for multi-arch docker images use the manifest to tag latest and maste…

…r images (#1213)

for single arch images allow passing additional tags into the image-tag step and into .tags file

.drone/docker-manifest.tmpl

@@ -1,6 +1,8 @@
 image: grafana/{{config.target}}:{{#if build.tag}}{{build.tag}}{{else}}{{build.branch}}-{{substr 0 7 build.commit}}{{/if}}
-{{#if build.tags}}
 tags:
+  - latest
+  - master
+{{#if build.tags}}
 {{#each build.tags}}
   - {{this}}
 {{/each}}

.drone/drone.jsonnet

@@ -43,7 +43,7 @@ local docker(arch, app) = {
   },
 };
 
-local arch_image(arch) = {
+local arch_image(arch,tags='') = {
   platform: {
     os: 'linux',
     arch: arch,
@@ -55,11 +55,11 @@ local arch_image(arch) = {
       'apk add --no-cache bash git',
       'git fetch origin --tags',
       'echo $(./tools/image-tag)-%s > .tags' % arch,
-    ],
+    ] + if tags != '' then ['echo ",%s" >> .tags' % tags] else [],
   }],
 };
 
-local fluentbit() = pipeline('fluent-bit-amd64') + arch_image('amd64') {
+local fluentbit() = pipeline('fluent-bit-amd64') + arch_image('amd64','latest,master') {
  steps+: [
     // dry run for everything that is not tag or master
     docker('amd64', 'fluent-bit') {

.drone/drone.yml

@@ -394,6 +394,7 @@ steps:
   - apk add --no-cache bash git
   - git fetch origin --tags
   - echo $(./tools/image-tag)-amd64 > .tags
+  - echo ",latest,master" >> .tags
   image: alpine
   name: image-tag
 - depends_on: