean the copyright owner or entity authorized by 13 | the copyright owner that is granting the License. 14 | 15 | "Legal Entity" shall mean the union of the acting entity and all 16 | other entities that control, are controlled by, or are under common 17 | control with that entity. For the purposes of this definition, 18 | "control" means (i) the power, direct or indirect, to cause the 19 | direction or management of such entity, whether by contract or 20 | otherwise, or (ii) ownership of fifty percent (50%) or more of the 21 | outstanding shares, or (iii) beneficial ownership of such entity. 22 | 23 | "You" (or "Your") shall mean an individual or Legal Entity 24 | exercising permissions granted by this License. 25 | 26 | "Source" form shall mean the preferred form for making modifications, 27 | including but not limited to software source code, documentation 28 | source, and configuration files. 29 | 30 | "Object" form shall mean any form resulting from mechanical 31 | transformation or translation of a Source form, including but 32 | not limited to compiled object code, generated documentation, 33 | and conversions to other media types. 34 | 35 | "Work" shall mean the work of authorship, whether in Source or 36 | Object form, made available under the License, as indicated by a 37 | copyright notice that is included in or attached to the work 38 | (an example is provided in the Appendix below). 39 | 40 | "Derivative Works" shall mean any work, whether in Source or Object 41 | form, that is based on (or derived from) the Work and for which the 42 | editorial revisions, annotations, elaborations, or other modifications 43 | represent, as a whole, an original work of authorship. For the purposes 44 | of this License, Derivative Works shall not include works that remain 45 | separable from, or merely link (or bind by name) to the interfaces of, 46 | the Work and Derivative Works thereof. 47 | 48 | "Contribution" shall mean any work of authorship, including 49 | the original version of the Work and any modifications or additions 50 | to that Work or Derivative Works thereof, that is intentionally 51 | submitted to Licensor for inclusion in the Work by the copyright owner 52 | or by an individual or Legal Entity authorized to submit on behalf of 53 | the copyright owner. For the purposes of this definition, "submitted" 54 | means any form of electronic, verbal, or written communication sent 55 | to the Licensor or its representatives, including but not limited to 56 | communication on electronic mailing lists, source code control systems, 57 | and issue tracking systems that are managed by, or on behalf of, the 58 | Licensor for the purpose of discussing and improving the Work, but 59 | excluding communication that is conspicuously marked or otherwise 60 | designated in writing by the copyright owner as "Not a Contribution." 61 | 62 | "Contributor" shall mean Licensor and any individual or Legal Entity 63 | on behalf of whom a Contribution has been received by Licensor and 64 | subsequently incorporated within the Work. 65 | 66 | 2. Grant of Copyright License. Subject to the terms and conditions of 67 | this License, each Contributor hereby grants to You a perpetual, 68 | worldwide, non-exclusive, no-charge, royalty-free, irrevocable 69 | copyright license to reproduce, prepare Derivative Works of, 70 | publicly display, publicly perform, sublicense, and distribute the 71 | Work and such Derivative Works in Source or Object form. 72 | 73 | 3. Grant of Patent License. Subject to the terms and conditions of 74 | this License, each Contributor hereby grants to You a perpetual, 75 | worldwide, non-exclusive, no-charge, royalty-free, irrevocable 76 | (except as stated in this section) patent license to make, have made, 77 | use, offer to sell, sell, import, and otherwise transfer the Work, 78 | where such license applies only to those patent claims licensable 79 | by such Contributor that are necessarily infringed by their 80 | Contribution(s) alone or by combination of their Contribution(s) 81 | with the Work to which such Contribution(s) was submitted. If You 82 | institute patent litigation against any entity (including a 83 | cross-claim or counterclaim in a lawsuit) alleging that the Work 84 | or a Contribution incorporated within the Work constitutes direct 85 | or contributory patent infringement, then any patent licenses 86 | granted to You under this License for that Work shall terminate 87 | as of the date such litigation is filed. 