batch-system: Introduce <slurm-api-batch-system> record type.

A <slurm-api-batch-system> record type allows us an easy way to group
and pass along parameters required by the slurm-api batch system.

* ravanan/batch-system.scm: New file.
* bin/ravanan: Import (ravanan batch-system).
(main): Create <slurm-api-batch-system> object for batch-system
argument. Do not pass #:slurm-api-endpoint and #:slurm-jwt arguments.
*
ravanan/command-line-tool.scm: Import (ravanan batch-system).
(command-line-tool-supported-requirements): Check for slurm-api batch
system using slurm-api-batch-system?.
(run-command-line-tool): Check for slurm-api batch system using
slurm-api-batch-system?. Do not accept #:slurm-api-endpoint and
#:slurm-jwt arguments.
* ravanan/workflow.scm: Import (ravanan batch-system).
(workflow-scheduler): Do not accept #:slurm-api-endpoint and
#:slurm-jwt arguments. Pass batch-system to job-state-status.
(run-workflow): Check for slurm-api batch system using
slurm-api-batch-system?. Do not accept #:slurm-api-endpoint and
#:slurm-jwt arguments.
* ravanan/job-state.scm: Import (ravanan batch-system).
(job-state-status): Do not accept #:slurm-api-endpoint and #:slurm-jwt
arguments. Accept batch-system argument.

5 files changed, 77 insertions, 59 deletions

diff --git a/bin/ravanan b/bin/ravanan
index cc9005d..5807a8e 100755
--- a/bin/ravanan
+++ b/bin/ravanan
@@ -27,6 +27,7 @@ exec guile --no-auto-compile -e main -s "$0" "$@"
              (ice-9 match)
              (web uri)
              (json)
+             (ravanan batch-system)
              (ravanan reader)
              (ravanan utils)
              (ravanan workflow))
@@ -145,11 +146,14 @@ files that have the token in the @verbatim{SLURM_JWT=token} format."
                                    (if (file-name-absolute? (assq-ref args 'store))
                                        (assq-ref args 'store)
                                        (canonicalize-path (assq-ref args 'store)))
-                                   (assq-ref args 'batch-system)
-                                   #:guix-daemon-socket (assq-ref args 'guix-daemon-socket)
-                                   #:slurm-api-endpoint (assq-ref args 'slurm-api-endpoint)
-                                   #:slurm-jwt (and (assq-ref args 'slurm-jwt)
-                                                    (read-jwt (assq-ref args 'slurm-jwt))))
+                                   (case (assq-ref args 'batch-system)
+                                     ((single-machine) 'single-machine)
+                                     ((slurm-api)
+                                      (slurm-api-batch-system
+                                       (assq-ref args 'slurm-api-endpoint)
+                                       (and (assq-ref args 'slurm-jwt)
+                                            (read-jwt (assq-ref args 'slurm-jwt))))))
+                                   #:guix-daemon-socket (assq-ref args 'guix-daemon-socket))
                      (current-output-port)
                      #:pretty #t)
           (newline (current-output-port))))))))
diff --git a/ravanan/batch-system.scm b/ravanan/batch-system.scm
new file mode 100644
index 0000000..726bff8
--- /dev/null
+++ b/ravanan/batch-system.scm
@@ -0,0 +1,30 @@
+;;; ravanan --- High-reproducibility CWL runner powered by Guix
+;;; Copyright © 2024 Arun Isaac <arunisaac@systemreboot.net>
+;;;
+;;; This file is part of ravanan.
+;;;
+;;; ravanan is free software: you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation, either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; ravanan is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with ravanan.  If not, see <https://www.gnu.org/licenses/>.
+
+(define-module (ravanan batch-system)
+  #:use-module (srfi srfi-9 gnu)
+  #:export (slurm-api-batch-system
+            slurm-api-batch-system?
+            slurm-api-batch-system-endpoint
+            slurm-api-batch-system-jwt))
+
+(define-immutable-record-type <slurm-api-batch-system>
+  (slurm-api-batch-system endpoint jwt)
+  slurm-api-batch-system?
+  (endpoint slurm-api-batch-system-endpoint)
+  (jwt slurm-api-batch-system-jwt))
diff --git a/ravanan/command-line-tool.scm b/ravanan/command-line-tool.scm
index 6225595..4254df9 100644
--- a/ravanan/command-line-tool.scm
+++ b/ravanan/command-line-tool.scm
@@ -35,6 +35,7 @@
   #:use-module (guix search-paths)
   #:use-module (guix store)
   #:use-module (json)
+  #:use-module (ravanan batch-system)
   #:use-module (ravanan javascript)
   #:use-module (ravanan job-state)
   #:use-module (ravanan reader)
@@ -75,11 +76,11 @@
         "ResourceRequirement"))
 
 (define (command-line-tool-supported-requirements batch-system)
-  (case batch-system
-    ((single-machine)
+  (cond
+    ((eq? batch-system 'single-machine)
      (delete "ResourceRequirement"
              %command-line-tool-supported-requirements))
-    ((slurm-api)
+    ((slurm-api-batch-system? batch-system)
      %command-line-tool-supported-requirements)
     (else
      (assertion-violation batch-system "Unknown batch system"))))
@@ -370,14 +371,12 @@ path."
 
