Build Jenkins Job Remotely | Fix: Error 403 No valid crumb was included in the request

In case you are a newbie with Jenkins read through this article: http://com.puter.tips/2017/09/getting-up-and-running-with-jenkins.html

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Build Jenkins Job Remotely

I have found two ways in which you can trigger a build on job remotely via scripting.

Both methods are simple HTTP Get/Post requests, nothing fancy here. Along with these Requests we need to pass login credentials.

Method 0: No protection enabled

=> This is the case when you are in a secure environment and have disabled all additional protection mechanism like CSRF (Method 1) and Authentication Token (Method 2). If this is the case then you can simply trigger a HTTP Request like this:

'http://username:password@jenkins_url:port/job/job_name/build'

e.g. http://admin:pass@localhost:8080/job/job1/build



Method 1: Using Crumb

=> Crumb is required when you want to enable Cross-Site Request Forgery (CSRF) protection. It is by default enabled.
=> You have a option to disable it, then you can simply call the URL as shown in Method 0. If it is enabled, then you are supposed to pass a 'crumb' in Header field along with the URL in your HTTP Request.
=> Crumb is auto-generated by Jenkins servers and fetched by client. It is common for all the jobs.
=> Crumb response can be retrieved via XML or JSON.
=> URL remains the same, just a header needs to be added in HTTP Request.

Please check this article for implementation in Perl, Python, Powershell and PHP.

Method 2: Using Authentication Token

=> Unlike default and common 'crumb' option, there is another option called Authentication Token.
=> It is like an additional password which is required to pass along with the URL.
=> It is user-generated, meaning you can set it to whatever value you want, and you can keep a unique token for each of the jobs if you want to.
=> URL changes to this:

'http://username:password@jenkins_url:port/job/job_name/build?token=auth_token'

e.g. http://admin:pass@localhost:8080/job/job1/build?token=job1_builder'

Please check this article for implementation in Perl, Python, Powershell and PHP.

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Solve Error 403 No valid crumb was included in the request

If you have CSRF protection enabled in Jenkins and are trying to trigger a build remotely with Method 0 then you will face this error stating No valid crumb was included in the request. To get away with this problem you have:

Option 1: Disable CSRF protection in Jenkins - Method 0 (I would discourage you to do it)

Option 2: Use Authentication Token - Method 2

Option 3: Fetch crumb from Jenkins and pass it in HTTP Request Header - Method 1