Perl API

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Vyatta::Config (/opt/vyatta/share/perl5/Vyatta/Config.pm) is a Perl API library for working with VyOS configuration (and Vyatta and EdgeOS too).

Using the Library

use lib '/opt/vyatta/share/perl5';
use Vyatta::Config;
$config = new Vyatta::Config;

Definitions

Active config is config, currently used by system.

Working config is config we are making during configuration session.

Effective config

The definition of "effective" is different under these two scenarios.

  1. When used outside a config session, "effective" == "active". In other words, in such cases the effective config is the same as the running config.
  2. When used during a config session, a config path (leading to either a "node" or a "value") is "effective" if ANY of the following is true.
  • active && working
    Path is in both active and working configs, i.e., unchanged.
  •  !active && working && committed
    Path is not in active, has been set in working, AND has already been committed, i.e., "commit" has successfully processed the addition/update of the path.
  • active && !working && !committed
    Path is in active, has been deleted from working, AND has not been committed yet, i.e., "commit" (per priority) has not processed the deletion of the path yet, or it has been processed but failed.

Note: during commit, deactivate has the same effect as delete. So in such cases, as far as these functions are concerned, deactivated nodes don't exist.

Method reference

Currently API has the following methods:

Method Arguments Returns Purpose
Low-level API functions that use the cstore library directly.
exists Configuration node True or false Returns true if specified node exists in current working config.
existsOrig Configuration node True or false Returns true if specified node exists in current active (running) config.
isDefault Configuration node True or false Returns true if specified node has default value in current working config.
isDefaultOrig Configuration node True or false Returns true if specified node had default value in current active (running) config.
listNodes Configuration path Array Returns array of all child nodes under specified path in working config.
listOrigNodes Configuration path Array Returns array of all child nodes under specified path in active config.
returnValue Configuration node Scalar Returns value of a node under specified path in working config.
returnOrigValue Configuration node Scalar Returns value of a node under specified path in active config.
returnValues Configuration multi-value node Array Returns array of all values of a multi-value node under specified path in working config.
returnOrigValues Configuration multi-value node Array Returns array of all values of a multi-value node under specified path in active config.
Observers of the "effective" config
isEffective Configuration node True or false Returns true if node under specified path is "effective".
isActive Configuration node True or false Same to isEffective.
listEffectiveNodes Configuration path Aray Returns array of "effective" child nodes during current commit under specified path.
listOrigPlusComNodes Configuration path Array Same to listEffectiveNodes.
returnEffectiveValue Configuration node Scalar Returns "effective" value of a node during current commit.
returnOrigPlusComValue Configuration node Scalar Returns "effective" value of a node during current commit.
returnEffectiveValues Configuraion multi-value node Array Returns array of "effective" values of a multi-value node during current commit.
returnOrigPlusComValues Configuraion multi-value node Array Returns array of "effective" values of a multi-value node during current commit.
isDeleted Configuration node True or false Returns true if node has been deleted in working config.
listDeleted Configuration path Array Returns array of nodes that have been deleted under specified level in working config.
returnDeletedValues Configuration multi-value node Array Returns array of values of a multi-value node that have been deleted in working config.
isAdded Configuration node True or false Returns true if specified node has been added in working config.
isChanged Configuration node True or false Returns true if specified node has been changed in working config.
listNodeStatus Configuration path Hash Return a hash of status of child nodes at specified level. Node name is the hash key. node status is the hash value. Node status can be one of

"deleted", "added", "changed", or "static".

getTmplChildren Configuration path Array Return list of child nodes in the template hierarchy at specified level.
validateTmplPath Configuration path True or false Return whether specified path is a valid template path.
parseTmplAll Configuration path Hash Return hash ref of parsed template of specified path, undef if path is invalid. note: if !allow_val, path must terminate at a "node", not "value".
hasTmplChildren Configuration path True or false Returns true if specified configuration path has child nodes.
"Deactivate-aware" observers of current working config or active config.
deactivated Configuration node True or false Return whether specified node is deactivated in working config. Note that this is different from "marked deactivated". If a node is "marked

deactivated", then the node itself and any descendants are "deactivated".

