Always push master-head image for agent in addition to numbered tag

.drone.yml

@@ -581,6 +581,23 @@ steps:
     - push
 
 - name: push-head-agent-manifest
+  image: plugins/manifest:1.1.0
+  settings:
+    ignore_missing: true
+    password:
+      from_secret: docker_password
+    spec: manifest-agent-head.tmpl
+    username:
+      from_secret: docker_username
+  when:
+    ref:
+      include:
+      - "refs/heads/master"
+      - "refs/heads/release/v*"
+    event:
+    - push
+
+- name: push-build-number-agent-manifest
   image: plugins/manifest:1.1.0
   settings:
     ignore_missing: true

manifest-agent-head.tmpl

@@ -0,0 +1,29 @@
+image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}
+manifests:
+  -
+    image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}-linux-amd64
+    platform:
+      architecture: amd64
+      os: linux
+  -
+    image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}-linux-arm64
+    platform:
+      architecture: arm64
+      os: linux
+  -
+    image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}-linux-arm
+    platform:
+      architecture: arm
+      os: linux
+  -
+    image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}-windows-1809
+    platform:
+      architecture: amd64
+      os: windows
+      version: 1809
+  -
+    image: rancher/rancher-agent:{{#if build.tag}}{{build.tag}}{{else}}{{replace "release/" "" build.branch }}-head{{/if}}-windows-1903
+    platform:
+      architecture: amd64
+      os: windows
+      version: 1903