Scenario Lifecycle Document - First version with content

1.step(patchset 1&2): provide index.rst and overview
2.step(patchset 3): provide sceleton
3.step(patchset 4): fix comments and provide first content
patchset 5: fix comments in 8 files, one file deleted.
patchset 6: fix more comments
patchset 7: fix more comments adding some editors notes

Jira OCTO-162
Change-Id: I8928953da29aef2bddeb42510fb5983eee9ea30f
Signed-off-by: ulik <ulrich.kleber@huawei.com>

19 files changed, 803 insertions, 0 deletions

diff --git a/docs/scenario-lifecycle/From OS-BASIC to NOSDN-FDIO.png b/docs/scenario-lifecycle/From OS-BASIC to NOSDN-FDIO.png
new file mode 100644
index 0000000..8ac9950
--- /dev/null
+++ b/docs/scenario-lifecycle/From OS-BASIC to NOSDN-FDIO.png
diff --git a/docs/scenario-lifecycle/From OS-BASIC to NOSDN-OVS.png b/docs/scenario-lifecycle/From OS-BASIC to NOSDN-OVS.png
new file mode 100644
index 0000000..15f3893
--- /dev/null
+++ b/docs/scenario-lifecycle/From OS-BASIC to NOSDN-OVS.png
diff --git a/docs/scenario-lifecycle/ODL Generic Scenarios Evolution.png b/docs/scenario-lifecycle/ODL Generic Scenarios Evolution.png
new file mode 100644
index 0000000..6f2e0a4
--- /dev/null
+++ b/docs/scenario-lifecycle/ODL Generic Scenarios Evolution.png
diff --git a/docs/scenario-lifecycle/creating-scenarios.rst b/docs/scenario-lifecycle/creating-scenarios.rst
new file mode 100644
index 0000000..f445a00
--- /dev/null
+++ b/docs/scenario-lifecycle/creating-scenarios.rst
@@ -0,0 +1,96 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Creating Scenarios
+--------------------
+
+Purpose
+^^^^^^^^^^^
+
+A new scenario needs to be created, when a new combination of upstream
+components or features shall be supported, that cannot be provided with the
+existing scenarios in parallel to their existing features.
+
+Typically new scenarios are created as children of existing scenarios.
+
+* In some cases an upstream implementation can be replaced by a different solution.
+  The most obvious example here is the SDN controller. In the first OPNFV release,
+  only ODL was supported. Later ONOS and OpenContrail were added, thus creating
+  new scenarios.
+
+  In most cases, only one of the SDN controllers is needed, thus OPNFV will support
+  the different SDN controllers by different scenarios. This support will be long-
+  term, so there will be multiple generic scenarios for these options.
+
+* Another usecase is feature incompatibilities. For instance, OVS and FD.io
+  cannot be combined today. Therefore we need different scenarios for them.
+  If it is expected that such an incompatibility is not solved for longer time,
+  there can be even separate generic scenarios for these options.
+
+The overlap between scenarios should only be allowed where they add components
+that cannot be integrated in a single deployment.
+
+If scenario A completely covers scenario B, support of scenario B will be
+only provided as long as isolation of development risks is necessary.
+However, there might be cases where somebody wants to use scenario B
+still as a parent for specific scenarios.
+
+This is especially the case for generic scenarios, since they need more CI and testing
+resources. Therefore a gating process will be introduced for generic scenarios.
+
+
+Creating Generic Scenarios
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Generic scenarios provide stable and mature deployments of an OPNFV release. Therefore
+it is important to have generic scenarios in place that provide the main capabilities
+needed for NFV environments. On the other hand the number of generic scenarios needs
+to be limited because of resources.
+
+* Creation of a new generic scenario needs TSC consensus.
+* Typically the generic scenario is created by promoting an existing specific
+  scenario. Thus the only the additional information needs to be provided.
+* The scenario owner needs to verify that the scenario fulfills the above requirements.
