Add check that only deploys if there is a new database

nixproc/derive-dysnomia-process-type.nix

@@ -9,4 +9,5 @@ else if processManager == "cygrunsrv" then "cygrunsrv-service"
 else if processManager == "launchd" then "launchd-daemon"
 else if processManager == "disnix" then "process"
 else if processManager == "docker" then "docker-container"
+else if processManager == "s6-rc" then "s6-rc-service"
 else throw "Unknown process manager: ${processManager}"

tools/s6-rc/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation {
 
     sed -e "s|/bin/bash|$SHELL|" \
       -e "s|@getopt@|${getopt}/bin/getopt|" \
-      -e "s|@readlink@|$(type -p readlink)|" \
+      -e "s|@readlink@|$(type -p readlink)|g" \
       -e "s|@commonchecks@|${../commonchecks}|" \
       -e "s|@s6rcchecks@|${./s6-rc-checks}|" \
       ${./nixproc-s6-rc-deploy.in} > $out/bin/nixproc-s6-rc-deploy

tools/s6-rc/nixproc-s6-rc-deploy.in

@@ -127,8 +127,12 @@ fi
 
 if [ -d "$liveDir" ]
 then
-    s6-rc-update -l $liveDir $compileDir/$compiledDatabaseName
-    rm -rf $(@readlink@ -f $compileDir/compiled)
+    # Only update when the database to be deployed is different
+    if [ ! -e "$compileDir/compiled" ] || [ "$(@readlink@ -f $compileDir/$compiledDatabaseName)" != "$(@readlink@ -f $compileDir/compiled)" ]
+    then
+        s6-rc-update -l $liveDir $compileDir/$compiledDatabaseName
+        rm -rf $(@readlink@ -f $compileDir/compiled)
+    fi
 else
     s6-rc-init -c $compileDir/$compiledDatabaseName -l $liveDir $scanDir
 fi