wb | check correct commit when using the nomadcloud backend

Author: fmaste

nix/workbench/backend/nomad.nix

@@ -52,7 +52,7 @@ let
   # path of this packages while keeping the extra details as a `jq` friendly
   # reference that are used to change it later appending the desired commit
   # (interchanging commits it's still an untested feature).
-  # For cloud runs references:
+  # For "nomadcloud" runs workbench's `$WB_GITREV` is used as commit:
   # installable="${flakeReference}/${commit}#${flakeOutput}"
   installables =
     {
@@ -142,7 +142,7 @@ let
     {
       # Provided that all the "start.sh" scripts are taking it into account,
       # this packages could be configured to come from a different commit than
-      # the one used to enter the shell ??????????
+      # the one used to enter the shell.
       cardano-node = rec {
         # Local reference only used if not "cloud".
         # Avoid rebuilding on every commit because of `set-git-rev`.

nix/workbench/backend/nomad/cloud.sh

@@ -334,8 +334,8 @@ allocate-run-nomadcloud() {
   # outputs it needs inside the container, these are built using the packages
   # metadata in "containerPkgs" and the current commit.
   local gitrev
-  gitrev="$(git rev-parse HEAD)"
-  msg $(blue "INFO: Found GitHub commit with ID \"$gitrev\"")
+  gitrev="${WB_GITREV:?"No WB_GITREV"}"
+  msg $(blue "INFO: Found GitHub commit with ID \"$gitrev\" set on shell creation")
   # Check if the Nix package was created from a dirty git tree
   if test "$gitrev" = "0000000000000000000000000000000000000000"
   then

nix/workbench/backend/runner.nix

@@ -38,6 +38,7 @@ let
   # build plan as computed by nix
   nixPlanJson = cardanoNodeProject.plan-nix.json;
 
+  # Optimize cache hits setting gitrev using bash once inside the shell.
   workbench-envars =
     ''
     export WB_CHAP_PATH=${chap}
@@ -50,6 +51,10 @@ let
     export WB_DEPLOYMENT_NAME=''${WB_DEPLOYMENT_NAME:-$(basename $(pwd))}
     export WB_MODULAR_GENESIS=''${WB_MODULAR_GENESIS:-0}
     export WB_LOCLI_DB=''${WB_LOCLI_DB:-1}
+    if test -z "$(git status --porcelain --untracked-files=no)"
+    then export WB_GITREV="$(git rev-parse HEAD)"
+    else export WB_GITREV="0000000000000000000000000000000000000000"
+    fi
     export CARDANO_NODE_SOCKET_PATH=${stateDir}/node-0/node.socket
     ''
     + lib.optionalString (profileBundle.profile.value.scenario == "chainsync") (
@@ -112,7 +117,7 @@ let
         gnused
         procps
         nix
-        git
+        git        # `workbench-envars` set the gitrev
         jq
       ]
     )