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user_data in MultipartMime is base64 encoded

asked 2017-06-07 12:35:57 +0300

dev-rowbot gravatar image


Using HEAT Templating. I am trying to make use of OS::Heat::MultipartMime to send a Powershell script and PEM certificate as user_data.

My initial yaml file can be found here:

My script is based on these examples:

The problem I am having is that no matter what I subtype I set for the Powershell script, it is always base64 encoded and it is not executed by Cloudbase-Init. Please see the debug log for more info -->

I have tried setting the subtype to both x-shellscript and x-cfninitdata. With x-shellscript defined clousbase-init attempts to execute the script but does not decode it before execution and the execution fails.

I can get the script working if I "inline" the data and do not use MultipartMime:

My goal is to pass the certificate (to be used by the WinRM plugin) and a few shell scripts (to configure services and add this host to the domain) to the Windows Instance but I cannot find any examples of this.

Is this possible?

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answered 2017-06-09 17:40:14 +0300

avladu gravatar image

Hello again, Can you try this CloudbaseInit beta installer and check if your problem is solved? Here is the patch in review: Thanks.

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Hi Adrian, Just realised I had not marked this as fixed. I have used the beta installer a couple times with no further issues. Do you know when this will become official?

dev-rowbot gravatar imagedev-rowbot ( 2017-06-19 16:07:18 +0300 )edit

The patch is already under review and soon enough, it will be merged in the main repo. Please check for the status. Thank you!

avladu gravatar imageavladu ( 2017-06-19 17:29:49 +0300 )edit

answered 2017-06-07 13:46:36 +0300

avladu gravatar image


The heat multipart mime has only one entry point - think about it like a int main(void) function in C - only one script that gets executed. It is mandatory to have it defined as here, where the filename is called cfn-userdata and its subtype is x-cfninitdata.

For the moment, there is no multipart type where you can put the content of a WinRM to be mapped certificate.There is already a bug opened on this, which refers to a similar scenario. If you have the same problem, we can open a feature request (blueprint) and start working on it.

A solution for the certificate is to write your own code in the main script that imports/maps the certificate.

Thank you,
Adrian Vladu

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Hi Adrian I have defined my MultipartMime as per the AD Controller example but unfortunately the behaviour is the same. Debug -> The cfn-userdata is still base64 encoded and I can see this WARNING in the debug log: Unsupported user_data format

dev-rowbot gravatar imagedev-rowbot ( 2017-06-07 15:05:42 +0300 )edit

Thanks for the logs. In order to try to reproduce your issue, what OpenStack version do you use?

avladu gravatar imageavladu ( 2017-06-07 15:37:18 +0300 )edit

the only diff I see is your heat_template_version. can you try using heat_template_version: 2013-05-23?

avladu gravatar imageavladu ( 2017-06-07 15:43:02 +0300 )edit

We are using the stable/ocata branch, tag version 15.1.3

dev-rowbot gravatar imagedev-rowbot ( 2017-06-07 15:45:29 +0300 )edit

I get the same result using the 2013-05-23 template version. Does cloudbase-init decode the content when the mime Content-Transfer-Encoding is base64?

dev-rowbot gravatar imagedev-rowbot ( 2017-06-07 16:05:44 +0300 )edit

Cloudbase-Init currently does support only raw encoding for mime parts. I have opened a bug here:

avladu gravatar imageavladu ( 2017-06-07 16:27:57 +0300 )edit

Thanks Adrian - for now I'll execute the 1 script inline and pull/execute anything else required from another web server. Out of interest is there a guide on how to get setup for cloudbase-init development? I don't mind making/testing minor changes myself

dev-rowbot gravatar imagedev-rowbot ( 2017-06-07 16:50:03 +0300 )edit

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Asked: 2017-06-07 12:35:57 +0300

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Last updated: Jun 07 '17