How to restage an app directly using V3 APIs (with examples)

1. Fetch the current droplet of the app to retrieve it's "current" package.

• Endpoint: GET /v3/apps/:guid/droplets/current
• Docs: Get Current Droplet
• Example:

$ cf curl /v3/apps/$(cf app my-app --guid)/droplets/current | jq .links.package.href
"https://api.neon-bite.capi.land/v3/packages/63f8c286-0df6-4837-86c8-544b594ab429"

2. Grab the package guid from the link. In the example above this would be: 63f8c286-0df6-4837-86c8-544b594ab429

3. Create a build (restage the package without affecting the app). This is functionally the same as cf v3-stage.

• Endpoint: POST /v3/builds
• Docs: Create a build
• Example:

$ cf curl -X POST /v3/builds -d '{ "package": {  "guid": "63f8c286-0df6-4837-86c8-544b594ab429" } }'

{
   "guid": "61b9dbea-a4da-479c-8873-31247cb1c1e6",
   "created_at": "2019-04-30T18:07:06Z",
   "updated_at": "2019-04-30T18:07:06Z",
   "state": "STAGING",
   "error": null,
   "lifecycle": {
      "type": "buildpack",
      "data": {
         "buildpacks": [],
         "stack": "cflinuxfs3"
      }
   },
   "package": {
      "guid": "63f8c286-0df6-4837-86c8-544b594ab429"
   },
   "droplet": null,
   "metadata": {
      "labels": {},
      "annotations": {}
   },
   "links": {
      "self": {
         "href": "https://api.neon-bite.capi.land/v3/builds/61b9dbea-a4da-479c-8873-31247cb1c1e6"
      },
      "app": {
         "href": "https://api.neon-bite.capi.land/v3/apps/6efc923a-82fe-4ff2-82c2-d8ae65927c12"
      }
   },
   "created_by": {
      "guid": "dc72353e-3d76-4f7b-8de7-f582a5e6ab20",
      "name": "admin",
      "email": "admin"
   }
}

4. Poll the status of the build until it succeeds (or fails)

• Endpoint: GET /v3/builds/:guid
• Docs: Get a build
• Example:

$ cf curl /v3/builds/61b9dbea-a4da-479c-8873-31247cb1c1e6

{
   "guid": "61b9dbea-a4da-479c-8873-31247cb1c1e6",
   "created_at": "2019-04-30T18:07:06Z",
   "updated_at": "2019-04-30T18:07:12Z",
   "state": "STAGED",
   "error": null,
   "lifecycle": {
      "type": "buildpack",
      "data": {
         "buildpacks": [
            "staticfile_buildpack"
         ],
         "stack": "cflinuxfs3"
      }
   },
   "package": {
      "guid": "63f8c286-0df6-4837-86c8-544b594ab429"
   },
   "droplet": {
      "guid": "b6b19703-22f7-41a8-b31a-c351237530a0",
      "href": "https://api.neon-bite.capi.land/v3/droplets/b6b19703-22f7-41a8-b31a-c351237530a0"
   },
   "metadata": {
      "labels": {},
      "annotations": {}
   },
   "links": {
      "self": {
         "href": "https://api.neon-bite.capi.land/v3/builds/61b9dbea-a4da-479c-8873-31247cb1c1e6"
      },
      "app": {
         "href": "https://api.neon-bite.capi.land/v3/apps/6efc923a-82fe-4ff2-82c2-d8ae65927c12"
      }
   },
   "created_by": {
      "guid": "dc72353e-3d76-4f7b-8de7-f582a5e6ab20",
      "name": "admin",
      "email": "admin"
   }
}

5. Note the state field. If the state is STAGED Grab the droplet guid from the response.

$ cf curl /v3/builds/61b9dbea-a4da-479c-8873-31247cb1c1e6 | jq .droplet.guid
"b6b19703-22f7-41a8-b31a-c351237530a0"

6. Update the app to use the new droplet guid (same as cf v3-set-droplet).

• Endpoint: PATCH /v3/apps/:guid/relationships/current_droplet
• Docs: Set current droplet
• Example:

$ cf curl -X PATCH /v3/apps/$(cf app my-app --guid)/relationships/current_droplet -d '{ "data": { "guid": "b6b19703-22f7-41a8-b31a-c351237530a0" } }'
{
   "data": {
      "guid": "b6b19703-22f7-41a8-b31a-c351237530a0"
   },
   "links": {
      "self": {
         "href": "https://api.neon-bite.capi.land/v3/apps/6efc923a-82fe-4ff2-82c2-d8ae65927c12/relationships/current_droplet"
      },
      "related": {
         "href": "https://api.neon-bite.capi.land/v3/apps/6efc923a-82fe-4ff2-82c2-d8ae65927c12/droplets/current"
      }
   }
}

7. Now restart the app to run it with this new droplet using cf restart or cf v3-zdt-restart (on newer Cloud Foundry foundations that support the beta rolling app deployments feature).