Project: gVisor (Runtime / Container Runtime)
File: configuration.md

This document describes how to configure runtime options for `containerd-shim-runsc-v1`. You can find the installation instructions and minimal requirements in . The shim can be provided with a configuration file containing options to the shim itself as well as a set of flags to runsc. Here is a quick example: ```shell cat <<EOF | sudo tee /etc/containerd/runsc.toml option = "value" [runsc_config] flag = "value" EOF ``` The set of options that can be configured can be found in . Values under `[runsc_config]` can be used to set arbitrary flags to runsc. `flag = "value"` is converted to `--flag="value"` when runsc is invoked. Run `runsc flags` so see which flags are available Next, containerd needs to be configured to send the configuration file to the shim. Starting in 1.3, containerd supports a configurable `ConfigPath` in the runtime configuration. Here is an example: ```shell cat <<EOF | sudo tee /etc/containerd/config.toml version = 2 [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc] runtime_type = "io.containerd.runc.v2" [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc] runtime_type = "io.containerd.runsc.v1" [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc.options] TypeUrl = "io.containerd.runsc.v1.options" ConfigPath = "/etc/containerd/runsc.toml" EOF ``` When you are done, restart containerd to pick up the changes. ```shell sudo systemctl restart containerd ``` When `shim_debug` is enabled in `/etc/containerd/config.toml`, containerd will forward shim logs to its own log. You can additionally set `level = "debug"` to enable debug logs. To see the logs run `sudo journalctl -u containerd`. Here is a containerd configuration file that enables both options: ```shell cat <<EOF | sudo tee /etc/containerd/config.toml version = 2 [debug] level = "debug" [plugins."io.containerd.runtime.v1.linux"] shim_debug = true [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc] runtime_type = "io.containerd.runc.v2" [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc] runtime_type = "io.containerd.runsc.v1" [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runsc.options] TypeUrl = "io.containerd.runsc.v1.options" ConfigPath = "/etc/containerd/runsc.toml" EOF ``` It can be hard to separate containerd messages from the shim's though. To create a log file dedicated to the shim, you can set the `logpath` and `loglevel` values in the shim configuration file: `log_path` is the directory where the shim logs will be created. `%ID%` is the path is replaced with the container ID. `log_level` sets the logs level. It is normally set to "debug" as there is not much interesting happening with other log levels. gVisor debug logging can be enabled by setting the `debug` and `debug-log` flag. The shim will replace "%ID%" with the container ID, and "%COMMAND%" with the runsc command (run, boot, etc.) in the path of the `debug-log` flag. Find out more about debugging in the . ```shell cat <<EOF | sudo tee /etc/containerd/runsc.toml log_path = "/var/log/runsc/%ID%/shim.log" log_level = "debug" [runsc_config] debug = "true" debug-log = "/var/log/runsc/%ID%/gvisor.%COMMAND%.log" EOF ```