feat(): transmit HTTP headers as env variables to the script

README.md

@@ -87,11 +87,17 @@ data: done
 
 ### Webhook parameters
 
-You can add query parameters to the webhook URL.
-Those parameters will be available as environment variables into the shell
-script.
-You can also send a payload (text/plain or application/json) as request body.
-This payload will be transmit to the shell script as first parameter.
+You have several way to provide parameters to your webhook script:
+
+- URL query parameters and HTTP headers are converted into environment
+  variables.
+  Variable names follows "snakecase" naming convention.
+  Therefore the name can be altered.
+
+  *ex: `CONTENT-TYPE` will become `content_type`.*
+
+- Body content (text/plain or application/json) is transmit to the script as
+  parameter.
 
 *Example:*
 
@@ -100,7 +106,8 @@ The script:
 ```bash
 #!/bin/bash
 
-echo "Environment parameters: foo=$foo"
+echo "Query parameter: foo=$foo"
+echo "Header parameter: user-agent=$user_agent"
 echo "Script parameters: $1"
 ```
 
@@ -110,9 +117,11 @@ data: Hook work request "echo" queued...
 
 data: Running echo script...
 
-data: Environment parameters: foo=bar
+data: Query parameter: foo=bar
 
-data: Script parameters: {"foo": "bar"}
+data: Header parameter: user-agent=curl/7.52.1
+
+data: Script parameter: {"foo": "bar"}
 
 data: done
 ```

pkg/api/api.go

@@ -43,6 +43,7 @@ func WebhookHandler(w http.ResponseWriter, r *http.Request) {
 
 	params := tools.QueryParamsToShellVars(r.URL.Query())
 	log.Printf("Calling hook script \"%s\" with params %s...\n", script, params)
+	params = append(params, tools.HTTPHeadersToShellVars(r.Header)...)
 
 	// Create work
 	work := new(worker.WorkRequest)

pkg/tools/http.go

@@ -0,0 +1,59 @@
+package tools
+
+import (
+	"bytes"
+	"net/http"
+	"net/url"
+	"strings"
+	"unicode"
+)
+
+// ToSnakeCase convert string to snakecase.
+func ToSnakeCase(in string) string {
+	runes := []rune(in)
+	length := len(runes)
+
+	var out []rune
+	for i := 0; i < length; i++ {
+		if i > 0 && unicode.IsUpper(runes[i]) && ((i+1 < length && unicode.IsLower(runes[i+1])) || unicode.IsLower(runes[i-1])) {
+			out = append(out, '_')
+		}
+		out = append(out, unicode.ToLower(runes[i]))
+	}
+
+	return strings.Replace(string(out), "-", "", -1)
+}
+
+// QueryParamsToShellVars convert URL query parameters to shell vars.
+func QueryParamsToShellVars(q url.Values) []string {
+	var params []string
+	for k, v := range q {
+		var buf bytes.Buffer
+		value, err := url.QueryUnescape(strings.Join(v[:], ","))
+		if err != nil {
+			continue
+		}
+		buf.WriteString(ToSnakeCase(k))
+		buf.WriteString("=")
+		buf.WriteString(value)
+		params = append(params, buf.String())
+	}
+	return params
+}
+
+// HTTPHeadersToShellVars convert HTTP headers to shell vars.
+func HTTPHeadersToShellVars(h http.Header) []string {
+	var params []string
+	for k, v := range h {
+		var buf bytes.Buffer
+		value, err := url.QueryUnescape(strings.Join(v[:], ","))
+		if err != nil {
+			continue
+		}
+		buf.WriteString(ToSnakeCase(k))
+		buf.WriteString("=")
+		buf.WriteString(value)
+		params = append(params, buf.String())
+	}
+	return params
+}

pkg/tools/query.go

@@ -1,31 +0,0 @@
-package tools
-
-import (
-	"bytes"
-	"net/url"
-	"regexp"
-	"strings"
-)
-
-var matchFirstCap = regexp.MustCompile("(.)([A-Z][a-z]+)")
-var matchAllCap = regexp.MustCompile("([a-z0-9])([A-Z])")
-
-// ToSnakeCase convert string to snakecase.
-func ToSnakeCase(str string) string {
-	snake := matchFirstCap.ReplaceAllString(str, "${1}_${2}")
-	snake = matchAllCap.ReplaceAllString(snake, "${1}_${2}")
-	return strings.ToLower(snake)
-}
-
-// QueryParamsToShellVars convert URL query parameters to shell vars.
-func QueryParamsToShellVars(q url.Values) []string {
-	var params []string
-	for k, v := range q {
-		var buf bytes.Buffer
-		buf.WriteString(ToSnakeCase(k))
-		buf.WriteString("=")
-		buf.WriteString(url.QueryEscape(strings.Join(v[:], ",")))
-		params = append(params, buf.String())
-	}
-	return params
-}

scripts/test.sh

@@ -5,6 +5,8 @@ echo "Running test script..."
 echo "Environment parameters:"
 echo "firstname: $firstname"
 echo "lastname: $lastname"
+echo "user-agent: $user_agent"
+echo "x-api-key: $x_api_key"
 
 echo "Script parameters: $1"
 

tests/test.sh

@@ -10,5 +10,6 @@ curl -H "Content-Type: application/json" \
 
 echo "Test hook"
 curl -H "Content-Type: application/json" \
+    -H "X-API-Key: test" \
     --data @test.json \
     $URL/test?firstname=obi-wan\&lastname=kenobi