[202205] [generate_dump] Optimize the execution time of the 'show techsupport' script to 5-10% by reducing calls to the 'tar append' operation (#2562)

- What I did
Optimize the execution time of the 'show techsupport' script to 5-10%.

- How I did it
The show techsupport CLI command calls the generate_dump bash script. In the script, there are a many functions that do the next scenario:

1. Run some CLI command
2. Save output from step 1 to the temporary file
3. Append the temporary file from step 2 to the `/var/dump/sonic_dump_XXXX.tar` file
4. Delete the temporary file from step 2
This PR removes the 3 and 4 step from those functions and creates a new function save_to_tar() which will add to .tar archive the whole directory with temporary files (which means it will not spawn a tar -v -rhf ... process for each temporary file)

- How to verify it
Run the time show techsupport CLI command and compare the execution time to the original script, the execution time will be decreased by 5-10%.

Signed-off-by: Vadym Hlushko <[email protected]>

Author: vadymhlushko-mlnx

scripts/generate_dump

@@ -106,7 +106,6 @@ save_bcmcmd() {
     local filename=$2
     local filepath="${LOGDIR}/$filename"
     local do_gzip=${3:-false}
-    local tarpath="${BASE}/dump/$filename"
     local timeout_cmd="timeout --foreground ${TIMEOUT_MIN}m"
     local cmd=$(escape_quotes "$cmd")
     if [ ! -d $LOGDIR ]; then
@@ -141,12 +140,9 @@ save_bcmcmd() {
     fi
     if $do_gzip; then
         gzip ${filepath} 2>/dev/null
-        tarpath="${tarpath}.gz"
         filepath="${filepath}.gz"
     fi
-    ($TAR $V -rhf $TARFILE -C $DUMPDIR "$tarpath" \
-        || abort "${EXT_TAR_FAILED}" "tar append operation failed. Aborting to prevent data loss.") \
-        && $RM $V -rf "$filepath"
+
     end_t=$(date +%s%3N)
     echo "[ save_bcmcmd:$cmd ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
 }
@@ -180,7 +176,7 @@ save_bcmcmd_all_ns() {
 }
 
 ###############################################################################
-# Runs a comamnd and saves its output to the incrementally built tar.
+# Runs a comamnd and saves its output to the file.
 # Command gets timedout if it runs for more than TIMEOUT_MIN minutes.
 # Globals:
 #  LOGDIR
@@ -208,7 +204,6 @@ save_cmd() {
     local filename=$2
     local filepath="${LOGDIR}/$filename"
     local do_gzip=${3:-false}
-    local tarpath="${BASE}/dump/$filename"
     local timeout_cmd="timeout --foreground ${TIMEOUT_MIN}m"
     local cleanup_method=${4:-dummy_cleanup_method}
     local redirect='&>'
@@ -230,7 +225,6 @@ save_cmd() {
     # as one argument, e.g. vtysh -c "COMMAND HERE" needs to have
     # "COMMAND HERE" bunched together as 1 arg to vtysh -c
     if $do_gzip; then
-        tarpath="${tarpath}.gz"
         filepath="${filepath}.gz"
         # cleanup_method will run in a sub-shell, need declare it first
         local cmds="$cleanup_method_declration; $cmd $redirect_eval | $cleanup_method | gzip -c > '${filepath}'"
@@ -260,13 +254,35 @@ save_cmd() {
         fi
     fi
 
-    ($TAR $V -rhf $TARFILE -C $DUMPDIR "$tarpath" \
-        || abort "${EXT_TAR_FAILED}" "tar append operation failed. Aborting to prevent data loss.") \
-        && $RM $V -rf "$filepath"
     end_t=$(date +%s%3N)
     echo "[ save_cmd:$cmd ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
 }
 
