Merge pull request #130 from warrensbox/master

Provide option to pass environment variable

Makefile

@@ -1,6 +1,6 @@
 EXE  := tfswitch
 PKG  := github.com/warrensbox/terraform-switcher
-VER := $(shell git ls-remote --tags git://github.com/warrensbox/terraform-switcher | awk '{print $$2}'| awk -F"/" '{print $$3}' | sort -n -t. -k1,1 -k2,2 -k3,3 | tail -n 1)
+VER := $(shell git ls-remote --tags git://github.com/warrensbox/terraform-switcher | awk '{print $$2}'| awk -F"/" '{print $$3}' | sort -n -t. -k1,1 -k2,2 -k3,3 | tail -n 2 | head -n1)
 PATH := build:$(PATH)
 GOOS ?= $(shell go env GOOS)
 GOARCH ?= $(shell go env GOARCH)

README.md

@@ -70,9 +70,16 @@ The most recently selected versions are presented at the top of the dropdown.
 2. For example, `tfswitch -l` or `tfswitch --list-all` to see all versions.
 3. Hit **Enter** to select the desired version.
 
+### Use environment variable
+You can also set the `TF_VERSION` environment version to your desired terraform version. 
+For example:   
+```bash
+export TF_VERSION=0.14.4
+tfswitch #will automatically switch to terraform version 0.14.4
+```
 ### Install latest version only
 1. Install the latest stable version only.
-2. Run `tfswitch -u` or `tfswitch --latest` to see all versions.
+2. Run `tfswitch -u` or `tfswitch --latest`.
 3. Hit **Enter** to install.
 ### Install latest implicit version for stable releases
 1. Install the latest implicit stable version.
@@ -96,7 +103,6 @@ terraform {
 ```
 <img src="https://s3.us-east-2.amazonaws.com/kepler-images/warrensbox/tfswitch/versiontf.gif#1" alt="drawing" style="width: 370px;"/>
 
-
 ### Use .tfswitch.toml file  (For non-admin - users with limited privilege on their computers)
 This is similiar to using a .tfswitchrc file, but you can specify a custom binary path for your terraform installation
 
@@ -123,7 +129,7 @@ version = "0.11.3"
 3. Run the command `tfswitch` in the same directory as your `.tfswitchrc`
 
 #### *Instead of a `.tfswitchrc` file, a `.terraform-version` file may be used for compatibility with [`tfenv`](https://github.com/tfutils/tfenv#terraform-version-file) and other tools which use it*
-
+## Automation
 **Automatically switch with bash**
 
 Add the following to the end of your `~/.bashrc` file:
@@ -256,7 +262,17 @@ jobs:
 
             terraform -v                    #testing version
 ```
+## Order of precedence
+
+| Order | Method |
+| --- | ----------- |
+| 1 | .tfswitch.toml |
+| 2 | .tfswitchrc |
+| 3 | .terraform-version |
+| 4 | Environment variable |
 
+With 1 being the highest precedence and 4 the lowest   
+*(If you disagree with this order of precedence, please open an issue)*
 ## How to contribute    
 An open source project becomes meaningful when people collaborate to improve the code.    
 Feel free to look at the code, critique and make suggestions. Lets make `tfswitch` better!   

