How to get http headers on a service in Jolie Programming Language - http

Question

I have a service written in Jolie, where I want to extract the http headers on request. In the same way the request.id can be printed out, I would like to print the headers. There is a try on the bold letter down in the code. Here the code:
execution { concurrent }
inputPort UserDB_Service {
Location: "socket://localhost:8002/"
Protocol: http { .format = "json"}
Interfaces: Users, ShutdownInterface, ConnectionPool
}
outputPort DB_Connector {
Location: "socket://localhost:1000/"
Protocol: sodep
Interfaces: ConnectionPool
}
init
{
connectionConfigInfo#DB_Connector()(connectionInfo);
connect#Database(connectionInfo)()
}
main
{
//Example: http://localhost:8002/retrieve?id=1
[ retrieve(request)(response) {
query#Database(
"select * from users where user_id=:id" {
.id = request.id
}
)(sqlResponse);
println#Console( "You have requested the user_id: " + request.id)();
**println#Console( "Request Headers: " + response.format)();**
if (#sqlResponse.row == 1) {
response -> sqlResponse.row[0]
}
} ]
}
Thanks for the help.

Answer 1

I did not understand if you know which headers you want to have in the inbound request or if you just want to print the whole http message for debugging purposes. It is quick in both cases, I report both solutions :)
In the first case you can set the headers parameter of the http protocol for the inputPort to include in the request message also the content of a specific header, e.g.,
http {
.headers.format = "format";
}
and then you can inspect the value in the usual way
println#Console( request.format )()
In the second case, you can use
http {
.debug = true;
.debug.showContent = true
}
to see the log of all http requests and responses and their bodies.
These and further info on protocols and in particular the http protocol is in the documentation of the Jolie site.

Answer 2

I put the output here again. I wonder if it is possible to extract the "iv-user: g47257" header, which I have injected by using Fiddler. Thanks again for the help.
The headers are like this (better format).
INFO: [UserDB_crud.ol] [HTTP debug] Receiving:
HTTP Code: 0
Resource: /retrieve?id=1
--> Header properties
iv-user: g47257
accept-language: en-US,en;q=0.8,da;q=0.6,es;q=0.4
host: localhost:8002
upgrade-insecure-requests: 1
connection: keep-alive
cache-control: max-age=0
accept-encoding: gzip, deflate, sdch
accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp
,*/*;q=0.8
user-agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTM
L, like Gecko) Chrome/48.0.2564.116 Safari/537.36
You have requested the user_id: 1
mar. 10, 2016 2:30:44 PM jolie.Interpreter logInfo
INFO: [UserDB_crud.ol] [HTTP debug] Sending:
HTTP/1.1 200 OK
Server: Jolie
X-Jolie-MessageID: 0
Content-Type: application/json; charset=utf-8
Content-Encoding: gzip
Content-Length: 72
?V*H,..?/JQ?R*I-.Q?Q*-N-??♦
↑?(?%?"dRs‼3s?\►?????T♂ %??WE
mar. 10, 2016 2:30:44 PM jolie.Interpreter logInfo
INFO: [UserDB_crud.ol] [HTTP debug] Receiving:
HTTP Code: 0
Resource: /favicon.ico
--> Header properties
iv-user: g47257
referer: http://localhost:8002/retrieve?id=1
accept-language: en-US,en;q=0.8,da;q=0.6,es;q=0.4
host: localhost:8002
connection: keep-alive
cache-control: no-cache
pragma: no-cache
accept-encoding: gzip, deflate, sdch
user-agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTM
L, like Gecko) Chrome/48.0.2564.116 Safari/537.36
accept: */*
mar. 10, 2016 2:30:44 PM jolie.Interpreter logWarning
WARNING: [UserDB_crud.ol] Received a message for operation favicon.ico, not specified in the input port at the receiving service. Sending IOException to the caller.
mar. 10, 2016 2:30:44 PM jolie.Interpreter logInfo
INFO: [UserDB_crud.ol] [HTTP debug] Sending:
HTTP/1.1 200 OK
Server: Jolie
X-Jolie-MessageID: 0
Content-Type: application/json; charset=utf-8
Content-Encoding: gzip
Content-Length: 102
?VJ-*?/R??V?M-.NLOU?R??w?HN-(???S?QJ?O☺?→←↓↑↑?(?$?$???%?d?(?↨?▬%?¶Z)?%?e&???☺ ??Z ?yd?Y

Answer 3

I re-post my last comment here since other people faced the same difficulties found by Efrin but might miss the solution I posted as a comment.
You can inspect the headers of a HTTP request as shown in the code below
include "console.iol"
inputPort Me {
Location: "socket://localhost:8000"
Protocol: http { .headers.iv_user = "ivUser" }
RequestResponse: myRequest
}
main {
myRequest( request )(){ println#Console( request.ivUser )() }
}
Remember that, as reported in the documentation, Jolie http.headers parameters map - in header names with _, e.g., in your case, header iv-user becomes iv_user in the Jolie HTTP protocol parameters.
Besides the description and code found in the Jolie documentation, you can find further examples and a more thorough explanation on how the HTTP protocol works in Jolie in its presentation paper wrote by Montesi https://doi.org/10.1016/j.scico.2016.05.002.