Re: [openstack-dev] [heat] Sofware Config progress
We work with images provided by vendors over which we do not always have
control. So we are considering the cases where vendor image does not come
installed with cloud-init. Is there a way to support heat software config
in such scenarios?
Thanks
Susaant
On Mon, Jan 6, 2014 at 4:47 PM, Steve Baker wrote:
> On 07/01/14 06:25, Susaant Kondapaneni wrote:
>
> Hi Steve,
>
> I am trying to understand the software config implementation. Can you
> clarify the following:
>
> i. To use Software config and deploy in a template, instance resource
> MUST always be accompanied by user_data. User_data should specify how to
> bootstrap CM tool and signal it. Is that correct?
>
> Yes, currently the user_data contains cfn-init formatted metadata which
> tells os-collect-config how to poll for config changes. What happens when
> new config is fetched depends on the os-apply-config templates and
> os-refresh-config scripts which are already on that image (or set up with
> cloud-init).
>
> ii. Supposing we were to use images which do not have cloud-init
> packaged in them, (and a custom CM tool that won't require bootstrapping on
> the instance itself), can we still use software config and deploy resources
> to deploy software on such instances?
>
> Currently os-collect-config is more of a requirement than cloud-init,
> but as Clint said cloud-init does a good job of boot config so you'll need
> to elaborate on why you don't want to use it.
>
> iii. If ii. were possible who would signal the deployment resource to
> indicate that the instance is ready for the deployment?
>
> os-collect-config polls for the deployment data, and triggers the
> resulting deployment/config changes. One day this may be performed by a
> different agent like the unified agent that has been discussed. Currently
> os-collect-collect polls via a heat-api-cfn metadata call. This too may be
> done in any number of ways in the future such as messaging or long-polling.
>
> So you *could* consume the supplied user_data to know what to poll for
> subsequent config changes without cloud-init or os-collect-config, but you
> would have to describe what you're doing in detail for us to know if that
> sounds like a good idea.
>
>
>
> Thanks
> Susaant
>
>
> On Fri, Dec 13, 2013 at 3:46 PM, Steve Baker wrote:
>
>> I've been working on a POC in heat for resources which perform software
>> configuration, with the aim of implementing this spec
>> https://wiki.openstack.org/wiki/Heat/Blueprints/hot-software-config-spec
>>
>> The code to date is here:
>> https://review.openstack.org/#/q/topic:bp/hot-software-config,n,z
>>
>> What would be helpful now is reviews which give the architectural
>> approach enough of a blessing to justify fleshing this POC out into a ready
>> to merge changeset.
>>
>> Currently it is possible to:
>> - create templates containing OS::Heat::SoftwareConfig and
>> OS::Heat::SoftwareDeployment resources
>> - deploy configs to OS::Nova::Server, where the deployment resource
>> remains in an IN_PROGRESS state until it is signalled with the output values
>> - write configs which execute shell scripts and report back with output
>> values that other resources can have access to.
>>
>> What follows is an overview of the architecture and implementation to
>> help with your reviews.
>>
>> REST API
>>
>> Like many heat resources, OS::Heat::SoftwareConfig and
>> OS::Heat::SoftwareDeployment are backed by "real" resources that are
>> invoked via a REST API. However in this case, the API that is called is
>> heat itself.
>>
>> The REST API for these resources really just act as structured storage
>> for config and deployments, and the entities are managed via the REST paths
>> /{tenant_id}/software_configs and /{tenant_id}/software_deployments:
>>
>> <https://review.openstack.org/#/c/58878/7/heat/api/openstack/v1/__init__.py>
>> https://review.openstack.org/#/c/58878/
>> RPC layer of REST API:
>> https://review.openstack.org/#/c/58877/
>> DB layer of REST API:
>> https://review.openstack.org/#/c/58876
>> heatclient lib access to REST API:
>> https://review.openstack.org/#/c/58885
>>
>> This data could be stored in a less structured datastore like swift, but
>> this API has a couple of important implementation details which I think
>> justify it existing:
>> - SoftwareConfig resources are immutable once created. There is no update
>> API to modify an existing config. This gives confidence that a config can
>> have a long lifecycle without changing, and a cer
Re: [openstack-dev] [heat] Sofware Config progress
Hi Steve,
I am trying to understand the software config implementation. Can you
clarify the following:
i. To use Software config and deploy in a template, instance resource MUST
always be accompanied by user_data. User_data should specify how to
bootstrap CM tool and signal it. Is that correct?
ii. Supposing we were to use images which do not have cloud-init packaged
in them, (and a custom CM tool that won't require bootstrapping on the
instance itself), can we still use software config and deploy resources to
deploy software on such instances?
iii. If ii. were possible who would signal the deployment resource to
indicate that the instance is ready for the deployment?
