17 Commits (c73a5fc07da195af2ee2b2958a04e495df00a7b1)

Author	SHA1	Message	Date
Martin Atkins	dd43926761	configs/configupgrade: Fix up uses of the .count pseudo-attribute ... Terraform 0.11 and prior had an odd special case where a resource attribute access for "count" would be resolved as the count for the whole resource, rather than as an attribute of an individual instance as for all other attributes. Because Terraform 0.12 makes test_instance.foo appear as a list when count is set (so it can be used in other expressions), it's no longer possible to have an attribute in that position: lists don't have attributes. Fortunately we don't really need that special case anymore since it doesn't do anything we can't now do with the length(...) function. This upgrade rule, then, detects references like test_instance.foo.count and rewrites to length(test_instance.foo). As a special case, if test_instance.foo doesn't have "count" set then it just rewrites as the constant 1, which mimics what would've happened in that case in Terraform 0.11.	7 years ago
Martin Atkins	fa0d6484df	configs/configupgrade: Detect and fix element(...) usage with sets ... Although sets do not have indexed elements, in Terraform 0.11 and earlier element(...) would work with sets because we'd automatically convert them to lists on entry to HIL -- with an arbitrary-but-consistent ordering -- and this return an arbitrary-but-consistent element from the list. The element(...) function in Terraform 0.12 does not allow this because it is not safe in general, but there was an existing pattern relying on this in Terraform 0.11 configs which this upgrade rule is intended to preserve: resource "example" "example" { count = "${length(any_set_attribute)}" foo = "${element(any_set_attribute, count.index}" } The above works because the exact indices assigned in the conversion are irrelevant: we're just asking Terraform to create one resource for each distinct element in the set. This upgrade rule therefore inserts an explicit conversion to list if it is able to successfully provide that the given expression will return a set type: foo = "${element(tolist(any_set_attribute), count.index}" This makes the conversion explicit, allowing users to decide if it is safe and rework the configuration if not. Since our static type analysis functionality focuses mainly on resource type attributes, in practice this rule will only apply when the given expression is a statically-checkable resource reference. Since sets are an SDK-only concept in Terraform 0.11 and earlier anyway, in practice that works out just right: it's not possible for sets to appear anywhere else in older versions anyway.	7 years ago
Martin Atkins	54bb0b1e25	configs/configupgrade: Silently ignore and trim .% .# in ignore_changes ... Prior to Terraform 0.12, ignore_changes was implemented in a flatmap-oriented fashion and so users found that they could (and in fact, were often forced to) use the internal .% and .# suffixes flatmap uses to ignore changes to the number of elements in a list or map. Terraform 0.12 no longer uses that representation, so we'll interpret ignoring changes to the length as ignoring changes to the entire collection. While this is not a totally-equivalent change, in practice this pattern was most often used in conjunction with specific keys from a map in order to _effectively_ ignore the entire map, even though Terraform didn't really support that.	7 years ago
Martin Atkins	1d35233a03	configs/configupgrade: Fix up internal HIL conversion functions ... HIL implemented its type conversions by rewriting its AST to include calls to some undocumented builtin functions. Unfortunately those functions were still explicitly callable if you could figure out the name for them, and so they may have been used in the wild. In particular, __builtin_StringToFloat was used as part of a workaround for a HIL design flaw where it would prefer to convert strings to integers rather than floats when performing arithmetic operations. This issue was, indeed, the main reason for unifying int ant float into a single number type in HCL. Since we published that as a suggested workaround, the upgrade tool ought to fix it up. The other cases have never been documented as a workaround, so they are less likely to appear in the wild, but we might as well fix them up anyway since we already have the conversion functions required to get the same result in the new language. To be safe/conservative, most of these convert to _two_ function calls rather than just one, which ensures that these new expressions retain the behavior of implicitly converting to the source type before running the conversion. The new conversion functions only specify target type, and so cannot guarantee identical results if the argument type does not exactly match what was previously given as the parameter type in HIL.	7 years ago
Martin Atkins	154911688a	configs/configupgrade: upgrade expressions inside heredocs ... HEREDOC tokens are a little more fussy than normal string sequences because we need to preserve the whitespace within them along with the start and end markers while we upgrade any interpolated expressions inside. We need to do some work locally here because the HCL heredoc processing "does too much" and throws away information we need to do a faithful upgrade. We also need to contend with the fact that Terraform <=0.11 had an older version of HCL that accidentally permitted a degenerate form of heredoc where the marker was at the end of the final line, like this: degenerate = <<EOT this should never have workedEOT When we migrate this, we'll introduce the additional newline that is now required, which will unfortunately slightly change the result string to include a newline when parsed by 0.12, and so we'll need to call this out as a caveat in the upgrade guide.	7 years ago
Kristin Laemmert	5f8916b4fd	configs/configupgrade: do not panic on HEREDOCs. (#20281) ... Previously, configupgrade would panic if it encountered a HEREDOC. For the time being, we will simply print out the HEREDOC as-is. Unfortunately, we discovered that terraform 0.11's version of HCL allowed for HEREDOCs with the termination delimiter inline (instead of on a newline, which is technically correct). Since 0.12configupgrade needs to be bug-compatible with terraform 0.11, we must roll back to the same version of HCL used in terraform 0.11.	7 years ago