+###############################################################################
+# Save all collected data to tar archive.
+# Globals:
+#  DUMPDIR
+#  TAR
+#  TARFILE
+#  V
+#  BASE
+# Arguments:
+#  None
+# Returns:
+#  None
+###############################################################################
+save_to_tar() {
+    trap 'handle_error $? $LINENO' ERR
+    local start_t=$(date +%s%3N)
+    local end_t=0
+
+    cd $DUMPDIR
+    $TAR $V -rhf $TARFILE "$BASE"
+
+    end_t=$(date +%s%3N)
+    echo "[ save_to_tar ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
+}
+
 ###############################################################################
 # Dummy cleanup method.
 # Globals:
@@ -407,7 +423,7 @@ get_vtysh_namespace() {
 ###############################################################################
 # Runs a vtysh command in all namesapces for a multi ASIC platform, and in
 # default (host) namespace in single ASIC platforms. Saves its output to the
-# incrementally built tar.
+# file.
 # Globals:
 #  None
 # Arguments:
@@ -437,7 +453,7 @@ save_vtysh() {
 }
 
 ###############################################################################
-# Runs an ip command and saves its output to the incrementally built tar.
+# Runs an ip command and saves its output to the file.
 # Globals:
 #  None
 # Arguments:
@@ -456,7 +472,7 @@ save_ip() {
 }
 
 ###############################################################################
-# Runs a bridge command and saves its output to the incrementally built tar.
+# Runs a bridge command and saves its output to the file.
 # Globals:
 #  None
 # Arguments:
@@ -769,8 +785,8 @@ save_proc() {
             ( [ -e $f ] && $CP $V -r $f $TARDIR/proc ) || echo "$f not found" > $TARDIR/$f
         fi
     done
-    $TAR $V -rhf $TARFILE -C $DUMPDIR --mode=+rw $BASE/proc
-    $RM $V -rf $TARDIR/proc
+
+    chmod ugo+rw -R $DUMPDIR/$BASE/proc
 }
 
 ###############################################################################
@@ -837,7 +853,7 @@ save_platform_info() {
 }
 
 ###############################################################################
-# Runs a comamnd and saves its output to the incrementally built tar.
+# Runs a comamnd and saves its output to the file.
 # Globals:
 #  LOGDIR
 #  BASE
@@ -862,16 +878,13 @@ save_file() {
     local orig_path=$1
     local supp_dir=$2
     local gz_path="$TARDIR/$supp_dir/$(basename $orig_path)"
-    local tar_path="${BASE}/$supp_dir/$(basename $orig_path)"
     local do_gzip=${3:-true}
-    local do_tar_append=${4:-true}
     if [ ! -d "$TARDIR/$supp_dir" ]; then
         $MKDIR $V -p "$TARDIR/$supp_dir"
     fi
 
     if $do_gzip; then
         gz_path="${gz_path}.gz"
-        tar_path="${tar_path}.gz"
         if $NOOP; then
             echo "gzip -c $orig_path > $gz_path"
         else
@@ -885,11 +898,6 @@ save_file() {
         fi
     fi
 
-    if $do_tar_append; then
-        ($TAR $V -rhf $TARFILE -C $DUMPDIR "$tar_path" \
-            || abort "${EXT_PROCFS_SAVE_FAILED}" "tar append operation failed. Aborting to prevent data loss.") \
-            && $RM $V -f "$gz_path"
-    fi
     end_t=$(date +%s%3N)
     echo "[ save_file:$orig_path] : $(($end_t-$start_t)) msec"  >> $TECHSUPPORT_TIME_INFO
 }
@@ -1269,16 +1277,12 @@ save_log_files() {
         # don't gzip already-gzipped log files :)
         # do not append the individual files to the main tarball
         if [ -z "${file##*.gz}" ]; then
-            save_file $file log false false
+            save_file $file log false
         else
-            save_file $file log true false
+            save_file $file log true
         fi
     done
 
-    # Append the log folder to the main tarball
-    ($TAR $V -rhf $TARFILE -C $DUMPDIR ${BASE}/log \
-        || abort "${EXT_TAR_FAILED}" "tar append operation failed. Aborting for safety") \
-        && $RM $V -rf $TARDIR/log
     end_t=$(date +%s%3N)
     echo "[ TAR /var/log Files ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
 
