8.2. Connecting and Disconnecting Remotely
Abstract
There are two alternative ways of connecting to a remote container. If you are already running an Red Hat JBoss Fuse command shell, you can invoke a console command to connect to the remote container. Alternatively, you can run a utility directly on the command-line to connect to the remote container.
8.2.1. Connecting to a Standalone Container from a Remote Container
Overview
Any container's command console can be used to access a remote container. Using SSH, the local container's console connects to the remote container and functions as a command console for the remote container.
Using the ssh:ssh console command
You connect to a remote container's console using the ssh:ssh console command.
Example 8.2. ssh:ssh Command Syntax
ssh:ssh {
-l username
} {
-P password
} {
-p port
} {
hostname
}
-
-l username - The username used to connect to the remote container. Use valid JAAS login credentials that have
adminprivileges (see Chapter 14, Configuring JAAS Security). -
-P password - The password used to connect to the remote container.
-
-p port - The SSH port used to access the desired container's remote console.By default this value is
8101. See the section called “Configuring a standalone container for remote access” for details on changing the port number. -
hostname - The hostname of the machine that the remote container is running on. See the section called “Configuring a standalone container for remote access” for details on changing the hostname.
Warning
We recommend that you customize the username and password in the
etc/users.properties file. See Chapter 14, Configuring JAAS Securityfor details.
Note
If your remote container is deployed on an Oracle VM Server for SPARC instance, it is likely that the default SSH port value, 8101, is already occupied by the Logical Domains Manager daemon. In this case, you will need to reconfigure the container's SSH port, as described in the section called “Configuring a standalone container for remote access”.
Example 8.3. Connecting to a Remote Console
JBossFuse:karaf@root>ssh:ssh -l smx -P smx -p 8108 hostname
To confirm that you have connected to the correct container, type
shell:info at the prompt. Information about the currently connected instance is returned, as shown in Example 8.4, “Output of the shell:info Command”.
Example 8.4. Output of the shell:info Command
Karaf Karaf version 2.4.0.redhat-630187 Karaf home /home/jboss-fuse-6.3.0.redhat-187 Karaf base /home/jboss-fuse-6.3.0.redhat-187 OSGi Framework org.apache.felix.framework - 4.4.1 JVM Java Virtual Machine Java HotSpot(TM) Server VM version 25.121-b13 Version 1.8.0_121 Vendor Oracle Corporation Pid 4647 Uptime 32.558 seconds Total compile time 45.154 seconds Threads Live threads 87 Daemon threads 69 Peak 88 Total started 113 Memory Current heap size 206,941 kbytes Maximum heap size 932,096 kbytes Committed heap size 655,360 kbytes Pending objects 0 Garbage collector Name = 'PS Scavenge', Collections = 13, Time = 0.343 seconds Garbage collector Name = 'PS MarkSweep', Collections = 2, Time = 0.272 seconds Classes Current classes loaded 10,152 Total classes loaded 10,152 Total classes unloaded 0 Operating system Name Linux version 4.8.14-100.fc23.x86_64 Architecture i386 Processors 4 Disconnecting from a remote console
To disconnect from a remote console, enter
logout or press Ctrl+D at the prompt.
You will be disconnected from the remote container and the console will once again manage the local container.
8.2.2. Connecting to a Fabric Container From another Fabric Container
Overview
When containers are deployed into a fabric, they are all connected to each other. You can easily connect to any container's command console from any of its peers. When connecting using fabric, you do not need to know any of the location details for the container you want to connect to. The fabric's runtime registry stores all of the location details needed to establish the remote connection.
Using the fabric:container-connect command
In the context of a fabric, you should connect to a remote runtime's console using the fabric:container-connect command.
Example 8.5. fabric:container-connect Command Syntax
fabric:container-connect {
-u username
} {
-p password
} {
containerName
}
-
-u username - The username used to connect to the remote console. The default value is
admin. -
-p password - The password used to connect to the remote console. The default value is
admin. -
containerName - The name of the container.
Warning
We recommend that you change the default administrator username and password. See Chapter 14, Configuring JAAS Security for details.
Example 8.6. Connecting to a Remote Container
JBossFuse:karaf@root>fabric:container-connect -u admin -p admin containerName
To confirm that you have connected to the correct container, type
shell:info at the prompt. Information about the currently connected instance is returned, as shown in Example 8.7, “Output of the shell:info Command”.
Example 8.7. Output of the shell:info Command
Karaf Karaf version 2.4.0.redhat-630187 Karaf home /home/aaki/Downloads/jboss-fuse-6.3.0.redhat-187 Karaf base /home/aaki/Downloads/jboss-fuse-6.3.0.redhat-187 OSGi Framework org.apache.felix.framework - 4.4.1 JVM Java Virtual Machine Java HotSpot(TM) Server VM version 25.121-b13 Version 1.8.0_121 Vendor Oracle Corporation Pid 4647 Uptime 32.558 seconds Total compile time 45.154 seconds Threads Live threads 87 Daemon threads 69 Peak 88 Total started 113 Memory Current heap size 206,941 kbytes Maximum heap size 932,096 kbytes Committed heap size 655,360 kbytes Pending objects 0 Garbage collector Name = 'PS Scavenge', Collections = 13, Time = 0.343 seconds Garbage collector Name = 'PS MarkSweep', Collections = 2, Time = 0.272 seconds Classes Current classes loaded 10,152 Total classes loaded 10,152 Total classes unloaded 0 Operating system Name Linux version 4.8.14-100.fc23.x86_64 Architecture i386 Processors 4 Disconnecting from a remote console
To disconnect from a remote console, enter
logout or press Ctrl+D at the prompt.
