[Bug]: Alert configuration host labels simple pattern negative matches don't work.

[boasmeier]

Bug description

I want to enable the ram_in_use alarm for all hosts except for hosts containing data in their hostnames. Until v1.44.3 I was using the following alarm config and the ram_in_use alarm was applied to all nodes except the ones containing the substring data in their hostname as expected.

    alarm: ram_in_use
       on: system.ram
    class: Utilization
     type: System
component: Memory
       os: linux
    hosts: !*data* *
     calc: $used * 100 / ($used + $cached + $free + $buffers)
    units: %
    every: 10s
     warn: $this > (($status >= $WARNING)  ? (80) : (90))
     crit: $this > (($status == $CRITICAL) ? (90) : (98))
    delay: down 15m multiplier 1.5 max 1h
  summary: System memory utilization
     info: System memory utilization
       to: sysadmin

For v1.45.1 I switched to the new syntax and my alarm config now looks like the following:

      alarm: ram_in_use
         on: system.ram
      class: Utilization
       type: System
  component: Memory
host labels: _os=linux _hostname=!*data* *
       calc: $used * 100 / ($used + $cached + $free + $buffers)
      units: %
      every: 10s
       warn: $this > (($status >= $WARNING)  ? (80) : (90))
       crit: $this > (($status == $CRITICAL) ? (90) : (98))
      delay: down 15m multiplier 1.5 max 1h
    summary: System memory utilization
       info: System memory utilization
         to: sysadmin

and now the ram_in_use alarm is applied to all nodes including the ones that contain the substring data in their hostnames.

Expected behavior

I expect the simple pattern used in the host labels config property to behave as described in https://learn.netdata.cloud/docs/developer-and-contributor-corner/libnetdata/simple-patterns.

Steps to reproduce

1. Edit an existing alert and add host labels: _hostname=!*xxxx* *.
2. Reload health configuration of the netdata agent.

Installation method

kickstart.sh

System info

Linux mon 6.5.0-17-generic #17~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Tue Jan 16 14:32:32 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
/etc/lsb-release:DISTRIB_ID=Ubuntu
/etc/lsb-release:DISTRIB_RELEASE=22.04
/etc/lsb-release:DISTRIB_CODENAME=jammy
/etc/lsb-release:DISTRIB_DESCRIPTION="Ubuntu 22.04.3 LTS"
/etc/os-release:PRETTY_NAME="Ubuntu 22.04.3 LTS"
/etc/os-release:NAME="Ubuntu"
/etc/os-release:VERSION_ID="22.04"
/etc/os-release:VERSION="22.04.3 LTS (Jammy Jellyfish)"
/etc/os-release:VERSION_CODENAME=jammy
/etc/os-release:ID=ubuntu
/etc/os-release:ID_LIKE=debian
/etc/os-release:UBUNTU_CODENAME=jammy

