Add gofmt checks to presubmit

config/jobs/presubmits.yaml

@@ -35,3 +35,14 @@ presubmits:
           - image: quay.io/peridot/ci:v0.3.16
             command:
               - hack/non_manual_build.sh
+
+    - name: pull-peridot-gofmt-check
+      branches:
+        - main
+      always_run: true
+      decorate: true
+      spec:
+        containers:
+          - image: quay.io/peridot/ci:v0.3.16
+            command:
+              - hack/gofmt_check.sh

hack/gofmt_check.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+set -o errexit
+
+bazel build --config=ci @go_sdk//...
+
+GO_BIN="$(bazel info output_base)/external/go_sdk/bin/go"
+
+if [[ -n $($GO_BIN fmt -n $(go list ./... | grep -v /vendor/) | sed 's/ -w//') ]]; then
+  echo "Go files must be formatted with gofmt. Please run:"
+  echo "  go fmt $(go list ./... | grep -v /vendor/)"
+  exit 1
+fi
+
+