+* Since specific scenarios typically are owned by the project who have initiated it,
+  and generic scenarios provide a much broader set of features, in many cases a
+  change of owner is appropriate. In most cases it will be appropriate to assign
+  a testing expert as scenario owner.
+
+Creating Specific Scenarios
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+As already stated, typically specific scenarios are created as children of existing
+scenarios. The parent can be a generic or a specific scenario.
+
+Creation of specific scenarios shall be very easy and can be done any time. However,
+support might be low priority during a final release preparation, e.g. after a MS6.
+
+* The PTL of the project developing the feature(s) or integrating a component etc can
+  request the scenario (tbd from whom: CI or release manager, no need for TSC)
+* The PTL shall provide some justification why a new scenario is needed.
+  It will be approptiate to discuss that justification in the weekly technical
+  discussion meeting.
+* The PTL should have prepared that by finding support from one of the installers.
+* The PTL should explain from which "parent scenario" (see below) the work will start,
+  and what are the planned additions.
+* The PTL shall assign a unique name. Naming rules will be set by TSC.
+* The PTL shall provide some time schedule plans when the scenario wants to join
+  a release, when he expects the scenario merge to other scenarios, and he expects
+  the features may be made available in generic scenarios.
+  A scenario can join a release at the MS0 after its creation.
+  It should join a release latest on the next MS0 6 month after its
+  creation (that is it should skip only one release) and merge to its parent
+  maximum 2 releases later.
+  .. Editors note: "2 releases" is rather strict maybe refine?
+* The PTL should explain the infrastructure requirements and clarify that sufficient
+  resources are available for the scenario.
+* The PTL shall assign a scenario owner.
+* The scenario owner shall maintain the scenario descriptor file according to the
+  template.
+* The scenario owner shall initiate the scenario be integrated in CI or releases.
+* When the scenario joins a release this needs to be done in time for the relevant
+  milestones.
+
+
diff --git a/docs/scenario-lifecycle/current-status.rst b/docs/scenario-lifecycle/current-status.rst
new file mode 100644
index 0000000..08a3776
--- /dev/null
+++ b/docs/scenario-lifecycle/current-status.rst
@@ -0,0 +1,50 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Current Status
+---------------
+
+tdb: this chapter will summarize the scenario analysis.
+
+Arno
+^^^^^^^^
+
+In Arno release, the scenario concept was not created yet.
+Looking back, we can say we had one scenario with OpenStack, ODL and KVM,
+that could be deployed in two ways, by the two installers available in Arno.
+
+Brahmaputra
+^^^^^^^^^^^^^^^^
+
+tbd
+
+Colorado
+^^^^^^^^^^^^
+
+tbd
+
+Danube
+^^^^^^^^^^
+
+tbd: Analysis of the 58 scenarios
+The analysis can be found in the slides at
+https://wiki.opnfv.org/display/INF/Scenario+Consolidation
+and will be explain with some text here.
+The text will also use the diagrams from the slides, e.g.
+show a scenario tree:
+
+.. figure:: scenario-tree.png
+
+and an idea about possible generic scenarios:
+
+.. figure:: scenario-tree+idea.png
+
+as well as possible ways to reach this.
+
+
+
+
+
+
diff --git a/docs/scenario-lifecycle/deployment-options.rst b/docs/scenario-lifecycle/deployment-options.rst
new file mode 100644
index 0000000..2c0a342
--- /dev/null
+++ b/docs/scenario-lifecycle/deployment-options.rst
@@ -0,0 +1,128 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Deployment Options
+-------------------
+
+What are deployment options?
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. Editors note: Some installers call it settings. Prefer options, because it allows
+.. cases with multiple options.
+
+During the analysis of scenario definitions in Colorado and Danube releases, it became
+visible, that HA and NOHA deployment of otherwise identical scenarios shouldn't be
+called different scenarios.
