Merge pull request #1144 from rabbitmq/version-go-in-prom-tests

Explicitly install a known golang version.

.github/workflows/prometheus-rules.yml

@@ -5,15 +5,21 @@ on:
     - main
     paths:
     - observability/prometheus/rules/**/*.y*ml
+
+env:
+  GO_VERSION: 1.19.1
+
 jobs:
   rules:
     runs-on: ubuntu-latest
     steps:
+      - name: Install Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ env.GO_VERSION }}
       - uses: actions/checkout@v2
       - name: Create Prometheus rule file
         run: |
-          export GOPATH=$HOME/go
-          export PATH=$PATH:$GOPATH/bin
           make install-tools
           cd observability/prometheus/
           echo "# This file got auto-generated by GitHub workflow '$GITHUB_WORKFLOW'" > rule-file.yml
@@ -31,8 +37,6 @@ jobs:
           yq eval-all --inplace --no-colors --prettyPrint "$append_rabbitmq_rules" rule-file.yml rules/rabbitmq/recording-rules.yml
       - name: Check Prometheus rule file
         run: |
-          export GOPATH=$HOME/go
-          export PATH=$PATH:$GOPATH/bin
           # need to use @main because of https://github.com/prometheus/prometheus/issues/8586#issuecomment-796976710
           GO111MODULE=on go get github.com/prometheus/prometheus/cmd/promtool@main
           promtool check rules observability/prometheus/rule-file.yml