Chapter 307. SSH Component

Available as of Camel version 2.10

The SSH component enables access to SSH servers such that you can send an SSH command, and process the response.

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

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

307.1. URI format

ssh:[username[:password]@]host[:port][?options]

307.2. Options

The SSH component supports 12 options which are listed below.

NameDescriptionDefaultType

configuration (advanced)

To use the shared SSH configuration

 

SshConfiguration

host (common)

Sets the hostname of the remote SSH server.

 

String

port (common)

Sets the port number for the remote SSH server.

 

int

username (security)

Sets the username to use in logging into the remote SSH server.

 

String

password (security)

Sets the password to use in connecting to remote SSH server. Requires keyPairProvider to be set to null.

 

String

pollCommand (common)

Sets the command string to send to the remote SSH server during every poll cycle. Only works with camel-ssh component being used as a consumer, i.e. from(ssh://…​). You may need to end your command with a newline, and that must be URL encoded %0A

 

String

keyPairProvider (security)

Sets the KeyPairProvider reference to use when connecting using Certificates to the remote SSH Server.

 

KeyPairProvider

keyType (security)

Sets the key type to pass to the KeyPairProvider as part of authentication. KeyPairProvider.loadKey(…​) will be passed this value. Defaults to ssh-rsa.

 

String

timeout (common)

Sets the timeout in milliseconds to wait in establishing the remote SSH server connection. Defaults to 30000 milliseconds.

 

long

certFilename (security)

Deprecated Sets the resource path of the certificate to use for Authentication.

 

String

certResource (security)

Sets the resource path of the certificate to use for Authentication. Will use ResourceHelperKeyPairProvider to resolve file based certificate, and depends on keyType setting.

 

String

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The SSH endpoint is configured using URI syntax:

ssh:host:port

with the following path and query parameters:

307.2.1. Path Parameters (2 parameters):

NameDescriptionDefaultType

host

Required Sets the hostname of the remote SSH server.

 

String

port

Sets the port number for the remote SSH server.

22

int

307.2.2. Query Parameters (28 parameters):

NameDescriptionDefaultType

failOnUnknownHost (common)

Specifies whether a connection to an unknown host should fail or not. This value is only checked when the property knownHosts is set.

false

boolean

knownHostsResource (common)

Sets the resource path for a known_hosts file

 

String

timeout (common)

Sets the timeout in milliseconds to wait in establishing the remote SSH server connection. Defaults to 30000 milliseconds.

30000

long

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.

false

boolean

pollCommand (consumer)

Sets the command string to send to the remote SSH server during every poll cycle. Only works with camel-ssh component being used as a consumer, i.e. from(ssh://…​) You may need to end your command with a newline, and that must be URL encoded %0A

 

String

sendEmptyMessageWhenIdle (consumer)

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

false

boolean

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options 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)

Sets the exchange pattern when the consumer creates an exchange.

 

ExchangePattern

pollStrategy (consumer)

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.

 

PollingConsumerPoll Strategy

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

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. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

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

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

1000

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.

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.

 

ScheduledExecutor Service

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz2 component

none

ScheduledPollConsumer Scheduler

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler.

 

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

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

true

boolean

certResource (security)

Sets the resource path of the certificate to use for Authentication. Will use ResourceHelperKeyPairProvider to resolve file based certificate, and depends on keyType setting.

 

String

keyPairProvider (security)

Sets the KeyPairProvider reference to use when connecting using Certificates to the remote SSH Server.

 

KeyPairProvider

keyType (security)

Sets the key type to pass to the KeyPairProvider as part of authentication. KeyPairProvider.loadKey(…​) will be passed this value. Defaults to ssh-rsa.

ssh-rsa

String

password (security)

Sets the password to use in connecting to remote SSH server. Requires keyPairProvider to be set to null.

 

String

username (security)

Sets the username to use in logging into the remote SSH server.

 

String

307.3. Usage as a Producer endpoint

When the SSH Component is used as a Producer (.to("ssh://…​")), it will send the message body as the command to execute on the remote SSH server.

Here is an example of this within the XML DSL. Note that the command has an XML encoded newline (&#10;).

<route id="camel-example-ssh-producer">
  <from uri="direct:exampleSshProducer"/>
  <setBody>
    <constant>features:list&#10;</constant>
  </setBody>
  <to uri="ssh://karaf:karaf@localhost:8101"/>
  <log message="${body}"/>
</route>

307.4. Authentication

The SSH Component can authenticate against the remote SSH server using one of two mechanisms: Public Key certificate or username/password. Configuring how the SSH Component does authentication is based on how and which options are set.

  1. First, it will look to see if the certResource option has been set, and if so, use it to locate the referenced Public Key certificate and use that for authentication.
  2. If certResource is not set, it will look to see if a keyPairProvider has been set, and if so, it will use that to for certificate based authentication.
  3. If neither certResource nor keyPairProvider are set, it will use the username and password options for authentication. Even though the username and password are provided in the endpoint configuration and headers set with SshConstants.USERNAME_HEADER (CamelSshUsername) and SshConstants.PASSWORD_HEADER (CamelSshPassword), the endpoint configuration is surpassed and credentials set in the headers are used.

The following route fragment shows an SSH polling consumer using a certificate from the classpath.

In the XML DSL,

<route>
  <from uri="ssh://scott@localhost:8101?certResource=classpath:test_rsa&amp;useFixedDelay=true&amp;delay=5000&amp;pollCommand=features:list%0A"/>
  <log message="${body}"/>
</route>

In the Java DSL,

from("ssh://scott@localhost:8101?certResource=classpath:test_rsa&useFixedDelay=true&delay=5000&pollCommand=features:list%0A")
    .log("${body}");

An example of using Public Key authentication is provided in examples/camel-example-ssh-security.

Certificate Dependencies

You will need to add some additional runtime dependencies if you use certificate based authentication. The dependency versions shown are as of Camel 2.11, you may need to use later versions depending what version of Camel you are using.

<dependency>
  <groupId>org.apache.sshd</groupId>
  <artifactId>sshd-core</artifactId>
  <version>0.8.0</version>
</dependency>
<dependency>
  <groupId>org.bouncycastle</groupId>
  <artifactId>bcpg-jdk15on</artifactId>
  <version>1.47</version>
</dependency>
<dependency>
  <groupId>org.bouncycastle</groupId>
  <artifactId>bcpkix-jdk15on</artifactId>
  <version>1.47</version>
</dependency>

307.5. Example

See the examples/camel-example-ssh and examples/camel-example-ssh-security in the Camel distribution.

307.6. See Also

  • Configuring Camel
  • Component
  • Endpoint
  • Getting Started