Allow EKG_HOST to use IPv4 and Host/Domain names (#1834)

## Description
* Splits the **isValidIPv4** function so that it returns 1 on invalid
IPv4 addresses.
* Adds new **isValidHostnameOrDomain** function to provide the extra
check that **isValidIPv4** was performing to allow cntools.sh to
validate the `relays_ip_enter`.
* Updates the EKG_HOST IP check to work for IPv4 or valid hostname /
domainnames

## Motivation and context
1. Allowing EKG_HOST to be a non IPv4 address (for decoupled &
containerized/k8s environments).
2. Ensure that isValidIPv4 correctly invalidates IPv4 addresses.

## Which issue it fixes?
Closes #1832 
Closes #1833 

## How has this been tested?
* Building locally into a test container and verifying that cncli.sh
`[sync|leaderlog|validatre]` no longer errors on valid hostnames or IPv6
and can connect via EKG.
* Resolvable names like `EKG_HOST=cardano-node` pass. The cncli.sh sync,
leaderlog, & validate subcommands all work as expected.
* EKG_HOST does not permit IPv6 as enabling IPv6 on the node does not
appear to enable it for EKG_PORT.

scripts/cnode-helper-scripts/cntools.sh

@@ -2195,14 +2195,14 @@ function main {
                       ;;
                     1) getAnswerAnyCust relay_ip_enter "Enter relays's IPv4/v6 address"
                       if [[ -n "${relay_ip_enter}" ]]; then
-                        if ! isValidIPv4 "${relay_ip_enter}" && ! isValidIPv6 "${relay_ip_enter}"; then
-                          println ERROR "${FG_RED}ERROR${NC}: invalid IPv4/v6 address format!"
+                        if ! isValidIPv4 "${relay_ip_enter}" && ! isValidIPv6 "${relay_ip_enter}" && ! isValidHostnameOrDomain "${relay_ip_enter}"; then
+                            println ERROR "${FG_RED}ERROR${NC}: Invalid IPv4/v6 address format or hostname/domain name format!"
                         else
                           getAnswerAnyCust relay_port_enter "Enter relays's port"
                           if [[ -n "${relay_port_enter}" ]]; then
                             if ! isNumber ${relay_port_enter} || [[ ${relay_port_enter} -lt 1 || ${relay_port_enter} -gt 65535 ]]; then
                               println ERROR "${FG_RED}ERROR${NC}: invalid port number!"
-                            elif isValidIPv4 "${relay_ip_enter}"; then
+                            elif isValidIPv4 "${relay_ip_enter}" || isValidHostnameOrDomain "${relay_ip_enter}"; then
                               relay_array+=( "type" "IPv4" "address" "${relay_ip_enter}" "port" "${relay_port_enter}" )
                               relay_output+="--pool-relay-port ${relay_port_enter} --pool-relay-ipv4 ${relay_ip_enter} "
                             else

scripts/cnode-helper-scripts/env

@@ -488,7 +488,24 @@ fractionToPCT() {
 isValidIPv4() {
   local ip=$1
   [[ -z ${ip} ]] && return 1
-  if [[ ${ip} =~ ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$ || ${ip} =~ ^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9_\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9_\-]*[A-Za-z0-9])$ ]]; then
+  ipv4_regex="^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
+  if [[ ${ip} =~ ${ipv4_regex} ]]; then
+    return 0
+  fi
+  return 1
+}
+
+# Description : Helper function to validate hostname or domain name
+#             : $1 = hostname or domain name
+isValidHostnameOrDomain() {
+  local name=$1
+  [[ -z ${name} ]] && return 1
+
+  # Regular expression for valid hostnames and domain names
+  hostname_regex="^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9_\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9_\-]*[A-Za-z0-9])$"
+
+  # Check if the input matches the hostname/domain name format
+  if [[ ${name} =~ ${hostname_regex} ]]; then
     return 0
   fi
   return 1
@@ -1163,14 +1180,8 @@ fi
 
 [[ -z ${EKG_TIMEOUT} ]] && EKG_TIMEOUT=3
 [[ -z ${EKG_HOST} ]] && EKG_HOST=127.0.0.1
-if [[ ${EKG_HOST} =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
-  IFS='.' read -ra EKG_OCTETS <<< ${EKG_HOST}
-  if ! [[ ${EKG_OCTETS[0]} -le 255 && ${EKG_OCTETS[1]} -le 255 && ${EKG_OCTETS[2]} -le 255 && ${EKG_OCTETS[3]} -le 255 ]]; then
-    echo "Not a valid IP range set for EKG host, please check env file for value of EKG_HOST (currently it is ${EKG_HOST} )!"
-    return 1
-  fi
-else
-  echo "Not a valid IP format set for EKG host, please check env file!"
+if ! isValidIPv4 "${EKG_HOST}" && ! isValidHostnameOrDomain "${EKG_HOST}"; then
+  echo "Not a valid IP or hostname set for EKG host, please check the env file (currently it is ${EKG_HOST})!"
   return 1
 fi
 

scripts/cnode-helper-scripts/topologyUpdater.sh

@@ -155,8 +155,9 @@ if [[ ${TU_FETCH} = "Y" ]]; then
           *) echo "ERROR: Invalid Custom Peer definition '${cpeer}'. Please double check CUSTOM_PEERS definition"
              exit 1 ;;
         esac
-        if [[ ${addr} = *.* ]]; then
-          ! isValidIPv4 "${addr}" && echo "ERROR: Invalid IPv4 address or hostname '${addr}'. Please check CUSTOM_PEERS definition" && continue
+        if ! isValidIPv4 "${addr}" && ! isValidHostnameOrDomain "${addr}"; then
+          echo "ERROR: Invalid IPv4 address or hostname '${addr}'. Please check CUSTOM_PEERS definition"
+          continue
         elif [[ ${addr} = *:* ]]; then
           ! isValidIPv6 "${addr}" && echo "ERROR: Invalid IPv6 address '${addr}'. Please check CUSTOM_PEERS definition" && continue
         fi