How to upload a Google App Engine (Go) project in a different folder than the app.yaml

My project has the following structure:

| appengine
|---- app.yaml
|---- myScript.go
| bower_components
|----|...
| build
|----|images
|----|----|branding
|----|----|---- favicon.ico
|----|styles
|----|----|*.css
|----|index.html
| src
| ...

I would like to upload the entire content of the build folder when running goapp deploy appengine.

My app.yaml looks like this:

application: myProject
version: 0-1
runtime: go
api_version: go1

handlers:
- url: /(.*\.(gif|png|jpg|ico|js|css))
  static_files: ../build/
  upload: ../build/(.*\.(gif|png|jpg|ico|js|css))

- url: /.*
  script: _go_app

and myScript.go looks like this:

package myProject

import (
    "fmt"
    "io/ioutil"
    "net/http"
)

func init() {
    http.HandleFunc("/", handler)
}

func handler(w http.ResponseWriter, r *http.Request) {
    site, err := ioutil.ReadFile("../build/index.html")
    
    if err != nil {
        panic(err)
    }
    
    fmt.Fprint(w, string(site))
}

When I run goapp serve appengine, the website displays properly. However, when I try to deploy it, it only clones two files, i.e. the ones inside the appengine folder.

You can preserve your desired app structure with 3rd party code residing outside your GAE app code directory yet still be able to upload the 3rd party code together with your GAE app code by just symlinking the 3rd party code files/dirs inside the GAE app dir in the desired locations.

The GAE upload/deploy utilities know to replace the symlinks and upload the actual files/dirs the symlinks point to instead, in the respective locations.

Some other GAE-related scenarios in which the symlink technique can be applied:

• https://stackoverflow.com/questions/34291075/sharing-entities-between-app-engine-modules/34291789#34291789
• https://stackoverflow.com/questions/33088104/how-can-i-share-files-html-templates-between-app-engine-modules/33091084#33091084
• https://stackoverflow.com/questions/33307128/do-i-need-to-copy-skip-files-across-multiple-yaml-files/33308640#33308640
• https://stackoverflow.com/questions/34973058/how-do-i-access-a-vendored-library-from-a-module-in-python-google-app-engine/34985211#34985211
• https://stackoverflow.com/questions/34110178/can-a-default-module-in-a-google-app-engine-app-be-a-sibling-of-a-non-default-mo/34111170#34111170