Hyperledger Composer REST Server

The Hyperledger Composer REST server, composer-rest-server, can be used to generate a REST API from a deployed blockchain business network that can be easily consumed by HTTP or REST clients.

Configuring the REST server using environment variables

The REST server can be configured using environment variables, instead of supplying configuration options via the command line. The REST server supports the following environment variables:

COMPOSER_CARD

You can use the COMPOSER_CARD environment variable to specify the name of the discovery business network card that the REST server should use to connect to the business network.

For example:
```
COMPOSER_CARD=admin@my-network
```
COMPOSER_NAMESPACES

You can use the COMPOSER_NAMESPACES environment variable to specify if the REST server should generate a REST API with namespaces or not. Valid values are always, required, and never.

For example:
```
COMPOSER_NAMESPACES=never
```
COMPOSER_AUTHENTICATION

You can use the COMPOSER_AUTHENTICATION environment variable to specify if the REST server should enable REST API authentication or not. Valid values are true and false.

For example:
```
COMPOSER_AUTHENTICATION=true
```
For more information, see Enabling authentication for the REST server.
COMPOSER_MULTIUSER

You can use the COMPOSER_MULTIUSER environment variable to specify if the REST server should enable multiple user mode or not. Valid values are true and false.

For example:
```
COMPOSER_MULTIUSER=true
```
For more information, see Enabling multiple user mode for the REST server.

COMPOSER_PROVIDERS

You can use the COMPOSER_PROVIDERS environment variable to specify the Passport strategies that the REST server should use to authenticate clients of the REST API.

For example:

COMPOSER_PROVIDERS='{
  "github": {
    "provider": "github",
    "module": "passport-github",
    "clientID": "REPLACE_WITH_CLIENT_ID",
    "clientSecret": "REPLACE_WITH_CLIENT_SECRET",
    "authPath": "/auth/github",
    "callbackURL": "/auth/github/callback",
    "successRedirect": "/",
    "failureRedirect": "/"
  }
}'

COMPOSER_DATASOURCES

You can use the COMPOSER_DATASOURCES environment variable to specify the LoopBack data sources and the connection information required by the selected LoopBack connector.

For example:
```
COMPOSER_DATASOURCES='{
  "db": {
    "name": "db",
    "connector": "mongodb",
    "host": "mongo"
  }
}'
```
COMPOSER_TLS

You can use the COMPOSER_TLS environment variable to specify if the REST server should enable HTTPS and TLS. Valid values are true and false.

For example:
```
COMPOSER_TLS=true
```
For more information, see Securing the REST server using HTTPS and TLS.
COMPOSER_TLS_CERTIFICATE

You can use the COMPOSER_TLS_CERTIFICATE environment variable to specify the certificate file that the REST server should use when HTTPS and TLS are enabled.

For example:
```
COMPOSER_TLS_CERTIFICATE=/tmp/cert.pem
```
COMPOSER_TLS_KEY

You can use the COMPOSER_TLS_KEY environment variable to specify the private key file that the REST server should use when HTTPS and TLS are enabled.

For example:
```
COMPOSER_TLS_KEY=/tmp/key.pem
```
COMPOSER_APIKEY

You can use the COMPOSER_APIKEY environment variable to specify the API key the server should accept for each request as a header parameter x-api-key.

For example:
```
COMPOSER_APIKEY=REPLACE_WITH_YOUR_API_KEY
```
COMPOSER_WEBSOCKETS

You can use the COMPOSER_WEBSOCKETS environment variable to specify whether the REST server publishes events. The default value is true

For example:
```
COMPOSER_WEBSOCKETS=true
```