Buildkite: Add an env variable to run single nightly steps

.buildkite/nightly.yml

@@ -11,6 +11,7 @@ steps:
  agents:
  system: x86_64-linux
  queue: benchmark
+ if: 'build.env("step") == null || build.env("step") =~ /restore-mainnet/'
 
 # Temporary disabled due to timing out (#2221)
 # - label: 'Restore benchmark - cardano testnet'
@@ -21,20 +22,23 @@ steps:
 # agents:
 # system: x86_64-linux
 # queue: benchmark
+# if: 'build.env("step") == null || build.env("step") =~ /restore-testnet/'
 
  - label: 'Database benchmark'
  command: "./.buildkite/bench-db.sh"
  timeout_in_minutes: 120
  agents:
  system: x86_64-linux
  queue: benchmark
+ if: 'build.env("step") == null || build.env("step") =~ /bench-db/'
 
  - label: 'Latency benchmark'
  command: "./.buildkite/bench-latency.sh"
  timeout_in_minutes: 120
  agents:
  system: x86_64-linux
  queue: benchmark
+ if: 'build.env("step") == null || build.env("step") =~ /bench-latency/'
 
  # TODO: ADP-549 Port migrations test to shelley
  # - label: 'Database Migrations Test'
@@ -45,6 +49,7 @@ steps:
  # timeout_in_minutes: 60
  # agents:
  # system: x86_64-linux
+ # if: 'build.env("step") == null || build.env("step") =~ /migration-tests/'
 
  - label: 'Full cabal build'
  command: 'nix-shell nix/cabal-shell.nix --arg withCabalCache true --run "scripts/buildkite/cabal-ci.sh build"'
@@ -53,10 +58,12 @@ steps:
  CABAL_STORE_DIR: "/build/cardano-wallet.store"
  agents:
  system: x86_64-linux
+ if: 'build.env("step") == null || build.env("step") =~ /cabal/'
 
  - wait
 
  - label: "Advance linux-tests-pass and all-tests-pass branches"
  command: "./.buildkite/push-branch.sh linux-tests-pass windows-tests-pass all-tests-pass"
  agents:
  system: x86_64-linux
+ if: 'build.env("step") == null'