fix: install script (#4230)

* fix: install script

install.sh

@@ -1,5 +1,5 @@
+#!/bin/bash 
 echo "Getting kubectl-testkube plugin"
-#!/bin/sh 
 
 if [ ! -z "${DEBUG}" ]; 
 then set -x 
@@ -31,27 +31,42 @@ _detect_os(){
 }
 
 _download_url() {
- local arch="$(_detect_arch)"
- local os="$(_detect_os)"
+ local arch
+ local os
+ local tag
+ local version
+
+ arch="$(_detect_arch)"
+ os="$(_detect_os)"
  if [ -z "$TESTKUBE_VERSION" ]; then
  if [ "$1" = "beta" ]; then
- local version=$(curl -s "https://api.github.com/repos/kubeshop/testkube/releases" 2>/dev/null | jq -r '.[].tag_name | select(test("beta"))' | head -n 1)
+ tag="$(
+ curl -s "https://api.github.com/repos/kubeshop/testkube/releases" \
+ 2>/dev/null \
+ | jq -r '.[].tag_name | select(test("beta"))' \
+ | head -n 1 \
+ )"
  else
- local version=$(curl -s "https://api.github.com/repos/kubeshop/testkube/releases/latest" 2>/dev/null | jq -r '.tag_name')
+ tag="$(
+ curl -s "https://api.github.com/repos/kubeshop/testkube/releases/latest" \
+ 2>/dev/null \
+ | jq -r '.tag_name' \
+ )"
  fi
  else
- local version="$TESTKUBE_VERSION"
+ tag="$TESTKUBE_VERSION"
  fi
+ version="${tag/#v/}" # remove leading v if present
 
- echo "https://github.com/kubeshop/testkube/releases/download/${version}/testkube_${version:1}_${os}_$arch.tar.gz"
+ echo "https://github.com/kubeshop/testkube/releases/download/${tag}/testkube_${version:-1}_${os}_$arch.tar.gz"
 }
 
 if [ "$1" = "beta" ]; then
  echo "Downloading testkube from URL: $(_download_url "beta")"
- curl -sSLf $(_download_url "beta") > testkube.tar.gz
+ curl -sSLf "$(_download_url "beta")" > testkube.tar.gz
 else
  echo "Downloading testkube from URL: $(_download_url)"
- curl -sSLf $(_download_url) > testkube.tar.gz
+ curl -sSLf "$(_download_url)" > testkube.tar.gz
 fi
 
 tar -xzf testkube.tar.gz kubectl-testkube