REST API

This manual describes the REST application programming interface (API) of the Heritrix Web crawler.

This document is intended for application developers and administrators interested in controlling the Heritrix Web crawler through its REST API.

Any client that supports HTTPS can be used to invoke the Heritrix API. The examples in this document use the command line tool curl which is typically found in most unix environments. Curl is available for many systems including Windows.

Get Engine Status

GET https://(heritrixhost):8443/engine

Returns information about this instance of Heritrix such as version number, memory usage and the list of crawl jobs.

XML Example:

curl -v -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine

Response:

<engine>
  <heritrixVersion>3.3.0-SNAPSHOT-2017-07-12T04:17:56Z</heritrixVersion>
  <heapReport>
    <usedBytes>69529904</usedBytes>
    <totalBytes>589824000</totalBytes>
    <maxBytes>2885681152</maxBytes>
  </heapReport>
  <jobsDir>/heritrix/jobs</jobsDir>
  <jobsDirUrl>https://localhost:8443/engine/jobsdir/</jobsDirUrl>
  <availableActions>
    <value>rescan</value>
    <value>add</value>
    <value>create</value>
  </availableActions>
  <jobs>
    <value>
      <shortName>myjob</shortName>
      <url>https://localhost:8443/engine/job/myjob</url>
      <isProfile>false</isProfile>
      <launchCount>0</launchCount>
      <lastLaunch/>
      <hasApplicationContext>false</hasApplicationContext>
      <statusDescription>Unbuilt</statusDescription>
      <isLaunchInfoPartial>false</isLaunchInfoPartial>
      <primaryConfig>/heritrix/jobs/myjob/crawler-beans.cxml</primaryConfig>
      <primaryConfigUrl>https://localhost:8443/engine/jobdir/crawler-beans.cxml</primaryConfigUrl>
      <key>myjob</key>
    </value>
  </jobs>
</engine>

Create New Job

POST https://(heritrixhost):8443/engine [action=create]

Creates a new crawl job. It uses the default configuration provided by the profile-defaults profile.

Form Parameters:  

• action – must be create
• createpath – the name of the new job

HTML Example:

curl -v -d "createpath=myjob&action=create" -k -u admin:admin --anyauth --location \
  https://localhost:8443/engine

XML Example:

curl -v -d "createpath=myjob&action=create" -k -u admin:admin --anyauth --location \
  -H "Accept: application/xml" https://localhost:8443/engine

Add Job Directory

POST https://(heritrixhost):8443/engine [action=add]

Adds a new job directory to the Heritrix configuration. The directory must contain a cxml configuration file.

Form Parameters:  

• action – must be add
• addpath – the job directory to add

HTML Example:

curl -v -d "action=add&addpath=/Users/hstern/job" -k -u admin:admin --anyauth --location https://localhost:8443/engine

XML Example:

curl -v -d "action=add&addpath=/Users/hstern/job" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine

Get Job Status

GET https://(heritrixhost):8443/engine/job/(jobname)

Returns status information and statistics about the chosen job.

XML Example:

curl -v -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Response:

