# Transfer Service 1.0 Implementation
The Transfer service provides a unified interface for file exchange between remote locations and the local device. It serves multiple purposes:
- Downloading application updates
- Exchanging monitoring and administrative data
- Uploading device information and logs
- Managing content distribution for modules
- Standardizing HTTP communication (POST, GET, etc.) for other services
## Store Concept
The service uses a flexible "store" abstraction to manage different storage locations. This design allows:
- Configuration-based location management
- Multiple storage backends
- Context-specific storage (logs, updates, monitoring)
- Easy switching between storage implementations
### Store Configuration
Stores are configured using JSON serialized configuration. Example from a production setup:
```json
{
"store_name": "config",
"bucket_name": "etabelone-dev-etabelonedevbootstrape71b79bd-kfzemjujlgbe",
"region": "eu-west-1",
"prefix": ""
}
```
## Service Configuration
The service can be configured through environment variables and service properties:
### Environment Variables
| Environment Variable | Description | Example |
|---------------------|-------------|---------|
| AWS_ACCESS_KEY_ID | AWS Access key for authentication | AKIATCKAQOQG77TZDSOH |
| AWS_SECRET_ACCESS_KEY | AWS Secret key for authentication | teEFXxZFWy10AzvQGSLTwGzqPq67hnY3rYk3MHzvV |
| S3_STORE_CUSTOM_HOSTANDPORT_ENDPOINT | if aws is not used, this define the host and port to call |
| S3_STORE_CUSTOM_HTTP_SCHEME | if S3_CUSTOM STORE is used, this define the protocol (can be either http or https) |
| STORE_CONFIGURATION | JSON serialized store configuration | See store configuration example above |
### Service Properties
The service can be configured as part of the application definition:
```json
{
"application_id": "aws_factory_transfert-1.0",
"service_name": "transfer",
"service_port": 8015,
"application_description": "transfer files to aws, with default aws device enrollment access",
"additional_properties": {
"AWS_ACCESS_KEY_ID": "AKIATCKAQOQG77TZDSOH",
"AWS_SECRET_ACCESS_KEY": "teEFXxZFWy10AzvQGSLTwGzqPq67hnY3rYk3MHzvV",
"AWS_STORE_CONFIGURATION": "[{\"store_name\":\"config\",\"bucket_name\":\"etabelone-dev-etabelonedevbootstrape71b79bd-kfzemjujlgbe\",\"region\":\"eu-west-1\",\"prefix\":\"\"}]"
}
}
```
## Store Implementations
The service currently supports two storage backends:
1. **Filesystem Store**
- Local file/folder storage
- Used for testing and validation
- Simple configuration with local paths
2. **AWS S3 Store**
- Cloud storage implementation
- Production-ready configuration
- Supports multiple buckets and regions
- Requires AWS credentials and bucket configuration
## Methods
### HTTP Request Method
The service provides a standardized way to make HTTP requests to external servers:
```python
call_service('transfer', 'http_request', 'https://www.google.fr', 'GET', {}, "")
```
Response format:
```json
{
"headers": [...],
"httpcode": 200,
"response_body": "..."
}
```
## Usage Examples
### AWS S3 Store Configuration
For AWS S3 storage, configure the store with:
- Store name (e.g., "config")
- Bucket name (e.g., "etabelone-dev-...")
- AWS region (e.g., "eu-west-1")
- Optional prefix for object organization
### HTTP Communication
The service standardizes HTTP communication for other modules:
- GET requests for data retrieval
- POST requests for data submission
- Support for custom headers and body content
- Response handling with status codes and headers
### Example of http_request calling from an other service/module
sending and http GET request to an external webserver,
example :
```
call_service('transfer','http_request','https://www.google.fr','GET',{},"")
```
this returns :
```
{
"headers": [
"date: Sun, 23 Feb 2025 15:57:58 GMT",
"expires: -1",
"cache-control: private, max-age=0",
"content-type: text/html; charset=ISO-8859-1",
"content-security-policy-report-only: object-src 'none';base-uri 'self';script-src 'nonce-7vwSUhE3dcP7hy_mah_bDg' 'strict-dynamic' 'report-sample' 'unsafe-eval' 'unsafe-inline' https: http:;report-uri https://csp.withgoogle.com/csp/gws/other-hp",
"accept-ch: Sec-CH-Prefers-Color-Scheme",
"p3p: CP=\"This is not a P3P policy! See g.co/p3phelp for more info.\"",
"server: gws",
"x-xss-protection: 0",
"x-frame-options: SAMEORIGIN",
"set-cookie: AEC=AVcja2ek4TuDGhyVR32F4wio5orc3vTLcsRvNye-GRM3i_8YyeP2EIvNr8Q; expires=Fri, 22-Aug-2025 15:57:58 GMT; path=/; domain=.google.fr; Secure; HttpOnly; SameSite=lax",
"set-cookie: __Secure-ENID=25.SE=iwktx4Am0W8OAF3ucW4LzTDvBpXYMPXa162ZlQP1HBDPG6RhYMGfLv7ERi04bHspPt6qG-Q8Y6fTHQMIt83iDi2_9Z3jlNDxCi1MSap9HlaxCTKX7JERTO81u8xr1F_JRyZyoYzOu5RSSYyPlgJJHQ_jj_-qxXWklb3ndC8Iwc9PYrG-loTm6NrXZSMA0e6DP4N3oRBzY4VfjSJbRS3YNzwfZL2IZigHVx53aIldSCX1QUsmi1P0; expires=Thu, 26-Mar-2026 08:16:16 GMT; path=/; domain=.google.fr; Secure; HttpOnly; SameSite=lax",
"alt-svc: h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000",
"accept-ranges: none",
"vary: Accept-Encoding",
"transfer-encoding: chunked"
],
"httpcode": 200,
"response_body": "Google"
}
```