+
+This understanding leads to the definition of another kind of attributes
+in scenario definitions. Many scenarios can be deployed in different ways:
+
+* **HA** configuration of OpenStack modules (that is redundancy using multiple
+  controllers running OpenStack services) versus NOHA with only a single controller
+  running a single instance of each OpenStack service
+* Some scenarios can be deployed on intel and on ARM **hardware**.
+* We can see the **installation tools** in the same way. Independent of the installer
+  that was used for the deployment of a scenario, the same functionality will be
+  provided and we can run the same testcases.
+
+Please note that a scenario can support multiple deployment options. And a scenario
+definition must specify at least one option of each type.
+
+In future there will be more deployment options, e.g. redundancy models or other
+clustering options of SDN controllers, or upscaling compute or control nodes.
+
+CI Pipeline needs to test all configuration options of a scenario.
+
+* Development cycles (verify-jobs, daily, weekly) don‘t need to run all
+  options each time
+* Release testing must cover all those combinations of configuration options that
+  will be part of the release. Typically the HA configurations are released on
+  bare metal with the allowed hardware options and all installers that can deploy
+  those. Release of an NOHA option should be an exception, e.g. for a scenarios
+  that are not mature yet.
+* Virtual deployments are not mentioned here. All scenarios should allow virtual
+  deployment where applicable.
+  But in release testing, bare metal deployment will be necessary.
+  CI will use virtual deployments as much as appropriate for resource reasons.
+
+
+Deployment options or new scenarios
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In general we can say that a different scenario is needed when the set of components
+is changed (or in some cases a general deploy-time configuration of a component). If
+we deploy the same components in a different way, we can define this via deployment
+options.
+
+**Examples**
+
+* Deploying different SDN controller or data plane (OVS/FD.IO) requires different
+  scenario.
+* HA/NOHA will deploy the same components on different number of nodes, so it is a
+  deployment option.
+* Different hardware types should not lead to new scenarios. Typically the same
+  scenario can be deployed on multiple hardware.
+
+
+HA and NOHA
+^^^^^^^^^^^^^
+
+Both, HA and NOHA options of a scenario are important.
+
+* HA deployment is important to be released in major OPNFV releases, because
+  telco deployments typically have strong requirements on availability.
+* NOHA deployments require less resources and are sufficient for many use cases.
+  For instance sandbox testing can be done easier and also automatic verification
+  in the CI pipeline can make use of it.
+* Generic scenarios shall support the HA and NOHA option.
+* Specific scenarios can focus on the NOHA option if their features are independent
+  from the controller redundancy. But before merging with generic scenarios, they
+  should provide both options.
+
+
+Hardware types
+^^^^^^^^^^^^^^^^^
+
+In its first releases, OPNFV could be deployed on Intel hardware only. Later, support
+for ARM hardware was added and now 5 scenarios can already be deployed on both.
+
+
+Virtual deployment
+^^^^^^^^^^^^^^^^^^^^^^
+
+Many, but not all scenarios can be deployed on virtual PODs. Therefore the scenario
+definition shall specify whether virtual deployment is possible.
+
+Typically a virtual HA deployment shall look very much the same as a bare-metal HA
+deployment, that is the distribution of modules on nodes/VMs is similar. But there
+might be cases where there are differences. Thus, the scenario specification needs
+to provide the data for each separately.
+
+
+Deployment tools
+^^^^^^^^^^^^^^^^^^^
+
+Deployment tools (installers) are in a very similar relation to the scenarios.
+Each scenario can be deployed by one or more installer. Thus we can specify the
+installers for a scenario as a deployment option.
+
+However, the installers need additional detailed information for the deployment.
+Every installer may not support the same HA, hardware, virtualization options,
+or same distribution of modules. Each deployment may look slightly different
+per installer.
+
+The scenario definition needs to provide such information in a way it can be easily
+consumed by the installers.
+
+
+
+Other deployment options
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This set of deployment options is based on what is required by Danube scenarios.
+Future releases will most likely introduce additional deployment options.
