diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index fcddfe1..4722dca 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -83,7 +83,7 @@ jobs:
           context: .
           push: true
           tags: |
-            lsstsqre/mobu:${{ steps.vars.outputs.tag }}
-            ghcr.io/lsst-sqre/mobu:${{ steps.vars.outputs.tag }}
+            lsstsqre/influx-bucket-mapper:${{ steps.vars.outputs.tag }}
+            ghcr.io/lsst-sqre/influx-bucket-mapper:${{ steps.vars.outputs.tag }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
diff --git a/bucketmapper b/bucketmapper
index b94e6d3..ab34ecf 100755
--- a/bucketmapper
+++ b/bucketmapper
@@ -9,8 +9,8 @@ import aiohttp
 
 # InfluxDB2 defaults
 
-DEFAULT_URL = "http://localhost:8086"
 DEFAULT_ORG = "default"
+DEFAULT_URL = "http://localhost:8086"
 
 # Simple typealiases to represent InfluxDB v2 object fields
 # Unless otherwise specified, they can be found at:
diff --git a/scripts/docker-tag.sh b/scripts/docker-tag.sh
new file mode 100755
index 0000000..080a9c9
--- /dev/null
+++ b/scripts/docker-tag.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+
+# Determine the tag for Docker images based on GitHub Actions environment
+# variables.
+
+set -eo pipefail
+
+if [ -n "$GITHUB_HEAD_REF" ]; then
+    # For pull requests
+    echo ${GITHUB_HEAD_REF} | sed -E 's,/,-,g'
+else
+    # For push events
+    echo ${GITHUB_REF} | sed -E 's,refs/(heads|tags)/,,' | sed -E 's,/,-,g'
+fi