Probe for an existing RPM before uploading to artifactapi

Avoid a failed/confusing re-upload by checking whether the package is already
published before PUTting it. artifactapi has no HEAD route (returns 405), so the
guard uses a GET against the served path (RPMs are stored under Packages/): a
200 means it exists and the upload is skipped, anything else proceeds.

Also point at the reachable artifactapi host (artifactapi.k8s.syd1.au.unkin.net,
as used by rpmbuilder) instead of the unresolvable artifactapi3 name.

.woodpecker/release.yml

@@ -17,11 +17,21 @@ steps:
     image: git.unkin.net/unkin/almalinux9-base:20260606
     commands:
       - |
+        HOST="https://artifactapi.k8s.syd1.au.unkin.net"
+        REPO="rpm-internal"
         for rpm in dist/*.rpm; do
           FILE=$$(basename "$$rpm")
-          echo "Uploading $${FILE} to artifactapi rpm-internal"
+          # Verify the package isn't already published before uploading.
+          # artifactapi has no HEAD route (returns 405), so probe with GET
+          # against the served path (RPMs are stored under Packages/).
+          code=$$(curl -s -o /dev/null -w '%{http_code}' "$$HOST/api/v2/remotes/$$REPO/files/Packages/$$FILE" || true)
+          if [ "$$code" = "200" ]; then
+            echo "$$FILE already exists in $$REPO (HTTP $$code); skipping upload"
+            continue
+          fi
+          echo "Uploading $$FILE to $$REPO (existence probe returned $$code)"
           curl -f -X PUT \
-            "https://artifactapi3.k8s.syd1.au.unkin.net/api/v2/remotes/rpm-internal/files/$${FILE}" \
+            "$$HOST/api/v2/remotes/$$REPO/files/$$FILE" \
             -H "Content-Type: application/x-rpm" \
             --data-binary @"$$rpm"
         done