+
+
+
diff --git a/docs/scenario-lifecycle/feature-compatibility-nosdn.png b/docs/scenario-lifecycle/feature-compatibility-nosdn.png
new file mode 100644
index 0000000..09520aa
--- /dev/null
+++ b/docs/scenario-lifecycle/feature-compatibility-nosdn.png
diff --git a/docs/scenario-lifecycle/feature-compatibility-odl.png b/docs/scenario-lifecycle/feature-compatibility-odl.png
new file mode 100644
index 0000000..600082a
--- /dev/null
+++ b/docs/scenario-lifecycle/feature-compatibility-odl.png
diff --git a/docs/scenario-lifecycle/generic-scenarios.rst b/docs/scenario-lifecycle/generic-scenarios.rst
new file mode 100644
index 0000000..f159c0c
--- /dev/null
+++ b/docs/scenario-lifecycle/generic-scenarios.rst
@@ -0,0 +1,53 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Generic Scenarios
+------------------
+
+Generic scenarios provide a stable environment for users who want to base their
+products on them.
+
+* Generic scenarios provide a basic combination of upstream components together
+  with the superset of possible mature features that can be deployed on them.
+* Generic scenarios should be supported by all installers.
+* All generic scenarios in a release should have the same common major versions
+  of the included upstream components.
+  These upstream versions can then be seen as the upstream versions for the
+  release. E.g. that way we can say: “OPNFV xxx contains OpenStack abc,
+  ODL def, ONOS ghi, OVS jkl“.
+  But most installers cannot directly reference any
+  upstream version. This may lead to minor differences.
+  Nevertheless features and test cases require all installers using the same
+  major versions.
+* Generic scenarios should use stable sources
+  and lock the versions before the release by either pointing to a tag or sha1.
+  According to the LF badging program it should be possible to reproduce
+  the release from source again.
+  Thus the upstream repos should be in safe locations.
+  Also only tagged source versions should be used for the release, so the
+  release can be reproduced identically for different purposes such as
+  reproducing a baug reported by users and issuing the fix appropriately,
+  even after the upstream project has applied patches.
+  .. Editors note: There is discussion ongoing in INFRA and SEC working groups how
+  .. to realize this. Thus the description is still a bit vague. Details will be
+  .. added later either here or in some INFRA document.
+* Generic scenarios should be stable and mature. Therefore they will be tested more
+  thoroughly and run special release testing so a high level of stability can be
+  provided.
+* Generic scenarios will live through many OPNFV releases.
+* More resources will be allocated to maintaining generic scenarios and they will
+  have priority for CI resources.
+  .. Editors note: Discussion ongoing in INFRA about toolchain issues.
+
+Note: in some cases it might be difficult for an installer to support all generic
+scenarios immediately. In this case an exception can be defined, but the installer
+has to provide a plan how to achieve support for all generic scenarios.
+
+Note: in some cases, upstream projects don‘t have proper CI process with
+tagged stable versions. Also some installers‘ way of working doesn‘t allow
+selecting the repo and tag. Thus a stepwise approach will be necessary to
+fulfill this requirement.
+
+
diff --git a/docs/scenario-lifecycle/index.rst b/docs/scenario-lifecycle/index.rst
new file mode 100644
index 0000000..36dd92a
--- /dev/null
+++ b/docs/scenario-lifecycle/index.rst
@@ -0,0 +1,24 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+**********************
+Scenario Lifecycle
+**********************
+
+Contents:
+
+.. toctree::
+   :numbered:
+   :maxdepth: 4
+
+   scenario-overview.rst
+   generic-scenarios.rst
+   specific-scenarios.rst
+   parent-child-relations.rst
+   creating-scenarios.rst
+   deployment-options.rst
+   mano-scenarios.rst
+   current-status.rst
+   scenario-descriptor-files.rst
+
diff --git a/docs/scenario-lifecycle/mano-scenarios.rst b/docs/scenario-lifecycle/mano-scenarios.rst
new file mode 100644
index 0000000..0eee143
--- /dev/null
+++ b/docs/scenario-lifecycle/mano-scenarios.rst
@@ -0,0 +1,31 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+MANO Scenarios
+---------------
+
+Since OPNFV organizes all deployments using scenarios, also MANO components need
+to be covered by scenarios.
