caddyhttp: Escaping placeholders in CEL, add vars and vars_regexp (#6594)

* caddyhttp: Escaping placeholders in CEL

* Simplify some of the test cases

* Implement vars and vars_regexp in CEL

* dupl lint is dumb

* Better consts for the placeholder CEL shortcut

* Bump CEL version, register a few extensions

* Refactor s390x test script for readability

* Add retries for s390x to smooth over flakiness

* Switch to `ph` for the CEL shortcut (match it in templates cause why not)

.github/workflows/ci.yml

@@ -156,13 +156,35 @@ jobs:
           # short sha is enough?
           short_sha=$(git rev-parse --short HEAD)
 
+          # To shorten the following lines
+          ssh_opts="-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
+          ssh_host="$CI_USER@ci-s390x.caddyserver.com"
+
           # The environment is fresh, so there's no point in keeping accepting and adding the key.
-          rsync -arz -e "ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null" --progress --delete --exclude '.git' . "$CI_USER"@ci-s390x.caddyserver.com:/var/tmp/"$short_sha"
-          ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -t "$CI_USER"@ci-s390x.caddyserver.com "cd /var/tmp/$short_sha; go version; go env; printf "\n\n";CGO_ENABLED=0 go test -p 1 -tags nobadger -v ./..."
+          rsync -arz -e "ssh $ssh_opts" --progress --delete --exclude '.git' . "$ssh_host":/var/tmp/"$short_sha"
+          ssh $ssh_opts -t "$ssh_host" bash <<EOF
+          cd /var/tmp/$short_sha
+          go version
+          go env
+          printf "\n\n"
+          retries=3
+          exit_code=0
+          while ((retries > 0)); do
+            CGO_ENABLED=0 go test -p 1 -tags nobadger -v ./...
+            exit_code=$?
+            if ((exit_code == 0)); then
+              break
+            fi
+            echo "\n\nTest failed: \$exit_code, retrying..."
+            ((retries--))
+          done
+          echo "Remote exit code: \$exit_code"
+          exit \$exit_code
+          EOF
           test_result=$?
 
           # There's no need leaving the files around
-          ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null "$CI_USER"@ci-s390x.caddyserver.com "rm -rf /var/tmp/'$short_sha'"
+          ssh $ssh_opts "$ssh_host" "rm -rf /var/tmp/'$short_sha'"
 
           echo "Test exit code: $test_result"
           exit $test_result