Netdata build info

Packaging:
    Netdata Version ____________________________________________ : v1.45.1
    Installation Type __________________________________________ : binpkg-deb
    Package Architecture _______________________________________ : x86_64
    Package Distro _____________________________________________ :  
    Configure Options __________________________________________ : dummy-configure-command
Default Directories:
    User Configurations ________________________________________ : /etc/netdata
    Stock Configurations _______________________________________ : /usr/lib/netdata/conf.d
    Ephemeral Databases (metrics data, metadata) _______________ : /var/cache/netdata
    Permanent Databases ________________________________________ : /var/lib/netdata
    Plugins ____________________________________________________ : /usr/libexec/netdata/plugins.d
    Static Web Files ___________________________________________ : /var/lib/netdata/www
    Log Files __________________________________________________ : /var/log/netdata
    Lock Files _________________________________________________ : /var/lib/netdata/lock
    Home _______________________________________________________ : /var/lib/netdata
Operating System:
    Kernel _____________________________________________________ : Linux
    Kernel Version _____________________________________________ : 6.5.0-17-generic
    Operating System ___________________________________________ : Ubuntu
    Operating System ID ________________________________________ : ubuntu
    Operating System ID Like ___________________________________ : debian
    Operating System Version ___________________________________ : 22.04.3 LTS (Jammy Jellyfish)
    Operating System Version ID ________________________________ : none
    Detection __________________________________________________ : /etc/os-release
Hardware:
    CPU Cores __________________________________________________ : 8
    CPU Frequency ______________________________________________ : 2294000000
    RAM Bytes __________________________________________________ : 32853594112
    Disk Capacity ______________________________________________ : 245761048576
    CPU Architecture ___________________________________________ : x86_64
    Virtualization Technology __________________________________ : kvm
    Virtualization Detection ___________________________________ : systemd-detect-virt
Container:
    Container __________________________________________________ : none
    Container Detection ________________________________________ : systemd-detect-virt
    Container Orchestrator _____________________________________ : none
    Container Operating System _________________________________ : none
    Container Operating System ID ______________________________ : none
    Container Operating System ID Like _________________________ : none
    Container Operating System Version _________________________ : none
    Container Operating System Version ID ______________________ : none
    Container Operating System Detection _______________________ : none
Features:
    Built For __________________________________________________ : Linux
    Netdata Cloud ______________________________________________ : YES
    Health (trigger alerts and send notifications) _____________ : YES
    Streaming (stream metrics to parent Netdata servers) _______ : YES
    Back-filling (of higher database tiers) ____________________ : YES
    Replication (fill the gaps of parent Netdata servers) ______ : YES
    Streaming and Replication Compression ______________________ : YES (zstd lz4 gzip)
    Contexts (index all active and archived metrics) ___________ : YES
    Tiering (multiple dbs with different metrics resolution) ___ : YES (5)
    Machine Learning ___________________________________________ : YES
Database Engines:
    dbengine ___________________________________________________ : YES
    alloc ______________________________________________________ : YES
    ram ________________________________________________________ : YES
    none _______________________________________________________ : YES
Connectivity Capabilities:
    ACLK (Agent-Cloud Link: MQTT over WebSockets over TLS) _____ : YES
    static (Netdata internal web server) _______________________ : YES
    h2o (web server) ___________________________________________ : YES
    WebRTC (experimental) ______________________________________ : NO
    Native HTTPS (TLS Support) _________________________________ : YES
    TLS Host Verification ______________________________________ : YES
Libraries:
    LZ4 (extremely fast lossless compression algorithm) ________ : YES
    ZSTD (fast, lossless compression algorithm) ________________ : YES
    zlib (lossless data-compression library) ___________________ : YES
    Brotli (generic-purpose lossless compression algorithm) ____ : NO
    protobuf (platform-neutral data serialization protocol) ____ : YES (system)
    OpenSSL (cryptography) _____________________________________ : YES
    libdatachannel (stand-alone WebRTC data channels) __________ : NO
    JSON-C (lightweight JSON manipulation) _____________________ : YES
    libcap (Linux capabilities system operations) ______________ : NO
    libcrypto (cryptographic functions) ________________________ : YES
    libyaml (library for parsing and emitting YAML) ____________ : YES
Plugins:
    apps (monitor processes) ___________________________________ : YES
    cgroups (monitor containers and VMs) _______________________ : YES
    cgroup-network (associate interfaces to CGROUPS) ___________ : YES
    proc (monitor Linux systems) _______________________________ : YES
    tc (monitor Linux network QoS) _____________________________ : YES
    diskspace (monitor Linux mount points) _____________________ : YES
    freebsd (monitor FreeBSD systems) __________________________ : NO
    macos (monitor MacOS systems) ______________________________ : NO
    statsd (collect custom application metrics) ________________ : YES
    timex (check system clock synchronization) _________________ : YES
    idlejitter (check system latency and jitter) _______________ : YES
    bash (support shell data collection jobs - charts.d) _______ : YES
    debugfs (kernel debugging metrics) _________________________ : YES
    cups (monitor printers and print jobs) _____________________ : YES
    ebpf (monitor system calls) ________________________________ : YES
    freeipmi (monitor enterprise server H/W) ___________________ : YES
    nfacct (gather netfilter accounting) _______________________ : YES
    perf (collect kernel performance events) ___________________ : YES
    slabinfo (monitor kernel object caching) ___________________ : YES
    Xen ________________________________________________________ : YES
    Xen VBD Error Tracking _____________________________________ : NO
    Logs Management ____________________________________________ : YES
Exporters:
    AWS Kinesis ________________________________________________ : NO
    GCP PubSub _________________________________________________ : NO
    MongoDB ____________________________________________________ : YES
    Prometheus (OpenMetrics) Exporter __________________________ : YES
    Prometheus Remote Write ____________________________________ : YES
    Graphite ___________________________________________________ : YES
    Graphite HTTP / HTTPS ______________________________________ : YES
    JSON _______________________________________________________ : YES
    JSON HTTP / HTTPS __________________________________________ : YES
    OpenTSDB ___________________________________________________ : YES
    OpenTSDB HTTP / HTTPS ______________________________________ : YES
    All Metrics API ____________________________________________ : YES
    Shell (use metrics in shell scripts) _______________________ : YES
Debug/Developer Features:
    Trace All Netdata Allocations (with charts) ________________ : NO
    Developer Mode (more runtime checks, slower) _______________ : NO

Additional info

No response