New helper ynh_local_curl (#288)

* New helper ynh_curl_abstract
Just an abstraction around curl command.
To prevent forgot arguments and simplify this difficult command.
* [enh] Switch args of ynh_curl_abstract
* [enh] Rename ynh_curl_abstract into ynh_local_curl
* Splitting the various key=value into several arguments
* Comment to clarify bash command
* Adding comment about $domain and $path_url

data/helpers.d/utils

@@ -24,3 +24,31 @@ ynh_get_plain_key() {
         fi
     done
 }
+
+# Curl abstraction to help with POST requests to local pages (such as installation forms)
+#
+# $domain and $path_url should be defined externally (and correspond to the domain.tld and the /path (of the app?))
+#
+# example: ynh_local_curl "/install.php?installButton" "foo=$var1" "bar=$var2"
+# 
+# usage: ynh_local_curl "page_uri" "key1=value1" "key2=value2" ...
+# | arg: page_uri    - Path (relative to $path_url) of the page where POST data will be sent
+# | arg: key1=value1 - (Optionnal) POST key and corresponding value
+# | arg: key2=value2 - (Optionnal) Another POST key and corresponding value
+# | arg: ...         - (Optionnal) More POST keys and values
+ynh_local_curl () {
+	# Define url of page to curl
+	full_page_url=https://localhost$path_url$1
+
+	# Concatenate all other arguments with '&' to prepare POST data
+	POST_data=""
+	for arg in "${@:2}"
+	do
+		POST_data="${POST_data}${arg}&"
+	done
+	# (Remove the last character, which is an unecessary '&')
+	POST_data=${POST_data::-1}
+
+	# Curl the URL
+	curl -kL -H "Host: $domain" --resolve $domain:443:127.0.0.1 --data "$POST_data" "$full_page_url" 2>&1
+}