integrated lv_api_do into qq2clone for load_template

lv_api_do.c

@@ -27,7 +27,7 @@ const char CONN_BAD[]= "# No Connection";
 const char CONN_GOOD[]="# Connected";
 
 /*After a command is issued, one of these displays. Only GOOD is followed
-  by the requested information */
+  by the requested information, then EOF */
 const char BAD_REQ[]="# Bad Request";
 const char FATAL[]=  "# Fatal error";
 const char GOOD[]=   "# Making API Request";
@@ -47,6 +47,7 @@ const char NOMATCH[]="# No matching domain";
  */
 
 int main () {
+  setlinebuf(stdout); /* Make sure output is always line buffered */
   /* Connect to libvirt API */
   conn=virConnectOpen(NULL);
   int loop=1;
@@ -117,30 +118,30 @@ int main () {
                   ***********************************/
 
 void pr_bad() {
-  printf("+%s\n",BAD_REQ);
+  printf("%s\n",BAD_REQ);
 }
 
 void pr_conn_bad() {
-  printf("+%s\n", CONN_BAD);
+  printf("%s\n", CONN_BAD);
 }
 
 void pr_conn_good() {
-  printf("+%s\n",CONN_GOOD);
+  printf("%s\n",CONN_GOOD);
 }
 
 /* Okay, this one provides a basic output sequence *and* quits */
 void pr_fatal_and_exit(int e) {
-  printf("+%s\n",FATAL);
+  printf("%s\n",FATAL);
   virConnectClose;
   exit(e);
 }
 
 void pr_good() {
-  printf("+%s\n",GOOD);
+  printf("%s\n",GOOD);
 }
 
 void pr_no_match() {
-  printf("+%s\n",NOMATCH);
+  printf("%s\n",NOMATCH);
 }
 
                 /*****************************************
@@ -197,6 +198,7 @@ void lv_get_name (char *uuid){
     if (name!=NULL){ printf("+%s\n",name); }
       else { pr_fatal_and_exit(E_LIBVIRT); }
     virDomainFree(domain);
+    printf("EOF\n");
   }else{
     pr_no_match();
   }
@@ -216,6 +218,7 @@ void lv_get_state(char *uuid){
     virDomainFree(domain);
     free(state);
     free(reason);
+    printf("EOF\n");
   }else{
     pr_no_match();
   }
@@ -228,7 +231,6 @@ void lv_get_xml(char *uuid){
     char *xml;
     xml=virDomainGetXMLDesc(domain, 0);
     if ( xml!=NULL ){
-
       char *token;
       token=strtok(xml, "\n");
       if(token==NULL) { free(xml); virDomainFree(domain); return; }
@@ -238,10 +240,10 @@ void lv_get_xml(char *uuid){
         token=strtok(NULL, "\n");
       }
       free(xml);
-    }
+    } else { pr_fatal_and_exit(E_LIBVIRT); }
-    else { pr_fatal_and_exit(E_LIBVIRT); }
     virDomainFree(domain);
-  }else{
+    printf("EOF\n");
+  } else {
     pr_no_match();
   }
 }
@@ -250,7 +252,7 @@ void lv_list_all_uuid() {
   virDomainPtr *domains;
   int ret_list, ret_uuid, i;
   ret_list=virConnectListAllDomains(conn,&domains,0);
-  if(ret_list<0){ virConnectClose(conn); 
+  if(ret_list<0){ virConnectClose(conn);
       pr_fatal_and_exit(E_LIBVIRT); };
   pr_good();
 
@@ -259,12 +261,13 @@ void lv_list_all_uuid() {
     ret_uuid=virDomainGetUUIDString(domains[i],uuid);
     if (ret_uuid==0) {
       printf("+%s\n",uuid);
-      virDomainFree(domains[i]);
     }
+    virDomainFree(domains[i]);
   }
 
   free(uuid);
   free(domains);
+  printf("EOF\n");
 }
 
 void lv_list_all_name() {
@@ -283,4 +286,5 @@ void lv_list_all_name() {
   }
 
   free(domains);
+  printf("EOF\n");
 }

qq2clone

@@ -1,11 +1,11 @@
 #!/bin/bash
 #shellcheck disable=1090 disable=2012
 
-                            #-----------------#
+                        #--------------------#
-                            #@@@@@@@@@@@@@@@@@#
+                        #@@@@@@@@@@@@@@@@@@@@#
-                            #---ERROR CODES---#
+                        #---LITERAL VALUES---#
-                            #@@@@@@@@@@@@@@@@@#
+                        #@@@@@@@@@@@@@@@@@@@@#
-                            #-----------------#
+                        #--------------------#
 
 E_permission=10 # No permission for access or file does not exist
 E_depends=11    # Lacking required software
@@ -20,6 +20,16 @@ E_timeout=17    # Timeout was exceeded before spice connection to clone
 E_file=18       # Expected file does not exist or is of wrong type/format
 E_unexpected=19 # Probably a bug in qq2clone
 
