Thus far our various interactions with the bits of state we keep
associated with a working directory have all been implemented directly
inside the "command" package -- often in the huge command.Meta type -- and
not managed collectively via a single component.
There's too many little codepaths reading and writing from the working
directory and data directory to refactor it all in one step, but this is
an attempt at a first step towards a future where everything that reads
and writes from the current working directory would do so via an object
that encapsulates the implementation details and offers a high-level API
to read and write all of these session-persistent settings.
The design here continues our gradual path towards using a dependency
injection style where "package main" is solely responsible for directly
interacting with the OS command line, the OS environment, the OS working
directory, the stdio streams, and the CLI configuration, and then
communicating the resulting information to the rest of Terraform by wiring
together objects. It seems likely that eventually we'll have enough wiring
code in package main to justify a more explicit organization of that code,
but for this commit the new "workdir.Dir" object is just wired directly in
place of its predecessors, without any significant change of code
organization at that top layer.
This first commit focuses on the main files and directories we use to
find provider plugins, because a subsequent commit will lightly reorganize
the separation of concerns for plugin launching with a similar goal of
collecting all of the relevant logic together into one spot.
Previously our graph walker expected to recieve a data structure
containing schemas for all of the provider and provisioner plugins used in
the configuration and state. That made sense back when
terraform.NewContext was responsible for loading all of the schemas before
taking any other action, but it no longer has that responsiblity.
Instead, we'll now make sure that the "contextPlugins" object reaches all
of the locations where we need schema -- many of which already had access
to that object anyway -- and then load the needed schemas just in time.
The contextPlugins object memoizes schema lookups, so we can safely call
it many times with the same provider address or provisioner type name and
know that it'll still only load each distinct plugin once per Context
object.
As of this commit, the Context.Schemas method is now a public interface
only and not used by logic in the "terraform" package at all. However,
that does leave us in a rather tenuous situation of relying on the fact
that all practical users of terraform.Context end up calling "Schemas" at
some point in order to verify that we have all of the expected versions
of plugins. That's a non-obvious implicit dependency, and so in subsequent
commits we'll gradually move all responsibility for verifying plugin
versions into the caller of terraform.NewContext, which'll heal a
long-standing architectural wart whereby the caller is responsible for
installing and locating the plugin executables but not for verifying that
what's installed is conforming to the current configuration and dependency
lock file.
In the v0.12 timeframe we made contextComponentFactory an interface with
the expectation that we'd write mocks of it for tests, but in practice we
ended up just always using the same "basicComponentFactory" implementation
throughout.
In the interests of simplification then, here we replace that interface
and its sole implementation with a new concrete struct type
contextPlugins.
Along with the general benefit that this removes an unneeded indirection,
this also means that we can add additional methods to the struct type
without the usual restriction that interface types prefer to be small.
In particular, in a future commit I'm planning to add methods for loading
provider and provisioner schemas, working with the currently-unused new
fields this commit has included in contextPlugins, as compared to its
predecessor basicComponentFactory.
For resources which are planned to move, render the previous run address
as additional information in the plan UI. For the case of a move-only
resource (which otherwise is unchanged), we also render that as a
planned change, but without any corresponding action symbol.
If all changes in the plan are moves without changes, the plan is no
longer considered "empty". In this case, we skip rendering the action
symbols in the UI.
Previously terraform.Context was built in an unfortunate way where all of
the data was provided up front in terraform.NewContext and then mutated
directly by subsequent operations. That made the data flow hard to follow,
commonly leading to bugs, and also meant that we were forced to take
various actions too early in terraform.NewContext, rather than waiting
until a more appropriate time during an operation.
This (enormous) commit changes terraform.Context so that its fields are
broadly just unchanging data about the execution context (current
workspace name, available plugins, etc) whereas the main data Terraform
works with arrives via individual method arguments and is returned in
return values.
Specifically, this means that terraform.Context no longer "has-a" config,
state, and "planned changes", instead holding on to those only temporarily
during an operation. The caller is responsible for propagating the outcome
of one step into the next step so that the data flow between operations is
actually visible.
However, since that's a change to the main entry points in the "terraform"
package, this commit also touches every file in the codebase which
interacted with those APIs. Most of the noise here is in updating tests
to take the same actions using the new API style, but this also affects
the main-code callers in the backends and in the command package.
My goal here was to refactor without changing observable behavior, but in
practice there are a couple externally-visible behavior variations here
that seemed okay in service of the broader goal:
- The "terraform graph" command is no longer hooked directly into the
core graph builders, because that's no longer part of the public API.
However, I did include a couple new Context functions whose contract
is to produce a UI-oriented graph, and _for now_ those continue to
return the physical graph we use for those operations. There's no
exported API for generating the "validate" and "eval" graphs, because
neither is particularly interesting in its own right, and so
"terraform graph" no longer supports those graph types.
