Moldova is a lightweight template interpreter, used to generate random values that plug into the template, as defined by a series of custom tokens.

It understands the tokens as defined further down in the document.

Moldova comes both as a library you can import, as well as a binary executable that you can run, which will output results to STDOUT.

The intended use is via the binary executable.

Moldova was originally designed as input to a database load testing tool, called the Slammer. It's primary purpose was to generate INSERT and SELECT statements, which were then loaded into the Slammer. If you're looking for a good tool to test the throughput and latency of database operations at scale, checkout the Slammer.

And if you're interested in using them together, checkout the Moldovan Slammer, a quick helper repo to demonstrate using them together

To use the command, first install

go install github.com/StabbyCutyou/moldova/cmd/moldova

The command accepts 2 arguments:

• n - How many templates to render to STDOUT. The default is 1, and it cannot be less than 1.
• t - The template to render

moldova -t "INSERT INTO floof VALUES ('{guid}','{guid:ordinal:0}','{country}',{int:min:-2000|max:0},{int:min:100|max:1000},{float:min:-1000.0|max:-540.0},{int:min:1|max:40},'{now}','{now:ordinal:0}','{country:case:up}',NULL,-3)" -n 100

This would provide sample output like the following:

...
INSERT INTO floof VALUES ('791add99-43df-44c8-8251-6f7af7a014df','791add99-43df-44c8-8251-6f7af7a014df','MU',-1540,392,-624.529332,39,'2016-01-24 23:42:49','2016-01-24 23:42:49','UN',NULL,-3)
INSERT INTO floof VALUES ('0ab4cc33-6689-404f-a801-4fd431ca3f30','0ab4cc33-6689-404f-a801-4fd431ca3f30','PL',-1707,112,-550.333145,1,'2016-01-24 23:42:49','2016-01-24 23:42:49','SS',NULL,-3)
INSERT INTO floof VALUES ('a3f4151a-a304-4190-a3df-7fd97ce58588','a3f4151a-a304-4190-a3df-7fd97ce58588','CM',-1755,569,-961.122173,25,'2016-01-24 23:42:49','2016-01-24 23:42:49','NE',NULL,-3)

Tokens are represented by special values placed inside of { } characters.

Each token follows this pattern:

{command:argument_name:value|argument_name:value|...|...}

Each token defines it's own set of arguments, which are outlined below. If you're provided multiple arguments, the key-value pairs of argument names to values are delimited by a | pipe character. These can be provided in any order, so long as they are valid arguments.

It is only necessary to provide a | when you have further arguments to provide. For example:

• {integer}
• {integer:min:10}
• {integer:min:10|max:50}
• {integer:min:10|max:50|ordinal:0}

• ordinal : integer >= 0

Slammer will replace any instance of {guid} with a GUID/UUID

If you provide the ordinal: option, for the current line of text being generated, you can have the Slammer insert an existing value, rather than a new one. For example:

"{guid} - {guid:ordinal:0}"

In this example, both guids will be replaced with the same value. This is a way to back-reference existing generated values, for when you need something repeated.

• format : string, either "simple", "simpletz", or a golang date format string
• ordinal : integer >= 0
• zone: A timezone to represent the time in. You can use any value accepted here

Slammer will replace any instance of {now} with a string representation of Golangs time.Now() function, formatted per the provided date format. There are 2 built in formats, for convenience, that are compatible with many databases.

• simple - "2006-01-02 15:04:05"
• simpletz - "2006-01-02 15:04:05 -0700"

Additionally, you can provide your own format string.

{now} also supports the ordinal: option

• min : integer < max, unix epoch value
• max : integer > min, unix epoch value
• format : string, either "simple", "simpletz", or a golang date format string
• ordinal : integer >= 0

Slammer will replace any instance of {time} with a string representation of a random time, between min and max in terms of Unix Epoch values. The defaults are between 0, and roughly Now (determined at runtime) There are 2 built in formats, for convenience, that are compatible with many databases.

• simple - "2006-01-02 15:04:05"
• simpletz - "2006-01-02 15:04:05 -0700"

Additionally, you can provide your own format string.

{time} also supports the ordinal: option

• min : integer < max
• max : integer > min
• ordinal : integer >= 0

Slammer will replace any instance of {int} with a random int value, optionally between the range provided. The defaults, if not provided, are 0 to 100.

{int} also supports ordinal: option

• min : integer < max
• max : integer > min
• ordinal : integer >= 0

Slammer will replace any instance of {float} with a random Float64, optionally between the range provided. The defaults, if not provided, are 0.0 to 100.0

{float} also supports ordinal: option

• length : integer >= 1
• case : "up" or "down"
• ordinal : integer >= 0

Slammer will replace any instance of {unicode} with a randomly generated set of unicode characters, of a length specified by :number. The default value is 2.

{unicode} also takes the :case argument, which is either 'up' or 'down', like so

{unicode:case:up} {unicode:case:down}

{unicode} also supports ordinal: option

Only a certain subset of unicode character ranges are supported by default, as defined in the moldova/data/unicode.go file.

• case : "up" or "down"
• ordinal : integer >= 0

Slammer will replace any instance of {country} with an ISO 3166-1 alpha-2 country code.

{country} supports the same case: argument as {unicode}. The default value is "up"

{country} also supports the ordinal: argument.

I'll continue to add support for more random value categories. There are also hooks to support ascii-only string generation, but as of yet it is not implemented.

Add proper support for escaping control characters, so they are not interpreted as part of a token. These characters are {, }, :, and |.

Apache v2 - See LICENSE