+# lv_api_do prints one of these when started
+CONN_BAD="# No Connection"
+CONN_GOOD="# Connected"
+
+# lv_api_do prints one of these immediately following a line of input
+BAD_REQ="# Bad Request"
+FATAL="# Fatal error"
+GOOD="# Making API Request"
+NOMATCH="# No matching domain"
+
            #---------------------------------------------------#
            #@@@#@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#
            #---NAMED PIPE FOR PASSING DATA BETWEEN FUNCTIONS---#
@@ -55,8 +65,7 @@ TEMPDIR=$(mktemp -d) || temp_error
 #shellcheck disable=2064
 trap "exec 3>&-; exec 3<&-;rm -rf $TEMPDIR" EXIT
 fifo_path="${TEMPDIR}/qq2clone_fifo"
-mkfifo "$fifo_path" ||
+mkfifo "$fifo_path" || fifo_error
-  { echo "Cannot make fifo" >&2; exit "$E_extcom" ;}
 exec 3<>"$fifo_path"
 return 0
 }
@@ -75,7 +84,7 @@ read_pipe ()
 echo "EOF" >&3
 local line match
 while IFS= read -r line <&3; do
-  # write_pipe puts a + at the start of every line for read_pipe
+  # write_pipe puts a + at the start of every line
   if [[ "$line" =~ ^\+(.*)$ ]]; then
     match="${BASH_REMATCH[1]}"
     echo "$match"
@@ -114,6 +123,78 @@ fi
 return 0
 }
 
+                          #-------------------#
+                          #@@@@@@@@@@@@@@@@@@@#
+                          #---USE LV_API_DO---#
+                          #@@@@@@@@@@@@@@@@@@@#
+                          #-------------------#
+
+#=========================================================================#
+lv_api_do_open ()
+# DESCRIPTION: Open lv_api_do in background
+# INPUT: None
+# OUTPUT: Return 0 on success, exit on failure
+# PARAMETERS: None
+#=========================================================================#
+{
+declare -g lv_api_temp;
+lv_api_temp="$(mktemp -d )" || temp_error
+mkfifo "${lv_api_temp}/lv_api_do_fifo" || fifo_error
+exec 4<>"${lv_api_temp}/lv_api_do_fifo"
+${QQ2_DIR}/lv_api_do <&4 >&3 2>/dev/null &
+
+local check
+read -r check <&3
+[[ "$check" == "$CONN_BAD" ]] && lv_api_do_bad_conn
+[[ "$check" == "$CONN_GOOD" ]] || unexpected_error lv_api_do_open
+
+return 0
+}
+#=========================================================================#
+lv_api_do_comm ()
+# DESCRIPTION: Issue a command to lv_api_do
+# INPUT: The command
+# OUTPUT: Return 0 on success, lv_api_do output can be accessed with 
+#   read_pipe. Return 1 on failure. Exit and error message if lv_api_do
+#   encounters a fatal error
+# PARAMETERS: $@: command string to lv_api_do
+#=========================================================================#
+{
+echo "$*" >&4
+local check
+read -r check <&3
+[[ "$check" == "$BAD_REQ" ]] && unexpected_error lv_api_do_comm
+[[ "$check" == "$NOMATCH" ]] && return 1
+[[ "$check" == "$FATAL" ]] &&
+  { echo "Error using libvirt API" >&2; exit "$E_libvirt"; }
+[[ "$check" == "$GOOD" ]] || unexpected_error lv_api_do_comm
+
+# This loop avoids a race condition when trying to read_pipe later by
+# ensuring that lv_api_do has finished its output before this function
+# returns
+local line
+while read -r line <&3; do
+  [[ "$line" == "EOF" ]] && break
+  write_pipe 0 "${line:1}"
+done
+
+return 0
+}
+#=========================================================================#
+lv_api_do_close ()
+# DESCRIPTION: Tell lv_api_do to exit and close the extra pipe
+# INPUT: None
+# OUTPUT: None
+# PARAMETERS: None
+#=========================================================================#
+{
+  echo "exit" >&4
+  exec 4>&-
+  exec 4<&-
+  rm -rf "${lv_api_temp:?}"
+  return 0
+}
+
               #-------------------------------------------#
               #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@#
               #---GET/ALTER CONFIGURATION, CHECK SYSTEM---#
@@ -1147,6 +1228,28 @@ check="$(sqlite3 "select exists ( select * from TEMPLATES where\
 return 1
 }
 #=========================================================================#
+fifo_error ()
+# DESCRIPTION: Error to display if fifo creation files
+# INPUT: None
+# OUTPUT: Error message and exit code
+# PARAMETERS: None
+#=========================================================================#
+{
+  echo "Cannot make fifo"
+  exit "$E_extcom"
+} >&2
+#=========================================================================#
+lv_api_do_bad_conn ()
+# DESCRIPTION: Error displayed when lv_api_do cannot connect to API
+# INPUT: None
+# OUTPUT: Error message and exit code
+# PARAMETERS: None
+#=========================================================================#
+{
+  echo "Cannot connect to libvirt API"
+  exit "$E_libvirt"
+} 2>/dev/null
+#=========================================================================#
 set_error ()
 # DESCRIPTION: Used when convert_to_seq fails
 # INPUT: None
@@ -2098,12 +2201,6 @@ load_template ()
 # PARAMETERS: None
 #=========================================================================#
 {
-# This is a hacky way of getting the information we need in a reasonably 
-# performant manner. It is a bit fragile, but not overly so assuming that
-# virsh's output is fairly consistent across versions. This method is
-# temporary, as later on qq2clone will include portions in C that use the
-# libvirt API instead of virsh
-
 check_template
 unset BAD_CL CL_MAP CL_STATE NAME_MAP
 declare -ga BAD_CL CL_MAP CL_STATE NAME_MAP
@@ -2123,29 +2220,13 @@ while read -r id; do
   uuid_map["$uuid"]="$id"
 done < <(sqlite3 "select id,uuid from CLONES where template='$t';")
 
