This is a tool meant to make the life of a support engineer easier when working with docker containers.
We often face issues where we would have loved to know more details about the environment a container is running in. This tool is meant to print as much information as possible to stdout (later possibly also to a log file) to aid in debugging:
It currently prints:
- CPU core count
- Memory (free, total, available)
- CGroup Limits
- Swap information
- Host name
- Kernel information
- CPU architecture
- Mount points and available space on those
- List of all network interfaces with names and IP addresses
- Reverse Lookup for those IP addresses (IP Address => List of hostnames)
- Forward lookup for those hostnames (Hostname => List of IP addresses)
Here is an example of what it looks like on my virtual machine:
2025-02-03T11:37:47.420479Z INFO containerdebug: stackable_operator::utils::logging: Starting
2025-02-03T11:37:47.420521Z INFO containerdebug: stackable_operator::utils::logging: This is version 0.1.1 (Git information: 0.1.1-1-gcf51ae1), built for x86_64-unknown-linux-gnu by rustc 1.84.1 (e71f9a9a9 2025-01-27) at Tue, 1 Jan 1980 00:00:00 +0000
2025-02-03T11:37:47.420544Z INFO containerdebug:SystemInformation::init: containerdebug::system_information: initializing
2025-02-03T11:37:47.426065Z INFO containerdebug:SystemInformation::init: containerdebug::system_information: init finished
2025-02-03T11:37:47.426135Z INFO containerdebug:SystemInformation::collect: containerdebug::system_information: Starting data collection
2025-02-03T11:37:47.426693Z INFO containerdebug:SystemInformation::collect:Resources::collect: containerdebug::system_information::resources: cpus cpus.physical=8 cpus.cores.physical=8
2025-02-03T11:37:47.426727Z INFO containerdebug:SystemInformation::collect:Resources::collect: containerdebug::system_information::resources: memory memory.total=24604889088 memory.free=17235124224 memory.available=22974955520 memory.used=1629933568
2025-02-03T11:37:47.426746Z INFO containerdebug:SystemInformation::collect:Resources::collect: containerdebug::system_information::resources: swap swap.total=0 swap.free=0 swap.used=0
2025-02-03T11:37:47.426857Z INFO containerdebug:SystemInformation::collect:Resources::collect: containerdebug::system_information::resources: not in a cgroup
2025-02-03T11:37:47.426940Z INFO containerdebug:SystemInformation::collect:OperatingSystem::collect: containerdebug::system_information::os: operating system os.name="NixOS" os.kernel.version="6.6.46" os.version="Linux 24.11 NixOS" os.host_name="nixos2" os.cpu_arch="x86_64"
2025-02-03T11:37:47.427031Z INFO containerdebug:SystemInformation::collect:User::collect_current: containerdebug::system_information::user: current user user.name="nat" user.uid="Uid(1000)" user.gid="Uid(1000)"
2025-02-03T11:37:47.427436Z INFO containerdebug:SystemInformation::collect:Disk::collect_all: containerdebug::system_information::disk: found disk disk.mount_point="/" disk.name="/dev/sda2" disk.space.total=106298343424 disk.space.available=72663478272
2025-02-03T11:37:47.427483Z INFO containerdebug:SystemInformation::collect:Disk::collect_all: containerdebug::system_information::disk: found disk disk.mount_point="/nix/store" disk.name="/dev/sda2" disk.space.total=106298343424 disk.space.available=72663478272
2025-02-03T11:37:47.427499Z INFO containerdebug:SystemInformation::collect:Disk::collect_all: containerdebug::system_information::disk: found disk disk.mount_point="/boot" disk.name="/dev/sda1" disk.space.total=1071624192 disk.space.available=1022820352
2025-02-03T11:37:47.428771Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="lo" network.interface.address=127.0.0.1
2025-02-03T11:37:47.428821Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="enp1s0" network.interface.address=192.168.122.138
2025-02-03T11:37:47.428836Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="br-82bbc663b8a3" network.interface.address=172.18.0.1
2025-02-03T11:37:47.428847Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="docker0" network.interface.address=172.17.0.1
2025-02-03T11:37:47.428861Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="lo" network.interface.address=::1
2025-02-03T11:37:47.428874Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="enp1s0" network.interface.address=fe80::5054:ff:fe91:5652
2025-02-03T11:37:47.428885Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: found network interface network.interface.name="br-82bbc663b8a3" network.interface.address=fc00:f853:ccd:e793::1
2025-02-03T11:37:47.428910Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: ip addresses network.addresses.ip={127.0.0.1, 172.17.0.1, 172.18.0.1, 192.168.122.138, ::1, fc00:f853:ccd:e793::1, fe80::5054:ff:fe91:5652}
2025-02-03T11:37:47.429002Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=127.0.0.1 hostnames=["localhost."]
