The purpose of the Web service in SeqWare is threefold. First, it allows individuals to connect to the database with user-specific permissions. Second, it prevents direct access to the database. Third, it allows remote users to query the database without needing to install the PostgreSQL client locally.
In the first case, not all users should be able to access all studies in the MetadataDB. Some studies have proprietary information that should not be widely available. PostgreSQL cannot grant row-specific permissions for users. Authentication through the Web Service will allow those users to view and change only those rows that they have permission to view.
Secondly, direct access to the database should be discouraged. There is a great deal of business logic built into SeqWare that is not available at the database level. The database allows for much more flexibility than SeqWare Pipeline expects. Therefore it is advisable to redirect all database queries through a business logic layer that will preserve the hierarchy in the database.
Thirdly, remote users can query the database without having to construct an SQL query and without needing to install the PostgreSQL client. We are using a RESTful Web service, in which most of the information needed by the Web service is provided in the HTTP URL and the message type. For example, navigating to /seqware-webservice-0.10.0/workflows is equivalent to ‘SELECT * FROM workflow;’ in psql, and going to /seqware-webservice-0.10.0/workflows/1 is equivalent to ‘SELECT * FROM workflow WHERE sw_accession = 1;’. These queries may be executed either in a browser or programmatically.
If you are working on our CentOS VM from the Installation guide your settings file will already be present. Otherwise, your SeqWare settings file needs to be configured to use the Web service rather than ‘database’ or ‘nometadata’. This file is usually located at ~/.seqware/settings.
There are four variables that need to be changed: SW_METADATA_METHOD, SW_REST_URL, SW_REST_USER, and SW_REST_PASS. The SW_REST_URL is the location of the deployed WebService. Below is an example snippet of a .seqware/settings file.
SW_METADATA_METHOD=webservice SW_REST_URL=http://localhost:8080/seqware-webservice-1.1.0 SW_REST_USERfirstname.lastname@example.org SW_REST_PASS=admin
Providing the Web service is already installed for you, there are three approaches to using the Web service. In order from least to most programming, these are the options:
The .seqware/settings file needs to be configured to use the Web service for these two options.
Most users will want to use our pre-configured VMs, see the SeqWare Install Guide for how to get the VM. The SeqWare Web service is the primary mechanism by which users can reach the SeqWare MetaDB. The Web service prevents the user from having to make SQL queries and facilitates building services on top of the MetaDB. Currently, there is a Java client located in the seqware-commons package that can be used to access the WebService, which is configured through the .seqware/settings file.
Please see the Install Guide
This API describes the resources that make up the SeqWare RESTful Web service.
The SeqWare Web service has two primary functions. First, it is the primary mechanism by which users can query the SeqWare MetaDB. The Web service prevents the user from having to make SQL queries and facilitates building services on top of the MetaDB. Secondly, it allows privileged users to launch and monitor next-generation sequencing workflows and pipelines remotely without having any local SeqWare dependencies. These two functions are split into ‘Metadata’ and ‘Pipeline’ functions.
Operations on the metadata resources are primarily for read-only access of the SeqWare metadata database. Any PUT or POST operations add only one row to one table in the SeqWare Metadata database. There are four classifications of resources:
These jobs loosely correspond with tasks performed by SeqWare Pipeline, for example, launching workflows, modules, and plugins. Pipeline tasks are distinguished from Metadata tasks because they trigger more advanced processing of the data by systems other than those associated with the Metadata DB. For example, jobs triggered on the pipeline may cause a job to be run on a server, or a ZIP file to be uploaded and installed as a workflow.
At the moment, a workflow can be launched through a job resource.
The reporting section of the Pipeline documentation includes information on various reporting tools built on top of the Web Service. Most users will be interested in using these command line tools directly since they greatly simplify the process of querying the web service for retrieving workflow results.