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tfts provides a type-safe way to use Terraform functions and operators through the Fn and Op classes.

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Functions (Fn)

The Fn class contains static methods corresponding to Terraform’s built-in functions.

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Numeric

  • Fn.abs(number)
  • Fn.ceil(number)
  • Fn.floor(number)
  • Fn.log(number, base)
  • Fn.max(...numbers)
  • Fn.min(...numbers)
  • Fn.pow(base, exponent)
  • Fn.signum(number)
const maxVal = Fn.max(1, 5, 2);
const absolute = Fn.abs(-10);

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String

  • Fn.chomp(string)
  • Fn.endswith(string, suffix)
  • Fn.format(format, ...args)
  • Fn.join(separator, list)
  • Fn.lower(string)
  • Fn.upper(string)
  • Fn.replace(string, substring, replacement)
  • Fn.split(separator, string)
  • Fn.trim(string, characters)
  • Fn.substr(string, offset, length)
const greeting = Fn.format("Hello, %s!", "World");
const joined = Fn.join(", ", ["a", "b", "c"]);

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Collection

  • Fn.alltrue(list)
  • Fn.anytrue(list)
  • Fn.chunklist(list, size)
  • Fn.coalesce(...args)
  • Fn.compact(list)
  • Fn.concat(...lists)
  • Fn.contains(list, value)
  • Fn.distinct(list)
  • Fn.element(list, index)
  • Fn.flatten(list)
  • Fn.keys(map)
  • Fn.length(collection)
  • Fn.lookup(map, key, default)
  • Fn.merge(...maps)
  • Fn.one(list)
  • Fn.range(start, end, step)
  • Fn.reverse(list)
  • Fn.slice(list, start, end)
  • Fn.sort(list)
  • Fn.sum(list)
  • Fn.values(map)
  • Fn.zipmap(keys, values)
const merged = Fn.merge({ a: 1 }, { b: 2 });
const hasValue = Fn.contains(["vpc-1", "vpc-2"], "vpc-1");

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Encoding

  • Fn.base64decode(string)
  • Fn.base64encode(string)
  • Fn.jsondecode(string)
  • Fn.jsonencode(value)
  • Fn.urlencode(string)
  • Fn.yamldecode(string)
  • Fn.yamlencode(value)
const encoded = Fn.jsonencode({ key: "value" });

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Filesystem

  • Fn.abspath(path)
  • Fn.dirname(path)
  • Fn.basename(path)
  • Fn.file(path)
  • Fn.fileexists(path)
  • Fn.fileset(path, pattern)
  • Fn.filebase64(path)
  • Fn.templatefile(path, vars)
const userData = Fn.templatefile("./user_data.sh.tftpl", {
  hostname: "my-server"
});

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Date/Time

  • Fn.formatdate(format, timestamp)
  • Fn.plantimestamp()
  • Fn.timeadd(timestamp, duration)
  • Fn.timecmp(timestamp_a, timestamp_b)
  • Fn.timestamp()

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Hash/Crypto

  • Fn.md5(string)
  • Fn.sha1(string)
  • Fn.sha256(string)
  • Fn.sha512(string)
  • Fn.uuid()
  • Fn.uuidv5(namespace, name)
  • Fn.base64sha256(string)
  • Fn.bcrypt(string, cost)

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IP Network

  • Fn.cidrhost(prefix, hostnum)
  • Fn.cidrnetmask(prefix)
  • Fn.cidrsubnet(prefix, newbits, netnum)
  • Fn.cidrsubnets(prefix, ...newbits)

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Type

  • Fn.can(expression)
  • Fn.nonsensitive(value)
  • Fn.sensitive(value)
  • Fn.tobool(value)
  • Fn.tolist(value)
  • Fn.tomap(value)
  • Fn.tonumber(value)
  • Fn.toset(value)
  • Fn.tostring(value)
  • Fn.try(...expressions)

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Conditionals

  • Fn.conditional(condition, trueValue, falseValue)
const instanceType = Fn.conditional(
  Op.eq(env, "prod"),
  "t3.large",
  "t3.micro"
);

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Operators (Op)

The Op class provides methods for Terraform operators.
  • Op.not(a)
  • Op.negate(a)
  • Op.add(a, b)
  • Op.sub(a, b)
  • Op.mul(a, b)
  • Op.div(a, b)
  • Op.mod(a, b)
  • Op.gt(a, b)
  • Op.gte(a, b)
  • Op.lt(a, b)
  • Op.lte(a, b)
  • Op.eq(a, b)
  • Op.neq(a, b)
  • Op.and(a, b)
  • Op.or(a, b)
const isLarge = Op.gt(count, 10);
const isValid = Op.and(Op.neq(id, ""), Op.not(isTerminated));