2025-02-03T11:37:47.437343Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=172.17.0.1 hostnames=["nixos2.", "nixos2.local."]
2025-02-03T11:37:47.439911Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=172.18.0.1 hostnames=["nixos2.", "nixos2.local."]
2025-02-03T11:37:47.440526Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=192.168.122.138 hostnames=["nixos2.kvm."]
2025-02-03T11:37:47.440678Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=::1 hostnames=["localhost."]
2025-02-03T11:37:47.441339Z WARN containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: reverse DNS lookup failed ip=fc00:f853:ccd:e793::1 error=no record found for Query { name: Name("1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.3.9.7.e.d.c.c.0.3.5.8.f.0.0.c.f.ip6.arpa."), query_type: PTR, query_class: IN }
2025-02-03T11:37:47.442068Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed reverse DNS lookup for IP ip=fe80::5054:ff:fe91:5652 hostnames=["nixos2."]
2025-02-03T11:37:47.442149Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: hostnames network.addresses.hostname={"localhost.", "nixos2.", "nixos2.kvm.", "nixos2.local."}
2025-02-03T11:37:47.442300Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed forward DNS lookup for hostname hostname="localhost." ips=[127.0.0.1]
2025-02-03T11:37:47.442755Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed forward DNS lookup for hostname hostname="nixos2." ips=[127.0.0.2]
2025-02-03T11:37:47.443144Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed forward DNS lookup for hostname hostname="nixos2.kvm." ips=[127.0.0.2]
2025-02-03T11:37:47.443628Z INFO containerdebug:SystemInformation::collect:SystemNetworkInfo::collect: containerdebug::system_information::network: performed forward DNS lookup for hostname hostname="nixos2.local." ips=[192.168.122.138, 172.18.0.1, 172.17.0.1]
2025-02-03T11:37:47.443837Z INFO containerdebug:SystemInformation::collect: containerdebug::system_information: Data collection finished
The log-style output above is written to stdout.
It can also be output to files by setting the environment variable
CONTAINERDEBUG_LOG_DIRECTORY=/path/to/logs/directory.
This file output will be output as JSON-formatted logs, in order to ease ingestion into a log aggregation system (such as Vector). These log files will also automatically be rotated over time.
The containerdebug tool can write its collected data into a JSON dump,
by setting the --output=/path/to/dump.json flag.
This is intended to be queried with tools like jq. However, note that the output format is currently not stable, and may change over time.
For example:
{
"resources": {
"cpu_count": 8,
"physical_core_count": 8,
"total_memory": 24604889088,
"free_memory": 17228574720,
"available_memory": 22974619648,
"used_memory": 1630269440,
"total_swap": 0,
"free_swap": 0,
"used_swap": 0,
"total_memory_cgroup": null,
"free_memory_cgroup": null,
"free_swap_cgroup": null
},
"os": {
"name": "NixOS",
"kernel_version": "6.6.46",
"version": "Linux 24.11 NixOS",
"host_name": "nixos2",
"cpu_arch": "x86_64"
},
"current_user": {
"name": "nat",
"uid": "1000",
"gid": "100"
},
"disks": [
{
"name": "/dev/sda2",
"mount_point": "/",
"total_space": 106298343424,
"available_space": 72267354112
},
{
"name": "/dev/sda2",
"mount_point": "/nix/store",
"total_space": 106298343424,
"available_space": 72267354112
},
{
"name": "/dev/sda1",
"mount_point": "/boot",
"total_space": 1071624192,
"available_space": 1022820352
}
],
"network": {
"interfaces": {
"enp1s0": [
"192.168.122.138",
"fe80::5054:ff:fe91:5652"
],
"lo": [
"127.0.0.1",
"::1"
],
"br-82bbc663b8a3": [
"172.18.0.1",
"fc00:f853:ccd:e793::1"
],
"docker0": [
"172.17.0.1"
]
},
"reverse_lookups": {
"fe80::5054:ff:fe91:5652": [
"nixos2."
],
"127.0.0.1": [
"localhost."
],
"192.168.122.138": [
"nixos2.kvm."
],
"::1": [
"localhost."
],
"172.17.0.1": [
"nixos2.",
"nixos2.local."
],
"172.18.0.1": [
"nixos2.",
"nixos2.local."
]
},
"forward_lookups": {
"nixos2.kvm.": [
"127.0.0.2"
],
"nixos2.": [
"127.0.0.2"
],
"nixos2.local.": [
"192.168.122.138",
"172.18.0.1",
"172.17.0.1"
],
"localhost.": [
"127.0.0.1"
]
}
}
}If given the --loop flag, containerdebug will stay in the background and
re-run on a fixed interval. The default interval is 30m (every 30 minutes), but
it can be customized as desired (e.g. --loop=30s).