I am using DigitalOcean App Platform to deploy a Django app. The initial deployment worked fine, but I’ve attempted to use the bulk editor on the component-level environment variables, and since then, the deployment fails when executing dj_database_url.config(default=config('DATABASE_URL').
For debugging, I added this line to settings.py:
print(f"[BUILD DEBUG] DATABASE_URL = {repr(os.environ.get('DATABASE_URL'))}")
This returns [BUILD DEBUG] DATABASE_URL = '${db.DATABASE_URL}' in the build logs.
I don’t understand why the environment variable is not resolving. My app spec looks like this:
services:
- environment_slug: python
envs:
- key: DATABASE_URL
scope: RUN_AND_BUILD_TIME
value: ${db.DATABASE_URL}
Could this be a bug, or am I doing something wrong? Yes, my database is named correctly:
databases:
- engine: PG
name: db
The only thing that changed between my last deployment and this failed deployment, besides a few lines of code, is that I used the bulk editor to add new environment variables. Some of the existing environment variables were encrypted, but they look OK in the app spec.
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Hi there,
I think that the ${db.DATABASE_URL} reference isn’t resolved during the build phase, only at runtime. If I remember correctly, App Platform doesn’t expose database credentials during build to prevent issues like accidental schema changes or migrations that aren’t backward compatible.
If you’re using dj_database_url.config() during build time (e.g., running migrations), it’ll fail because DATABASE_URL is still just the literal string ${db.DATABASE_URL}.
To fix this, make sure database access (like migrate) happens at runtime, not during build.
Or, if absolutely needed, manually set a fallback DATABASE_URL value for build purposes, just be cautious not to expose production credentials.
- Bobby
While this doesn’t really answer the question of why my DigitalOcean App only broke after using the bulk editor, I fixed my problem by wrapping my DATABASES declaration in a try/except block:
database_url = config('DATABASE_URL', default=None, cast=str)
try:
DATABASES = {
'default': dj_database_url.config(
default=database_url, conn_max_age=600)
}
except Exception as e:
print(f"Failed to parse DATABASE_URL, using default SQLite. Reason: {e}")
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.sqlite3',
'NAME': BASE_DIR / 'db.sqlite3',
}
}
Although rudimentary, this works in both development (where DATABASE_URL is absent from the environment variables) and in production.
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