ds-identify: only run once per boot unless --force is given.

This makes ds-identify run only once.  Previously it would run multiple
times each boot as the generator would run more than once.  This is
potentially dangerous, in that running again might find more attached
disks.  However that is really only a "lucky" fix if it happens to
result differently than the first run.

Additionally, we now log the uptime that we started and ended at.

1 files changed, 42 insertions, 3 deletions

diff --git a/tools/ds-identify b/tools/ds-identify
index 3ba36f8f..7bb63862 100755
--- a/tools/ds-identify
+++ b/tools/ds-identify
@@ -63,9 +63,11 @@ PATH_DI_CONFIG="${PATH_DI_CONFIG:-${PATH_ROOT}/etc/cloud/ds-identify.cfg}"
 PATH_PROC_CMDLINE="${PATH_PROC_CMDLINE:-${PATH_ROOT}/proc/cmdline}"
 PATH_PROC_1_CMDLINE="${PATH_PROC_1_CMDLINE:-${PATH_ROOT}/proc/1/cmdline}"
 PATH_PROC_1_ENVIRON="${PATH_PROC_1_ENVIRON:-${PATH_ROOT}/proc/1/environ}"
+PATH_PROC_UPTIME=${PATH_PROC_UPTIME:-${PATH_ROOT}/proc/uptime}
 PATH_CLOUD_CONFD="${PATH_CLOUD_CONFD:-${PATH_ROOT}/etc/cloud}"
 PATH_RUN_CI="${PATH_RUN_CI:-${PATH_RUN}/cloud-init}"
 PATH_RUN_CI_CFG=${PATH_RUN_CI_CFG:-${PATH_RUN_CI}/cloud.cfg}
+PATH_RUN_DI_RESULT=${PATH_RUN_DI_RESULT:-${PATH_RUN_CI}/.ds-identify.result}
 
 DI_LOG="${DI_LOG:-${PATH_RUN_CI}/ds-identify.log}"
 _DI_LOGGED=""
@@ -750,6 +752,8 @@ _print_info() {
 write_result() {
     local runcfg="${PATH_RUN_CI_CFG}" ret="" line=""
     if [ "$DI_REPORT" = "true" ]; then
+        # if report is true, then we write to .report, but touch the other.
+        : > "$runcfg"
         runcfg="$runcfg.report"
     fi
     for line in "$@"; do
@@ -924,12 +928,24 @@ manual_clean_and_existing() {
     [ -f "${PATH_VAR_LIB_CLOUD}/instance/manual-clean" ]
 }
 
-main() {
+read_uptime() {
+    local up idle
+    _RET="${UNAVAILABLE}"
+    [ -f "$PATH_PROC_UPTIME" ] &&
+        read up idle < "$PATH_PROC_UPTIME" && _RET="$up"
+    return
+}
+
+_main() {
     local dscheck="" ret_dis=1 ret_en=0
+
+    read_uptime
+    debug 1 "[up ${_RET}s]" "ds-identify $*"
     collect_info
 
-    if [ ! -e "$PATH_RUN_CI_CFG" ]; then
-        # the first time the generator is run.
+    if [ "$DI_LOG" = "stderr" ]; then
+        _print_info 1>&2
+    else
         _print_info >> "$DI_LOG"
     fi
 
@@ -1022,6 +1038,29 @@ main() {
     return 3
 }
 
+main() {
+    local ret=""
+    [ -d "$PATH_RUN_CI" ] || mkdir -p "$PATH_RUN_CI"
+    if [ "${1:+$1}" != "--force" ] && [ -f "$PATH_RUN_CI_CFG" ] &&
+        [ -f "$PATH_RUN_DI_RESULT" ]; then
+        if read ret < "$PATH_RUN_DI_RESULT"; then
+            if [ "$ret" = "0" ] || [ "$ret" = "1" ]; then
+                debug 2 "used cached result $ret. pass --force to re-run."
+                return $ret;
+            fi
+            debug 1 "previous run returned unexpected '$ret'. Re-running."
+        else
+            error "failed to read result from $PATH_RUN_DI_RESULT!"
+        fi
+    fi
+    _main "$@"
+    ret=$?
+    echo "$ret" > "$PATH_RUN_DI_RESULT"
+    read_uptime
+    debug 1 "[up ${_RET}s]" "returning $ret"
+    return $ret
+}
+
 noop() {
     :
 }