]>
<chapter id="kea-shell">
- <title>Kea Shell</title>
+ <title>The Kea Shell</title>
<section id="shell-overview">
<title>Overview</title>
- <para>Kea 1.2.0 introduced Control Agent (see <xref linkend="kea-ctrl-agent"/>) that
+ <para>Kea 1.2.0 introduced the Control Agent (CA, see <xref linkend="kea-ctrl-agent"/>) that
provides a RESTful control interface over HTTP. That API is typically expected to be used by
- various IPAMs and similar management systems. Nevertheless, there are cases when a simple
- client is required to issue commands. Kea shell fulfills that need. It is a simple,
- command-line, scripting friendly text client that is able connect to CA, send commands with
- parameters, retrieve and print CA responses.</para>
+ various IPAMs and similar management systems. Nevertheless, there may be cases when you want
+ to send a command to the CA directly. The Kea Shell provides a way to do this. It is a simple
+ command-line, scripting-friendly text client that is able connect to the CA, send it commands
+ with parameters, retrieve the responses and display them.</para>
- <para>The primary use case for shell is to be used as a tool in scriting environment,
- therefore the tool is not interactive. However, with simple tricks it can be run manually.
+ <para>As the primary purpose of the Kea Shell is as a tool in scripting environment,
+ it is not interactive. However, with simple tricks it can be run manually.
</para>
</section>
<section id="shell-usage">
<title>Shell Usage</title>
-
- <para>kea-shell accepts a number of optional parameters:
+ <para><command>kea-shell</command> is run as follows:
+<screen>
+kea-shell [--host hostname] [--port number] [--timeout seconds] [command]
+</screen>
+ where:
</para>
<itemizedlist>
<listitem>
<simpara>
<command>--host <replaceable>hostname</replaceable></command> specifies the hostname
- of CA. If not specified, "localhost" is used.
+ of the CA. If not specified, "localhost" is used.
</simpara>
</listitem>
<listitem>
<simpara>
<command>--port <replaceable>number</replaceable></command> specifies the TCP port
- on which CA listens. If not specified, 8000 is used.
+ on which the CA listens. If not specified, 8000 is used.
</simpara>
</listitem>
<listitem>
<simpara>
<command>--timeout <replaceable>seconds</replaceable></command> specifies the
- timeout in seconds for connection. If not specified, 10 seconds is used.
+ timeout (in seconds) for the connection. If not given, 10 seconds is used.
</simpara>
</listitem>
<listitem>
<simpara>
- <command>-h</command> prints out help message.
+ <command>command</command> specifies the command to be sent. If not specified,
+ <command>list-commands</command> command is used.
</simpara>
</listitem>
+ </itemizedlist>
+
+ <para>Other switches are:</para>
+ <itemizedlist>
<listitem>
<simpara>
- <command>-v</command> prints software version.
+ <command>-h</command> prints a help message.
</simpara>
</listitem>
<listitem>
<simpara>
- <command>command</command> specifies the command to be sent. If not specified,
- <command>list-commands</command> command is used.
+ <command>-v</command> prints the software version.
</simpara>
</listitem>
</itemizedlist>
<para>
- Once started, the shell reads command parameters from the standard input. Those are
- expected to be in JSON format. After read ends, the shell establishes connection using
- http protocol to CA, sends the command and awaits response. Once the response becomes
- available it is being printed on standart output.
+ Once started, the shell reads parameters for the command from standard input, which are
+ expected to be in JSON format. When all have been read, the shell establishes a connection
+ with the CA using HTTP, sends the command and awaits a response. Once that is received,
+ it is printed on standard output.
</para>
<para>
For a list of available commands, see <xref linkend="ctrl-channel"/>. Additional commands
- may be provided by hook libraries. If unsure which commands are supported, please use
- <command>list-commands</command> command. It will instruct CA to list all supported commands.
+ may be provided by hook libraries. If unsure which commands are supported, use the
+ <command>list-commands</command> command. It will instruct the CA to return a list of
+ all supported commands.
</para>
- <para>Several examples of kea-shell usage are presented below. This example will expect
- parameters to be provided on standard input. Since list-commands does not take any
- arguments, ctrl-d may be pressed to indicate end of file. Kea shell will then contact
- CA and will print out a list of available commands.
+ <para>The following shows a simple example of usage:
<screen>
$ <userinput>kea-shell --host 192.0.2.1 --port 8001 list-commands</userinput>
+^D
</screen>
+ After the command line is entered, the program waits for command parameters to be entered.
+ Since <command>list-commands</command> does not take any
+ arguments, CTRL-D (represented in the above example by "^D") is pressed to indicate end
+ of file (and so terminate the parameter input). The Shell will then contact
+ the CA and print out the list of available commands returned.
</para>
- <para>Kea shell is envisaged to be most frequently used in scripts. Here is an example of
- very simple scripted execution. It will issue command "config-write" with parameters
- specified in param.json. The result will be stored in result.json.
+ <para>It is envisaged that Kea Shell will be most frequently used in scripts. The next example
+ shows a simple scripted execution. It sends the command "config-write" to the CA, along
+ with the parameters specified in param.json. The result will be stored in result.json.
<screen>
$ cat param.json
"filename": "my-config-file.json"
</screen>
</para>
- <para>Kea shell requires python to run. It was tested with python 2.7 and various versions
- of python 3, up to 3.5. Since not every Kea deployment uses this feature and there are
- certainly deployments that do not have python, Kea shell is not enabled by default. To
- enable it, make sure you pass <command>--enable-shell</command> to configure script.</para>
+ <para>Kea Shell requires Python to to be installed on the system. It was tested with
+ Python 2.7 and various versions
+ of Python 3, up to 3.5. Since not every Kea deployment uses this feature and there are
+ deployments that do not have Python, the Kea Shell is not enabled by default. To use it,
+ you must specify <command>--enable-shell</command> to when running "configure" during the
+ installation of Kea.</para>
- <para>Kea shell is intended to serve more a demonstration of the RESTful interface
- capabilities and perhaps an illustration for people interested in integrating their
- management evironments with Kea, rather than a serious management client. Do not expect it
- to be significantly expanded in the future. It is and will remain a simple tool.</para>
- </section>
+ <para>The Kea Shell is intended to serve more as a demonstration of the RESTful interface
+ capabilities (and, perhaps, an illustration for people interested in integrating their
+ management evironments with Kea) than as a serious management client. Do not expect it
+ to be significantly expanded in the future. It is, and will remain, a simple tool.</para>
+ </section>
</chapter>
projects / thirdparty / kea.git / commitdiff
