veraPDF-rest

Dropwizard based veraPDF REST Services

Introduction

This represents a development prototype, there's little in the way of exception handling and unit testing. The services are capable of serving up XML or JSON dependent upon the content type requested.

Technologies

The project's a Maven managed Java application, the application is based on DropWizard, this brings together a set of reliable libraries, the following are most used and may prove informative if your reading the code:

• Jetty as a lean HTTP server,
• Jersey for REST services and associated, and
• Jackson for JSON and XML serialisation.

A good place to get going is the Dropwizard getting started guide. The Dropwizard core documentation covers the features used in the code base.

Building and running

Docker

This uses a Docker multi-stage build so the final container image which may be deployed does not require more than the base OpenJDK JRE without the entire build tool-chain.

Tested lightly:

docker build -t verapdf-rest:latest . && docker run -d -p 8080:8080 -p 8081:8081 verapdf-rest:latest

If you encounter an error during docker run about "Can't set cookie dm_task_set_cookie failed", try:

sudo dmsetup udevcomplete_all

The built verapdf-rest image is notable smaller than just the base Maven image even before you consider the downloaded dependencies so the multi-stage build is definitely worthwhile:

cadams@ganymede:~ $ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
verapdf-rest        latest              c3c2a52a7bc0        5 minutes ago       297MB
maven               latest              88714384d642        11 days ago         749MB

Using the Alpine-based OpenJRE images provides a further hefty size reduction and we don't seem to be using anything which would be easier on Ubuntu:

verapdf-rest        latest              c69af6445b35        31 seconds ago      103MB

There's an "official" docker image that can be grabbed by docker pull verapdf/rest:latest.

Project structure

Currently it's delivered as a single Maven module, veraPDF-rest.

Want to try?

First clone this project, got to the project directory and then build the Maven project:

git clone [email protected]:veraPDF/veraPDF-rest.git
cd veraPDF-rest
git checkout integration
mvn clean package

To start up the server:

java -jar target/verapdf-rest-0.1.0-SNAPSHOT.jar server

Go to localhost:8080/api/info to see if the server is running, you should see something like:

<Environment>
	<os>
		<name>Linux</name>
		<version>4.2.0-30-generic</version>
		<architecture>amd64</architecture>
	</os>
	<java>
		<vendor>Oracle Corporation</vendor>
		<version>1.7.0_95</version>
		<architecture>x64</architecture>
		<home>/usr/lib/jvm/java-7-openjdk-amd64/jre</home>
	</java>
	<server>
		<ipAddress>127.0.1.1</ipAddress>
		<hostName>dm-wrkstn</hostName>
		<machAddress></machAddress>
	</server>
</Environment>

You can also list the available validation profiles at localhost:8080/api/profiles:

<Set>
  <item>
    <dateCreated>1456384991133</dateCreated>
    <creator>veraPDF Consortium</creator>
    <name>PDF/A-1A validation profile</name>
    <description>Validation rules against ISO 19005-1:2005, Cor.1:2007 and Cor.2:2011</description>
  </item>
  <item>
    <dateCreated>1456480484892</dateCreated>
    <creator>veraPDF Consortium</creator>
    <name>PDF/A-2B validation profile</name>
    <description>Validation rules against ISO 19005-2:2011</description>
  </item>
  <item>
    <dateCreated>1456480579375</dateCreated>
    <creator>veraPDF Consortium</creator>
    <name>PDF/A-3B validation profile</name>
    <description>Validation rules against ISO 19005-3:2012</description>
  </item>
  <item>
  <dateCreated>1456385033982</dateCreated>
  <creator>veraPDF Consortium</creator>
  <name>PDF/A-1B validation profile</name>
  <description>Validation rules against ISO 19005-1:2005, Cor.1:2007 and Cor.2:2011</description>
  </item>
</Set>

Services and curl tests

There are a few services that you can test a few with curl.

API Environment service

Shows some simple information about the server environment on localhost:8080/api

curl localhost:8080/api/info

Validation Profile services

Validation Profiles contain the PDF/A validation tests and their description. A list of profile details is available at localhost:8080/api/profiles/. To test with curl:

curl localhost:8080/api/profiles

Each profile is identified by a 2 letter code made up the PDF/A version amd level. These are listed at localhost:8080/api/profiles/ids/:

curl localhost:8080/api/profiles/ids

An individual profile can be obtained by ID at http://localhost:8080/api/profiles/*id*, e.g. localhost:8080/api/profiles/1b/:

curl localhost:8080/api/profiles/1b

The curl call defaults to a JSON representation, to obtain the XML profile:

curl localhost:8080/api/profiles/1b -H  "Accept:application/xml"

PDF/A Validation services

PDF/A validation is also available as a POST service at http://localhost:8080/api/validate/*id*. There's currently no client application or page, but curl can be used:

curl -F "file=@veraPDF-corpus/PDF_A-1b/6.1 File structure/6.1.12 Implementation limits/veraPDF test suite 6-1-12-t01-fail-a.pdf" localhost:8080/api/validate/1b

or to obtain the result in XML:

curl -F "file=@veraPDF-corpus/PDF_A-1b/6.1 File structure/6.1.12 Implementation limits/veraPDF test suite 6-1-12-t01-fail-a.pdf" localhost:8080/api/validate/1b -H  "Accept:application/xml"