+
+On the other side all NFVI/VIM level scenarios need to be orchestrated using a
+set of components from the NFVO and VNFM layer.
+
+The idea here is therefore to specify for a MANO scenario:
+
+* The MANO components to deploy
+* A list of supported NFVI/VIM level scenarios that can be orchestrated
+  using this MANO scenario.
+
+The MANO test cases will define the VNFs to use.
+
+MANO scenarios will have more work to do if they require new nodes to be deployed on.
+They should include this aspect in their resource planning/requests and contact
+Infra/Pharos in case that a change of the Pharos spec is needed and new PODs need
+to be made available based on the amended spec.
+
+More details need to be investigated as we gain experience with the MANO scenarios
+
+
+
diff --git a/docs/scenario-lifecycle/parent-child-relations.rst b/docs/scenario-lifecycle/parent-child-relations.rst
new file mode 100644
index 0000000..ca15619
--- /dev/null
+++ b/docs/scenario-lifecycle/parent-child-relations.rst
@@ -0,0 +1,62 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Parent - Child Relations
+-------------------------
+
+In many cases, development adds a feature to an existing scenario by adding additional
+components. This is called creating a child scenario from a parent.
+
+* Parent scenarios typically are more stable than children.
+* Children should plan to merge their feature back to the parent.
+* Merge back will often add components to the parent.
+
+.. figure:: parent-child.png
+
+* Child scenarios can be part of releases.
+* Child scenarios should merge back to their parent after 2 releases.
+* If a child scenario lives through several releases, it might be desirable
+  to “rebase/cherrypick” a child scenario to follow changes in the parent scenario.
+* Child scenarios typically support a smaller number of deployment options than
+  their parent
+
+Child scenarios are specific scenarios. Parent scenarios can be generic or specific
+scenarios.
+
+Child scenarios can be created any time. If they want to join a release, they have
+to be created before MS0 of that release.
+
+
+Siblings
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In some cases it could make more sense to create a sibling rather than a child
+(e.g. if expected that merging back to parent will be difficult).
+In other words, the content of a child scenario will be incompatible with content
+of the parent scenario.
+In that case, the child scenario should rather become a new branch instead of
+merging back to the parent.
+
+.. figure:: sibling.png
+
+Typically the sibling uses alternate components/solutions than the parent – in
+long term it might evolve into a new generic scenario, that is a new branch
+in the scenario tree.
+
+Creation of the sibling shall not be gated. It should be covered in the scope of
+an approved project, so there cannot be too big surprises.
+
+But at a certain time the new scenario will want to change its status from a
+specific scenario to a generic scenario. This move will need TSC approval.
+For the application, the scenario owner shall demonstrate that the scenario
+fulfills the requirements of a generic scenario (see later).
+
+Examples: SDN controller options, Container technologies, data plane solutions,
+MANO solutions.
+
+Please note that from time to time, the TSC will need to review the
+set of generic scenarios and "branches" in the scenario tree.
+
+
diff --git a/docs/scenario-lifecycle/parent-child.png b/docs/scenario-lifecycle/parent-child.png
new file mode 100644
index 0000000..2f71149
--- /dev/null
+++ b/docs/scenario-lifecycle/parent-child.png
diff --git a/docs/scenario-lifecycle/scenario-descriptor-files.rst b/docs/scenario-lifecycle/scenario-descriptor-files.rst
new file mode 100644
index 0000000..b6c44f7
--- /dev/null
+++ b/docs/scenario-lifecycle/scenario-descriptor-files.rst
@@ -0,0 +1,228 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Scenario Descriptor Files
+----------------------------
+
+What are Scenario Descriptor Files?
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Every scenario is described in its own descriptor file.
