This question is a follow-up to Groovy/Jenkins: how to refactor sh(script:"curl ...") to URL?.
Though I intend to try invoking REST API with HTTP Request - as the one answerer has suggested - I'd like to also specifically learn about/understand the original problem RE: non-serializability.
I've reduced the code in the linked Q&A to more minimally demonstrate the problem.
This code:
@Library('my-sandbox-libs@dev') sandbox_lib
pipeline {
agent any
stages {
stage( "1" ) { steps { script { echo "hello" } } }
stage( "2" ) {
steps {
script {
try {
my_lib.v4()
}
catch(Exception e) {
echo "Jenkinsfile: ${e.toString()}"
throw e
}
}
}
}
stage( "3" ) { steps { script { echo "world" } } }
}
}
// vars/my_lib.groovy
import groovy.json.JsonOutput
def v4() {
def post = new URL("https://bitbucket.company.com/rest/build-status/1.0/commits/86c36485c0cbf956a62cbc1c370f1f3eecc8665d").openConnection();
def dict = [:]
dict.state = "INPROGRESS"
dict.key = "foo_42"
dict.url = "http://url/to/nowhere"
def message = JsonOutput.toJson(dict).toString()
post.setRequestMethod("POST")
post.setDoOutput(true)
post.setRequestProperty("Content-Type", "application/json")
post.getOutputStream().write(message.getBytes("UTF-8"));
def postRC = post.getResponseCode();
println(postRC);
if (postRC.equals(200)) {
println(post.getInputStream().getText());
}
}
...generates HTTP error 401. This is expected, because it invokes a Bitbucket REST API without necessary authentication.
What's missing is the "Bearer: xyz" secret-text. In the past, I've gotten this secret-text using Jenkins'/Groovy's withCredentials function, as in the modified function v4() below:
// vars/my_lib.groovy
import groovy.json.JsonOutput
def v4() {
def post = new URL("https://bitbucket.company.com/rest/build-status/1.0/commits/86c36485c0cbf956a62cbc1c370f1f3eecc8665d").openConnection();
def dict = [:]
dict.state = "INPROGRESS"
dict.key = "foo_42"
dict.url = "http://url/to/nowhere"
def message = JsonOutput.toJson(dict).toString()
post.setRequestMethod("POST")
post.setDoOutput(true)
post.setRequestProperty("Content-Type", "application/json")
withCredentials([string(credentialsId: 'bitbucket_cred_id',
variable: 'auth_token')]) {
post.setRequestProperty("Authorization", "Bearer " + auth_token)
}
post.getOutputStream().write(message.getBytes("UTF-8"));
def postRC = post.getResponseCode();
println(postRC);
if (postRC.equals(200)) {
println(post.getInputStream().getText());
}
}
...but I've discovered that the addition of that withCredentials-block, specifically, introduces a java.io.NotSerializableException: sun.net.www.protocol.https.HttpsURLConnectionImpl runtime exception.
At the linked Stack Overflow Q&A, one commenter has informed me that the problem has to do with serializable vs. non-serializable objects in this function. But I'm having a hard time understanding what non-serializable object is introduced by use of the withCredentials-block.
As a point of reference, use of the same withCredentials-block works just fine when I invoke the same REST API using curl instead of "native" Jenkins/Groovy functions. I.e. the following code works fine:
def v1() {
def dict = [:]
dict.state = "INPROGRESS"
dict.key = "foo_42"
dict.url = "http://url/to/nowhere"
withCredentials([string(credentialsId: 'bitbucket_cred_id',
variable: 'auth_token')]) {
def cmd = "curl -f -L " +
"-H \"Authorization: Bearer ${auth_token}\" " +
"-H \"Content-Type:application/json\" " +
"-X POST https://bitbucket.company.com/rest/build-status/1.0/commits/86c36485c0cbf956a62cbc1c370f1f3eecc8665d " +
"-d \'${JsonOutput.toJson(dict)}\'"
sh(script: cmd, returnStatus: true)
}
}
So, in summary, this question is why does withCredentials() introduce non-serializable objects (and what is the non-serializable object), which causes NonSerializableException exceptions with use of URL and/or HttpURLConnection, and does one work around this?
I'm not unwilling to use a different solution, such as httpRequest objects, but this question is about learning the nature of this specific problem, and how to work around it with the existing objects, i.e. URL and HttpURLConnection objects.
Update: As it turns out, I'm unable to use the suggested alternate solution using httpRequest objects, because the HTTP Request plugin is only available to Jenkins versions 2.222.4 or newer, which our Jenkins does not meet. It's outside my privilege to update our Jenkins version, and basically I'll need to assume an inability to upgrade Jenkins.
Our Jenkins version is 2.190.3, which has Groovy version 2.4.12.
