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>
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. |
true |
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:
|
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. |
last |
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:
|
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:
|
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. |
500 |
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. |
1000 |
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 |
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. |
none |
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. |
true |
boolean |
timeUnit (scheduler) |
Time unit for initialDelay and delay options. Enum values:
|
MILLISECONDS |
TimeUnit |
useFixedDelay (scheduler) |
Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details. |
true |
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 |