Support setting environment variable - current version

[warrensbox]

Support setting environment variable - current version

[boxrick]

Hey sorry for the slow response, I appreciate your reply! This is more along the lines of:

Run tfswitch 0.14.2 then as a net result of that an environment variable is potentially set showing the current version

So for example in this case something like CURRENT_TF_VERSION=0.14.2

This would then allow us to consume this variable for usage in shell integration and such.

[warrensbox]

@yermulnik it looks like you have a .tfswitch.toml file in your home directory. In that .tfswitch.toml file, you probably have set set a version constrain for the terraform version. The environment variable that you've set has a lower precedent than the configuration in the .toml file.
See:

Order of precedence

Order	Method
1	.tfswitch.toml
2	.tfswitchrc
3	.terraform-version
4	Environment variable

https://github.com/warrensbox/terraform-switcher/blob/master/README.md#order-of-precedence.

.tfswitch.toml > Environment variable

I did this because some users set their default bin path in their toml file (located in the home directory).

bin = "/Users/<username>/bin/terraform"
version = "0.11.3" ///DO NOT set this if you want to define version as environment variable

[yermulnik]

Oh, I see. Thanks.
Is there a way to sort of force precedence?
So in my use case I wouldn't want to use the most recent version of terraform which is 1.0.1 but would prefer to use the one which fits the constraint (0.13.5). I do understand that this is not what tfswitch was designed for though, but I do need to override its logic and use specific TF version w/o changing the constraint from version.tf.

Thanks for helping! And the BIG THANK YOU for this marvelous tool! 🙇‍♂️

[boxrick]

Hello! Thanks again for this great tool, use it almost every day.

I wonder if precedent should be instead set by ENV vars first, this is the usual method most tools take ( Ansible / Terraform / AWS-cli etc ... rather than config files first.

[warrensbox]

@boxrick something like this?
//user set TF version
export TF=0.13.0

//if the $TF environment variable is set, users would be able to simply run tfswitch command to switch to their desired terraform version?
tfswitch

[warrensbox]

Use environment variable

You can set the TF_VERSION environment variable to your desired terraform version.
For example:

export TF_VERSION=0.14.4
tfswitch #will automatically switch to terraform version 0.14.4

@boxrick Can you please test this feature?
Upgrade to the latest tfswitch for this feature:
https://tfswitch.warrensbox.com/Upgrade-or-Uninstall/

[boxrick]

Hello! Thanks for the amazing software it works really nicely. I think this feature may be the inverse of what I meant.

I want tfswitch to export to the environment the 'current' running version rather than tfswitch change based on the environment if that makes sense?

The idea is then I can then take this env var and use it on the console to show a prompt with the current version we are switched to.

[warrensbox]

@boxrick I don't think we can export the version to the environment:

When tfswitch runs, it is executing in its own shell. This shell(child) gets a copy of its parent shell's environment when it is forked. When tfswitch completes running, the child is removed. There is no way to pass the environment variable to the parent.

Environment variables can only be passed from parent to child (as part of environment export/inheritance), not the other way around.

https://unix.stackexchange.com/a/372628
https://askubuntu.com/a/784805
https://golangcode.com/get-and-set-environment-variables/ (won't work).

[yermulnik]

Am I doing something wrong? 😕

> export TF_VERSION=0.13.5

> echo $TF_VERSION
0.13.5

> tfswitch
Reading configuration from home directory for .tfswitch.toml
Reading required version from terraform file
Reading required version from constraint: >= 0.13
Matched version: 1.0.1
Switched terraform to version "1.0.1"

> tfswitch --version

Version: 0.12.1119

[yermulnik]

Hey @warrensbox
Thanks for looking into this.
Here's the content of my conf file:

> cat ~/.tfswitch.toml
bin = "$HOME/bin/terraform"

No version constrain.
Is there any option/way to investigate why tfswitch doesn't pick env var?

Here's some more info if it may help to help me 😄 :

> strace tfswitch 2>&1 | egrep "\.tfswitch|\.terraform-version"
newfstatat(AT_FDCWD, "/home/giermulnik/data/XXX/XXXr/github.com/XXX/aws_infrastructure/wafv2/fe_api_apps/.tfswitch.toml", 0xc00013d968, 0) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/home/giermulnik/.tfswitch.toml", {st_mode=S_IFREG|0600, st_size=28, ...}, 0) = 0
newfstatat(AT_FDCWD, "/home/giermulnik/data/XXX/XXXr/github.com/XXX/aws_infrastructure/wafv2/fe_api_apps/.tfswitch.toml", 0xc00013db08, 0) = -1 ENOENT (No such file or directory)
write(1, "Reading configuration from home "..., 61Reading configuration from home directory for .tfswitch.toml
newfstatat(AT_FDCWD, "/home/giermulnik/.tfswitch.json", 0xc00013dbd8, 0) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/home/giermulnik/.tfswitch.toml", {st_mode=S_IFREG|0600, st_size=28, ...}, 0) = 0
openat(AT_FDCWD, "/home/giermulnik/.tfswitch.toml", O_RDONLY|O_CLOEXEC) = 3
newfstatat(AT_FDCWD, "/home/giermulnik/data/XXX/XXXr/github.com/XXX/aws_infrastructure/wafv2/fe_api_apps/.tfswitchrc", 0xc00013de48, 0) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/home/giermulnik/data/XXX/XXXr/github.com/XXX/aws_infrastructure/wafv2/fe_api_apps/.terraform-version", 0xc00013df18, 0) = -1 ENOENT (No such file or directory)

> locate .tfswitch.toml .tfswitchrc .terraform-version
/home/giermulnik/.tfswitch.toml
/home/giermulnik/RCS/.tfswitch.toml,v

[warrensbox]

In your directory, where you run tfswitch, do you have the version specified in the .tf file?
For example, do you have:

terraform {
  required_version = ">= 0.13"

  required_providers {
    aws        = ">= 2.52.0"
    kubernetes = ">= 1.11.1"
  }
}

in your terraform file? @yermulnik

[yermulnik]

@warrensbox Yep, I do. This can be seen from tfswitch output:

> tfswitch
Reading configuration from home directory for .tfswitch.toml
Reading required version from terraform file            <- THIS
Reading required version from constraint: >= 0.13  <- and THIS
Matched version: 1.0.1
Switched terraform to version "1.0.1"

And here's the TF contraint:

> cat version.tf
terraform {
  required_version = ">= 0.13"
}

[warrensbox]

The version.tf has higher precedent compared to env vars.
version.tf > Environment variable
I should have documented that in the readme

[warrensbox]

Yes, I can look into that.