<div dir="ltr"><div class="gmail_default" style="font-size:small">Hi Stan,</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">It is good that we are on a common ground here :)</div>
<div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Of course this can be done by Heat. In fact - it will be, in the very same manner as it always was, I am pretty sure we've discussed this many times already. When Heat Software config is fully implemented, it will be possible to use it instead of our Agent execution plans for software configuration - it the very same manner as we use "regular" heat templates for resource allocation.</div>
<div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Heat does indeed support template composition - but we don't want our end-users to do learn how to do that: we want them just to combine existing application on higher-level. Murano will use the template composition under the hood, but only in the way which is designed by application publisher. If the publisher has decided to configure the software with using Heat Software Config, then this option will be used. If some other (probably some legacy ) way of doing this was preferred, Murano should be able to support that and allow to create such workflows. <br>
</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">Also, there may be workflow steps which are not covered by Heat by design. For example, application publisher may include creating instance snapshots, data migrations, backups etc into the deployment or maintenance workflows. I don't see how these may be done by Heat, while Murano should definitely support this scenarios.</div>
<div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">So, as a conclusion, Murano should not be though of as a Heat alternative: it is a different tool located on the different layer of the stack, aiming different user audience - and, the most important - using the Heat underneath. </div>
<div class="gmail_default" style="font-size:small"> </div><div class="gmail_extra"><br clear="all"><div><div dir="ltr"><font>--<br></font><div dir="ltr"><font>Regards,<br>Alexander Tivelkov</font></div></div></div>
<br><br><div class="gmail_quote">On Mon, Feb 24, 2014 at 8:36 PM, Stan Lagun <span dir="ltr"><<a href="mailto:slagun@mirantis.com" target="_blank">slagun@mirantis.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div>Hi Alex,<br><br></div>Personally I like the approach and how you explain it. I just would like to know your opinion on how this is better from someone write Heat template that creates Active Directory lets say with one primary and one secondary controller and then publish it somewhere. Since Heat do supports software configuration as of late and has concept of environments [1] that Steven Hardy generously pointed out in another mailing thread that can be used for composition as well it seems like everything you said can be done by Heat alone<br>
<br>[1]: <a href="http://hardysteven.blogspot.co.uk/2013/10/heat-providersenvironments-101-ive.html" target="_blank">http://hardysteven.blogspot.co.uk/2013/10/heat-providersenvironments-101-ive.html</a><br></div><div class="gmail_extra">
<br><br><div class="gmail_quote"><div><div class="h5">On Mon, Feb 24, 2014 at 7:51 PM, Alexander Tivelkov <span dir="ltr"><<a href="mailto:ativelkov@mirantis.com" target="_blank">ativelkov@mirantis.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">
<div dir="ltr"><div style="font-size:small">Sorry folks, I didn't put the proper image url. Here it is:</div><div style="font-size:small"><span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br></span></p><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><a href="https://creately.com/diagram/hrxk86gv2/kvbckU5hne8C0r0sofJDdtYgxc%3D" target="_blank">https://creately.com/diagram/hrxk86gv2/kvbckU5hne8C0r0sofJDdtYgxc%3D</a></span></p>
<div><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br></span></div></span></div></div><div class="gmail_extra"><br clear="all"><div>
<div dir="ltr"><font>--<br></font><div dir="ltr"><font>Regards,<br>Alexander Tivelkov</font></div></div></div><div><div>
<br><br><div class="gmail_quote">On Mon, Feb 24, 2014 at 7:39 PM, Alexander Tivelkov <span dir="ltr"><<a href="mailto:ativelkov@mirantis.com" target="_blank">ativelkov@mirantis.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div style="font-size:small"><span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">Hi,</span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">I would like to initiate one more discussion about an approach we selected to solve a particular problem in Murano. </span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">The problem statement is the following: We have multiple entities like low level resources and high level application definitions. Each entity does some specific actions for example to create a VM or deploy application configuration. We want each entity's workflow code reusable in order to simplify development for a new application as the current approach with XML based rules requires significant efforts.</span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">After internal discussions inside Murano team we come up to the solution which uses a well known programmatic concept - classes, their inheritance and composition.</span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">In this thread I would like to share our ideas and discuss the implementation details.</span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">We want to represent each and every entity being manipulated by Murano, as an instance of some “class”. These classes will define structure of the entities and their behavior. Different entities may be combined together, interacting with each other, forming a composite environment. The inheritance may be used to extract common structure and functionality into generic superclasses, while having their subclasses to define only their specific attributes and actions.</span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">This approach is better to explain on some example. Let’s consider the Active Directory windows service. This is one of the currently present Murano Applications, and its structure and deployment workflow is pretty complex. Let’s see how it may be simplified by using the proposed object-oriented approach.