Chapter 139. SSH
Chapter 139. SSH Since Camel 2.10 Both producer and consumer are supported The SSH component enables access to SSH servers so that you can send an SSH command and process the response. 139.1. Dependencies When using camel-ssh with Red Hat build of Camel Spring Boot, add the following Maven dependency to your pom.xml to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-ssh-starter</artifactId> </dependency> 139.2. URI format 139.3. Configuring Options Camel components are configured on two separate levels: component level endpoint level 139.3.1. Configuring Component Options At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level. 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. You can configure components using: the Component DSL . in a configuration file (application.properties, *.yaml files, etc). directly in the Java code. 139.3.2. Configuring Endpoint Options You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both. Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java. A good practice when configuring options is to use Property Placeholders . Property placeholders provide a few benefits: They help prevent using hardcoded urls, port numbers, sensitive information, and other settings. They allow externalizing the configuration from the code. They help the code to become more flexible and reusable. The following two sections list all the options, firstly for the component followed by the endpoint. 139.4. Component Options The SSH component supports 25 options, which are listed below. Name Description Default Type 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 (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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 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. false 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 channelType (advanced) Sets the channel type to pass to the Channel as part of command execution. Defaults to exec. exec String clientBuilder (advanced) Autowired Instance of ClientBuilder used by the producer or consumer to create a new SshClient. ClientBuilder compressions (advanced) Whether to use compression, and if so which. String configuration (advanced) Component configuration. SshConfiguration shellPrompt (advanced) Sets the shellPrompt to be dropped when response is read after command execution. String sleepForShellPrompt (advanced) Sets the sleep period in milliseconds to wait reading response from shell prompt. Defaults to 100 milliseconds. 100 long healthCheckConsumerEnabled (health) Used for enabling or disabling all consumer based health checks from this component. true boolean healthCheckProducerEnabled (health) Used for enabling or disabling all producer based health checks from this component. Note By default all producer based health-checks are disabled. You can turn on producer checks globally by setting camel.health.producersEnabled=true . 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 certResourcePassword (security) Sets the password to use in loading certResource, if certResource is an encrypted key. String ciphers (security) Comma-separated list of allowed/supported ciphers in their order of preference. String kex (security) Comma-separated list of allowed/supported key exchange algorithms in their order of preference. 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. From Camel 3.0.0 / 2.25.0, by default Camel will select the first available KeyPair that is loaded. Prior to this, a KeyType of 'ssh-rsa' was enforced by default. String macs (security) Comma-separated list of allowed/supported message authentication code algorithms in their order of preference. The MAC algorithm is used for data integrity protection. String password (security) Sets the password to use in connecting to remote SSH server. Requires keyPairProvider to be set to null. String signatures (security) Comma-separated list of allowed/supported signature algorithms in their order of preference. String username (security) Sets the username to use in logging into the remote SSH server. String 139.5. Endpoint Options The SSH endpoint is configured using URI syntax: With the following path and query parameters: 139.5.1. Path Parameters (2 parameters) Name Description Default Type host (common) Required Sets the hostname of the remote SSH server. String port (common) Sets the port number for the remote SSH server. 22 int 139.5.2. Query Parameters (39 parameters) Name Description Default Type 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 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 bridgeErrorHandler (consumer (advanced)) Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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 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 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 lazyStartProducer (producer (advanced)) 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 channelType (advanced) Sets the channel type to pass to the Channel as part of command execution. Defaults to exec. exec String clientBuilder (advanced) Autowired Instance of ClientBuilder used by the producer or consumer to create a new SshClient. ClientBuilder compressions (advanced) Whether to use compression, and if so which. String shellPrompt (advanced) Sets the shellPrompt to be dropped when response is read after command execution. String sleepForShellPrompt (advanced) Sets the sleep period in milliseconds to wait reading response from shell prompt. Defaults to 100 milliseconds. 100 long 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 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 poll. 500 long greedy (scheduler) If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the run polled 1 or more messages. false 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. 0 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 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: NANOSECONDS MICROSECONDS MILLISECONDS SECONDS MINUTES HOURS DAYS 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 certResourcePassword (security) Sets the password to use in loading certResource, if certResource is an encrypted key. String ciphers (security) Comma-separated list of allowed/supported ciphers in their order of preference. String kex (security) Comma-separated list of allowed/supported key exchange algorithms in their order of preference. 