You will be disconnected from the remote container and the console will once again manage the local container.
8.2.3. Connecting to a Container Using the Client Command-Line Utility
Using the remote client
The remote client allows you to securely connect to a remote Red Hat JBoss Fuse container without having to launch a full JBoss Fuse container locally.
For example, to quickly connect to a JBoss Fuse instance running in server mode on the same machine, open a command prompt and run the client[.bat] script (which is located in the
InstallDir/bin directory), as follows:
client
More usually, you would provide a hostname, port, username, and password to connect to a remote instance. If you were using the client within a larger script, for example in a test suite, you could append console commands as follows:
client -a 8101 -h hostname -u username -p password shell:info
Alternatively, if you omit the
-p option, you will be prompted to enter a password.
For a standalone container, use any valid JAAS user credentials that have
admin privileges.
For a container in a fabric, the default username and password is
admin and admin.
To display the available options for the client, type:
client --helpExample 8.8. Karaf Client Help
Apache Karaf client -a [port] specify the port to connect to -h [host] specify the host to connect to -u [user] specify the user name -p [password] specify the password (optional, if not provided, the password is prompted) NB: this option is deprecated and will be removed in next Karaf version --help shows this help message -v raise verbosity -l set client logging level. Set to 0 for ERROR logging and up to 4 for TRACE. -r [attempts] retry connection establishment (up to attempts times) -d [delay] intra-retry delay (defaults to 2 seconds) -b batch mode, specify multiple commands via standard input -f [file] read commands from the specified file -k [keyFile] specify the private keyFile location when using key login [commands] commands to run If no commands are specified, the client will be put in an interactive mode Remote client default credentials
You might be surprised to find that you can log into your Karaf container using
bin/client, without supplying any credentials. This is because the remote client program is pre-configured to use default credentials. If no credentials are specified, the remote client automatically tries to use the following default credentials (in sequence):
- Default SSH key—tries to login using the default Apache Karaf SSH key. The corresponding configuration entry that would allow this login to succeed is commented out by default in the
etc/keys.propertiesfile. - Red Hat Fuse does not use
admin/adminas the remote default credential. When you log into the application, Fuse would try to useusername/passwordof an item randomly chosen from theetc/users.propertiesfile. However, it is recommended not to usebin/clientscript without-uoption, when you need to useusername/password.
Hence, if you create a new user in the Karaf container simply by uncommenting the default
admin/admin credentials in users.properties, you will find that the bin/client utility can log in without supplying credentials.
Important
For your security, JBoss Fuse has disabled the default credentials (by commenting out) when the Karaf container is first installed. If you simply uncomment these default credentials, however, without changing the default password or SSH public key, you will open up a security hole in your Karaf container. You must never do this in a production environment. If you find that you can login to your container using
bin/client without supplying credentials, this shows that your container is insecure and you must take steps to fix this in a production environment.
Disconnecting from a remote client console
If you used the remote client to open a remote console, as opposed to using it to pass a command, you will need to disconnect from it. To disconnect from the remote client's console, enter logout or press Ctrl+D at the prompt.
The client will disconnect and exit.
8.2.4. Connecting to a Container Using the SSH Command-Line Utility
Overview
You can also use the
ssh command-line utility (a standard utility on UNIX-like operating systems) to log in to the Red Hat JBoss Fuse container, where the authentication mechanism is based on public key encryption (the public key must first be installed in the container). For example, given that the container is configured to listen on TCP port 8101, you could log in as follows:
ssh -p 8101 jdoe@localhost
Important
Key-based login is currently supported only on standalone containers, not on Fabric containers.
Prerequisites
To use key-based SSH login, the following prerequisites must be satisfied:
- The container must be standalone (Fabric is not supported) with the
PublickeyLoginModuleinstalled. - You must have created an SSH key pair (see the section called “Creating a new SSH key pair”).
- You must install the public key from the SSH key pair into the container (see the section called “Installing the SSH public key in the container”).
Default key location
The
ssh command automatically looks for the private key in the default key location. It is recommended that you install your key in the default location, because it saves you the trouble of specifying the location explicitly.
On a *NIX operating system, the default locations for an RSA key pair are:
~/.ssh/id_rsa ~/.ssh/id_rsa.pub
On a Windows operating system, the default locations for an RSA key pair are:
C:\Documents and Settings\Username\.ssh\id_rsa C:\Documents and Settings\Username\.ssh\id_rsa.pub
Note
Red Hat JBoss Fuse supports only RSA keys. DSA keys do not work.
