Local GAE Datastore is empty after restart on OSX

I'm building a Google App Engine application with a Go backend + Polymer frontend. As a result, I'm using a dispatch.yaml file to serve both at the same time.

The problem I'm facing is that the datastore is empty when I restart my computer. I've tested this on both OSX 10.9.5 and 10.10.4. Both exhibit the same response upon a system reboot. Windows 7, however, seems to hold on to the data.

The documentation suggests that data should persist, since I'm not explicitly calling a clear. It's not. I've tried to set the datastore location myself using this:

dev_appserver.py --datastore_path=~/go_apps/data ~/go_apps/my_app

I'm receiving this error:

google.appengine.tools.devappserver2.errors.AppConfigNotFoundError: "/Users/anthony/go_apps/my_app is a directory but does not contain app.yaml or app.yml

Obviously, since I'm using a dispatch.yaml file, it wouldn't. So, since the backend, which handles the data, does have an app.yaml file, I try to set it there. I use this command:

dev_appserver.py --datastore_path=~/go_apps/data ~/go_apps/my_app/backend

That doesn't seem to work either, as I get this error:

sqlite3.OperationalError: unable to open database file

Okay? Well, not sure where to turn now. From what I could gather from other posts, that data is stored temporarily. But, I can't seem to set a custom, non-temporary location for the data. So, now I'm populating a datastore every time I reboot, which seems ridiculous.

*** Edit ***

I've tried the following, which seems like it tries to launch the app, and creates a datastore.db file at the correct location:

dev_appserver.py --datastore_path ~/go_apps/my_app/data/datastore.db  ~/go_apps/my_app/dispatch.yaml ~/go_apps/my_app/backend/app.yaml ~/go_apps/my_app/frontend/app.yaml

However, I'm getting a weird error now:

/var/folders/04/3hxnpxc15wj2k4v40lkdncd00000gn/T/tmpkcQYnFappengine-go-bin/backend.go:13: can't find import: "github.com/gorilla/mux"

Does Go build to that folder temporarily? That import is definitely available, and always builds fine calling goapp serve.

Here is what my imports look like on backend.go

import (
    //standard library
    "fmt"
    "net/http"
    "time"
    "log"

    //third party
    "github.com/gorilla/mux"
    "github.com/gorilla/securecookie"
    "github.com/dgrijalva/jwt-go"
    "golang.org/x/crypto/bcrypt"

    //my imports
    "github.com/section14/go_polymer_comm_pkg/controller"
)

You have to pass the name of the file to be used as the persisted datastore, not a folder.

And next provide the folder of your app (which contains app.yaml). Don't mix the 2. So it should be something like:

dev_appserver.py --datastore_path=~/my_app/my_app.db ~/go_apps/my_app

Details can be found here:

The Go Development Server / Using the Datastore

Notes:

The default datastore file is in the temp folder, and your OS-X most likely clears that on system restart, that's why it is not preserved for you. On the other hand Windows 7 for example does not clear the temp folder on system restarts.

Got it up and running by adding both GOPATH and GOROOT environment variables to my .bash_profile. In total, these three paths (first path was already set) are needed for it to run:

# Add Google AppEngine path
export PATH=/Users/anthony/go_appengine:$PATH

# GOPATH
export GOPATH=/Users/anthony/go_appengine/gopath
export PATH=$PATH:$GOPATH

# GOROOT
export GOROOT=/Users/anthony/go_appengine/goroot
export PATH=$PATH:$GOROOT

This command is called from inside the project folder (mine resides outside of the appengine folder) for it to launch:

dev_appserver.py --datastore_path data/datastore.db  dispatch.yaml backend/app.yaml frontend/app.yaml

Notice that the .yaml files are still there. It builds fine with them, and probably builds fine without them if you don't need a dispatch.yaml file.

Thanks @icza for the direction. Wanted to organize the steps in a post for easier reading.