@@ -1303,11 +1307,7 @@ save_warmboot_files() {
     else
         mkdir -p $TARDIR
         $CP $V -rf /host/warmboot $TARDIR
-
-        ($TAR $V --warning=no-file-removed  -rhf $TARFILE -C $DUMPDIR --mode=+rw \
-            $BASE/warmboot \
-            || abort "${EXT_TAR_FAILED}" "Tar append operation failed. Aborting for safety.") \
-            && $RM $V -rf $TARDIR
+        chmod ugo+rw -R $DUMPDIR/$BASE/warmboot
     fi
     end_t=$(date +%s%3N)
     echo "[ Warm-boot Files ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
@@ -1469,8 +1469,7 @@ main() {
         /proc/pagetypeinfo /proc/partitions /proc/sched_debug /proc/slabinfo \
         /proc/softirqs /proc/stat /proc/swaps /proc/sysvipc /proc/timer_list \
         /proc/uptime /proc/version /proc/vmallocinfo /proc/vmstat \
-        /proc/zoneinfo \
-        || abort "${EXT_PROCFS_SAVE_FAILED}" "Proc saving operation failed. Aborting for safety."
+        /proc/zoneinfo
     end_t=$(date +%s%3N)
     echo "[ Capture Proc State ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
 
@@ -1574,9 +1573,6 @@ main() {
     # 2nd counter snapshot late. Need 2 snapshots to make sense of counters trend.
     save_counter_snapshot $asic 2
 
-    $RM $V -rf $TARDIR
-    $MKDIR $V -p $TARDIR
-    $MKDIR $V -p $LOGDIR
     # Copying the /etc files to a directory and then tar it
     $CP -r /etc $TARDIR/etc
     rm_list=$(find -L $TARDIR/etc -maxdepth 5 -type l)
@@ -1588,30 +1584,13 @@ main() {
     # Remove secret from /etc files before tar
     remove_secret_from_etc_files $TARDIR
 
-    start_t=$(date +%s%3N)
-    ($TAR $V --warning=no-file-removed -rhf $TARFILE -C $DUMPDIR --mode=+rw \
-        --exclude="etc/alternatives" \
-        --exclude="*/etc/passwd*" \
-        --exclude="*/etc/shadow*" \
-        --exclude="*/etc/group*" \
-        --exclude="*/etc/gshadow*" \
-        --exclude="*/etc/ssh*" \
-        --exclude="*get_creds*" \
-        --exclude="*snmpd.conf*" \
-        --exclude="*/etc/mlnx" \
-        --exclude="*/etc/mft" \
-        --exclude="*/etc/sonic/*.cer" \
-        --exclude="*/etc/sonic/*.crt" \
-        --exclude="*/etc/sonic/*.pem" \
-        --exclude="*/etc/sonic/*.key" \
-        --exclude="*/etc/ssl/*.pem" \
-        --exclude="*/etc/ssl/certs/*" \
-        --exclude="*/etc/ssl/private/*" \
-        $BASE/etc \
-        || abort "${EXT_TAR_FAILED}" "Tar append operation failed. Aborting for safety.") \
-        && $RM $V -rf $TARDIR
-    end_t=$(date +%s%3N)
-    echo "[ TAR /etc Files ] : $(($end_t-$start_t)) msec" >> $TECHSUPPORT_TIME_INFO
+    # Remove unecessary files
+    $RM $V -rf $TARDIR/etc/alternatives $TARDIR/etc/passwd* \
+    $TARDIR/etc/shadow* $TARDIR/etc/group* $TARDIR/etc/gshadow* \
+    $TARDIR/etc/ssh* $TARDIR/get_creds* $TARDIR/snmpd.conf* \
+    $TARDIR/etc/mlnx $TARDIR/etc/mft $TARDIR/etc/sonic/*.cer \
+    $TARDIR/etc/sonic/*.crt $TARDIR/etc/sonic/*.pem $TARDIR/etc/sonic/*.key \
+    $TARDIR/etc/ssl/*.pem $TARDIR/etc/ssl/certs/ $TARDIR/etc/ssl/private/*
 
     save_log_files
     save_crash_files
@@ -1631,6 +1610,8 @@ finalize() {
     # Save techsupport timing profile info
     save_file $TECHSUPPORT_TIME_INFO log false
 
+    save_to_tar
+
     if $DO_COMPRESS; then
         RC=0
         $GZIP $V $TARFILE || RC=$?