Merge branch 'fix/envsubst-enhancements' into 'master'

    fail "... timeout reached: halt"

  }

  function awkenvsubst() {

    # performs variables escaping: '&' for gsub + JSON chars ('\' and '"')

    awk '{while(match($0,"[$%]{[^}]*}")) {var=substr($0,RSTART+2,RLENGTH-3);val=ENVIRON[var];gsub(/["\\&]/,"\\\\&",val);gsub("[$%]{"var"}",val)}}1'

  function tbc_envsubst() {

    awk '

      BEGIN {

        count_replaced_lines = 0

        # ASCII codes

        for (i=0; i<=255; i++)

          char2code[sprintf("%c", i)] = i

      }

      # determine encoding (from env or from file extension)

      function encoding() {

        enc = ENVIRON["TBC_ENVSUBST_ENCODING"]

        if (enc != "")

          return enc

        if (match(FILENAME, /\.(json|yaml|yml)$/))

          return "jsonstr"

        return "raw"

      }

      # see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent

      function uriencode(str) {

        len = length(str)

        enc = ""

        for (i=1; i<=len; i++) {

          c = substr(str, i, 1);

          if (index("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'\''()", c))

            enc = enc c

          else

            enc = enc "%" sprintf("%02X", char2code[c])

        }

        return enc

      }

      !/# *nosubst/ {

        orig_line = $0

        line = $0

        count_repl_in_line = 0

        # /!\ 3rd arg (match) not supported in BusyBox awk

        while (match(line, /[$%]\{([[:alnum:]_]+)\}/)) {

          expr_start = RSTART

          expr_len = RLENGTH

          # get var name

          var = substr(line, expr_start+2, expr_len-3)

          # get var value (from env)

          val = ENVIRON[var]

          # check variable is set

          if (val == "") {

            printf("[\033[1;93mWARN\033[0m] Environment variable \033[33;1m%s\033[0m is not set or empty\n", var) > "/dev/stderr"

          } else {

            enc = encoding()

            if (enc == "jsonstr") {

              gsub(/["\\]/, "\\\\&", val)

              gsub("\n", "\\n", val)

              gsub("\r", "\\r", val)

              gsub("\t", "\\t", val)

            } else if (enc == "uricomp") {

              val = uriencode(val)

            } else if (enc == "raw") {

            } else {

              printf("[\033[1;93mWARN\033[0m] Unsupported encoding \033[33;1m%s\033[0m: ignored\n", enc) > "/dev/stderr"

            }

          }

          # replace expression in line

          line = substr(line, 1, expr_start - 1) val substr(line, expr_start + expr_len)

          count_repl_in_line++

        }

        if (count_repl_in_line) {

          if (count_replaced_lines == 0)

            printf("[\033[1;94mINFO\033[0m] Variable expansion occurred in file \033[33;1m%s\033[0m:\n", FILENAME) > "/dev/stderr"

          count_replaced_lines++

          printf("> line %s: %s\n", NR, orig_line) > "/dev/stderr"

        }

        print line

      }

    ' "$@"

  }

  function configure_registries_auth() {

    mkdir -p "$BUILDTOOL_HOME/.docker"

    if [ -f "${DOCKER_CONFIG_FILE}" ]

    then

      awkenvsubst < "${DOCKER_CONFIG_FILE}" > "$BUILDTOOL_HOME/.docker/config.json"

      TBC_ENVSUBST_ENCODING=jsonstr tbc_envsubst "${DOCKER_CONFIG_FILE}" > "$BUILDTOOL_HOME/.docker/config.json"

    else

      echo "${docker_snapshot_config_json}" > "$BUILDTOOL_HOME/.docker/config.json"

    fi