[CAMEL-10727] camel-ftp: knownHostsUri configuration with camel 2.18.1

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.18.1
• Fix Version/s: 2.18.2, 2.19.0
• Component/s: camel-ftp
• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Johan Vandeweerd
• Created: 19/Jan/17 15:40
• Updated: 06/Mar/17 10:51
• Resolved: 20/Jan/17 10:05

Description

I have a known_hosts file on my classpath and I want the ftp-component to use this known_hosts file when connecting to an sftp server (and not be dependent on the ~/.ssh/known_hosts file).
The documentation (http://camel.apache.org/ftp2.html) mentions that u can use the option knownHostsUri to configure the (classpath) location of a known_hosts file.
When using this option (in combination with the option useUserKnownHostsFile=false), camel fails to connect to the server because of a NullPointerException (see below).
When debugging, it seems that the list of known_hosts from the classpath are first loaded succesfully (SftpOperations:268) but afterwards the known_hosts are ALWAYS overridden (SftpOperations:284). When setting the option useUserKnownHostsFile to false, there is no file to load (no fallback to the known_hosts file from the home directory) and the exception is thrown.
I made a small github project (https://github.com/johanvandeweerd/camel-sftp) that can be cloned and run to reproduce the error. You can play with the options in SftpRouteBuilder.

Stacktrace:

2017-01-17 18:19:33.397  WARN 2652 --- [           main] o.a.c.c.file.remote.SftpConsumer         : Error auto creating directory: pub/example due Cannot connect to sftp://[e-mail]:22. This exception is ignored. 

org.apache.camel.component.file.GenericFileOperationFailedException: Cannot connect to sftp://[e-mail]:22 
        at org.apache.camel.component.file.remote.SftpOperations.connect(SftpOperations.java:146) ~[camel-ftp-2.18.1.jar:2.18.1] 
        at org.apache.camel.component.file.remote.RemoteFileConsumer.connectIfNecessary(RemoteFileConsumer.java:203) ~[camel-ftp-2.18.1.jar:2.18.1] 
        at org.apache.camel.component.file.remote.SftpConsumer.doStart(SftpConsumer.java:53) ~[camel-ftp-2.18.1.jar:2.18.1] 
        at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.startService(DefaultCamelContext.java:3371) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRouteConsumers(DefaultCamelContext.java:3688) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doStartRouteConsumers(DefaultCamelContext.java:3624) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.safelyStartRouteServices(DefaultCamelContext.java:3544) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRoutes(DefaultCamelContext.java:3308) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3162) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.access$000(DefaultCamelContext.java:182) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2957) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext$2.call(DefaultCamelContext.java:2953) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:2976) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:2953) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:61) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:2920) [camel-core-2.18.1.jar:2.18.1] 
        at org.apache.camel.spring.boot.RoutesCollector.maybeStart(RoutesCollector.java:141) [camel-spring-boot-2.18.1.jar:2.18.1] 
        at org.apache.camel.spring.boot.RoutesCollector.onApplicationEvent(RoutesCollector.java:116) [camel-spring-boot-2.18.1.jar:2.18.1] 
        at org.apache.camel.spring.boot.RoutesCollector.onApplicationEvent(RoutesCollector.java:41) [camel-spring-boot-2.18.1.jar:2.18.1] 
        at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:337) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:882) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.finishRefresh(EmbeddedWebApplicationContext.java:144) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:545) [spring-context-4.3.5.RELEASE.jar:4.3.5.RELEASE] 
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE] 
        at be.engine31.camel.Application.main(Application.java:10) [classes/:na] 
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91] 
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91] 
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91] 
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91] 
        at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) [idea_rt.jar:na] 
Caused by: java.lang.NullPointerException: null 
        at com.jcraft.jsch.Util.checkTilde(Util.java:489) ~[jsch-0.1.54.jar:na] 
        at com.jcraft.jsch.KnownHosts.setKnownHosts(KnownHosts.java:54) ~[jsch-0.1.54.jar:na] 
        at com.jcraft.jsch.JSch.setKnownHosts(JSch.java:317) ~[jsch-0.1.54.jar:na] 
        at org.apache.camel.component.file.remote.SftpOperations.createSession(SftpOperations.java:284) ~[camel-ftp-2.18.1.jar:2.18.1] 
        at org.apache.camel.component.file.remote.SftpOperations.connect(SftpOperations.java:115) ~[camel-ftp-2.18.1.jar:2.18.1] 
        ... 38 common frames omitted

Issue Links

• is cloned by: CAMEL-10946 camel-ftp: knownHostsUri configuration with camel 2.18.2