deactivatedOrig Configuration node True or false Return whether specified node is deactivated in active config.
returnValuesDA Configuration multi-value node Array Deactivate aware version of returnValues().
returnOrigValuesDA Configuration multi-value node Array DA version of returnOrigValues().
returnValueDA Configuration node Scalar DA version of returnOrigValue().
listOrigNodesDA Configuration path Array DA version of listOrigNodes()
listNodeStatusDA Configuration path Hash DA version of listNodeStatus().
returnComment Configuration node Scalar Returns comment of "node" in working config or undef if comment doesn't exist.
returnOrigComment Configuration node Scalar Returns comment of "node" in active config or undef if comment doesn't exist
High-level API functions (not using the cstore library directly)
setLevel Configuration path Current level Set the current level of config hierarchy to specified level (if defined).
returnParent Configuration node Scalar Returns the name of ancestor node relative to the current level. Each level up is represented by a ".." in the argument.
parseTmpl Configuration path Array Parse template of specified path and return ($is_multi, $is_text, $default) or undef if specified path is not valid.
isTagNode Configuration path True or false Returns true if specified path is a tag node.
isLeafNode Configuration node True or false Returns true if specified path is a "leaf node", i.e., single-/multi-value node.
isLeafValue Configuration node True or false Returns true if specified path is a "leaf value", i.e., value of a leaf node.
compareValueLists Original value list and new value list Lists of deleted and added nodes Compare two value lists and return "deleted" and "added" lists. Since this is for multi-value nodes, there is no "changed" (if a value's ordering changed, it is deleted then added).

Usage example

Background: Your helpdesk guys ask you to make a spreadsheet with remote-access PPTP VPN user information and keep it up to date. Of course you do not want to copy and paste this information by hand.

All spreadsheet software supports import from CSV, so the only thing we need to do is to extract values from config and print then as comma separated lines, passwords enclosed into double quotes for the case they contain a comma and add some header. Like this:

user,password,address,is_disabled
johnsmith,"this,isapass",192.0.2.41,no

Here we go:

#!/usr/bin/perl

use strict;
# using the Vyatta perl API
use lib "/opt/vyatta/share/perl5/";
use Vyatta::Config;

# Settings
my $proto = "pptp";
my $delimiter = ",";
# CSV RFC4180 requires to use CRLF (\r\n) as line break
my $header = "user,password,address,disabled\r\n";

# Create a config instance
my $config = new Vyatta::Config;

# Set default config level, this allows to use relative paths
$config->setLevel("vpn pptp remote-access authentication local-users username");

# Obtain array of user names
my @users = $config->listNodes();

# Print file header
print $header;

# Now walk through the user names, obtain values and print them
foreach my $user (@users) {
    # Since we set config level to "vpn pptp remote-access authentication local-users username"
    # we now can specify only the remaining part as methods argument,
    # it will be appended to the path we used in setLevel()
    my $password = $config->returnValue("$user password");
    my $address = $config->returnValue("$user static-ip");
    #"disable" is a leaf node with no value, so we should check
    # if it exists instead of obtaining its value
    my $disabled = $config->exists("$user disable") ? "yes" : "no";

    # It's not prohibited to use "," in passwords,
    # so we should enclose them into quotes to prevent
    # the parser from treating them as delimiters
    $password = "\"$password\"";

    my $line = join($delimiter, $user, $password, $address, $disabled);
    print "$line\r\n";
}

Check it works:

vyatta@R1# show vpn pptp remote-access authentication local-users 
 username joerandomuser {
     disable
     password qwerrty
     static-ip 10.91.17.105
 }
 username johnsmith {
     password this,isapass
 }

vyatta@R1# perl ./pptpusers.pl 
user,password,address,disabled
joerandomuser,"qwerrty",10.91.17.105,yes
johnsmith,"this,isapass",,no