Pulled build script out of Dockerfile to facilitate native builds, changed the base image from alpine-s6 to alpine and used tini as entrypoint

latest_version.sh

@@ -11,34 +11,53 @@ fi
 
 function validate_version_format() {
     local v="$1"
-    [[ "$v" =~ ^v?[0-9]+\.[0-9]+\.[0-9]+$ ]]
+    [[ "${v}" =~ ^v?[0-9]+\.[0-9]+\.[0-9]+$ ]]
 }
 
 function get_latest_version() {
     local json version
     json="$(curl -fsSL https://api.github.com/repos/Psiphon-Labs/psiphon-tunnel-core/releases/latest)"
     if command -v jq >/dev/null 2>&1; then
-        version="$(printf '%s' "$json" | jq -r .tag_name)"
+        version="$(printf '%s' "${json}" | jq -r .tag_name)"
     else
-        version="$(printf '%s' "$json" \
+        version="$(printf '%s' "${json}" \
             | grep -m1 '"tag_name":' \
             | sed -E 's/.*"tag_name": ?"([^"]+)".*/\1/')"
     fi
 
-    if ! validate_version_format "$version"; then
+    if ! validate_version_format "${version}"; then
         echo "I tried to get the latest version of Psiphon without jq but it didn't work." >&2 
         echo "Please install jq or specify the version manually." >&2
         exit 1
     fi
 
-    printf '%s\n' "$version"
+    printf '%s\n' "${version}"
 }
 
 function normalize_version() {
     local v="$1"
-    if [[ "$v" =~ ^v ]]; then
-        echo "$v"
+    if [[ "${v}" =~ ^v ]]; then
+        echo "${v}"
     else
-        echo "v$v"
+        echo "v${v}"
+    fi
+}
+
+function get_supported_targets() {
+    echo "linux/amd64,linux/386,linux/arm64,linux/arm/v7,linux/arm/v6"
+}
+
+function get_current_target() {
+    echo "$(go env GOOS)/$(go env GOARCH)"
+}
+
+function decipher_targets() {
+    local targets="$1"
+    if [[ "${targets}" == "current" ]]; then
+        echo "$(get_current_target)"
+    elif [[ "${targets}" == "all" ]]; then
+        echo "$(get_supported_targets)"
+    else
+        echo "${targets}"
     fi
 }