+The scenario descriptor file will be used by several parties:
+
+* Installer tools will read from it the list of components to be installed
+  and the configuration (e.g. deployment options and necessary details) to use.
+* The dynamic CI process will read from it the prerequisites of the scenario
+  to select the resource that has the needed capabilities for the deployment.
+  It will also select the installer
+  from the list of supported installers and the other deployment options as
+  supported in their combination.
+
+  The dynamic CI process will provide the installers with the deployment option
+  to use for a particular deployment.
+
+* The scenario owner needs to provide the descriptor file.
+
+  When compiling it the scenario owner typically needs to work together with
+  the installers, so the installers will support the required components and
+  options.
+* The testing framework can read from the scenario descriptor file necessary
+  information to know which features can be tested on the scenario.
+* The scenario descriptor file will also contain some maintenance information
+
+
+Structure of the file
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The scenario descriptor file is a yaml file. The syntax will allow to specify
+additional descriptor files, to make it better readable or structure common
+configurations across multiple scenarios.
+
+The file has following main sections:
+
+* metadata (owner, history, description)
+* list of components (names, versions, submodules)
+* deployment options (HA/NOHA, hardware&virtualization, installers, including
+  possible combinations and necessary details)
+* other prerequisites (e.g. memory requirement more than pharos spec)
+* list of features to be tested
+
+More information to be provided in next version of this document. The file will
+be defined based on the installer-specific files for scenario specification
+used by the 4 installers in Danube release. Thus it will be made sure that the
+information needed by the installers will be covered.
+
+All scenario files will be stored in a central repo, e.g. Octopus. There will
+also be a commented template to help create scenario descriptor files.
+
+
+Metadata
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In Danube timeframe only Fuel installer has some metadata in the descriptor file.
+The new template contains:
+
+* Unique name
+
+  This is a free name, there is a recommendation to take fish for names, matching
+  OPNFV release naming with rivers.
+
+* A free text title
+
+  This should be a short descriptive text telling the main purpose
+
+* A version number for the descriptor file
+
+  Three digits, separated with dots, as used by Fuel in Danube
+
+* Creation date
+* Comment
+
+  The file should contain a clear description of the purpose of the scenario,
+  including the main benefits and major features.
+  If applicable, the parent scenario should be mentioned.
+
+* First OPNFV version to use the scenario
+* Author/Owner
+
+* A list of additional contact persons, e.g. from installers or major components
+
+Components
+^^^^^^^^^^^^^^^^
+
+In this section all components are listed together with their version.
+For some components in addtion submodules can be listed.
+
+More details will be added.
+
+
+Deployment options
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This section will list the supported deployment options. In each category at least
+one option must be supported.
+
+* hardware (cpu) types (intel or ARM)
+* Virtualization (bare-metal or vPOD)
+* availability (HA or NOHA)
+
+  This subsection needs to specify also what does an HA deployment need, e.g.:
+
+::
+
+  availability:
+
+    - type: HA
+        nodes:
+          - name: host1
+            roles:
+              - openstack-controller
+              - odl
+              - ceph-adm
+              - ceph-mon
+          - name: host2
+            roles:
+              - openstack-controller
+              - odl
+              - ceph-adm
+              - ceph-mon
+          - name: host3
+            roles:
+              - openstack-controller
+              - odl
+              - ceph-adm
+              - ceph-mon
+          - name: host4
+              - openstack-compute
+              - ceph-osd
+          - name: host5
+              - openstack-compute
+              - ceph-osd
+    - type: NOHA
+        hosts:
+          - name: host1
+            roles:
+              - openstack-controller
+              - odl
+              - ceph-adm
+              - ceph-mon
+          - name: host2
+              - openstack-compute
+              - ceph-osd
+          - name: host3
+              - openstack-compute
+              - ceph-osd
+
+
+
+* deployment tool (apex, compass, fuel, daisy, joid)
+
+  In the section for each deployment tool, the combinations of the first three
+  options have to be listed, e.g.:
+
+::
+
+  deployment-tools:
+
+    - type: fuel
+         cpu: intel
+         pod: baremetal
+         availability: HA
+    - type: fuel
+         cpu: intel
+         pod: virtual
+         availability: HA
+    - type: fuel
+         cpu: intel
+         pod: virtual
+         availability: NOHA
+
+Please note that this allows easy definition of other availability options
+including scaling and redundant configuration of SDN controllers.
