ci: conditional apk add (to support rootless images)

        fi

      }

    - install_ca_certs "${CUSTOM_CA_CERTS:-$DEFAULT_CA_CERTS}"

    - apk add --update --no-cache git curl jq bash

    - |

      function maybe_install_pkg() {

        pkg_name="$1"

        cmd_name="${2:-$pkg_name}"

        if ! command -v "$cmd_name" > /dev/null

        then

          echo "[INFO] $pkg_name not found: install..."

          if command -v apt-get > /dev/null

          then

            apt-get install -yq "$pkg_name"

          elif command -v apk > /dev/null

          then

            apk add --no-cache "$pkg_name"

          elif command -v yum > /dev/null

          then

            yum install -yq "$pkg_name"

          elif command -v dnf > /dev/null

          then

            dnf install -yq "$pkg_name"

          elif command -v zypper > /dev/null

          then

            zypper -nq install "$pkg_name"

          else

            echo "[ERROR] ... didn't find any known package manager to install $pkg_name!"

            exit 1

          fi

        fi

      }

    - maybe_install_pkg git

    - maybe_install_pkg curl

    - maybe_install_pkg jq

    - maybe_install_pkg bash

    # done twice because /etc/ssl/certs/ca-certificates.crt is altered during apk add

    # we can't use update-ca-certificates --fresh because $CUSTOM_CA_CERTS can contains several certificates

    - install_ca_certs "${CUSTOM_CA_CERTS:-$DEFAULT_CA_CERTS}"