init of a client in go

diff --git a/client/go-client/scientia.go b/client/go-client/scientia.go
new file mode 100644 (file)
index 0000000..e1f669c
--- /dev/null
+++ b/client/go-client/scientia.go
@@ -0,0 +1,254 @@
+package main
+
+import (
+       "errors"
+       "fmt"
+       "log"
+       "math/rand"
+       "os"
+       "flag"
+       "gopkg.in/yaml.v2"
+       "net/http"
+       "io/ioutil"
+       "bytes"
+       "mime/multipart"
+       "encoding/json"
+)
+
+/**
+ * scientia
+ *
+ * Copyright 2022 Johannes Keßler
+ *
+ * https://www.bananas-playground.net/projekt/scientia/
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the COMMON DEVELOPMENT AND DISTRIBUTION LICENSE
+ *
+ * You should have received a copy of the
+ * COMMON DEVELOPMENT AND DISTRIBUTION LICENSE (CDDL) Version 1.0
+ * along with this program.  If not, see http://www.sun.com/cddl/cddl.html
+ */
+
+const website = "https://www.bananas-playground.net/projekt/selfpaste"
+const version = "1.0"
+// used for non-existing default config
+const letters = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-_"
+
+// command line parameters
+var optsVerbose bool
+var optsCreateConfig bool
+var optsDebug bool
+
+// config
+var cfg Config
+// config file struct
+type Config struct {
+       Endpoint struct {
+               Host string `yaml:"host"`
+               Secret string `yaml:"secret"`
+       } `yaml:"endpoint"`
+}
+
+// response json struct
+type Response struct {
+       Message string `json:"message"`
+       Status int `json:"status"`
+}
+
+/**
+ * Main
+ */
+func main() {
+
+       // parse commandline parameters
+       flag.BoolVar(&optsVerbose, "verbose", false, "Produce verbose output")
+       flag.BoolVar(&optsCreateConfig, "create-config-file", false, "Create default config file")
+       flag.BoolVar(&optsDebug, "debug", false, "Print debug infos")
+       flag.Parse()
+       if optsDebug {
+               fmt.Println("verbose:", optsVerbose)
+               fmt.Println("create-config-file:", optsCreateConfig)
+               fmt.Println("debug:", optsDebug)
+       }
+
+       // load the config and populate Config
+       loadConfig()
+
+       // get the payload
+       payload := getInput()
+       if optsDebug { log.Println(payload) }
+
+       // do the upload and get the response
+       responseString := uploadCall(payload)
+       response := Response{}
+       json.Unmarshal([]byte(responseString), &response)
+
+       // print the result and link to the pasty
+       fmt.Printf("Status: %d\n", response.Status)
+       fmt.Printf("Message: %s\n", response.Message)
+}
+
+
+
+
+/**
+ * Check and display error with additional message
+ */
+func errorCheck(e error, msg string) {
+       if e != nil {
+               log.Fatal(msg,e)
+       }
+}
+
+/**
+ * just a random string
+ */
+func randStringBytes(n int) string {
+       b := make([]byte, n)
+       for i := range b {
+               b[i] = letters[rand.Intn(len(letters))]
+       }
+       return string(b)
+}
+
+/**
+ * load or even create a default config
+ * $HOME/.scientia.yaml
+ */
+func loadConfig() {
+       homeDir, err := os.UserHomeDir()
+       errorCheck(err, "No $HOME directory available?")
+       if optsVerbose { log.Printf("Your $HOME: %s \n", homeDir) }
+
+       var configFile = homeDir + "/.selfpaste.yaml"
+
+       if _, err := os.Stat(configFile); errors.Is(err, os.ErrNotExist) {
+               log.Printf("Config file not found: %s \n", configFile)
+
+               if optsCreateConfig {
+                       log.Printf("Creating new default config file: %s \n", configFile)
+
+                       newConfig, err := os.Create(configFile)
+                       errorCheck(err, "Can not create config file!")
