opentofu/website/docs
Alisdair McDiarmid c5c1f31db3 backend: Validate remote backend Terraform version
When using the enhanced remote backend, a subset of all Terraform
operations are supported. Of these, only plan and apply can be executed
on the remote infrastructure (e.g. Terraform Cloud). Other operations
run locally and use the remote backend for state storage.

This causes problems when the local version of Terraform does not match
the configured version from the remote workspace. If the two versions
are incompatible, an `import` or `state mv` operation can cause the
remote workspace to be unusable until a manual fix is applied.

To prevent this from happening accidentally, this commit introduces a
check that the local Terraform version and the configured remote
workspace Terraform version are compatible. This check is skipped for
commands which do not write state, and can also be disabled by the use
of a new command-line flag, `-ignore-remote-version`.

Terraform version compatibility is defined as:

- For all releases before 0.14.0, local must exactly equal remote, as
  two different versions cannot share state;
- 0.14.0 to 1.0.x are compatible, as we will not change the state
  version number until at least Terraform 1.1.0;
- Versions after 1.1.0 must have the same major and minor versions, as
  we will not change the state version number in a patch release.

If the two versions are incompatible, a diagnostic is displayed,
advising that the error can be suppressed with `-ignore-remote-version`.
When this flag is used, the diagnostic is still displayed, but as a
warning instead of an error.

Commands which will not write state can assert this fact by calling the
helper `meta.ignoreRemoteBackendVersionConflict`, which will disable the
checks. Those which can write state should instead call the helper
`meta.remoteBackendVersionCheck`, which will return diagnostics for
display.

In addition to these explicit paths for managing the version check, we
have an implicit check in the remote backend's state manager
initialization method. Both of the above helpers will disable this
check. This fallback is in place to ensure that future code paths which
access state cannot accidentally skip the remote version check.
2020-11-19 13:19:40 -05:00
..
backends website: Fix a random typo in azurerm backend 2020-11-18 10:47:52 -08:00
cli website: Update all links to {expressions,modules,resources}.html 2020-11-17 16:30:51 -08:00
commands backend: Validate remote backend Terraform version 2020-11-19 13:19:40 -05:00
configuration website: "coalesce" function unifies its argument types 2020-11-18 08:03:37 -08:00
configuration-0-11 website: Update all links to {expressions,modules,resources}.html 2020-11-17 16:30:51 -08:00
import website: Update all Learn crosslinks (#26442) 2020-10-02 11:02:59 -07:00
internals website: Fix inconsistencies in the registry protocol page 2020-11-16 10:06:27 -08:00
modules website: Reword confusing statement about module sources in TFE 2020-11-18 08:04:10 -08:00
plugins website: Make most of /docs/plugins into ghost pages on Extend 2020-10-26 18:21:29 -07:00
providers website: Document alternatives to terraform_remote_state 2020-11-17 09:41:54 -08:00
provisioners website: Fix confusing example for local-exec provisioner 2020-11-18 08:04:41 -08:00
registry website: Update all links to {expressions,modules,resources}.html 2020-11-17 16:30:51 -08:00
state Merge pull request #26723 from hashicorp/oct20_language_and_cli_docs 2020-11-11 19:31:05 -08:00
cli-index.html.md website: Add new "glue"/overview pages for CLI and language docs 2020-11-11 19:13:23 -08:00