Better Terraform Bash Completion

terraform_bash_completion.sh

# Bash Terraform completion
#
# Originally adapted from
# https://gist.github.com/cornfeedhobo/8bc08747ec3add1fc5adb2edb7cd68d3
#
# Author: Jeremy Melanson
#
# Features of this version:
# - Uses built-in bash routines for text processing, instead of external tools
#   (awk, sed, grep, ...).
#
# - fixes the retrieval of options from the Terraform executble.
#
# - Optional _init_terraform_completion function, which can enable
#   command-completion for multiple Terraform executables.
#

#--- Get options listing from Terraform command.
#
_terraform_completion_get_opts () {
  local CMD_EXEC="${1}"
  local TF_OPT="${2}"

  local IFS=$'\n'

  #-- "terraform -help"
  if [[ "${TF_OPT}" == "" ]]; then

    for O in $(${CMD_EXEC} -help); do
      if [[ "${O}" =~ ^\ +([^\ ]+) ]]; then
        echo -e "${BASH_REMATCH[1]}"
      fi
    done

  #-- "terraform -help XXXX"
  else

    for O in $(${CMD_EXEC} -help ${TF_OPT}); do
      if [[ "${O}" =~ ^\ +(-[^\ =]+=?) ]]; then
        echo -e "${BASH_REMATCH[1]}"
      fi
    done

  fi
}


#--- This function is passed to 'complete' for handling completion.
#
_terraform_completion () {
  local cur prev words cword opts

  local O_COMP_WORDBREAKS="${COMP_WORDBREAKS}"
  export COMP_WORDBREAKS="${COMP_WORDBREAKS//=/}"

  _init_completion -s || return

  _get_comp_words_by_ref -n : cur prev words cword
  COMPREPLY=()

  local opts=""

  local CMD_EXEC="${COMP_WORDS[0]}"

  if [[ ${cword} -eq 1 ]]; then
    if [[ ${cur} == -* ]]; then


      if [[ ${cur} == -c* ]]; then
        compopt -o nospace

        local CUR_DIR=${cur//-chdir=/}
        opts="$(compgen -P "-chdir=" -d -- ${CUR_DIR})"
        opts="${opts:--chdir=}"

      else
        opts="-chdir= -help -version"

      fi
    else
      opts="$(_terraform_completion_get_opts ${CMD_EXEC})"

    fi

  elif [[ ${cword} -gt 1 ]]; then
    if [[ ${cword} -eq 2 && ${prev} == -help ]]; then
      opts="$(_terraform_completion_get_opts ${CMD_EXEC})"

    else

      if [[ "${NEW_OPT_TYPE}" != "" ]]; then
        compopt -o nospace

      else
        local TF_COMMAND="${words[1]}"
        opts="$(_terraform_completion_get_opts ${CMD_EXEC} ${TF_COMMAND})"

      fi
    fi
  fi

  COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )

  if [[ ${#COMPREPLY[@]} -eq 1 ]]; then
    if [[ "${COMPREPLY[0]}" =~ =$ ]]; then
      compopt -o nospace
    fi
  fi

  export COMP_WORDBREAKS="${O_COMP_WORDBREAKS}"

  return 0
}


#--- Initialize Bash Command Completion for multiple Terraform executables.
# It searches the PATH for files starting with "terraform", but does not
# contain "-" characters. This avoids adding Completion for third-party
# Terraform provider plugins that exist as a separate executable
# (terraform-provider-XXXX).
#
_init_terraform_completion () {

  #-- Regex used when looking for terraform executables.
  # Looks for "terraform", or "terraform[anything else that isn't a dash]".
  # This enables Command Completion for multiple versions of Terraform,
  # if you have them.
  #
  local TF_EXEC_PREFIX='^terrafor(m[^-]+|m)$'
  local ORIG_DIR="${PWD}"

  local IFS=':'
  for P in ${PATH}; do
    if [ -d "${P}" ]; then
      cd "${P}"

    else
      continue

    fi

    for E in *; do
      if [[ "${E}" =~ ${TF_EXEC_PREFIX} ]]; then
        complete -F _terraform_completion ${E}
      fi
    done

  done

  cd "${ORIG_DIR}"
}

complete -F _terraform_completion terraform


#--- Optionally enable command completion for multiple Terraform executables.
# It currently works with executables in the PATH, that are named similar
# to "terraform_XXXX".
#
# ** If your files are named differently, then you may need to modify the REGEX
# ** in TF_EXEC_PREFIX to suit your needs.
#
# This provides a little simplicity, when working with multiple Terraform versions.
#
# Uncomment this line to enable:
#
_init_terraform_completion

#--- Remove the initialization function. It is only needed once.
unset -f _init_terraform_completion


#--- Include command completion for the optional "tf" command.
complete -F _terraform_completion tf

Hi @jwhitcraft. I noticed this problem happening when trying to use autocomplete after the first "-xxxx" option. I just updated the gist with a working version.
I've also verified that using "tf" works. Just update the value of TF_EXEC_PREFIX to be TF_EXEC_PREFIX="^tf$".

Thanks! This is great!

Small nit: Typo on line 133.
It is onluy needed once. should be It is only needed once.

There's an undefined function (_init_completion) at line 44. I've removed from my copy and seems to be fine.

Thanks for pointing it out @ProfMoo

@jwhitcraft Check out complete-alias. I've tested it with this gist, and I was able to get completion for an alias.

@bgmonroe Are you still experiencing this issue? What version of bash-completion is installed?

No, I've since switched over to zsh, so no longer use the above. Thanks for the follow-up though.