The REST Service for the USGS Land Change Monitoring Assessment and Projection (LCMAP) Computation and Analysis Platform
About ↟
The Land Change Monitoring Assessment and Projection (LCMAP) system will provide the science community with real-time access to decades of Landsat Analysis Ready Data (ARD). To make this system available to the public scientific computing community, an API service will be provided. The LCMAP REST service API is codified in this project and prototypes the functionality necessary to support the public service.
Documentation ↟
The server code is slowly being updated with docstrings. Auto-generated documentation for the server is available here:
However, it may be of more interest and use to view the client documentation for the LCMAP service:
Usage ↟
Versioned Service API ↟
The LCMAP service version is selected via an Accept
header, as demonstrated
with the following:
$ curl -v -X POST \
-H "Accept: application/vnd.usgs.lcmap.v0.0+json" \
-d "username=alice" \
-d "password=secret" \
http://localhost:1077/api/auth/login
Sample Model ↟
The LCMAP REST service provides a sample execution API for testing purposes. To kick off a new job, you can run something like the following:
curl -v -X POST \
-H "Accept: application/vnd.usgs.lcmap.v0.0+json" \
-H "X-AuthToken: 3efc6475b5034309af00549a77b7a6e3" \
-d "seconds=15" \
-d "year=2016" \
http://localhost:1077/api/models/sample/os-process
Structure ↟
The codebase for lcmap.rest is structured along the following lines:
lcmap.rest.api
- This contains all the code that actually returns HTTP response data. This is also where all the service routes are defined. Actual "business logic" is in the rest of the codebase. If you find yourself adding new features with more than just Ring repoonse and status calls, then you need to reorganize that logic someplace other thanlcmap.rest.api
. Under thelcmap.rest.api
namespace we have the following:compatibility
- supports alternate APIs, e.g., WMTSdata
- resources for querying stored datajobs
- resources for submitting, checking, and updating jobsmodels
- model execution resourcessystem
- resources such as metrics
lcmap.rest.auth
- Logic for logging in and out of the LCMAP systemlcmap.rest.components
- This is where all major parts of the system are defined so that they may be easily started and stopped in the correct order. Example components are application configuration, logging, database connections, event services, and the REST services HTTP daemon.lcmap.rest.dev
- The default module for development mode; loaded automatically when one executeslein repl
lcmap.rest.exceptions
- Custom LCMAP exceptionslcmap.rest.job
- Job tracking business logiclcmap.rest.logger
- Logging support setuplcmap.rest.middleware
- Custom Ring middleware needed by LCMAP RESTlcmap.rest.types
- Custom Schema types for such things as validationlcmap.rest.user
- User management logic and storage functionslcmap.rest.util
- Utility functions
Development ↟
Component Dependencies ↟
If you are developing from sources and you need the latest code from the various LCMAP projects/components, then you will need to override the dependencies that are in the project.clj
file with a checkouts
directory. In your lcmap.rest working directory:
$ mkdir checkouts
$ cd checkouts
$ git clone [email protected]:USGS-EROS/lcmap-config.git
$ git clone [email protected]:USGS-EROS/lcmap-logger.git
$ git clone [email protected]:USGS-EROS/lcmap-client-clj.git
$ git clone [email protected]:USGS-EROS/lcmap-data.git
$ git clone [email protected]:USGS-EROS/lcmap-see.git
$ git clone [email protected]:USGS-EROS/lcmap-event.git
If these repositories have already been cloned to your workstation, you may optionally make symbolic links (i.e., ln -s ../../path/to/repo .
) in your checkouts
directory.
Daemon Dependencies ↟
In order for the LCMAP system to run successfully, it will need to have access to the following:
- Cassandra (host and port)
- RabbitMQ (host, port, and vhost)
- Test Auth Server (includedd in lcmap-rest; run with
make test-auth-server
)
Startup ↟
To start the REST server and dependent components, do the following:
$ lein trampoline run
(The trampoline
lein task is needed in order to properly handle SIGINT
and SIGTERM
.)
To run the system in the REPL, simply start the REPL:
$ lein repl
This will drop you into the lcmap.rest.dev
namespace:
lcmap.rest.dev=>
From here you can start the system components and also reset them after changes to lcmap.rest files:
lcmap.rest.dev=> (run)
17:14:29.863 [nREPL-worker-6] INFO l-r.c.config - Setting up LCMAP configuration ...
17:14:29.864 [nREPL-worker-6] INFO l-r.c.config - Using lein profile: dev
17:14:29.864 [nREPL-worker-6] INFO l-r.c.logger - Setting up LCMAP logging ...
17:14:29.864 [nREPL-worker-6] INFO l-r.c.logger - Using log-level :info
17:14:29.907 [nREPL-worker-6] INFO l-r.c.db - Starting DB client ...
Any subsequent changes to source files (including project.clj
) can be
brought into the REPL by resetting (reloading, rereading, etc.):
lcmap.rest.dev=> (reset)
:reloading (lcmap.rest.util lcmap.rest.job.db)
A quick test for this is to change the log-level
in project.clj
and
then run (reset)
, since the difference in log output will be obvious.
We use kibit to double-check idiomatic use of Clojure (we've got Rubyists, Pythonistas, Erlangers, and old Lispers using this software, so the probability for non-idiomatic contributions is high!). To check the code base, simply run the lein plugin:
$ lein kibit
Deployment ↟
TBD
Testing & Staging ↟
TBD
Production ↟
TBD
License ↟
Copyright © 2015-2016 United States Government
NASA Open Source Agreement, Version 1.3