First working version

build-functions/check-commands.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+NEEDED_COMMANDS="curl jq docker skopeo"
+for c in $NEEDED_COMMANDS; do
+  if ! command -v "$c" &>/dev/null; then
+    echo "⚠️  '$c' is not installed. Can't proceed with build."
+    exit 1
+  fi
+done

build-functions/get-public-image-config.sh

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+#!/bin/bash
+
+check_if_tags_exists() {
+  local image=$1
+  local tag=$2
+  skopeo list-tags "docker://$image" | jq -r ".Tags | contains([\"$tag\"])"
+}
+
+get_image_label() {
+  local label=$1
+  local image=$2
+  skopeo inspect "docker://$image" | jq -r ".Labels[\"$label\"]"
+}
+
+get_image_last_layer() {
+  local image=$1
+  skopeo inspect "docker://$image" | jq -r ".Layers | last"
+}

build-functions/gh-functions.sh

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+#!/bin/bash
+
+###
+# A regular echo, that only prints if ${GH_ACTION} is defined.
+###
+gh_echo() {
+  if [ -n "${GH_ACTION}" ]; then
+    echo "${@}"
+  fi
+}
+
+###
+# Prints the output to the file defined in ${GITHUB_ENV}.
+# Only executes if ${GH_ACTION} is defined.
+# Example Usage: gh_env "FOO_VAR=bar_value"
+###
+gh_env() {
+  if [ -n "${GH_ACTION}" ]; then
+    echo "${@}" >>"${GITHUB_ENV}"
+  fi
+}
+
+###
+# Prints the output to the file defined in ${GITHUB_OUTPUT}.
+# Only executes if ${GH_ACTION} is defined.
+# Example Usage: gh_env "FOO_VAR=bar_value"
+###
+gh_out() {
+  if [ -n "${GH_ACTION}" ]; then
+    echo "${@}" >>"$GITHUB_OUTPUT"
+  fi
+}