From d9ea3f1b307dad08beeff73db7f505651d2f1577 Mon Sep 17 00:00:00 2001
From: Matthias Kruk <m@m10k.eu>
Date: Sun, 6 Jun 2021 11:03:56 +0900
Subject: [PATCH] include/inst: Implement instance status messages

In order to make the status of an instance visible to users and other
processes, functions are needed that can be used to set status messages
from within an instance.
This commit adds status messages for instances, which can be manipulated
through the following functions.

 - inst_set_status(): Set the status of the running instance
 - inst_get_status_message(): The the status message of an instance
 - inst_get_status_timestamp(): Get the timestamp of a status message
 - inst_get_status(): Get status message and timestamp of an instance
---
 include/inst.sh | 75 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 74 insertions(+), 1 deletion(-)

diff --git a/include/inst.sh b/include/inst.sh
index 8e900f5..1bd5842 100644
--- a/include/inst.sh
+++ b/include/inst.sh
@@ -64,6 +64,9 @@ inst_list() {
 		local semval
 		local state
 		local argv
+		local status_text
+		local status_time
+		local timestamp
 
 		owner="${sem##*/}"
 		semval=$(sem_peek "$sem")
@@ -72,13 +75,22 @@ inst_list() {
 			continue
 		fi
 
+		if ! status_text=$(inst_get_status_message "$owner") ||
+		   ! status_time=$(inst_get_status_timestamp "$owner"); then
+			continue
+		fi
+
+		if ! timestamp=$(date --date="@$status_time" +"%Y-%m-%d %H:%M:%S %z"); then
+			continue
+		fi
+
 		if (( semval > 0 )); then
 			state="STOPPING"
 		else
 			state="RUNNING"
 		fi
 
-		echo "$owner $state $__inst_name $argv"
+		echo "$owner $state [$timestamp:$status_text] $__inst_name $argv"
 	done < <(find "$__inst_path" -regex ".*/[0-9]+")
 
 	return 0
@@ -114,12 +126,17 @@ _inst_run() {
 	local ret
 
 	declare -xgr __inst_sem="$__inst_path/$BASHPID"
+	declare -xgr __inst_status="$__inst_path/$BASHPID.status"
 
 	if ! opt_get_argv > "$__inst_path/$BASHPID.argv"; then
 		log_error "Could not save args"
 		return 1
 	fi
 
+	if ! inst_set_status "unset"; then
+		return 1
+	fi
+
 	if ! sem_init "$__inst_sem" 0; then
 		log_error "Could not initialize semaphore $__inst_sem"
 		return 1
@@ -144,3 +161,59 @@ inst_start() {
 
 	return 0
 }
+
+inst_set_status() {
+	local status="$1"
+
+	local timestamp
+
+	if ! timestamp=$(date +"%s"); then
+		log_error "Couldn't make timestamp"
+		return 1
+	fi
+
+	if ! echo "$timestamp:$status" > "$__inst_status"; then
+		log_error "Could not write to $__inst_status"
+		return 1
+	fi
+
+	return 0
+}
+
+inst_get_status() {
+	local pid="$1"
+
+	local status
+
+	if ! status=$(< "$__inst_path/$pid.status"); then
+		log_error "Could not read from $__inst_path/$pid.status"
+		return 1
+	fi
+
+	echo "$status"
+	return 0
+}
+
+inst_get_status_message() {
+	local pid="$1"
+
+	if ! status=$(inst_get_status "$pid"); then
+		return 1
+	fi
+
+	echo "${status#*:}"
+	return 0
+}
+
+inst_get_status_timestamp() {
+	local pid="$1"
+
+	local status
+
+	if ! status=$(inst_get_status "$pid"); then
+		return 1
+	fi
+
+	echo "${status%%:*}"
+	return 0
+}
-- 
2.47.3