Backup and Restore Sequences

Backup and restore sequences are sets of rules used to backup and restore device configurations respectively.

Each sequence (rule set) is used to read and write configurations from/to devices of a certain manufacturer, family, model or make. The usage scope of a rule set varies depending on how it's designed and how similar is configuration backup/restoration performed with different devices of a certain manufacturer.

All sequences (rule sets) are fully independent from each other. Each set includes one or more rules that work in sequential order. Each rule set may take certain parameters, and its processing always results in a single object (of any type, e.g. number, string, or date).

Each rule in a set consists of target, expression, and condition. A rule either returns result of the whole rule set or (re-)defines a single environment variable that is valid until the end of the rule set processing.

It's also possible to add comments to individual rules.

Each rule does one of the following:

• Performs some action, e.g. executes a Telnet/SSH script
• Evaluates a certain temporary value
• Retrieves and returns text of device configuration

Rule target defines how to treat the outcome of this rule. If rule target is Final Rule Set Result, this rule stops sequence processing. It the rule is a part of a Backup Sequence, it must return text of device configuration (as a String value). If it's a part of a Restore Sequence, the rule set result is ignored.

In other cases a target defines a name of the environment variable that will be defined once rule processing is over. This variable can be referred from other rules' expressions and conditions.

Rule expression is an Iotellect expression that returns result of any type. This result is:

• Returned as the result of the whole rule set if Target rule is Final Rule Set Result.
• Stored as rule set's internal environment variable rewriting value of this variable if was already defined by other rules. This environment variable will be valid during the current rule set processing cycle.

Rule expressions may refer to results of other rules from this set via {env/rule_target_variable_name} references.

Rule Condition is an Iotellect expression that should result in a Boolean value. If this value is false, the rule processing will be skipped and the next rule will be processed.

Rule conditions may refer to results of other rules from this set via {env/rule_target_variable_name} references.

The rule condition is optional.

This example describes a rule set that retrieves configuration from a radio modem. It performs the following actions:

• Logs in to a modem using Telnet protocol and executes a series of commands that force modem to dump current configuration to its internal flash disk
• Logs in to the modem using FTP protocol and downloads configuration file

The first rule executes an Expect script by calling executeExpectScript() function. The script (which is not a part of current example) will send a series of commands to the device to force its saving configuration to its internal disk that will be available for downloading via FTP protocol. Rule result is actually discarded (by putting it to a variable named Dummy that's not used by the following rules).

The second rule downloads a configuration file from the device by executing ftpDownload() function. The function accepts device address, port, login, password, remote directory path and file name to download as parameters. Some parameters are taken from a device account context (by references, such as {.:connectionProperties$address} or {.:ftpSettings$userName}) while others come from a default table that contains properties described in Backup Parameters Format (e.g. {ftpDirectory} or {ftpFileName}). ftpDownload() function returns contents of downloaded device configuration file that's returned from the backup sequence as a result.

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