-# To use virsh in shell mode without having to repeatedly invoke it in
+lv_api_do_open
-# different subshells for a large performance penalty, we will run it in
-# the background and write to it with one fifo while reading it from 
-# another
-local temp
-temp="$(mktemp -d)" || temp_error
-mkfifo "$temp/fifo" &>/dev/null || unexpected_error load_template
-exec 4<>"$temp/fifo"
-virsh <&3 >&4 2>&4 &
-# virsh prepends 5 lines of useless output.
-local c; for ((c=5;c>0;c--)); do read -r <&4; done
 
-local prompt="virsh #" # In the virsh shell, input lines start with this
+lv_api_do_comm list
-
+while read -r uuid; do
-  echo "list --all --uuid" >&3
+  [[ -n "${uuid_map["$uuid"]}" ]] &&
-  echo "echo EOF" >&3
+    CL_MAP["${uuid_map["$uuid"]}"]="$uuid"
-  while read -r uuid <&4; do
+done < <(read_pipe);
-    { [[ "$uuid" =~ ^$prompt ]] || [[ -z "$uuid" ]] ; } && continue
-    [[ "$uuid" == "EOF" ]] && break
-
-    [[ -n "${uuid_map["$uuid"]}" ]] && 
-      CL_MAP["${uuid_map["$uuid"]}"]="$uuid"
-  done
 
 local match _uuid
 for uuid in "${!uuid_map[@]}"; do
@@ -2157,43 +2238,15 @@ for uuid in "${!uuid_map[@]}"; do
   BAD_CL["${uuid_map["$uuid"]}"]="$uuid"
 done
 
-local line
+local state="" name=""
 for id in "${!CL_MAP[@]}"; do
-  uuid="${CL_MAP["$id"]}"
+    lv_api_do_comm get_state "$uuid" && state="$(read_pipe)"
-  echo "domstate $uuid" >&3
+    CL_STATE["$id"]="$state"
-  echo "echo EOF" >&3
+    lv_api_do_comm get_name "$uuid" && name="$(read_pipe)"
-  while read -r line <&4; do
+    NAME_MAP["$id"]="$name"
-  { [[ "$line" =~ ^$prompt ]] || [[ -z "$line" ]] ; } && continue
-  [[ "$line" == "EOF" ]] && break
-    [[ "$line" == "in shutdown" ]] && line="in-shutdown"
-    [[ "$line" == "shut off" ]] && line="off"
-    CL_STATE["$id"]="$line"
-  done
-
-  echo "domname $uuid" >&3
-  echo "echo EOF" >&3
-  while read -r line <&4; do
-  { [[ "$line" =~ ^$prompt ]] || [[ -z "$line" ]] ; } && continue
-  [[ "$line" == "EOF" ]] && break
-    NAME_MAP["$id"]="$line"
-  done
 done
 
-echo "list --all --uuid --with-managed-save" >&3
+lv_api_do_close
-echo "echo EOF" >&3
-
-while read -r uuid <&4; do
-  { [[ "$uuid" =~ ^$prompt ]] || [[ -z "$uuid" ]] ; } && continue
-  [[ "$uuid" == "EOF" ]] && break
-  id="${uuid_map["$uuid"]}"
-  [[ -z "$id" ]] && continue;  [[ -z "${CL_MAP["$id"]}" ]] && continue;
-  CL_STATE["$id"]="saved"
-done
-
-echo "quit" >&3
-exec 4>&-
-exec 4<&-
-rm -rf "$temp" &>/dev/null
 
 return 0
 }