<job>
  <shortName>myjob</shortName>
  <crawlControllerState>FINISHED</crawlControllerState>
  <crawlExitStatus>FINISHED</crawlExitStatus>
  <statusDescription>Finished: FINISHED</statusDescription>
  <availableActions>
    <value>teardown</value>
  </availableActions>
  <launchCount>1</launchCount>
  <lastLaunch>2020-04-01T02:07:42.531Z</lastLaunch>
  <isProfile>false</isProfile>
  <primaryConfig>/heritrix/jobs/myjob/crawler-beans.cxml</primaryConfig>
  <primaryConfigUrl>https://localhost:8443/engine/job/myjob/jobdir/crawler-beans.cxml</primaryConfigUrl>
  <url>https://localhost:8443/engine/job/myjob/job/myjob</url>
  <jobLogTail>
    <value>2020-04-01T03:50:44.708Z INFO FINISHED 20200401020744</value>
    <value>2020-04-01T03:50:42.670Z INFO EMPTY 20200401020744</value>
    <value>2020-04-01T03:50:42.669Z INFO STOPPING 20200401020744</value>
  </jobLogTail>
  <uriTotalsReport>
    <downloadedUriCount>3920</downloadedUriCount>
    <queuedUriCount>0</queuedUriCount>
    <totalUriCount>3920</totalUriCount>
    <futureUriCount>0</futureUriCount>
  </uriTotalsReport>
  <sizeTotalsReport>
    <dupByHash>0</dupByHash>
    <dupByHashCount>0</dupByHashCount>
    <notModified>0</notModified>
    <notModifiedCount>0</notModifiedCount>
    <novel>2177235508</novel>
    <novelCount>3920</novelCount>
    <total>2177235508</total>
    <totalCount>3920</totalCount>
    <warcNovelContentBytes>2177235508</warcNovelContentBytes>
    <warcNovelUrls>3920</warcNovelUrls>
  </sizeTotalsReport>
  <rateReport>
    <currentDocsPerSecond>0.0</currentDocsPerSecond>
    <averageDocsPerSecond>0.6354171124312226</averageDocsPerSecond>
    <currentKiBPerSec>0</currentKiBPerSec>
    <averageKiBPerSec>344</averageKiBPerSec>
  </rateReport>
  <loadReport>
    <busyThreads>0</busyThreads>
    <totalThreads>0</totalThreads>
    <congestionRatio>NaN</congestionRatio>
    <averageQueueDepth>0</averageQueueDepth>
    <deepestQueueDepth>0</deepestQueueDepth>
  </loadReport>
  <elapsedReport>
    <elapsedMilliseconds>6169176</elapsedMilliseconds>
    <elapsedPretty>1h42m49s176ms</elapsedPretty>
  </elapsedReport>
  <threadReport/>
  <frontierReport>
    <totalQueues>1</totalQueues>
    <inProcessQueues>0</inProcessQueues>
    <readyQueues>0</readyQueues>
    <snoozedQueues>0</snoozedQueues>
    <activeQueues>0</activeQueues>
    <inactiveQueues>0</inactiveQueues>
    <ineligibleQueues>0</ineligibleQueues>
    <retiredQueues>0</retiredQueues>
    <exhaustedQueues>1</exhaustedQueues>
    <lastReachedState>FINISH</lastReachedState>
  </frontierReport>
  <crawlLogTail>
    ...
  </crawlLogTail>
  <configFiles>
    ...
  </configFiles>
  <isLaunchInfoPartial>false</isLaunchInfoPartial>
  <isRunning>false</isRunning>
  <isLaunchable>false</isLaunchable>
  <hasApplicationContext>true</hasApplicationContext>
  <alertCount>549</alertCount>
  <checkpointFiles></checkpointFiles>
  <alertLogFilePath>/heritrix/jobs/myjob/20200401020744/logs/alerts.log</alertLogFilePath>
  <crawlLogFilePath>/heritrix/jobs/myjob/20200401020744/logs/crawl.log</crawlLogFilePath>
  <reports>
    <value>
      <className>CrawlSummaryReport</className>
      <shortName>CrawlSummary</shortName>
    </value>
    ...
  </reports>
  <heapReport>
    <usedBytes>66893400</usedBytes>
    <totalBytes>589824000</totalBytes>
    <maxBytes>2885681152</maxBytes>
  </heapReport>
</job>

Build Job Configuration

POST https://(heritrixhost):8443/engine/job/(jobname) [action=build]

Builds the job configuration for the chosen job. It reads an XML descriptor file and uses Spring to build the Java objects that are necessary for running the crawl. Before a crawl can be run it must be built.

Form Parameters:  

• action – must be build

HTML Example:

curl -v -d "action=build" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=build" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Launch Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=launch]

Launches a crawl job. The job can be launched in the “paused” state or the “unpaused” state. If launched in the “unpaused” state the job will immediately begin crawling.

Form Parameters:  

• action – must be launch
• checkpoint – optional field: If supplied, Heritrix will attempt to launch from a checkpoint. Should be the name of a checkpoint (e.g. cp00001-20180102121229) or (since version 3.3) the special value latest, which will automatically select the most recent checkpoint. If no checkpoint is specified (or if the latest checkpoint is requested and there are no valid checkpoints) a new crawl will be launched.

HTML Example:

curl -v -d "action=launch" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=launch" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Rescan Job Directory

POST https://(heritrixhost):8443/engine [action=rescan]

Rescans the main job directory and returns an HTML page containing all the job names. It also returns information about the jobs, such as the location of the job configuration file and the number of job launches.

Form Parameters:  

• action – must be rescan

HTML Example:

curl -v -d "action=rescan" -k -u admin:admin --anyauth --location https://localhost:8443/engine

XML Example:

curl -v -d "action=rescan" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine

Pause Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=pause]

Pauses an unpaused job. No crawling will occur while a job is paused.

Form Parameters:  

• action – must be pause

HTML Example:

curl -v -d "action=pause" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=pause" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Unpause Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=unpause]

This API unpauses a paused job. Crawling will resume (or begin, in the case of a job launched in the paused state) if possible.