 (define* (run-command-line-tool name manifest-file cwl inputs
                                 scratch store batch-system
-                                #:key guix-daemon-socket
-                                slurm-api-endpoint slurm-jwt)
+                                #:key guix-daemon-socket)
   "Run @code{CommandLineTool} class workflow @var{cwl} named @var{name} with
 @var{inputs} using tools from Guix manifest in @var{manifest-file}.
 
-@var{scratch}, @var{store}, @var{batch-system}, @var{guix-daemon-socket},
-@var{slurm-api-endpoint} and @var{slurm-jwt} are the same as in
-@code{run-workflow} from @code{(ravanan workflow)}."
+@var{scratch}, @var{store}, @var{batch-system} and @var{guix-daemon-socket} are
+the same as in @code{run-workflow} from @code{(ravanan workflow)}."
   ;; TODO: Write to the store atomically.
   (let* ((script
           (build-command-line-tool-script name manifest-file cwl inputs
@@ -422,8 +421,8 @@ path."
           (when (file-exists? store-files-directory)
             (delete-file-recursively store-files-directory))
           (mkdir store-files-directory)
-          (case batch-system
-            ((single-machine)
+          (cond
+            ((eq? batch-system 'single-machine)
              (setenv "WORKFLOW_OUTPUT_DIRECTORY" store-files-directory)
              (setenv "WORKFLOW_OUTPUT_DATA_FILE" store-data-file)
              (format (current-error-port)
@@ -434,7 +433,7 @@ path."
                                                 (lambda ()
                                                   (with-error-to-file stderr-file
                                                     (cut system* script)))))))
-            ((slurm-api)
+            ((slurm-api-batch-system? batch-system)
              (format (current-error-port)
                      "Submitting job ~a~%"
                      script)
@@ -447,8 +446,8 @@ path."
                                        cpus
                                        name
                                        script
-                                       #:api-endpoint slurm-api-endpoint
-                                       #:jwt slurm-jwt)))
+                                       #:api-endpoint (slurm-api-batch-system-endpoint batch-system)
+                                       #:jwt (slurm-api-batch-system-jwt batch-system))))
                (format (current-error-port)
                        "~a submitted as job ID ~a~%"
                        script
@@ -610,10 +609,10 @@ named @var{name} with @var{inputs} using tools from Guix manifest in
                                  "listing")))
 
   (define (cores batch-system)
-    (case batch-system
-      ((slurm-api)
+    (cond
+      ((slurm-api-batch-system? batch-system)
        #~(string->number (getenv "SLURM_CPUS_ON_NODE")))
-      ((single-machine)
+      ((eq? batch-system 'single-machine)
        #~(total-processor-count))
       (else
        (assertion-violation batch-system "Unknown batch system"))))
diff --git a/ravanan/job-state.scm b/ravanan/job-state.scm
index 88ed4b7..834a5bd 100644
--- a/ravanan/job-state.scm
+++ b/ravanan/job-state.scm
@@ -26,6 +26,7 @@
 
 (define-module (ravanan job-state)
   #:use-module (srfi srfi-9 gnu)
+  #:use-module (ravanan batch-system)
   #:use-module (ravanan slurm-api)
   #:use-module (ravanan work vectors)
   #:export (single-machine-job-state
@@ -54,12 +55,10 @@
      slurm-job-state-script))
    state))
 
-(define* (job-state-status state #:key slurm-api-endpoint slurm-jwt)
-  "Return current status and updated state of job with @var{state}. The status is
-one of the symbols @code{completed}, @code{failed} or @code{pending}.
-
-@var{slurm-api-endpoint} and @var{slurm-jwt} are the same as in
-@code{run-workflow} from @code{(ravanan workflow)}."
+(define* (job-state-status state batch-system)
+  "Return current status and updated state of job with @var{state} on
+@var{batch-system}. The status is one of the symbols @code{completed},
+@code{failed} or @code{pending}."
   (values (cond
            ;; Single machine jobs are run synchronously. So, they return success
            ;; or failure immediately.
@@ -70,15 +69,13 @@ one of the symbols @code{completed}, @code{failed} or @code{pending}.
            ;; Poll slurm for job state.
            ((slurm-job-state? state)
             (job-state (slurm-job-state-job-id state)
-                       #:api-endpoint slurm-api-endpoint
-                       #:jwt slurm-jwt))
+                       #:api-endpoint (slurm-api-batch-system-endpoint batch-system)
+                       #:jwt (slurm-api-batch-system-jwt batch-system)))
            ;; For vector states, poll each state element and return 'completed
            ;; only if all state elements have completed.
            ((vector? state)
             (or (vector-every (lambda (state-element)
-                                (case (job-state-status state-element
-                                                        #:slurm-api-endpoint slurm-api-endpoint
-                                                        #:slurm-jwt slurm-jwt)
+                                (case (job-state-status state-element batch-system)
                                   ((completed) => identity)
                                   (else #f)))
                               state)
diff --git a/ravanan/workflow.scm b/ravanan/workflow.scm
index 95dfb73..61a1297 100644
--- a/ravanan/workflow.scm
+++ b/ravanan/workflow.scm
@@ -27,6 +27,7 @@
   #:use-module (ice-9 filesystem)
   #:use-module (ice-9 match)
   #:use-module (web uri)
+  #:use-module (ravanan batch-system)
   #:use-module (ravanan command-line-tool)
   #:use-module (ravanan job-state)
   #:use-module (ravanan propnet)
@@ -246,8 +247,7 @@ propagator."
            scheduler))
 
