ci: build magnum images (#1066)

Signed-off-by: Mohammed Naser <mnaser@vexxhost.com>
diff --git a/docker-bake.hcl b/docker-bake.hcl
index ea8a9be..7237361 100644
--- a/docker-bake.hcl
+++ b/docker-bake.hcl
@@ -52,8 +52,47 @@
     }
 }
 
+target "magnum" {
+    name = "magnum-${release.tgt}"
+
+    context = "."
+    target = "magnum"
+
+    cache-from = cache_from("magnum:${release.name}")
+    cache-to = cache_to("magnum:${release.name}")
+
+    tags = [
+        "${REGISTRY}/magnum:${release.name}",
+        "${REGISTRY}/magnum:${release.ref}"
+    ]
+
+    matrix = {
+        release = [
+            {
+                tgt = "zed",
+                name = "zed",
+                ref = "0ee979099a01ae2c8b1b5d6757897a8993e4e34c"
+            },
+            {
+                tgt = "bobcat",
+                name = "2023.2",
+                ref = "5f921a72d22d7e96fb3584c4906a39de9a085a41"
+            }
+        ]
+    }
+
+    args = {
+        RELEASE = release.name
+        BRANCH = format("stable/%s", release.name)
+        PROJECT = "magnum"
+        MAGNUM_GIT_REF = release.ref
+    }
+}
+
+
 group "default" {
     targets = [
-        "barbican"
+        "barbican",
+        "magnum"
     ]
 }