DCD-545: Import the templater script.

.dockerignore

@@ -1,3 +1,2 @@
 .git
-scripts
-.idea
+.idea

scripts/templater.sh

@@ -0,0 +1,97 @@
+#!/bin/bash
+
+# Replaces all {{VAR}} by the $VAR value in a template file and outputs it
+# Use with -h to output all variables
+
+# Original from https://github.com/lavoiesl/bash-templater/commit/265e91f31affdb2fdc56e011592ba21e1b95ba74
+# MIT License: https://github.com/lavoiesl/bash-templater/blob/265e91f31affdb2fdc56e011592ba21e1b95ba74/LICENSE
+
+if [[ ! -f "$1" ]]; then
+    echo "Usage: VAR=value $0 template" >&2
+    exit 1
+fi
+
+template="$1"
+vars=$(grep -oE '\{\{\s*[A-Za-z0-9_]+\s*\}\}' "$template" | sort | uniq | sed -e 's/^{{//' -e 's/}}$//')
+
+if [[ -z "$vars" ]]; then
+    echo "Warning: No variable was found in $template, syntax is {{VAR}}" >&2
+fi
+
+var_value() {
+    var="${1}"
+    eval echo \$"${var}"
+}
+
+##
+# Escape custom characters in a string
+# Example: escape "ab'\c" '\' "'"   ===>  ab\'\\c
+#
+function escape_chars() {
+    local content="${1}"
+    shift
+
+    for char in "$@"; do
+        content="${content//${char}/\\${char}}"
+    done
+
+    echo "${content}"
+}
+
+function echo_var() {
+    local var="${1}"
+    local content="${2}"
+    local escaped="$(escape_chars "${content}" "\\" '"')"
+
+    echo "${var}=\"${escaped}\""
+}
+
+declare -a replaces
+replaces=()
+
+# Reads default values defined as {{VAR=value}} and delete those lines
+# There are evaluated, so you can do {{PATH=$HOME}} or {{PATH=`pwd`}}
+# You can even reference variables defined in the template before
+defaults=$(grep -oE '^\{\{[A-Za-z0-9_]+=.+\}\}$' "${template}" | sed -e 's/^{{//' -e 's/}}$//')
+IFS=$'\n'
+for default in $defaults; do
+    var=$(echo "${default}" | grep -oE "^[A-Za-z0-9_]+")
+    current="$(var_value "${var}")"
+
+    # Replace only if var is not set
+    if [[ -n "$current" ]]; then
+        eval "$(echo_var "${var}" "${current}")"
+    else
+        eval "${default}"
+    fi
+
+    # remove define line
+    replaces+=("-e")
+    replaces+=("/^{{${var}=/d")
+    vars="${vars} ${var}"
+done
+
+vars="$(echo "${vars}" | tr " " "\n" | sort | uniq)"
+
+if [[ "$2" = "-h" ]]; then
+    for var in $vars; do
+        value="$(var_value "${var}")"
+        echo_var "${var}" "${value}"
+    done
+    exit 0
+fi
+
+# Replace all {{VAR}} by $VAR value
+for var in $vars; do
+    value="$(var_value "${var}")"
+    if [[ -z "$value" ]]; then
+        echo "Warning: $var is not defined and no default is set, replacing by empty" >&2
+    fi
+
+    # Escape slashes
+    value="$(escape_chars "${value}" "\\" '/' ' ')";
+    replaces+=("-e")
+    replaces+=("s/{{\s*${var}\s*}}/${value}/g")
+done
+
+sed "${replaces[@]}" "${template}"