+
+
+Prerequisites
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This section will list additional prerequisites. Currently there is only
+one case where a scenario has additional prerequisites to the Pharos spec.
+E.g. a component could requires more RAM on the nodes than defined in
+Pharos spec.
+In general it should be preferred to issue such requirements to pharos
+using the pharos change request process, but in some cases in might be
+better to specify additional prerequisites.
+
+Another use case for these prerequisites will be usage of specilized
+hardware, e.g. for acceleration. This needs further study.
+
+The section can be empty or omitted.
+
+
+Testcases
+^^^^^^^^^^^^^^^^
+
+This section will provide information for functest and yardstick to decide
+on the proper test cases for the scenario.
+
+More details will be added.
+
+
+Shared settings
+^^^^^^^^^^^^^^^^
+
+This descriptor file might get quite long and complex. Also some of the settings
+will be shared between several scenarios, e.g. a long OpenStack module list.
+
+Therefore it shall be possible to reference another file like a macro.
+In that case all the file content is included in that place, e.g.:
+
+::
+
+  availability:
+
+    - type: HA
+        file: odl-ha-configuration.yaml
+
+
diff --git a/docs/scenario-lifecycle/scenario-overview.rst b/docs/scenario-lifecycle/scenario-overview.rst
new file mode 100644
index 0000000..9c9c508
--- /dev/null
+++ b/docs/scenario-lifecycle/scenario-overview.rst
@@ -0,0 +1,97 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+.. Scenario Lifecycle
+.. ==========================================
+
+Note: This document is still work in progress.
+
+Overview
+-------------
+
+Problem Statement:
+^^^^^^^^^^^^^^^^^^^
+
+OPNFV provides the NFV reference platform in different variants, using different
+upstream open source projects.
+In many cases this includes also different upstream projects providing similar or
+overlapping functionality.
+
+OPNFV introduces scenarios to define various combinations of components from upstream
+projects or configuration options for these components.
+
+The number of such scenarios has increased over time, so it is necessary to clearly
+define how to handle the scenarios.
+
+Introduction:
+^^^^^^^^^^^^^^^^^^^
+Some OPNFV scenarios have an experimental nature, since they introduce
+new technologies that are not yet mature enough to provide a stable release.
+Nevertheless there also needs to be a way to provide the user with the
+opportunity to try these new features in an OPNFV release context.
+
+Other scenarios are used to provide stable environments for users
+that wish to build products or live deployments on them.
+
+OPNFV scenario lifecycle process will support this by defining two types of scenarios:
+
+* **Generic scenarios** cover a stable set of common features provided
+  by different components and target long-term usage.
+* **Specific scenarios** are needed during development to introduce new upstream
+  components or new features.
+  They are intended to merge with other specific scenarios
+  and bring their features into at least one generic scenario.
+
+OPNFV scenarios are deployed using one of the installer tools.
+A scenario can be deployed by multiple installers and the result will look
+very similar but different. The capabilities provided by the deployments
+should be identical. Results of functional tests should be the same,
+independent of the installer that had been used. Performance or other
+behavioral aspects could be different.
+The scenario lifecycle process will also define how to document which installer
+can be used for a scenario and how the CI process can trigger automatic deployment
+for a scenario via one of the supported installers.
+
+When a developer decides to define a new scenario, he typically will take one
+of the existing scenarios and does some changes, such as:
+
+* add additional components
+* change a deploy-time configuration
+* use a component in a more experimental version
+
+In this case the already existing scenario is called a "parent" and the new
+scenario a "child".
