Shell-call

Definition

Many IT applications, within their business process, need to invoke shell commands. Gvvcl-shell plug-in can be used to invoke a command shell. It is very simple to configure.

GreenVulcano^® ESB provides two different tools, GV Console^® and VulCon^®, to configure all supported plug-ins in GreenVulcano^® ESB services.

VulCon / GV Console Configuration

shell-call is the operation that must be configured into VulCon^® or GV Console^® System section to invoke command shell.

In order to add an operation shell-call you must define the following fields:

Attribute	Type	Description
type	fixed	This attribute must assume the value call.
class	fixed	This attribute must assume the value it.greenvulcano.gvesb.virtual.shell.ShellCallOperation (java class that manages the shell-call invocation).
name	required	This field identify the operation name that you will use in service definition.
directory	optional	Pathname of the directory in which the command is executed. This pathname can be static or may contain placeholders that are replaced at runtime. If this attribute is not present, the command is executed within the current working directory.
encoding	optional	The encoding with which encodes the command output in the GVBuffer body. If not specified, is used the file.encoding system property value.

The following example shows the configuration generated from VulCon^® or GV Console^® when you configure a shell-call operation:

<?xml version="1.0" encoding="UTF-8"?>
<Channel id-channel="CHANNEL-NAME">
    <shell-call class="it.greenvulcano.gvesb.virtual.shell.ShellCallOperation"
      directory="/home/greenvulcano/script" name="cat_file"
      type="call">
     <cmd>cat greenvulcano.log</cmd>
    </shell-call>
</Channel>

To use an excelreader-call in a GreenVulcano^® ESB service, you need to define a node of type GVOperationNode in Service section and define in the field operation-name the name defined in excelreader-call operation.

The following example shows the configuration generated from VulCon^® or GV Console^® when you configure an shell-call operation in GreenVulcano^® ESB service:

<?xml version="1.0" encoding="UTF-8"?>
<GVServices name="SERVICES" type="module">
    <Groups>
        <Group group-activation="on" id-group="DEFAULT_GRP"/>
    </Groups>
    <Services>
        <Service group-name="DEFAULT_GRP" id-service="SERVICE-NAME"
                 service-activation="on">
            <Client id-system="SYSTEM-NAME" statistics="off" system-activation="on">
                <Operation name="RequestReply" operation-activation="on"
                           out-check-type="none" type="operation">
                    <Participant id-channel="CHANNEL-NAME" id-system="SYSTEM-NAME"/>
                    <Flow first-node="cat_log_file" point-x="20" point-y="112">
                        <GVOperationNode class="it.greenvulcano.gvesb.core.flow.GVOperationNode"
                                         id="shell-call" id-system="YOUR_SYSTEM"
                                         input="input" next-node-id="end"
                                         op-type="call"
                                         operation-name="cat_file"
                                         output="output" point-x="158"
                                         point-y="112" type="flow-node"/>
                        <GVEndNode class="it.greenvulcano.gvesb.core.flow.GVEndNode"
                                   end-business-process="yes" id="end" op-type="end"
                                   output="output" point-x="358" point-y="112"
                                   type="flow-node"/>
                    </Flow>
                </Operation>
            </Client>    
        </Service>
    </Services>
</GVServices>

At this point you have configured a service with a shell-call operation.