TT#120752 Add 'ngcpcfg edit' to speedup YML editing

Normally it is necessary to press TAB multiple times, e.g:
> vim /etc/ngcp-conf<TAB>/con<TAB>f<TAB>...
For new NGCP users it is even longer.

In the same time we have a nice usability experience for ngcp-ppa,
where users are just pressing "ngcp-ppa<ENTER>1<ENTER>1<ENTER>".

Let's add the same concept here as the order of the main files is static:
> 1) /etc/ngcp-config/config.yml
> 2) /etc/ngcp-config/network.yml
> 3) /etc/ngcp-config/constants.yml

if I need to edit network.yml I will type:
> ngcpc<TAB> e<TAB><ENTER>2<ENTER>

or even:
> ngcpc<TAB> e<TAB>2<ENTER>

Change-Id: Id20fec8c931c15c73a73689a3f8b552a72ef11f7

debian/ngcp-ngcpcfg.install

@@ -25,6 +25,7 @@ scripts/clean               usr/share/ngcp-ngcpcfg/scripts/
 scripts/commit              usr/share/ngcp-ngcpcfg/scripts/
 scripts/del                 usr/share/ngcp-ngcpcfg/scripts/
 scripts/diff                usr/share/ngcp-ngcpcfg/scripts/
+scripts/edit                usr/share/ngcp-ngcpcfg/scripts/
 scripts/etckeeper           usr/share/ngcp-ngcpcfg/scripts/
 scripts/get                 usr/share/ngcp-ngcpcfg/scripts/
 scripts/initialise          usr/share/ngcp-ngcpcfg/scripts/

debian/ngcpcfg.completion

@@ -70,6 +70,11 @@ _ngcpcfg()
             fi
             return
             ;;
+        edit)
+            cur=${cur:-/etc/ngcp-config/}
+            _filedir
+            return
+            ;;
         get)
             # XXX - would be nice to get completion based on content of /etc/ngcp-config/*.yml
             return

docs/ngcpcfg.txt

@@ -413,6 +413,11 @@ to specify revisions). If the tool doesn't report anything it means that there
 are neither any uncommitted changes nor any new or removed files (files which are
 not yet (un)registered to the repository).
 
+  **edit**::
+
+Helper to edit the ngcpcfg's YML configuration files in a faster way
+(it prevents unnecessary <TAB> pressing).
+
   **encrypt**::
 
 Encrypt /etc/ngcp-config and all resulting configuration files with a user

sbin/ngcpcfg

@@ -48,6 +48,7 @@ Actions:
   commit [<msg>]      commit and record changes (without pushing)
   del [<opts>]        delete YAML option from defined file
   diff [<opts>]       display pending configuration changes
+  edit                edit YAML configuration files
   get <key>           print key value from YAML configuration files
   help                display this help screen and exit
   initialise          initialise setup (to be executed only once on setup)
@@ -141,6 +142,7 @@ case ${1:-} in
   init-shared|\
   initialise|\
   get|\
+  edit|\
   show)
     main_action "$@"
     ;;

scripts/edit

@@ -0,0 +1,76 @@
+#!/bin/bash
+# Purpose: edit ngcp-config's configuration YML file
+################################################################################
+
+set -e
+set -u
+
+# support testsuite
+FUNCTIONS="${FUNCTIONS:-/usr/share/ngcp-ngcpcfg/functions/}"
+HELPER="${HELPER:-/usr/share/ngcp-ngcpcfg/helper/}"
+
+if ! [ -r "${FUNCTIONS}"/main ] ; then
+  printf "Error: %s/main could not be read. Exiting.\n" "${FUNCTIONS}" >&2
+  exit 1
+fi
+
+if [ -z "${EDITOR:-}" ] ; then
+  if [ -x "/usr/bin/vim" ]; then
+    EDITOR="/usr/bin/vim"
+  else
+    printf "Error: Missing \$EDITOR environmanent variable. Exiting.\n" >&2
+    exit 1
+  fi
+fi
+
+# shellcheck disable=SC1090
+. "${FUNCTIONS}"/main
+
+# main script
+RC=0
+file=""
+
+if [ "${#:-}" -ge 1 ] ; then
+  file=$1
+  case ${file,,} in
+    1|config|config.yml)
+      file="${NGCPCTL_MAIN}/config.yml"
+      ;;
+    2|network|network.yml)
+      file="${NGCPCTL_MAIN}/network.yml"
+      ;;
+    3|constants|constants.yml)
+      file="${NGCPCTL_MAIN}/constants.yml"
+      ;;
+    *)
+      echo "Error: Unknown choise '${file}'. Aborting." >&2
+      exit 1
+      ;;
+  esac
+else
+  # Get the list of configs in static order to be constant over the time
+  # and process the main YML configs first: config.yml network.yml constants.yml
+  # NOTE: the file are loaded/merged into ngcpcfg in different order!
+  declare -a CONFIGS
+  for f in ${NGCPCTL_CONFIG:?} ${NETWORK_CONFIG:?} ${CONSTANTS_CONFIG:?} ${HA_CONFIG:-} ${PAIR_CONFIG:-} ${HOST_CONFIG:-} ${LOCAL_CONFIG:-} "${EXTRA_CONFIG_FILES[@]}" ; do
+    if [ -r "$f" ] ; then
+      CONFIGS+=("${f}")
+    fi
+  done
+
+  select f in "${CONFIGS[@]}" ; do
+      if [[ -z "${f}" ]]; then
+        echo "Exit as requested."
+        exit 0
+      else
+        file=$f
+        break
+      fi
+  done
+fi
+
+"${EDITOR}" "${file}" || RC=$?
+
+exit "$RC"
+
+## END OF FILE #################################################################