Creating a new SSH key pair
Generate an RSA key pair using the
ssh-keygen utility. Open a new command prompt and enter the following command:
ssh-keygen -t rsa -b 2048
The preceding command generates an RSA key with a key length of 2048 bits. You will then be prompted to specify the file name for the key pair:
Generating public/private rsa key pair. Enter file in which to save the key (/Users/Username/.ssh/id_rsa):
Type return to save the key pair in the default location. You will then be prompted for a pass phrase:
Enter passphrase (empty for no passphrase):
You can optionally enter a pass phrase here or type return twice to select no pass phrase.
Note
If you want to use the same key pair for running Fabric console commands, it is recommended that you select no pass phrase, because Fabric does not support using encrypted private keys.
Installing the SSH public key in the container
To use the SSH key pair for logging into the Red Hat JBoss Fuse container, you must install the SSH public key in the container by creating a new user entry in the
InstallDir/etc/keys.properties file. Each user entry in this file appears on a single line, in the following format:
Username=PublicKey,Role1,Role2,...
For example, given that your public key file,
~/.ssh/id_rsa.pub, has the following contents:
ssh-rsa AAAAB3NzaC1kc3MAAACBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9EAMMeP4C2USZpRV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7 gB00b/JmYLdrmVClpJ+f6AR7ECLCT7up1/63xhv4O1fnfqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv8iIDGZ3RSAHHAAAAFQCX YFCPFSMLzLKSuYKi64QL8Fgc9QAAAnEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCBgLRJFnEj6Ewo FhO3zwkyjMim4TwWeotifI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImog9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoAAACB AKKSU2PFl/qOLxIwmBZPPIcJshVe7bVUpFvyl3BbJDow8rXfskl8wO63OzP/qLmcJM0+JbcRU/53Jj7uyk31drV2qxhIOsLDC9dGCWj4 7Y7TyhPdXh/0dthTRBy6bqGtRPxGa7gJov1xm/UuYYXPIUR/3x9MAZvZ5xvE0kYXO+rx jdoe@doemachine.local
You can create the
jdoe user with the admin role by adding the following entry to the InstallDir/etc/keys.properties file (on a single line):
jdoe=AAAAB3NzaC1kc3MAAACBAP1/U4EddRIpUt9KnC7s5Of2EbdSPO9EAMMeP4C2USZpRV1AIlH7WT2NWPq/xfW6MPbLm1Vs14E7 gB00b/JmYLdrmVClpJ+f6AR7ECLCT7up1/63xhv4O1fnfqimFQ8E+4P208UewwI1VBNaFpEy9nXzrith1yrv8iIDGZ3RSAHHAAAAFQCX YFCPFSMLzLKSuYKi64QL8Fgc9QAAAnEA9+GghdabPd7LvKtcNrhXuXmUr7v6OuqC+VdMCz0HgmdRWVeOutRZT+ZxBxCBgLRJFnEj6Ewo FhO3zwkyjMim4TwWeotifI0o4KOuHiuzpnWRbqN/C/ohNWLx+2J6ASQ7zKTxvqhRkImog9/hWuWfBpKLZl6Ae1UlZAFMO/7PSSoAAACB AKKSU2PFl/qOLxIwmBZPPIcJshVe7bVUpFvyl3BbJDow8rXfskl8wO63OzP/qLmcJM0+JbcRU/53Jj7uyk31drV2qxhIOsLDC9dGCWj4 7Y7TyhPdXh/0dthTRBy6bqGtRPxGa7gJov1xm/UuYYXPIUR/3x9MAZvZ5xvE0kYXO+rx,admin
Important
Do not insert the entire contents of the
id_rsa.pub file here. Insert just the block of symbols which represents the public key itself.
Checking that public key authentication is supported
After starting the container, you can check whether public key authentication is supported by running the
jaas:realms console command, as follows:
Index Realm Module Class
1 karaf org.apache.karaf.jaas.modules.properties.PropertiesLoginModule
2 karaf org.apache.karaf.jaas.modules.publickey.PublickeyLoginModule
You should see that the
PublickeyLoginModule is installed. With this configuration you can log in to the container using either username/password credentials or public key credentials.
Logging in using key-based SSH
You are now ready to login to the container using the key-based SSH utility. For example:
$ ssh -p 8101 jdoe@localhost
_ ____ ______
| | _ \ | ____|
| | |_) | ___ ___ ___ | |__ _ _ ___ ___
_ | | _ / _ \/ __/ __| | __| | | / __|/ _ \
| |__| | |_) | (_) \__ \__ \ | | | |_| \__ \ __/
\____/|____/ \___/|___/___/ |_| \__,_|___/\___|
JBoss Fuse (6.3.0.redhat-xxx)
http://www.redhat.com/products/jbossenterprisemiddleware/fuse/
Hit '<tab>' for a list of available commands
and '[cmd] --help' for help on a specific command.
Hit '<ctrl-d>' or 'osgi:shutdown' to shutdown JBoss Fuse.
JBossFuse:karaf@root>Note
If you are using an encrypted private key, the
ssh utility will prompt you to enter the pass phrase.