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. From Camel 3.0.0 / 2.25.0, by default Camel will select the first available KeyPair that is loaded. Prior to this, a KeyType of 'ssh-rsa' was enforced by default. String macs (security) Comma-separated list of allowed/supported message authentication code algorithms in their order of preference. The MAC algorithm is used for data integrity protection. String password (security) Sets the password to use in connecting to remote SSH server. Requires keyPairProvider to be set to null. String signatures (security) Comma-separated list of allowed/supported signature algorithms in their order of preference. String username (security) Sets the username to use in logging into the remote SSH server. String 139.6. Message Headers The SSH component supports 4 message header(s), which is/are listed below: Name Description Default Type CamelSshUsername (common) Constant: USERNAME_HEADER The user name. String CamelSshPassword (common) Constant: PASSWORD_HEADER The password. String CamelSshStderr (common) Constant: STDERR The value of this header is a InputStream with the standard error stream of the executable. InputStream CamelSshExitValue (common) Constant: EXIT_VALUE The value of this header is the exit value that is returned, after the execution. By convention a non-zero status exit value indicates abnormal termination. Note that the exit value is OS dependent. Integer 139.7. Usage as a Producer endpoint When the SSH Component is used as a Producer (`.to("ssh://... ")`), it sends the message body as the command to execute on the remote SSH server. XML DSL example 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="USD{body}"/> </route> 139.8. Authentication The SSH Component can authenticate against the remote SSH server using one of two mechanisms: Public Key certificate Username/password Configuring how the SSH Component does authentication is based on how and which options are set. 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. If certResource is not set, it will look to see if a keyPairProvider has been set, and if so, it will use that for certificate-based authentication. 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. 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="USD{body}"/> </route> Java DSL from("ssh://scott@localhost:8101?certResource=classpath:test_rsa&useFixedDelay=true&delay=5000&pollCommand=features:list%0A") .log("USD{body}"); An example of using Public Key authentication is provided in examples/camel-example-ssh-security . 139.9. Certificate Dependencies You need to add some additional runtime dependencies if you use certificate-based authentication. You may need to use later versions depending on what version of Camel you are using. The component uses sshd-core library which is based on either bouncycastle or eddsa security providers. camel-ssh is picking explicitly bouncycastle as security provider. <dependency> <groupId>org.apache.sshd</groupId> <artifactId>sshd-core</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcpg-jdk18on</artifactId> <version>1.71</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcpkix-jdk18on</artifactId> <version>1.71</version> </dependency> 139.10. Spring Boot Auto-Configuration The component supports 26 options, which are listed below. Name Description Default Type camel.component.ssh.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.ssh.bridge-error-handler Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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.ssh.cert-resource 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 camel.component.ssh.cert-resource-password Sets the password to use in loading certResource, if certResource is an encrypted key. String camel.component.ssh.channel-type Sets the channel type to pass to the Channel as part of command execution. Defaults to exec. exec String camel.component.ssh.ciphers Comma-separated list of allowed/supported ciphers in their order of preference. String camel.component.ssh.client-builder Instance of ClientBuilder used by the producer or consumer to create a new SshClient. The option is a org.apache.sshd.client.ClientBuilder type. ClientBuilder camel.component.ssh.compressions Whether to use compression, and if so which. String camel.component.ssh.configuration Component configuration. The option is a org.apache.camel.component.ssh.SshConfiguration type. SshConfiguration camel.component.ssh.enabled Whether to enable auto configuration of the ssh component. This is enabled by default. Boolean camel.component.ssh.fail-on-unknown-host 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 camel.component.ssh.health-check-consumer-enabled Used for enabling or disabling all consumer based health checks from this component. true Boolean camel.component.ssh.health-check-producer-enabled Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true. true Boolean camel.component.ssh.kex Comma-separated list of allowed/supported key exchange algorithms in their order of preference. String camel.component.ssh.key-pair-provider Sets the KeyPairProvider reference to use when connecting using Certificates to the remote SSH Server. The option is a org.apache.sshd.common.keyprovider.KeyPairProvider type. KeyPairProvider camel.component.ssh.key-type Sets the key type to pass to the KeyPairProvider as part of authentication. KeyPairProvider.loadKey(... ) will be passed this value. From Camel 3.0.0 / 2.25.0, by default Camel will select the first available KeyPair that is loaded. Prior to this, a KeyType of 'ssh-rsa' was enforced by default. String camel.component.ssh.known-hosts-resource Sets the resource path for a known_hosts file. String camel.component.ssh.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.ssh.macs Comma-separated list of allowed/supported message authentication code algorithms in their order of preference. The MAC algorithm is used for data integrity protection. String camel.component.ssh.password Sets the password to use in connecting to remote SSH server. Requires keyPairProvider to be set to null. String camel.component.ssh.poll-command 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 camel.component.ssh.shell-prompt Sets the shellPrompt to be dropped when response is read after command execution. String camel.component.ssh.signatures Comma-separated list of allowed/supported signature algorithms in their order of preference. String camel.component.ssh.sleep-for-shell-prompt Sets the sleep period in milliseconds to wait reading response from shell prompt. Defaults to 100 milliseconds. 100 Long camel.component.ssh.timeout Sets the timeout in milliseconds to wait in establishing the remote SSH server connection. Defaults to 30000 milliseconds. 30000 Long camel.component.ssh.username Sets the username to use in logging into the remote SSH server. String
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-ssh-starter</artifactId> </dependency> ssh:[username[:password]@]host[:port][?options] ssh:host:port <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="USD{body}"/> </route> <route> <from uri="ssh://scott@localhost:8101?certResource=classpath:test_rsa&amp;useFixedDelay=true&amp;delay=5000&amp;pollCommand=features:list%0A"/> <log message="USD{body}"/> </route> from("ssh://scott@localhost:8101?certResource=classpath:test_rsa&useFixedDelay=true&delay=5000&pollCommand=features:list%0A") .log("USD{body}"); <dependency> <groupId>org.apache.sshd</groupId> <artifactId>sshd-core</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcpg-jdk18on</artifactId> <version>1.71</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcpkix-jdk18on</artifactId> <version>1.71</version> </dependency>