- terraform.NewContext no longer has the responsibility for collecting
all of the provider schemas up front. Instead, we wait until we need
them. However, that means that some of our error messages now have a
slightly different shape due to unwinding through a differently-shaped
call stack. As of this commit we also end up reloading the schemas
multiple times in some cases, which is functionally acceptable but
likely represents a performance regression. I intend to rework this to
use caching, but I'm saving that for a later commit because this one is
big enough already.
The proximal reason for this change is to resolve the chicken/egg problem
whereby there was previously no single point where we could apply "moved"
statements to the previous run state before creating a plan. With this
change in place, we can now do that as part of Context.Plan, prior to
forking the input state into the three separate state artifacts we use
during planning.
However, this is at least the third project in a row where the previous
API design led to piling more functionality into terraform.NewContext and
then working around the incorrect order of operations that produces, so
I intend that by paying the cost/risk of this large diff now we can in
turn reduce the cost/risk of future projects that relate to our main
workflow actions.
The -force-copy flag to init should automatically migrate state.
Previously this was not applied to one case: when migrating from
a backend with multiple workspaces to another backend supporting
multiple workspaces. I believe this was an oversight so this commit
fixes that.
We're aware of several quirks of this command's current design, which
result from some existing architectural limitations that we can't address
immediately.
However, we do still want to make this command available in its current
capacity as an incremental improvement, so as a compromise we'll document
it as experimental. Our intent here is to exclude it from the
Terraform 1.0 Compatibility Promises so that we can have the space to
continue to improve the design as other parts of the overall Terraform
system gain new capabilities.
We don't currently have any concrete plan for this command to be
stabilized and subject to compatibility promises. That decision will
follow from ongoing discussions with other teams whose systems may need to
change in order to support the final design of "terraform add".
The code adopted from block diffs was not set to handle null and unknown
values, as those are not allowed for blocks.
We also revert the change to formatting nested object types as single
attributes, because the attribute formatter cannot handle sensitive
values from the schema. This presents some awkward syntax for diffs for
now, but should suffice until the entire formatter can be refactored to
better handle these new nested types.
This includes the addition of the new "//go:build" comment form in addition
to the legacy "// +build" notation, as produced by gofmt to ensure
consistent behavior between Go versions. The new directives are all
equivalent to what was present before, so there's no change in behavior.
Go 1.17 continues to use the Unicode 13 tables as in Go 1.16, so this
upgrade does not require also upgrading our Unicode-related dependencies.
This upgrade includes the following breaking changes which will also
appear as breaking changes for Terraform users, but that are consistent
with the Terraform v1.0 compatibility promises.
- On MacOS, Terraform now requires macOS 10.13 High Sierra or later.
This upgrade also includes the following breaking changes which will
appear as breaking changes for Terraform users that are inconsistent with
our compatibility promises, but have justified exceptions as follows:
- cidrsubnet, cidrhost, and cidrnetmask will now reject IPv4 CIDR
addresses whose decimal components have leading zeros, where previously
they would just silently ignore those leading zeros.
This is a security-motivated exception to our compatibility promises,
because some external systems interpret zero-prefixed octets as octal
numbers rather than decimal, and thus the previous lenient parsing could
lead to a different interpretation of the address between systems, and
thus potentially allow bypassing policy when configuring firewall rules
etc.
This upgrade also includes the following breaking changes which could
_potentially_ appear as breaking changes for Terraform users, but that do
not in practice for the reasons given:
- The Go net/url package no longer allows query strings with pairs
separated by semicolons instead of ampersands. This primarily affects
HTTP servers written in Go, and Terraform includes a special temporary
HTTP server as part of its implementation of OAuth for "terraform login",
but that server only needs to accept URLs created by Terraform itself
and Terraform does not generate any URLs that would be rejected.
Extend the outputs JSON log message to support an `action` field (and
make the `type` and `value` fields optional). This allows us to emit a
useful output change summary as part of the plan, bringing the JSON log
output into parity with the text output.
While we do have access to the before/after values in the output
changes, attempting to wedge those into a structured log message is not
appropriate. That level of detail can be extracted from the JSON plan
output from `terraform show -json`.
This test would previously fail randomly due to the use of multiple
resource instances. Instance keys are iterated over as a map for
presentation, which has intentionally inconsistent ordering.
To fix this, I changed the test to use different resource addresses for
the three drift cases. I also extracted them to a separate test, and
tweaked the test helper functions to reduce the number of fatal exit
points, to make failed test debugging easier.
The logic behind this code took me a while to understand, so I wrote
down what I understand to be the reasoning behind how it works. The
trickiest part is rendering changing objects as updates. I think the
other pieces are fairly common to LCS sequence diff rendering, so I
didn't explain those in detail.
The previous name didn't fit with the naming scheme for addrs types:
The "Abs" prefix typically means that it's an addrs.ModuleInstance
combined with whatever type name appears after "Abs", but this is instead
a ModuleCallOutput combined with an InstanceKey, albeit structured the
other way around for convenience, and so the expected name for this would
be the suffix "Instance".
We don't have an "Abs" type corresponding with this one because it would
represent no additional information than AbsOutputValue.