+                       defer newConfig.Close()
+
+
+                       _, err = fmt.Fprintf(newConfig, "# scientia go client config file.\n")
+                       errorCheck(err, "Can not write to new config file")
+                       fmt.Fprintf(newConfig, "# See %s for more details.\n", website)
+                       fmt.Fprintf(newConfig, "# Version: %s\n", version)
+                       fmt.Fprintf(newConfig, "endpoint:\n")
+                       fmt.Fprintf(newConfig, "  host: http://your-scientia-endpoi.nt\n")
+                       fmt.Fprintf(newConfig, "  secret: %s\n", randStringBytes(50))
+
+                       log.Fatalf("New default config file created: - %s - Edit and launch again!",configFile)
+               }
+       }
+
+       existingConfigFile, err := os.Open(configFile)
+       errorCheck(err, "Can not open config file")
+       defer existingConfigFile.Close()
+       if optsVerbose { log.Printf("Reading config file: %s \n", configFile) }
+
+       var decoder = yaml.NewDecoder(existingConfigFile)
+       err = decoder.Decode(&cfg)
+       errorCheck(err, "Can not decode config file")
+
+       if cfg.Endpoint.Host == "" || cfg.Endpoint.Secret == "" {
+               log.Fatal("Empty config?")
+       }
+
+       if optsDebug {
+               log.Println(cfg.Endpoint.Host)
+               log.Println(cfg.Endpoint.Secret)
+       }
+}
+
+/**
+ * Do a http POST call to the defined endpoint
+ * and upload the payload
+ * Return response body as string
+ */
+func uploadCall(payload string) string {
+
+       if optsVerbose { log.Println("Starting to upload data") }
+       if optsDebug { log.Println(payload) }
+       if len(payload) == 0 {
+               log.Fatal("Nothing provided to upload")
+       }
+
+       // Buffer to store our request body as bytes
+       var requestBody bytes.Buffer
+
+       // Create a multipart writer
+       multiPartWriter := multipart.NewWriter(&requestBody)
+
+       // file field
+       fileWriter, err := multiPartWriter.CreateFormFile("pasty", "pastyfile")
+       errorCheck(err, "Can not create form file field")
+       fileWriter.Write([]byte(payload))
+
+       dlField, err := multiPartWriter.CreateFormField("dl")
+       errorCheck(err, "Can not create form dl field")
+       dlField.Write([]byte(cfg.Endpoint.Secret))
+
+       multiPartWriter.Close()
+
+       req, err := http.NewRequest(http.MethodPost, cfg.Endpoint.Host, &requestBody)
+       errorCheck(err, "Can not create http request")
+       // We need to set the content type from the writer, it includes necessary boundary as well
+       req.Header.Set("Content-Type", multiPartWriter.FormDataContentType())
+       req.Header.Set("User-Agent", "selfpasteAgent/1.0");
+
+       // Do the request
+       client := &http.Client{}
+       response, err := client.Do(req)
+       errorCheck(err, "POST request failed")
+
+       responseBody, err := ioutil.ReadAll(response.Body)
+       errorCheck(err, "Can not read response body")
+
+       if optsVerbose { log.Println("Request done") }
+       if optsDebug {
+               log.Printf("Response status code: %d\n",response.StatusCode)
+               log.Printf("Response headers: %#v\n", response.Header)
+               log.Println(string(responseBody))
+       }
+
+       return string(responseBody)
+}
+
+/**
+ * check if file is provided as commandline argument
+ * or piped into
+ * return the read data as string
+ */
+func getInput() string {
+       if optsVerbose { log.Println("Getting input") }
+
+       var inputString string
+
+       if filename := flag.Arg(0); filename != "" {
+               if optsVerbose { log.Println("Read from file argument") }
+
+               bytes, err := os.ReadFile(filename)
+               errorCheck(err, "Error opening file")
+               inputString = string(bytes)
+       } else {
+               stat, _ := os.Stdin.Stat()
+               if (stat.Mode() & os.ModeCharDevice) == 0 {
+                       if optsVerbose { log.Println("data is being piped") }
+
+                       bytes, _ := ioutil.ReadAll(os.Stdin)
+                       inputString = string(bytes)
+               }
+       }
+
+       if len(inputString) == 0 {
+               log.Fatal("Nothing provided to upload")
+       }
+
+       return inputString
+}