+
+Typically parent scenarios are generic scenarios, but this is not mandated.
+In most times the child scenario will develop the new functionality over some
+time and then try to merge its configuration back to the parent.
+But in other cases, the child will introduce a technology that cannot easily
+be combined with the parent.
+For this case this document will define how a new generic scenario can be created.
+
+Many OPNFV scenarios can be deployed in a HA (high availability) or non-HA
+configuration.
+HA configurations deploy some components according to a redundancy model,
+as the components support.
+In these cases multiple deployment options are defined for the same scenario.
+
+Deployment options will also be used if the same scenario can be deployed
+on multiple types of hardware, i.e. Intel and ARM.
+
+Every scenario will be described in a scenario descriptor yaml file.
+This file shall contain all the necessary information for different users, such
+as the installers (which components to deploy etc.),
+the ci process (to find the right resources),
+the test projects (to select correct test cases), etc.
+
+In early OPNFV releases, scenarios covered components of the infrastructure,
+that is NFVI and VIM.
+With the introduction of MANO, an additional dimension for scenarios is needed.
+The same MANO components need to be used together with each of the infrastructure
+scenarios. Thus MANO scenarios will define the MANO components and a list of
+infrastructure scenarios to work with. Please note that MANO scenarios follow
+the same lifecycle and rules for generic and specific scenarios like the
+infrastructure scenarios.
+
diff --git a/docs/scenario-lifecycle/scenario-tree+idea.png b/docs/scenario-lifecycle/scenario-tree+idea.png
new file mode 100644
index 0000000..b6d4d8a
--- /dev/null
+++ b/docs/scenario-lifecycle/scenario-tree+idea.png
diff --git a/docs/scenario-lifecycle/scenario-tree.png b/docs/scenario-lifecycle/scenario-tree.png
new file mode 100644
index 0000000..619b5a3
--- /dev/null
+++ b/docs/scenario-lifecycle/scenario-tree.png
diff --git a/docs/scenario-lifecycle/sibling.png b/docs/scenario-lifecycle/sibling.png
new file mode 100644
index 0000000..82d4805
--- /dev/null
+++ b/docs/scenario-lifecycle/sibling.png
diff --git a/docs/scenario-lifecycle/specific-scenarios.rst b/docs/scenario-lifecycle/specific-scenarios.rst
new file mode 100644
index 0000000..5f426e7
--- /dev/null
+++ b/docs/scenario-lifecycle/specific-scenarios.rst
@@ -0,0 +1,34 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+.. (c) 2017 OPNFV Ulrich Kleber (Huawei)
+
+
+Specific Scenarios
+------------------
+
+Specific scenarios are used for OPNFV development and help to isolate a path of development.
+
+* Specific scenarios typically focus on a feature or topic.
+* Specific scenarios allow to advance in development for their main feature without
+  de-stabilizing other features.
+* Specific scenarios provide additional flexibility in their handling to allow the
+  development be agile.
+* Specific scenarios can use new version of their main upstream component or even
+  apply midstream patches during OPNFV deployment, i.e. the deployable artifact
+  is created via cross community CI or even only in OPNFV and not upstream.
+* Specific scenarios should have a limited life time. After a few releases, the feature
+  development should have matured and the feature made available different configurations
+  if possible. Typically the scenario then should be merged with other scenarios, best
+  with generic scenarios.
+* Normally specific scenarios will be released within the major OPNFV releases. But
+  they don't need to fulfill maturity requirements (stable upstream versions and repos,
+  stability testing), and can deviate in the used upstream versions.
+* In exceptional cases we might release a specific scenario independently, in case there
+  is a need. Thus specific scenarios provide a way to a more DevOps-like process.
+* Specific scenarios will likely have a shorter support period after release as they are of
+  interest to a smaller user community vs generic scenarios.
+* They will be granted less CI resources than generic scenarios, e.g. for periodic
+  CI jobs.
+* We may need to prioritize resources post-release for maintenance / regression testing.
+
+