Form Parameters:  

• action – must be unpause

HTML Example:

curl -v -d "action=unpause" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=unpause" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Terminate Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=terminate]

Terminates a running job.

Form Parameters:  

• action – must be terminate

HTML Example:

curl -v -d "action=terminate" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=terminate" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Teardown Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=teardown]

Removes the Spring code that is used to run the job. Once a job is torn down it must be rebuilt in order to run.

Form Parameters:  

• action – must be teardown

HTML Example:

curl -v -d "action=teardown" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=teardown" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Copy Job

POST https://(heritrixhost):8443/engine/job/(jobname) [copyTo]

Copies an existing job configuration to a new job configuration. If the “as profile” checkbox is selected, than the job configuration is copied as a non-runnable profile configuration.

Form Parameters:  

• copyTo – the name of the new job or profile configuration
• asProfile – whether to copy the job as a runnable configuration or as a non-runnable profile. The value on means the job will be copied as a profile. If omitted the job will be copied as a runnable configuration.

HTML Example:

curl -v -d "copyTo=mycopy&asProfile=on" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "copyTo=mycopy&asProfile=on" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Checkpoint Job

POST https://(heritrixhost):8443/engine/job/(jobname) [action=checkpoint]

This API checkpoints the chosen job. Checkpointing writes the current state of a crawl to the file system so that the crawl can be recovered if it fails.

Form Parameters:  

• action – must be checkpoint

HTML Example:

curl -v -d "action=checkpoint" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob

XML Example:

curl -v -d "action=checkpoint" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob

Execute Script in Job

POST https://(heritrixhost):8443/engine/job/(jobname)/script

Executes a script. The script can be written as Beanshell, ECMAScript, Groovy, or AppleScript.

Form Parameters:  

• engine – the script engine to use. One of beanshell, js, groovy or AppleScriptEngine.
• script – the script code to execute

HTML Example:

curl -v -d "engine=beanshell&script=System.out.println%28%22test%22%29%3B" -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob/script

XML Example:

curl -v -d "engine=beanshell&script=System.out.println%28%22test%22%29%3B" -k -u admin:admin --anyauth --location -H "Accept: application/xml" https://localhost:8443/engine/job/myjob/script

Submitting a CXML Job Configuration File

PUT https://(heritrixhost):8443/engine/job/(jobname)/jobdir/crawler-beans.cxml

Submits the contents of a CXML file for a chosen job. CXML files are the configuration files used to control a crawl job. Each job has a single CXML file.

Example:

curl -v -T my-crawler-beans.cxml -k -u admin:admin --anyauth --location https://localhost:8443/engine/job/myjob/jobdir/crawler-beans.cxml

Status Codes:

• 200 OK – On success, the Heritrix REST API will return a HTTP 200 with no body.

Conventions and Assumptions

The following curl parameters are used when invoking the API.

curl Parameter	Description
-v	Verbose. Output a detailed account of the curl command to standard out.
-d	Data. These are the name/value pairs that are send in the body of a POST.
-k	Insecure. Allows connections to SSL sites without certificates.
-u	User. Allows the submission of a username and password to authenticate the HTTP request.
–anyauth	Any authentication type. Allows authentication of the request based on any type of authentication method.
–location	Follows HTTP redirects. This option is used so that API calls that return data (such as HTML) will not halt upon receipt of a redirect code (such as an HTTP 303).
-H	Set the value of an HTTP header. For example, “Accept: application/xml”.

It is assumed that the reader has a working knowledge of the HTTP protocol and Heritrix functionality.  Also, the examples assume that Heritrix is run with an administrative username and password of “admin.”

About the REST implementation

Representational State Transfer (REST) is a software architecture for distributed hypermedia systems such as the World Wide Web (WWW). REST is built on the concept of representations of resources. Resources can be any coherent and meaningful concept that may be addressed. A URI is an example of a resource. The representation of the resource is typically a document that captures the current or intended state of the resource. An example of a representation of a resource is an HTML page.

Heritrix uses REST to expose its functionality. The REST implementation used by Heritrix is Restlet. Restlet implements the concepts defined by REST, including resources and representations. It also provides a REST container that processes RESTful requests. The container is the Noelios Restlet Engine. For detailed information on Restlet, visit http://www.restlet.org/.

Heritrix exposes its REST functionality through HTTPS. The HTTPS protocol is used to send requests to retrieve or modify configuration settings and manage crawl jobs.