trellis-rosid-app

Trellis Application

A deployable Trellis application using a file-based persistence layer and an internal Kafka-based event bus.

Requirements

• A Zookeeper ensemble (3.4.x or later)
• A Kafka cluster (0.11.x or later)
• Java 8 or 9
• An asynchronous processing application

The location of Kafka and Zookeeper will be defined in the ./etc/config.yml file.

Running Trellis

Unpack a zip or tar distribution. In that directory, modify ./etc/config.yml to match the desired values for your system.

To run trellis directly from within a console, issue this command:

$ ./bin/trellis-rosid-app server ./etc/config.yml

Note: When running trellis, please be sure to also have an active asynchronous processor.

Installation

To install Trellis as a systemd service on linux, follow the steps below. systemd is used by linux distributions such as CentOS/RHEL 7+ and Ubuntu 15+.

1. Move the unpacked Trellis directory to a location such as /opt/trellis. If you choose a different location, please update the ./etc/trellis.service script.

2. Edit the ./etc/environment file as desired (optional).

3. Edit the ./etc/config.yml file as desired (optional).

4. Create a trellis user:

$ sudo useradd -r trellis -s /sbin/nologin

5. Create data directories. A different location can be used, but then please update the ./etc/config.yml file.

$ sudo mkdir /var/lib/trellis
$ sudo chown trellis.trellis /var/lib/trellis

6. Install the systemd file:

$ sudo ln -s /opt/trellis/etc/trellis.service /etc/systemd/system/trellis.service

7. Reload systemd to see the changes

$ sudo systemctl daemon-reload

8. Start the trellis service

$ sudo systemctl start trellis

To check that trellis is running, check the URL: http://localhost:8080

Application health checks are available at http://localhost:8081/healthcheck

Building Trellis

1. Run ./gradlew clean install to build the application or download one of the releases.
2. Unpack the appropriate distribution in ./build/distributions
3. Start the application according to the steps above

Configuration

The web application wrapper (Dropwizard.io) makes many configuration options available. Any of the configuration options defined by Dropwizard can be part of your application's configuration file.

Trellis defines its own configuration options, including:

binaries:
  path: /path/to/binaries

Name	Default	Description
path	(none)	The path for storing binaries

resources:
  path: /path/to/resources

Name	Default	Description
path	(none)	The path for storing resources

baseUrl: http://localhost:8080/

Name	Default	Description
baseUrl	(none)	A defined baseUrl for resources in this partition. If not defined, the Host request header will be used

namespaces:
    file: /path/to/namespaces.json

Name	Default	Description
file	(none)	The path to a JSON file defining namespace prefixes

zookeeper:
    ensembleServers: localhost:2181

Name	Default	Description
ensembleServers	(none)	The location of the zookeeper ensemble servers (comma separated)

kafka:
    bootstrapServers: localhost:9092

Name	Default	Description
bootstrapServers	(none)	The location of the kafka servers (comma separated)

auth:
    webac:
        enabled: true
    anon:
        enabled: true
    jwt:
        enabled: true
        base64Encoded: false
        key: secret
    basic:
        enabled: true
        usersFile: /path/to/users.auth

Name	Default	Description
webac / enabled	true	Whether WebAC authorization is enabled
anon / enabled	false	Whether anonymous authentication is enabled
jwt / enabled	true	Whether jwt authentication is enabled
jwt / base64Encoded	false	Whether the key is base64 encoded
jwt / key	(none)	The signing key for JWT tokens
basic / enabled	true	Whether basic authentication is enabled
basic / usersFile	(none)	The path to a file where user credentials are stored

cors:
    enabled: true
    allowOrigin:
        - "*"
    allowMethods:
        - "GET"
        - "POST"
        - "PATCH"
    allowHeaders:
        - "Content-Type"
        - "Link"
    exposeHeaders:
        - "Link"
        - "Location"
    maxAge: 180
    allowCredentials: true

Name	Default	Description
enabled	false	Whether CORS is enabled
allowOrigin	"*"	A list of allowed origins
allowMethods	"PUT", "DELETE", "PATCH", "GET", "HEAD", "OPTIONS", "POST"	A list of allowed methods
allowHeaders	"Content-Type", "Link", "Accept", "Accept-Datetime", "Prefer", "Want-Digest", "Slug", "Digest"	A list of allowed request headers
exposeHeaders	"Content-Type", "Link", "Memento-Datetime", "Preference-Applied", "Location", "Accept-Patch", "Accept-Post", "Digest", "Accept-Ranges", "ETag", "Vary"	A list of allowed response headers
maxAge	180	The maximum age (in seconds) of pre-flight messages
allowCredentials	true	Whether the actual request can be made with credentials

async: false

Name	Default	Description
async	false	Set this to true if resource caches should be generated by an async processor; otherwise they will be generated synchronously. Note: setting this to true will make write operations faster for clients, but the availability of the updated content will appear to lag (because it is generated asynchronously).

cacheMaxAge: 86400

Name	Default	Description
cacheMaxAge	86400	The value of the Cache-Control: max-age= response header

jsonLdWhitelist:
    - "http://example.com/context.json"

Name	Default	Description
jsonLdWhitelist	an empty list	a user-supplied whitelist of valid JSON-LD profile values

jsonLdDomainWhitelist:
    - "http://example.com/"

Name	Default	Description
jsonLdDomainWhitelist	an empty list	a user-supplied whitelist of domains for valid JSON-LD profile values

jsonLdCacheExpireHours: 24

Name	Default	Description
jsonLdCacheExpireHours	24	The number of hours that a JSON-LD profile value will be stored in a cache.

jsonLdCacheSize: 100

Name	Default	Description
jsonLdCacheSize	100	The number of entries stored in the JSON-LD profile cache.

HTTP/2

Trellis supports the HTTP/2 protocol. For more information about how to enable HTTP/2 with Trellis, please refer to the dropwizard documentation. In particular, an h2 connector type must be used, typically with a corresponding TLS configuration.

Metrics reporting

Application metrics can be configured by defining a frequency and a reporter. For more information about configuring these reports, please refer to the dropwizard metrics configuration reference.