[#3666] kea-admin lease-upload: write SQL statements to file

Avoids "Argument list too long".

Also considerably speeds up the lease upload. The slowdown was
noticeable for large number of leases, where for each lease, the whole
set of statements added up to that point had to be printed in order to
append another SQL statement. This is no longer the case since the SQL
statement is appended to a file.

src/bin/admin/kea-admin.in

@@ -709,10 +709,22 @@ lease_upload() {
         exit 1
     fi
 
-    # Invoke LFC on the input file.
-    log_info "Looking at ${input_file_line_length} lines of CSV in ${input_file}..."
+    if test "${backend}" = 'mysql'; then
+        function_call="CALL lease${dhcp_version}"
+    elif test "${backend}" = 'pgsql'; then
+        function_call="SELECT lease${dhcp_version}"
+    else
+        log_error "lease-upload not implemented for ${backend}"
+        exit 1
+    fi
+
     cleaned_up_csv="/tmp/$(basename "${input_file}").tmp"
     check_file_overwrite "${cleaned_up_csv}"
+    sql_statement_file="/tmp/$(basename "${input_file}").sql.tmp"
+    check_file_overwrite "${sql_statement_file}"
+
+    # Invoke LFC on the input file.
+    log_info "Looking at ${input_file_line_length} lines of CSV in ${input_file}..."
     cp "${input_file}" "${cleaned_up_csv}"
     "${KEA_LFC}" "-${dhcp_version}" -x "${cleaned_up_csv}" \
         -i "${cleaned_up_csv}.1" -o "${cleaned_up_csv}.output" \
@@ -738,37 +750,31 @@ lease_upload() {
 
     # Construct the SQL insert statements.
     header_parsed=false
-    sql_statement='START TRANSACTION;'
+    echo 'START TRANSACTION;' > "${sql_statement_file}"
     while read -r line; do
-        if "${header_parsed}"; then
-            line=$(stringify_positions_in_line "${string_positions}" "${line}")
-            if test "${backend}" = 'mysql'; then
-                sql_statement="${sql_statement} CALL lease${dhcp_version}Upload(${line}); "
-            elif test "${backend}" = 'pgsql'; then
-                sql_statement="${sql_statement} SELECT lease${dhcp_version}Upload(${line}); "
-            else
-                log_error "lease-upload not implemented for ${backend}"
-                exit 1
-            fi
-        else
+        if ! "${header_parsed}"; then
             header_parsed=true
+            continue
         fi
+        line=$(stringify_positions_in_line "${string_positions}" "${line}")
+        echo "${function_call}Upload(${line});" >> "${sql_statement_file}"
     done < "${cleaned_up_csv}"
-    sql_statement="${sql_statement} COMMIT;"
+    echo 'COMMIT;' >> "${sql_statement_file}"
 
     # Execute the SQL insert statements.
     if test "${backend}" = 'mysql'; then
-        output="$(mysql_execute "${sql_statement}")"
+        output="$(mysql_execute_script "${sql_statement_file}")"
     elif test "${backend}" = 'pgsql'; then
-        output="$(pgsql_execute "${sql_statement}")"
+        output="$(pgsql_execute_script "${sql_statement_file}")"
     else
         log_error "lease-upload not implemented for ${backend}"
         exit 1
     fi
 
     # Clean up the temporary CSV.
     rm -f "${cleaned_up_csv}"
-    log_info "Removed temporary file ${cleaned_up_csv}."
+    rm -f "${sql_statement_file}"
+    log_info "Removed temporary files: ${cleaned_up_csv}, ${sql_statement_file}."
 
     # Print a confirmation message.
     log_info "Successfully updated table lease${dhcp_version}."