Martin Atkins	954d38e870	lang: New file-hashing functions ... In prior versions, we recommended using hash functions in conjunction with the file function as an idiom for detecting changes to upstream blobs without fetching and comparing the whole blob. That approach relied on us being able to return raw binary data from file(...). Since Terraform strings pass through intermediate representations that are not binary-safe (e.g. the JSON state), there was a risk of string corruption in prior versions which we have avoided for 0.12 by requiring that file(...) be used only with UTF-8 text files. The specific case of returning a string and immediately passing it into another function was not actually subject to that corruption risk, since the HIL interpreter would just pass the string through verbatim, but this is still now forbidden as a result of the stricter handling of file(...). To avoid breaking these use-cases, here we introduce variants of the hash functions a with "file" prefix that take a filename for a disk file to hash rather than hashing the given string directly. The configuration upgrade tool also now includes a rule to detect the documented idiom and rewrite it into a single function call for one of these new functions. This does cause a bit of function sprawl, but that seems preferable to introducing more complex rules for when file(...) can and cannot read binary files, making the behavior of these various functions easier to understand in isolation.	7 years ago
Martin Atkins	f93f7e5b5c	configs/configupgrade: Remove redundant list brackets ... In early versions of Terraform where the interpolation language didn't have any real list support, list brackets around a single string was the signal to split the string on a special uuid separator to produce a list just in time for processing, giving expressions like this: foo = ["${test_instance.foo.*.id}"] Logically this is weird because it looks like it should produce a list of lists of strings. When we added real list support in Terraform 0.7 we retained support for this behavior by trimming off extra levels of list during evaluation, and inadvertently continued relying on this notation for correct type checking. During the Terraform 0.10 line we fixed the type checker bugs (a few remaining issues notwithstanding) so that it was finally possible to use the more intuitive form: foo = "${test_instance.foo.*.id}" ...but we continued trimming off extra levels of list for backward compatibility. Terraform 0.12 finally removes that compatibility shim, causing redundant list brackets to be interpreted as a list of lists. This upgrade rule attempts to identify situations that are relying on the old compatibility behavior and trim off the redundant extra brackets. It's not possible to do this fully-generally using only static analysis, but we can gather enough information through or partial type inference mechanism here to deal with the most common situations automatically and produce a TF-UPGRADE-TODO comment for more complex scenarios where the user intent isn't decidable with only static analysis. In particular, this handles by far the most common situation of wrapping list brackets around a splat expression like the first example above. After this and the other upgrade rules are applied, the first example above will become: foo = test_instance.foo.*.id	7 years ago
Martin Atkins	ef017345f1	configs/configupgrade: Upgrade the resource "lifecycle" nested block ... The main tricky thing here is ignore_changes, which contains strings that are better given as naked traversals in 0.12. We also handle here mapping the old special case ["*"] value to the new "all" keyword.	7 years ago
Martin Atkins	8490fc36f7	configs/configupgrade: Fix up references to counted/uncounted resources ... Prior to v0.12 Terraform was liberal about these and allowed them to mismatch, but now it's important to get this right so that resources and resource instances can be used directly as object values, and so we'll fix up any sloppy existing references so things keep working as expected. This is particularly important for the pattern of using count to create conditional resources, since previously the "true" case would create one instance and Terraform would accept an unindexed reference to that.	7 years ago
Martin Atkins	ceedeb69a9	configs/configupgrade: Normalize and upgrade reference expressions ... The reference syntax is not significantly changed, but there are some minor additional restrictions on identifiers in HCL2 and as a special case we need to rewrite references to data.terraform_remote_state . Along with those mandatory upgrades, we will also switch references to using normal index syntax where it's safe to do so, as part of de-emphasizing the old strange integer attribute syntax (like foo.0.bar).	7 years ago
Martin Atkins	39c3e7112f	configs/configupgrade: Use break to cancel default function rendering ... We're using break elsewhere in here so it was weird to have a small set of situations that return instead, which could then cause confusion for future maintenance if a reader doesn't notice that control doesn't always leave the outer switch statement.	7 years ago
Martin Atkins	48f1245e6b	configs/configupgrade: Replace lookup(...) with index syntax ... If lookup is being used with only two arguments then it is equivalent to index syntax and more readable that way, so we'll replace it. Ideally we'd do similarly for element(...) here but sadly we cannot because we can't prove in static analysis that the user is not relying on the modulo wraparound behavior of that function.	7 years ago
Martin Atkins	4927a4105b	configs/configupgrade: Replace calls to list() and map() ... We now have native language features for declaring tuples and objects, which are the idiomatic way to construct sequence and mapping values that can then be converted to list, set, and map types as needed.	7 years ago
Martin Atkins	8cf024d45a	configs/configupgrade: Upgrade expressions nested in HCL list/object ... In the old world, lists and maps could be created either using functions in HIL or list/object constructs in HCL. Here we ensure that in the HCL case we'll apply any required expression transformations to the individual items within HCL's compound constructs.	7 years ago
Martin Atkins	adb88eaa16	configupgrade: Analysis of input configuration ... In order to properly migrate the contents of resource, data, provider and provisioner blocks we will need the provider's schema in order to understand what is expected, so we can resolve some ambiguities inherent in the legacy HCL AST. This includes an initial prototype of migrating the content of resource blocks just to verify that the information is being gathered correctly. As with the rest of the upgrade_native.go file, this will be reorganized significantly once the basic end-to-end flow is established and we can see how to organize this code better.	8 years ago
Martin Atkins	95b7b883a3	configupgrade: Basic expression formatting ... This covers all of the expression node types in HIL's AST, and also includes initial support for some of our top-level blocks so that we can easily test that. The initial implementations of the "variable" and "output" blocks are pretty redundant and messy, so we can hopefully improve on these in a later pass.	8 years ago