add command line jobspec

Problem: we cannot define a shape on the command line
to map into a job specification resources section.
Solution: first add a command line jobspec that defines
this shape.

Signed-off-by: vsoch <[email protected]>

Author: vsoch

index.rst

@@ -185,6 +185,7 @@ I/O streams in the Flux KVS.
 Version 1 of the domain specific job specification language
 canonically defined in RFC14.
 
+
 :doc:`26/Job Dependency Specification <spec_26>`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -257,6 +258,13 @@ and other directives in files.
 The File Archive Format defines a JSON representation of a set or list
 of file system objects.
 
+:doc:`38/Command Line Job Specification Version 1 <spec_38>`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The command line jobspec describes how to define a shape on the
+command line that expands out to a full Job Specification. 
+It can be provided to several Flux commands.
+
 .. Each file must appear in a toctree
 .. toctree::
    :hidden:
@@ -297,3 +305,4 @@ of file system objects.
    spec_35
    spec_36
    spec_37
+   spec_38

spec_38.rst

@@ -0,0 +1,221 @@
+.. github display
+   GitHub is NOT the preferred viewer for this file. Please visit
+   https://flux-framework.rtfd.io/projects/flux-rfc/en/latest/spec_37.html
+
+38/Command Line Job Specification Version 1
+===========================================
+
+The Command Line Job Specification includes specification of a shape string
+that can be provided to several Flux commands by a user to expand into a resource
+graph. This RFC describes version 1 of jobspec, which represents a request 
+to run one or more tasks, and can be provided to a flux run, batch, or submit.
+
+-  Name: github.com/flux-framework/rfc/spec_37.rst
+-  Editor: Vanessa Sochat <[email protected]>
+-  State: raw
+
+Language
+--------
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
+"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to
+be interpreted as described in `RFC 2119 <https://tools.ietf.org/html/rfc2119>`__.
+
+
+Related Standards
+-----------------
+
+-  :doc:`4/Flux Resource Model <spec_4>`
+
+-  :doc:`8/Flux Task and Program Execution Services <spec_8>`
+
+-  :doc:`14/Canonical Job Specification <spec_14>`
+
+-  :doc:`20/Resource Set Specification Version 1 <spec_20>`
+
+-  :doc:`25/Job Specification Version 1 <spec_25>`
+
+-  :doc:`26/Job Dependency Specification <spec_26>`
+
+-  :doc:`31/Job Constraints Specification <spec_31>`
+
+
+Goals
+-----
+
+-  Express a resource specification on the command line, a "shape." to expand into the resources of a Job Specification (rfc 25).
+
+-  The shape should include resources, counts, attributes, and grouping.
+
+-  Allow to be included in several submission contexts, including submit, run, and batch.
+
+
+Overview
+--------
+
+This RFC describes the version 1 form of the command line jobspec,
+a string that can be expanded out into a Job Specification resources section.
+The version 1 of the command line jobspec SHALL consist of
+a single string of resources, attributes, and groups that can be mapped out
+into a YAML document representing a reusable request to run
+one or more tasks on a set of resources. 
+
+
+Command Line Job Definition
+---------------------------
+
+A command line V1 specification SHALL consist of a shape definition,
+a string that describes resources, attributes, and groups. This
+shape specification can be expanded to the ``resources`` section
+of a YAML document. The shape SHALL meet the form and requirements
+listed in detail in the sections below. 
+
+
+Shape
+~~~~~
+
+The value of the ``shape`` key SHALL be a single shape (string value).
+A shape is expanded into a resource definition. Only one of shape OR
+resources is allowed, and one is required. A shape takes the general format
+of ``Resource[Count+Attribute]`` where:
+
+- ``Resource`` includes the set defined below
+- ``Count`` is a positive intege to indicate the number of the resource
+- ``Attribute`` is indicated by the presence of a ``+`` and can be a key value pair ``+label=nodes`` or a boolean value ``+exclusive``
+
+And groups of resources can be indicated by adding parentheses, and having
+resources inside the group separated by a comma. E.g.,: ``A(B[1],C[2])``.
+
+
+Each of these will be described in further detail.
+
+Resource
+^^^^^^^^
+
+A resource is a named entity that represents a physical or virtual resource.
+The name of the resource MAY be lowercase, but it SHOULD be capitalized.
+Resource groups are separated by colons ``:``.
+As an example, the following shape indicates a single node with 1 core:
+
+.. ::code-block console
+
+    Node:Core
+
+and is expanded to
+
+.. ::code-block yaml
+
+    resources:
+    - type: Node
+      count: 1
+      with:
+        - type: Core
+          count: 1
+
+In the YAML above, note that the resource name (e.g., "Node" or "Core") is mapped
+to the resources "type," and is always added as an item in a list. Given that a resource
+list has children, these are appended via the "with" attribute. 
+
+
+Count
+^^^^^
+
+Note that for a count of 1 for any resource, it MAY be defined but is optional.
+All of these shapes would expand to the same resources shown above:
+
+.. ::code-block console
+
+    Node:Core
+    Node:Core[1]
+    Node[1]:Core
+    Node[1]:Core[1]
+
+
+The ``count`` is thus optional, and when provided, must be a positive integer value.
+The count maps directly to the number we provided in brackets, and when not present, it defaults to 
+1.
+
+Attributes
+^^^^^^^^^^
+
+Attributes are additional qualifiers that can be added to any resource, inside
+of the brackets. An attribute MUST be a known resource vertex as defined in RFC
+25. Attributes can be key value pairs or booleans, where each is prefixed by a
+``+``. For a key value pair, the format is ``[+key=value]`` and for a boolean
+flag (to indicate presence) it takes the general format ``[+flag]``.
+As an example, starting with these shapes (that are equivalent):
+
+
+.. ::code-block console
+
+    Node[4]:Slot:Core[2]
+    Node[4]:Slot[1]:Core[2]
+
+Are equivalent and are expanded to:
+
+.. ::code-block yaml
+
+    resources:
+      - type: node
+        count: 4
+        with:
+          - type: slot
+            count: 1
+            with:
+              - type: core
+                count: 2
+
+
+To add the attribute "label" to the same graph we might do:
+
+.. ::code-block console
+
+    Node[4]:Slot[+label=default]:Core[2]
+    Node[4]:Slot[1+label=default]:Core[2]
+
+
+To generate this YAML document:
+
+.. ::code-block yaml
+
+    resources:
+      - type: node
+        count: 4
+        with:
+          - type: slot
+            count: 1
+            label: default
+            with:
+              - type: core
+                count: 2
+
+
+Note that when a number is provided, it doesn't need an additional separator
+between the count (1) and label as the ``+`` acts as this delimiter.
+
+Groups
+^^^^^^
+
+Finally, it is possible to define multiple resources at the same level with the addition
+of parentheses. We call this a group. As an example, this shape:
+
+.. ::code-block console
+
+    Node[5]:(Core[5],GPU[1])
+
+Would map to this resource graph:
+
+.. ::code-block yaml
+
+    resources:
+      - type: node
+        count: 5
+        with:
+          - type: core
+            count: 5
+          - type: gpu
+            count: 1
+
+The assumption of this design is that most shape specifications would not have
+huge complexity of nesting. Any resource specification that warrants such complexity
+would best be defined in a YAML document directly.