watchbot: Implement multiple-instance support

Watchbot currently allows only one instance to run at a time. However,
it might be desirable to have multiple watchbots running simultaneously,
watching one or more repositories at a time.
This commit implements support for multiple instances using the new inst
module.

diff --git a/watchbot.sh b/watchbot.sh
index 6535dae0a85dbcb216abfdc637cd1c248d8ab7b0..649d45f27a25d6532a9cdcd9ba463586eb5a5772 100755 (executable)
--- a/watchbot.sh
+++ b/watchbot.sh
@@ -1,7 +1,5 @@
 #!/bin/bash
 
-sem="watchbot"
-
 watch_repos() {
        local queue="$1"
        local watches=("${@:2}")
@@ -13,17 +11,12 @@ watch_repos() {
        heads=()
        nwatches="${#watches[@]}"
 
-       if ! sem_init "$sem" 0; then
-               log_info "Another instance is already running"
-               return 1
-       fi
-
        for (( i = 0; i < nwatches; i++ )); do
                heads["$i"]=$(<"${watches[$i]}")
        done
 
-       while ! sem_trywait "$sem"; do
-               log_debug "Watching $nwatches files: ${watches[@]}"
+       while inst_running; do
+               log_debug "Watching $nwatches files: ${watches[*]}"
                if ! inotifywait -qq -t 15 "${watches[@]}"; then
                        continue
                fi
@@ -31,7 +24,10 @@ watch_repos() {
                for (( i = 0; i < nwatches; i++ )); do
                        local cur_head
 
-                       cur_head=$(<"${watches[$i]}")
+                       if ! cur_head=$(<"${watches[$i]}"); then
+                               log_error "Could not read ${watches[$i]}"
+                               continue
+                       fi
 
                        log_debug "${watches[$i]}: ${heads[$i]} -> $cur_head"
 
@@ -46,19 +42,6 @@ watch_repos() {
                done
        done
 
-       if ! sem_destroy "$sem"; then
-               log_error "Could not clean up semaphore $sem"
-       fi
-
-       return 0
-}
-
-stop() {
-       if ! sem_post "$sem"; then
-               log_info "Looks like no instances are running"
-               return 1
-       fi
-
        return 0
 }
 
@@ -66,7 +49,9 @@ watchlist_add() {
        local opt="$1"
        local repo="$2"
 
+       log_debug "$opt: $repo"
        watchlist+=("$repo")
+
        return 0
 }
 
@@ -109,20 +94,11 @@ main() {
 
        opt_add_arg "r" "repo"    "yes" "" "Repository to watch (format: /repo/path[#branch])" watchlist_add
        opt_add_arg "q" "queue"   "yes" "" "Queue used to distribute work"
-       opt_add_arg "s" "stop"    "no"  0  "Stop a running instance"
 
        if ! opt_parse "$@"; then
                return 1
        fi
 
-       if (( $(opt_get "stop") > 0 )); then
-               if ! stop; then
-                       return 1
-               fi
-
-               return 0
-       fi
-
        queue=$(opt_get "queue")
 
        if [ -z "$queue" ]; then
@@ -148,8 +124,7 @@ main() {
                return 1
        fi
 
-       start "$queue" "${watches[@]}" </dev/null &>/dev/null &
-       disown
+       inst_start watch_repos "$queue" "${watches[@]}"
 
        return 0
 }
@@ -159,7 +134,7 @@ main() {
                exit 1
        fi
 
-       if ! include "log" "opt" "sem" "queue"; then
+       if ! include "log" "opt" "queue" "inst"; then
                exit 1
        fi