A Jenkins Workflow shared library class to perform a Form Based authentication to a Jenkins Server and retrieve the body from a URL.

Server.groovy

package net.harniman.workflow.jenkins


//import org.apache.commons.httpclient.*
//import org.apache.commons.httpclient.auth.*
import org.apache.commons.httpclient.Header 
import org.apache.commons.httpclient.HostConfiguration
import org.apache.commons.httpclient.HttpClient
import org.apache.commons.httpclient.NameValuePair
import org.apache.commons.httpclient.methods.GetMethod
import org.apache.commons.httpclient.methods.PostMethod
import org.apache.commons.httpclient.cookie.CookiePolicy
import org.apache.commons.httpclient.params.HttpClientParams


class Server  {
    String user
    String password
    String host
    Integer port
    String proto
    HttpClient client = new HttpClient()
    
Server(    String user, String password, String host, Integer port, String proto) {
    this.user = user
    this.password=password
    this.host=host
    this.port=port
    this.proto=proto
    client.getHostConfiguration().setHost(host, port, proto);
    client.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);
}
HttpClient getHttpClient() {
    return client
}
Integer logon() {
    String logonIniationURL = proto + "://" + host + ":" + port + "/login?from=%2F"
    String logonSubmitURL = proto + "://" + host + ":" + port + "/j_acegi_security_check"

    // We need to make a call first to set up the session
    // HttpClient will automatically handle cookies based on the CookiePolicy set above
    GetMethod get = new GetMethod(logonIniationURL)
    client.executeMethod(get);
    get.releaseConnection()
    PostMethod authpost = new PostMethod(logonSubmitURL)

    def json='{"j_username": "'+user+'", "j_password": "'+password+'", "remember_me": false, "from": "/"}'

    def param1=new NameValuePair("j_username", user)
    def param2=new NameValuePair("j_password", password)
    def param3=new NameValuePair("from", "/")
    def param4=new NameValuePair("json", json)
    def param5=new NameValuePair("Submit", "log in")

    authpost.addParameters(param1)
    authpost.addParameters(param2)
    authpost.addParameters(param3)
    authpost.addParameters(param4)
    authpost.addParameters(param5)

    client.executeMethod(authpost)
    
    // We need to follow the redirect to understand whether authentication 
    // was successful
    // 200 = Success
    // 401 = Credentials failure
    
    Header header = authpost.getResponseHeader("location");
    def response
    if (header != null) {
        String newuri = header.getValue();
        if ((newuri == null) || (newuri.equals(""))) {
            newuri = "/";
        }
        GetMethod redirect = new GetMethod(newuri);
        client.executeMethod(redirect);
        response=redirect.getStatusCode()
        redirect.releaseConnection()
    }
    authpost.releaseConnection()
    return response 
}

String getURL(String URL) {
    GetMethod get = new GetMethod(URL)
    client.executeMethod(get)
    def body = get.getResponseBodyAsString()
    get.releaseConnection()
    return body
}
        
}