Thanks
Susaant
On Fri, Dec 13, 2013 at 3:46 PM, Steve Baker wrote:
> I've been working on a POC in heat for resources which perform software
> configuration, with the aim of implementing this spec
> https://wiki.openstack.org/wiki/Heat/Blueprints/hot-software-config-spec
>
> The code to date is here:
> https://review.openstack.org/#/q/topic:bp/hot-software-config,n,z
>
> What would be helpful now is reviews which give the architectural approach
> enough of a blessing to justify fleshing this POC out into a ready to merge
> changeset.
>
> Currently it is possible to:
> - create templates containing OS::Heat::SoftwareConfig and
> OS::Heat::SoftwareDeployment resources
> - deploy configs to OS::Nova::Server, where the deployment resource
> remains in an IN_PROGRESS state until it is signalled with the output values
> - write configs which execute shell scripts and report back with output
> values that other resources can have access to.
>
> What follows is an overview of the architecture and implementation to help
> with your reviews.
>
> REST API
>
> Like many heat resources, OS::Heat::SoftwareConfig and
> OS::Heat::SoftwareDeployment are backed by "real" resources that are
> invoked via a REST API. However in this case, the API that is called is
> heat itself.
>
> The REST API for these resources really just act as structured storage for
> config and deployments, and the entities are managed via the REST paths
> /{tenant_id}/software_configs and /{tenant_id}/software_deployments:
>
>
> https://review.openstack.org/#/c/58878/
> RPC layer of REST API:
> https://review.openstack.org/#/c/58877/
> DB layer of REST API:
> https://review.openstack.org/#/c/58876
> heatclient lib access to REST API:
> https://review.openstack.org/#/c/58885
>
> This data could be stored in a less structured datastore like swift, but
> this API has a couple of important implementation details which I think
> justify it existing:
> - SoftwareConfig resources are immutable once created. There is no update
> API to modify an existing config. This gives confidence that a config can
> have a long lifecycle without changing, and a certainty of what exactly is
> deployed on a server with a given config.
> - Fetching all the deployments and configs for a given server is an
> operation done repeatedly throughout the lifecycle of the stack, so is
> optimized to be able to do in a single operation. This is called by using
> the deployments index API call,
> /{tenant_id}/software_deployments?server_id=. The resulting list
> of deployments include the their associated config data[1].
>
> OS::Heat::SoftwareConfig resource
> =
> OS::Heat::SoftwareConfig can be used directly in a template, but it may
> end be more frequently used in a resource provider template which provides
> a resource aimed at a particular configuration management tool.
>
> http://docs-draft.openstack.org/79/58879/7/check/gate-heat-docs/911a250/doc/build/html/template_guide/openstack.html#OS::Heat::SoftwareConfig
> The contents of the config property will depend on the CM tool being used,
> but at least one value in the config map will be the actual script that the
> CM tool invokes. An inputs and outputs schema is also defined here. The
> group property is used when the deployments data is actually delivered to
> the server (more on that later).
>
> Since a config is immutable, any changes to a OS::Heat::SoftwareConfig on
> stack update result in replacement.
>
> OS::Heat::SoftwareDeployment resource
> =
> OS::Heat::SoftwareDeployment joins a OS::Heat::SoftwareConfig resource
> with a OS::Nova::Server resource. It allows server-specific input values to
> be specified that map to the OS::Heat::SoftwareConfig inputs schema. Output
> values that are signaled to the deployment resource are exposed as resource
> attributes, using the names specified in the outputs schema. The
> OS::Heat::SoftwareDeployment resource remains in an IN_PROGRESS state until
> it receives a signal (containing any outputs) from the server.
>
> http://docs-draft.openstack.org/79/58879/7/check/gate-heat-docs/911a250/doc/build/html/template_guide/openstack.html#OS::Heat::SoftwareDeplo
