SSH Remote Command

Discover more about the SSH Remote Command component and how to use it on the Digibee Integration Platform.

SSH Remote Command allows a connection with an SSH server to be established and shell scripts to be executed.

Parameters

Take a look at the configuration options for the component. Parameters supported by Double Braces expressions are marked with (DB).

Parameter	Description	Default value	Data type
Account (DB)	Account to be used by the component. Supported accounts: Basic, Kerberos, and Private Key.	N/A	String
Username (DB)	Must be used only when the account type is Private Key.	N/A	String
Host (DB)	Name of the host or IP address to make the connection.	N/A	String
Port (DB)	Number of the port - generally 22.	22	Integer
Server Host Key	Specifies any additional algorithms to be supported for the server host key configuration. Each algorithm must be set separately.	N/A	String
Public Key Algorithms	Specifies any additional algorithms to be supported for the public key algorithms configuration. Each algorithm must be set separately.	N/A	String
KEX Algorithms	Specifies any additional algorithms to be supported for the KEX (key exchange) algorithms configuration. Each algorithm must be set separately.	N/A	String
Custom Environment Variables	If the option is enabled, you must inform the environment variables in a custom way in the Environment Variables field (e.g., [{"key": "MYVAR", "value": "VAR_VALUE"}])	N/A	String (JSON)
Environment Properties	Name and value of the environment variables to be provided for the remote SSH server execution. These variables must be registered in sshd_config. Example of register in ssh_config: AcceptEnv MYVAR	N/A	String (JSON)
Command	Field used to specify the commands to be executed in the SSH server.	N/A	String
Ignore Output	If the option is enabled, the pipeline execution ignores the responses displayed in stdout or stderr in the SSH server. Otherwise, they’ll be displayed in the stdout and stderr fields of the component output.	False	Boolean
Stdout As File	If the option is enabled, the stdout result answer will be recorded in a file. Otherwise, it’ll be displayed as a string in the component output.	False	Boolean
Stdout File Name	Name of the file to be created with the stdout information.	N/A	String
Stderr As File	If the option is enabled, the stderr result answer will be recorded in a file. Otherwise, it’ll be displayed as a string in the component output.	False	Boolean
Stderr File Name	Name of the file to be created with the stderr information.	N/A	String
Connection Timeout	Expiration time of the connection with the server (in milliseconds).	30000	Integer
Server Alive Interval	Time the component will keep the connection active (in milliseconds).	30000	Integer
Fail On Error	If the option is enabled, the execution of the pipeline with error will be interrupted; otherwise, the pipeline execution proceeds, but the result will show a false value for the “success” property.	False	Boolean

The SSH Remote Command connector uses an implementation library that has disabled by default specific algorithms that are considered unsafe. The Server Host Key, Public Key Algorithms and KEX Algorithms parameters are available for when it's necessary to enable those algorithms to be able to establish a SSH connection. Although is possible to use this configuration, it's not recommended to use unsafe algorithms.

Messages flow

Input

No specific input message is expected.

Output

When executing an SFTP component using the download, upload, or move operations, the following JSON structure will be generated:

{
    "stdout": "xpto",
    "stderr": "xpto_err",
    "stdoutFileName": "stdout.txt",
    "stderrFileName": "stderr.txt",
    "success": "true"
}

• stdout: successful response of the script execution.

• stderr: response with errors of the script execution.

• stdoutFileName: file path saved with the information displayed in stdout. This property will be displayed only if the Stdout As File flag is enabled.

• stderrFileName: file path saved with the information displayed in stderr. This property will be displayed only if the Stderr As File flag is enabled.

• success: "true" if there’s been a connection and the script has been executed, even if errors in stderr were returned.

Output with error

{
 "success": false,
 "message": "Could not execute the SSH remote command",
 "error": "java.net.SocketTimeoutException: connect timed out"
}

• success: “false” when the operation fails.

• message: a message about the error.

• exception: information about the occurred error type.

The file manipulation inside a pipeline occurs in a protected way. The files are available in a temporary directory that only the pipeline being executed has access to.

To better understand the messages flow in the Digibee Integration Platform, read the Messages processing article.

SSH Remote Command in Action

Executing a script and receiving the information in the component JSON answer

Hostname: <HOST>

Port: <PORT>

Command: echo $MYNAME && echo error output >&2

Environment Variables: [{"key":"MYNAME", "value":"TEST"}]

Stdout As File: disabled

Stderr As File: disabled

Fail On Error: disabled

Result:

{
    "stdout": "TEST",
    "stderr": "error output",
    "success": "true"
}

Executing a script and saving the information in files

Hostname: <HOST>

Port: <PORT>

Command: echo $MYNAME && echo error output >&2

Environment Variables: [{"key":"MYNAME", "value":"TEST"}]

Stdout As File: enabled

Stdout File Name: stdout.txt

Stderr As File: enabled

Stderr File Name: stderr.txt

Fail On Error: disabled

Result:

{
    "stdoutFileName": "stdout.txt",
    "stderrFileName": "stderr.txt",
    "success": "true"
}