88 | 89 | 4. Redistribution. You may reproduce and distribute copies of the 90 | Work or Derivative Works thereof in any medium, with or without 91 | modifications, and in Source or Object form, provided that You 92 | meet the following conditions: 93 | 94 | (a) You must give any other recipients of the Work or 95 | Derivative Works a copy of this License; and 96 | 97 | (b) You must cause any modified files to carry prominent notices 98 | stating that You changed the files; and 99 | 100 | (c) You must retain, in the Source form of any Derivative Works 101 | that You distribute, all copyright, patent, trademark, and 102 | attribution notices from the Source form of the Work, 103 | excluding those notices that do not pertain to any part of 104 | the Derivative Works; and 105 | 106 | (d) If the Work includes a "NOTICE" text file as part of its 107 | distribution, then any Derivative Works that You distribute must 108 | include a readable copy of the attribution notices contained 109 | within such NOTICE file, excluding those notices that do not 110 | pertain to any part of the Derivative Works, in at least one 111 | of the following places: within a NOTICE text file distributed 112 | as part of the Derivative Works; within the Source form or 113 | documentation, if provided along with the Derivative Works; or, 114 | within a display generated by the Derivative Works, if and 115 | wherever such third-party notices normally appear. The contents 116 | of the NOTICE file are for informational purposes only and 117 | do not modify the License. You may add Your own attribution 118 | notices within Derivative Works that You distribute, alongside 119 | or as an addendum to the NOTICE text from the Work, provided 120 | that such additional attribution notices cannot be construed 121 | as modifying the License. 122 | 123 | You may add Your own copyright statement to Your modifications and 124 | may provide additional or different license terms and conditions 125 | for use, reproduction, or distribution of Your modifications, or 126 | for any such Derivative Works as a whole, provided Your use, 127 | reproduction, and distribution of the Work otherwise complies with 128 | the conditions stated in this License. 129 | 130 | 5. Submission of Contributions. Unless You explicitly state otherwise, 131 | any Contribution intentionally submitted for inclusion in the Work 132 | by You to the Licensor shall be under the terms and conditions of 133 | this License, without any additional terms or conditions. 134 | Notwithstanding the above, nothing herein shall supersede or modify 135 | the terms of any separate license agreement you may have executed 136 | with Licensor regarding such Contributions. 137 | 138 | 6. Trademarks. This License does not grant permission to use the trade 139 | names, trademarks, service marks, or product names of the Licensor, 140 | except as required for reasonable and customary use in describing the 141 | origin of the Work and reproducing the content of the NOTICE file. 142 | 143 | 7. Disclaimer of Warranty. Unless required by applicable law or 144 | agreed to in writing, Licensor provides the Work (and each 145 | Contributor provides its Contributions) on an "AS IS" BASIS, 146 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 147 | implied, including, without limitation, any warranties or conditions 148 | of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A 149 | PARTICULAR PURPOSE. You are solely responsible for determining the 150 | appropriateness of using or redistributing the Work and assume any 151 | risks associated with Your exercise of permissions under this License. 152 | 153 | 8. Limitation of Liability. In no event and under no legal theory, 154 | whether in tort (including negligence), contract, or otherwise, 155 | unless required by applicable law (such as deliberate and grossly 156 | negligent acts) or agreed to in writing, shall any Contributor be 157 | liable to You for damages, including any direct, indirect, special, 158 | incidental, or consequential damages of any character arising as a 159 | result of this License or out of the use or inability to use the 160 | Work (including but not limited to damages for loss of goodwill, 161 | work stoppage, computer failure or malfunction, or any and all 162 | other commercial damages or losses), even if such Contributor 163 | has been advised of the possibility of such damages. 164 | 165 | 9. Accepting Warranty or Additional Liability. While redistributing 166 | the Work or Derivative Works thereof, You may choose to offer, 167 | and charge a fee for, acceptance of support, warranty, indemnity, 168 | or other liability obligations and/or rights consistent with this 169 | License. However, in accepting such obligations, You may act only 170 | on Your own behalf and on Your sole responsibility, not on behalf 171 | of any other Contributor, and only if You agree to indemnify, 172 | defend, and hold each Contributor harmless for any liability 173 | incurred by, or claims asserted against, such Contributor by reason 174 | of your accepting any such warranty or additional liability. 175 | 176 | END OF TERMS AND CONDITIONS 177 | 178 | APPENDIX: How to apply the Apache License to your work. 179 | 180 | To apply the Apache License to your work, attach the following 181 | boilerplate notice, with the fields enclosed by brackets "[]" 182 | replaced with your own identifying information. (Don't include 183 | the brackets!) The text should be enclosed in the appropriate 184 | comment syntax for the file format. We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright [yyyy] [name of copyright owner] 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | --------------------------------------------------------------------------------