</span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">First, let’s just describe an Active Directory service in plain English.</span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">Active Directory service consists of several Controllers: exactly one Primary Domain Controller and, optionally, several Secondary Domain Controllers. Controllers (both primary and Secondary) are special Windows Instances, having an active directory server role activated. Their specific difference is in the configuration scripts which are executed on them after the roles are activated. Also, Secondary Domain Controllers have an ability to join to a domain, while Primary Domain Controller cannot do it. </span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">Windows Instances are regular machines having some limitations on the their images (it should, obviously, be Windows image) and hardware flavor (windows is usually demanding on resources). Also, windows machines may have some specific operations, like configuring windows firewall rules or defining local administrator password. </span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">And the machines in general (both Windows and any others) are simple entities which know how to create virtual machines in OpenStack clouds.</span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">Now, let’s map this model to object-oriented concept. We get the following classes:</span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"> </span></p>
<ol style="margin-top:0pt;margin-bottom:0pt"><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">Instance. Defines common properties of virtual machines (flavor, image, hostname) and deployment workflow which executes a HEAT template to create an instance in the cloud.</span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">WindowsInstance - inherits Instance. Defines local administrator account password and extends base deployment workflow to set this password and configure windows firewall - after the instance is deployed.</span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">DomainMember - inherits Windows instance, defines a machine which can join an Active Directory. Adds a “join domain” workflow step</span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">DomainController - inherits Windows instance, adds an “Install AD Role” workflow steps and extends the “Deploy” step to call it. </span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">PrimaryController - inherits DomainContoller, adds a “Configure as Primary DC” workflow step and extends “Deploy” step to call it. Also adds a domainIpAddress property which is set during the deployment.</span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">SecondaryController, inherits both DomainMember and DomainController. Adds a “Configure as Secondary DC” worflow step and extends Deploy() step to call it and the “join domain” step inherited from the “Domain Member” class.</span></p>
</li><li dir="ltr" style="vertical-align:baseline;list-style-type:decimal;font-size:15px;background-color:transparent;font-family:Arial"><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="background-color:transparent;vertical-align:baseline;white-space:pre-wrap">ActiveDirectory - a primary class which defines an Active Directory application. Defines properties for PrimaryController and SecondaryControllers and a “Deploy” workflow which call appropriate workflows on the controllers. </span></p>
</li></ol><br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">The simplified class diagram may look like this:</span></p><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br></span></p><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt">
<span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><img><br></span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br>
</span></p><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">So, this approach allows to decompose the AD deployment workflow into simple isolated parts, explicitly manage the state and create reusable entities (of course classes like Instance, WindowsInstance, DomainMember may be used by other Murano Applications). For me this looks much, much better than the current implicit state machine which we run based on XML rules. </span></p>
<br><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"></span><p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">What do you think about this approach, folks? Do you think it will be easily understood by application developers? Will it be easy to write workflows this way? Do you see any drawbacks here? </span></p>
<p dir="ltr" style="line-height:1.15;margin-top:0pt;margin-bottom:0pt"><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial">Waiting for your feedback.</span></p>
<div><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br></span></div><div><span style="vertical-align:baseline;font-size:15px;white-space:pre-wrap;background-color:transparent;font-family:Arial"><br>
</span></div></span></div><div><div dir="ltr"><font>--<br></font><div dir="ltr"><font>Regards,<br>Alexander Tivelkov</font></div></div></div>
</div>
</blockquote></div><br></div></div></div>
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<br></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><br>-- <br><div dir="ltr"><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:'Times New Roman';word-spacing:0px"><span style="font-family:arial;font-size:small">Sincerely yours<br>
Stanislav (Stan) Lagun<br>Senior Developer<br>Mirantis</span></span><br><span style="text-indent:0px;letter-spacing:normal;font-variant:normal;font-style:normal;font-weight:normal;line-height:normal;border-collapse:separate;text-transform:none;font-size:medium;white-space:normal;font-family:'Times New Roman';word-spacing:0px"><span style="font-family:arial;font-size:small"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"" lang="EN-US">35b/3, Vorontsovskaya
St.</span><br>Moscow, Russia<br>Skype: stanlagun<br><a href="http://www.mirantis.com/" target="_blank">www.mirantis.com</a><br><a href="mailto:slagun@mirantis.com" target="_blank">slagun@mirantis.com</a></span></span></div>
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