GitHub

Since Camel 2.15

Both producer and consumer are supported

The GitHub component interacts with the GitHub API by encapsulating egit-github. It currently provides polling for new pull requests, pull request comments, tags, and commits. It is also able to produce comments on pull requests, as well as close the pull request entirely.

Rather than webhooks, this endpoint relies on simple polling. Reasons include:

  • Concern for reliability/stability

  • The types of payloads we’re polling aren’t typically large (plus, paging is available in the API)

  • The need to support apps running somewhere not publicly accessible where a webhook would fail

Note that the GitHub API is fairly expansive. Therefore, this component could be easily expanded to provide additional interactions.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-github</artifactId>
    <version>${camel-version}</version>
</dependency>

URI format

github://endpoint[?options]

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The GitHub component supports 4 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

oauthToken (security)

GitHub OAuth token. Must be configured on either component or endpoint.

String

Endpoint Options

The GitHub endpoint is configured using URI syntax:

github:type/branchName

with the following path and query parameters:

Path Parameters (3 parameters)

Name Description Default Type

type (common)

Required What git operation to execute.

Enum values:

  • CLOSEPULLREQUEST

  • PULLREQUESTCOMMENT

  • COMMIT

  • PULLREQUEST

  • TAG

  • PULLREQUESTSTATE

  • PULLREQUESTFILES

  • GETCOMMITFILE

  • CREATEISSUE

  • EVENT

GitHubType

branchName (consumer)

Name of branch.

String

startingSha (consumer)

The starting sha to use for polling commits with the commit consumer. The value can either be a sha for the sha to start from, or use beginning to start from the beginning, or last to start from the last commit.

String

Query Parameters (27 parameters)

Name Description Default Type

repoName (common)

Required GitHub repository name.

String

repoOwner (common)

Required GitHub repository owner (organization).

String

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

boolean

eventFetchStrategy (consumer (advanced))

To specify a custom strategy that configures how the EventsConsumer fetches events.

GitHubEventFetchStrategy

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

  • InOptionalOut

ExchangePattern

pollStrategy (consumer (advanced))

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

PollingConsumerPollStrategy

encoding (producer)

To use the given encoding when getting a git commit file.

String

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

state (producer)

To set git commit status state.

Enum values:

  • error

  • failure

  • pending

  • success

String

targetUrl (producer)

To set git commit status target url.

String

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

int

delay (scheduler)

Milliseconds before the next poll.

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts.

long

repeatCount (scheduler)

Specifies a maximum limit of number of fires. So if you set it to 1, the scheduler will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever.

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

Enum values:

  • TRACE

  • DEBUG

  • INFO

  • WARN

  • ERROR

  • OFF

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

ScheduledExecutorService

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz component. Use value spring or quartz for built in scheduler.

Object

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz, Spring based scheduler.

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

Enum values:

  • NANOSECONDS

  • MICROSECONDS

  • MILLISECONDS

  • SECONDS

  • MINUTES

  • HOURS

  • DAYS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

boolean

oauthToken (security)

GitHub OAuth token. Must be configured on either component or endpoint.

String

Configuring authentication

The github component requires to be configured with an authentication token on either the component or endpoint level.

For example to set it on the component:

GitHubComponent ghc = context.getComponent("github", GitHubComponent.class);
ghc.setOauthToken("mytoken");

Consumer Endpoints:

Endpoint Context Body Type

pullRequest

polling

org.eclipse.egit.github.core.PullRequest

pullRequestComment

polling

org.eclipse.egit.github.core.Comment (comment on the general pull request discussion) or org.eclipse.egit.github.core.CommitComment (inline comment on a pull request diff)

tag

polling

org.eclipse.egit.github.core.RepositoryTag

commit

polling

org.eclipse.egit.github.core.RepositoryCommit

Producer Endpoints:

Endpoint Body Message Headers

pullRequestComment

String (comment text)

- GitHubPullRequest (integer) (REQUIRED): Pull request number.

- GitHubInResponseTo (integer): Required if responding to another inline comment on the pull request diff. If left off, a general comment on the pull request discussion is assumed.

closePullRequest

none

- GitHubPullRequest (integer) (REQUIRED): Pull request number.

createIssue

String (issue body text)

- GitHubIssueTitle (String) (REQUIRED): Issue Title.

Spring Boot Auto-Configuration

When using github with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-github-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 5 options, which are listed below.

Name Description Default Type

camel.component.github.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.github.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.github.enabled

Whether to enable auto configuration of the github component. This is enabled by default.

Boolean

camel.component.github.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.github.oauth-token

GitHub OAuth token. Must be configured on either component or endpoint.

String