 (define* (workflow-scheduler manifest-file scratch store batch-system
-                             #:key guix-daemon-socket
-                             slurm-api-endpoint slurm-jwt)
+                             #:key guix-daemon-socket)
   (define (schedule proc inputs scheduler)
     "Schedule @var{proc} with inputs from the @var{inputs} association list. Return a
 job state object. @var{proc} may either be a @code{<propnet>} object or a
@@ -296,9 +296,7 @@ job state object. @var{proc} may either be a @code{<propnet>} object or a
                                       scratch
                                       store
                                       batch-system
-                                      #:guix-daemon-socket guix-daemon-socket
-                                      #:slurm-api-endpoint slurm-api-endpoint
-                                      #:slurm-jwt slurm-jwt)
+                                      #:guix-daemon-socket guix-daemon-socket)
                (assoc-ref* cwl "outputs")))
              ((string=? class "ExpressionTool")
               (error "Workflow class not implemented yet" class))
@@ -335,8 +333,7 @@ exit if job has failed."
        ((command-line-tool-state? state)
         (let ((status updated-job-state
                       (job-state-status (command-line-tool-state-job-state state)
-                                        #:slurm-api-endpoint slurm-api-endpoint
-                                        #:slurm-jwt slurm-jwt)))
+                                        batch-system)))
           (values (case status
                     ((failed)
                      (raise-exception (job-failure
@@ -572,29 +569,18 @@ error out."
 
 (define* (run-workflow name manifest-file cwl inputs
                        scratch store batch-system
-                       #:key guix-daemon-socket
-                       slurm-api-endpoint slurm-jwt)
+                       #:key guix-daemon-socket)
   "Run a workflow @var{cwl} named @var{name} with @var{inputs} using
 tools from Guix manifest in @var{manifest-file}.
 
-@var{scratch} is the path to the scratch area on all worker nodes. The
-scratch area need not be shared. @var{store} is the path to the shared
-ravanan store. @var{batch-system} is a symbol representing one of the
-supported batch systems (either @code{'single-machine} or
-@code{'slurm-api}).
+@var{scratch} is the path to the scratch area on all worker nodes. The scratch
+area need not be shared. @var{store} is the path to the shared ravanan store.
+@var{batch-system} is an object representing one of the supported batch systems.
 
-@var{guix-daemon-socket} is the Guix daemon socket to connect to.
-
-@var{slurm-api-endpoint}, a @code{<uri>} object, is the slurm API
-endpoint to connect to. @var{slurm-jwt}, a string, is the JWT token to
-authenticate to the slurm API with. @var{slurm-api-endpoint} and
-@var{slurm-jwt} are only used when @var{batch-system} is
-@code{'slurm-api}."
+@var{guix-daemon-socket} is the Guix daemon socket to connect to."
   (let ((scheduler (workflow-scheduler
                     manifest-file scratch store batch-system
-                    #:guix-daemon-socket guix-daemon-socket
-                    #:slurm-api-endpoint slurm-api-endpoint
-                    #:slurm-jwt slurm-jwt)))
+                    #:guix-daemon-socket guix-daemon-socket)))
     (let loop ((state ((scheduler-schedule scheduler)
                        (scheduler-proc name cwl %nothing %nothing)
                        inputs
@@ -605,11 +591,13 @@ authenticate to the slurm API with. @var{slurm-api-endpoint} and
             (begin
               ;; Pause before looping and polling again so we don't bother the
               ;; job server too often.
-              (sleep (case batch-system
+              (sleep (cond
                        ;; Single machine jobs are run synchronously. So, there
                        ;; is no need to wait to poll them.
-                       ((single-machine) 0)
-                       ((slurm-api) %job-poll-interval)))
+                       ((eq? batch-system 'single-machine)
+                        0)
+                       ((slurm-api-batch-system? batch-system)
+                        %job-poll-interval)))
               (loop state))
             ;; Capture outputs.
             ((scheduler-capture-output scheduler) state))))))