yaml.sh

#!/usr/bin/env bash
# shellcheck disable=SC1003

# Based on https://gist.github.com/pkuczynski/8665367
# Source: https://github.com/jasperes/bash-yaml/blob/master/script/yaml.sh

parse_yaml() {
    local yaml_file=$1
    local prefix=$2
    local s
    local w
    local fs

    s='[[:space:]]*'
    w='[a-zA-Z0-9_.-]*'
    fs="$(echo @|tr @ '\034')"

    (
        sed -e '/- [^\“]'"[^\']"'.*: /s|\([ ]*\)- \([[:space:]]*\)|\1-\'$'\n''  \1\2|g' |

        sed -ne '/^--/s|--||g; s|\"|\\\"|g; s/[[:space:]]*$//g;' \
            -e 's/\$/\\\$/g' \
            -e "/#.*[\"\']/!s| #.*||g; /^#/s|#.*||g;" \
            -e "s|^\($s\)\($w\)$s:$s\"\(.*\)\"$s\$|\1$fs\2$fs\3|p" \
            -e "s|^\($s\)\($w\)${s}[:-]$s\(.*\)$s\$|\1$fs\2$fs\3|p" |

        awk -F"$fs" '{
            indent = length($1)/2;
            if (length($2) == 0) { conj[indent]="+";} else {conj[indent]="";}
            vname[indent] = $2;
            for (i in vname) {if (i > indent) {delete vname[i]}}
                if (length($3) > 0) {
                    vn=""; for (i=0; i<indent; i++) {vn=(vn)(vname[i])("_")}
                    printf("%s%s%s%s=(\"%s\")\n", "'"$prefix"'",vn, $2, conj[indent-1], $3);
                }
            }' |

        sed -e 's/_=/+=/g' |

        awk 'BEGIN {
                FS="=";
                OFS="="
            }
            /(-|\.).*=/ {
                gsub("-|\\.", "_", $1)
            }
            { print }'
    ) < "$yaml_file"
}

unset_variables() {
  # Pulls out the variable names and unsets them.
  #shellcheck disable=SC2048,SC2206 #Permit variables without quotes
  local variable_string=($*)
  unset variables
  local variables=()
  local tmpvar
  local variable

  for variable in "${variable_string[@]}" ; do
    tmpvar=$(echo "$variable" | grep '=' | sed 's/=.*//' | sed 's/+.*//')
    variables+=("$tmpvar")
  done
  for variable in "${variables[@]}"; do
  if [ -n "$variable" ] ; then
    unset "$variable"
  fi
  done
}

create_variables() {
    local yaml_file="$1"
    local prefix="$2"
    local yaml_string
    yaml_string="$(parse_yaml "$yaml_file" "$prefix")"
    unset_variables "${yaml_string}"
    eval "${yaml_string}"
}