We've previously been copying this function around so it could remain
unexported while being used in various packages. However, it's a
non-trivial function with lots of specific assumptions built into it, so
here we'll put it somewhere that other packages can depend on it _and_
document the assumptions it seems to be making for future reference.
As a bonus, this now uses os.SameFile to detect when two paths point to
the same physical file, instead of the slightly buggy local implementation
we had before which only worked on Unix systems and did not correctly
handle when the paths were on different physical devices.
The copy of the function I extracted here is the one from internal/initwd,
so this commit also includes the removal of that unexported version and
updating the callers in that package to use at at this new location.
In an earlier change we switched to defining our own sets of detectors,
getters, etc for go-getter in order to insulate us from upstream changes
to those sets that might otherwise change the user-visible behavior of
Terraform's module installer.
However, we apparently neglected to actually refer to our local set of
detectors, and continued to refer to the upstream set. Here we catch up
with the latest detectors from upstream (taken from the version of
go-getter we currently have vendored) and start using that fixed set.
Currently we are maintaining these custom go-getter sets in two places
due to the configload vs. initwd distinction. That was already true for
goGetterGetters and goGetterDecompressors, and so I've preserved that for
now just to keep this change relatively simple; in later change it would
be nice to factor these "get with go getter" functions out into a shared
location which we can call from both configload and initwd.
* configs/configupgrade: detect possible relative module sources
If a module source appears to be a relative local path but does not have
a preceding ./, print a #TODO message for the user.
* internal/initwd: limit go-getter detectors to those supported by terraform
* internal/initwd: move isMaybeRelativeLocalPath check into getWithGoGetter
To avoid making two calls to getter.Detect, which potentially makes
non-trivial API calls, the "isMaybeRelativeLocalPath" check was moved to
a later step and a custom error type was added so user-friendly
diagnostics could be displayed in the event that a possible relative local
path was detected.
Identify module sources that look like relative paths ("child" instead
of "./child", for example) and surface a helpful error.
Previously, such module sources would be passed to go-getter, which
would fail because it was expecting an absolute, or properly relative,
path. This commit moves the check for improper relative paths sooner so
a user-friendly error can be displayed.
Martin Atkins