main.go

@@ -106,29 +106,44 @@ func main() {
 		}
 
 		switch {
+		/* GIVEN A TOML FILE, */
+		/* show all terraform version including betas and RCs*/
 		case *listAllFlag:
 			listAll := true //set list all true - all versions including beta and rc will be displayed
 			installOption(listAll, &binPath)
+		/* latest pre-release implicit version. Ex: tfswitch --latest-pre 0.13 downloads 0.13.0-rc1 (latest) */
 		case *latestPre != "":
 			preRelease := true
 			installLatestImplicitVersion(*latestPre, custBinPath, preRelease)
+		/* latest implicit version. Ex: tfswitch --latest 0.13 downloads 0.13.5 (latest) */
 		case *latestStable != "":
 			preRelease := false
 			installLatestImplicitVersion(*latestStable, custBinPath, preRelease)
+		/* latest stable version */
 		case *latestFlag:
 			installLatestVersion(custBinPath)
+		/* version provided on command line as arg */
 		case len(args) == 1:
 			installVersion(args[0], &binPath)
+		/* provide an tfswitchrc file (IN ADDITION TO A TOML FILE) */
 		case fileExists(RCFile) && len(args) == 0:
 			readingFileMsg(rcFilename)
 			tfversion := retrieveFileContents(RCFile)
 			installVersion(tfversion, &binPath)
+		/* if .terraform-version file found (IN ADDITION TO A TOML FILE) */
 		case fileExists(TFVersionFile) && len(args) == 0:
 			readingFileMsg(tfvFilename)
 			tfversion := retrieveFileContents(TFVersionFile)
 			installVersion(tfversion, &binPath)
+		/* if versions.tf file found (IN ADDITION TO A TOML FILE) */
 		case checkTFModuleFileExist(dir) && len(args) == 0:
 			installTFProvidedModule(dir, &binPath)
+		/* if Terraform Version environment variable is set */
+		case checkTFEnvExist() && len(args) == 0 && version == "":
+			tfversion := os.Getenv("TF_VERSION")
+			fmt.Printf("Terraform version environment variable: %s\n", tfversion)
+			installVersion(tfversion, custBinPath)
+		// if no arg is provided - but toml file is provided
 		case version != "":
 			installVersion(version, &binPath)
 		default:
@@ -174,6 +189,12 @@ func main() {
 	case checkTFModuleFileExist(dir) && len(args) == 0:
 		installTFProvidedModule(dir, custBinPath)
 
+	/* if Terraform Version environment variable is set */
+	case checkTFEnvExist() && len(args) == 0:
+		tfversion := os.Getenv("TF_VERSION")
+		fmt.Printf("Terraform version environment variable: %s\n", tfversion)
+		installVersion(tfversion, custBinPath)
+
 	// if no arg is provided
 	default:
 		listAll := false //set list all false - only official release will be displayed
@@ -273,6 +294,15 @@ func checkTFModuleFileExist(dir string) bool {
 	return false
 }
 
+// checkTFEnvExist - checks if the TF_VERSION environment variable is set
+func checkTFEnvExist() bool {
+	tfversion := os.Getenv("TF_VERSION")
+	if tfversion != "" {
+		return true
+	}
+	return false
+}
+
 /* parses everything in the toml file, return required version and bin path */
 func getParamsTOML(binPath string, dir string) (string, string) {
 	path, _ := homedir.Dir()

snapcraft.yaml

@@ -1,13 +1,14 @@
 name: tfswitch
-version: git
+version: '0.10.958'
 summary: A command line tool to switch between different versions of terraform
 description: |
   The `tfswitch` command line tool lets you switch between different versions of terraform(https://www.terraform.io/).
   If you do not have a particular version of terraform installed, `tfswitch` will download the version you desire.
   The installation is minimal and easy.
   Once installed, simply select the version you require from the dropdown and start using terraform.
 architectures:
-  - build-on: arm64
+  - build-on: [amd64,arm64]
+    run-on: [amd64,arm64]
 assumes: [snapd2.45]
 base: core18
 
@@ -27,9 +28,9 @@ parts:
     source: .
     plugin: go
     go-importpath: github.com/warrensbox/terraform-switcher
-    build-packages:
-      - gcc-multilib
+    build-packages: [gcc, g++, make]
     go-buildtags:
       - tfswitch
     override-build: 
-      go build  -o ../install/bin/tfswitch
+      VER=$(git ls-remote --tags git://github.com/warrensbox/terraform-switcher | awk '{print $2}'| awk -F"/" '{print $3}' | sort -n -t. -k1,1 -k2,2 -k3,3 | tail -n 2 | head -n1)
+      go build  -v -ldflags "-X main.version=0.10.958"  -o ../install/bin/tfswitch

www/docs/Quick-Start.md

@@ -22,9 +22,16 @@ The most recently selected versions are presented at the top of the dropdown.
 1. Display all versions including beta, alpha and release candidates(rc). 
 2. For example, `tfswitch -l` or `tfswitch --list-all` to see all versions.
 3. Hit **Enter** to select the desired version.
+### Use environment variables
+You can also set the `TF_VERSION` environment version to your desired terraform version. 
+For example:   
+```bash
+export TF_VERSION=0.14.4
+tfswitch #will automatically switch to terraform version 0.14.4
+```
 ### Install latest version only
 1. Install the latest stable version only.
-2. Run `tfswitch -u` or `tfswitch --latest` to see all versions.
+2. Run `tfswitch -u` or `tfswitch --latest`.
 3. Hit **Enter** to install.
 ### Install latest implicit version for stable releases
 1. Install the latest implicit stable version.