Drone allows you to store secret variables in an encrypted `.drone.sec` file in the root of your repository. This is useful when your build requires sensitive information that should not be stored in plaintext in your `.drone.yml` file.
An example `.drone.sec` yaml file, prior to being encryped:
An encrypted string is returned to the browser. This string should be copied and pasted into a `.drone.sec` file in the root of your repository, alongside your `.drone.yml` file.
## Environment
The `environment` section of the `.drone.sec` file is a list of secret variables that get injected into your `.drone.yml` file at runtime using the `$$` notation. Secret variables are not injected as environment variables. Instead, we use a simple find and replace algorithm.
An example `.drone.yml` expecting the `HEROKU_TOKEN` private variable:
```yaml
build:
image: golang
commands:
- go get
- go build
- go test
deploy:
heroku:
app: pied_piper
token: $$HEROKU_TOKEN
```
## Pull Requests
Secret variables are **not** injected into to the build section of the `.drone.yml` if your repository is **public** and the build is a **pull request**. This is for security purposes to prevent a malicious pull request from leaking your secrets.
Please note that you may still want secrets available to plugins when building a pull request. This is possible if you include a checksum of the `.drone.yml` file in your `.drone.sec` file.
## Checksum
The `checksum` field in the `.drone.yml` is a sha of your `.drone.yml` file. It is optional, but highly recommended. The `checksum` is used to verify the integrity of your `.drone.yml` file. If the checksum does not match, secret variables are not injected into your Yaml.