* command/jsonstate: remove redundant remarking of resource instance
ResourceInstanceObjectSrc.Decode already handles marking values with any marks stored in ri.Current.AttrSensitivePaths, so re-applying those marks is not necessary.
We've gotten reports of panics coming from this line of code, though I have yet to reproduce the panic in a test.
* Implement test to reproduce panic on #29042
Co-authored-by: David Alger <davidmalger@gmail.com>
Because our snippet generator is trying to select whole lines to include
in the snippet, it has some edge cases for odd situations where the
relevant source range starts or ends directly at a newline, which were
previously causing this logic to return out-of-bounds offsets into the
code snippet string.
Although arguably it'd be better for the original diagnostics to report
more reasonable source ranges, it's better for us to report a
slightly-inaccurate snippet than to crash altogether, and so we'll extend
our existing range checks to check both bounds of the string and thus
avoid downstreams having to deal with out-of-bounds indices.
For completeness here I also added some similar logic to the
human-oriented diagnostic formatter, which consumes the result of the
JSON diagnostic builder. That's not really needed with the additional
checks in the JSON diagnostic builder, but it's nice to reinforce that
this code can't panic (in this way, at least) even if its input isn't
valid.
* terraform: use hcl.MergeBodies instead of configs.MergeBodies for provider configuration
Previously, Terraform would return an error if the user supplied provider configuration via interactive input iff the configuration provided on the command line was missing any required attributes - even if those attributes were already set in config.
That error came from configs.MergeBody, which was designed for overriding valid configuration. It expects that the first ("base") body has all required attributes. However in the case of interactive input for provider configuration, it is perfectly valid if either or both bodies are missing required attributes, as long as the final body has all required attributes. hcl.MergeBodies works very similarly to configs.MergeBodies, with a key difference being that it only checks that all required attributes are present after the two bodies are merged.
I've updated the existing test to use interactive input vars and a schema with all required attributes. This test failed before switching from configs.MergeBodies to hcl.MergeBodies.
* add a command package test that shows that we can still have providers with dynamic configuration + required + interactive input merging
This test failed when buildProviderConfig still used configs.MergeBodies instead of hcl.MergeBodies
Previously, if any resources were found to have drifted, the JSON plan
output would include a drift entry for every resource in state. This
commit aligns the JSON plan output with the CLI UI, and only includes
those resources where the old value does not equal the new value---i.e.
drift has been detected.
Also fixes a bug where the "address" field was missing from the drift
output, and adds some test coverage.
* command: new command, terraform add, generates resource templates
terraform add ADDRESS generates a resource configuration template with all required (and optionally optional) attributes set to null. This can optionally also pre-populate nonsesitive attributes with values from an existing resource of the same type in state (sensitive vals will be populated with null and a comment indicating sensitivity)
* website: terraform add documentation
* jsonplan and jsonstate: include sensitive_values in state representations
A sensitive_values field has been added to the resource in state and planned values which is a map of all sensitive attributes with the values set to true.
It wasn't entirely clear to me if the values in state would suffice, or if we also need to consult the schema - I believe that this is sufficient for state files written since v0.15, and if that's incorrect or insufficient, I'll add in the provider schema check as well.
I also updated the documentation, and, since we've considered this before, bumped the FormatVersions for both jsonstate and jsonplan.
It's been a long while since we gave close attention to the codepaths for
module source address parsing and external module package installation.
Due to their age, these codepaths often diverged from our modern practices
such as representing address types in the addrs package, and encapsulating
package installation details only in a particular location.
In particular, this refactor makes source address parsing a separate step
from module installation, which therefore makes the result of that parsing
available to other Terraform subsystems which work with the configuration
representation objects.
This also presented the opportunity to better encapsulate our use of
go-getter into a new package "getmodules" (echoing "getproviders"), which
is intended to be the only part of Terraform that directly interacts with
go-getter.
This is largely just a refactor of the existing functionality into a new
code organization, but there is one notable change in behavior here: the
source address parsing now happens during configuration loading rather
than module installation, which may cause errors about invalid addresses
to be returned in different situations than before. That counts as
backward compatible because we only promise to remain compatible with
configurations that are _valid_, which means that they can be initialized,
planned, and applied without any errors. This doesn't introduce any new
error cases, and instead just makes a pre-existing error case be detected
earlier.
Our module registry client is still using its own special module address
type from registry/regsrc for now, with a small shim from the new
addrs.ModuleSourceRegistry type. Hopefully in a later commit we'll also
rework the registry client to work with the new address type, but this
commit is already big enough as it is.
When performing state migration to a remote backend target, Terraform
may fail due to mismatched remote and local Terraform versions. Here we
add the `-ignore-remote-version` flag to allow users to ignore this
version check when necessary.
When migrating multiple local workspaces to a remote backend target
using the `prefix` argument, we need to perform the version check
against all existing workspaces returned by the `Workspaces` method.
Failing to do so will result in a version check error.
This was dead code, and there is no clear way to retrieve this
information, as we currently only derive the drift information as part
of the rendering process.
Martin Atkins