docs: update for containerd v2

Fix issue 10132

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

docs/PLUGINS.md

@@ -262,12 +262,24 @@ If you want to get the configuration combined with your configuration, run `cont
 
 ##### Version header
 
-containerd has two configuration versions:
+containerd has several configuration versions:
-- Version 2 (Recommended): Introduced in containerd 1.3.
+- Version 3 (Recommended for containerd 2.x): Introduced in containerd 2.0.
-- Version 1 (Default): Introduced in containerd 1.0. Removed in containerd 2.0.
+  Several plugin IDs have changed in this version.
+- Version 2 (Recommended for containerd 1.x): Introduced in containerd 1.3.
+  Still supported in containerd v2.x.
+  Plugin IDs are changed to have prefixes like "io.containerd.".
+- Version 1: Introduced in containerd 1.0. Removed in containerd 2.0.
 
-A configuration with Version 2 must have `version = 2` header, and must have
+A configuration for Version 2 or 3 must specify the version `version = 2` or `version = 3` in the header, and must have
 fully qualified plugin IDs in the `[plugins]` section:
+```toml
+version = 3
+
+[plugins]
+  [plugins.'io.containerd.monitor.task.v1.cgroups']
+    no_prometheus = false
+```
+
 ```toml
 version = 2
 

docs/cri/config.md

@@ -9,6 +9,18 @@ for more information about containerd config.
 Note that the `[plugins."io.containerd.grpc.v1.cri"]` section is specific to CRI,
 and not recognized by other containerd clients such as `ctr`, `nerdctl`, and Docker/Moby.
 
+## Config versions
+The content of `/etc/containerd/config.toml` must start with a version header, for example:
+```toml
+version = 3
+```
+
+The config version 3 was introduced in containerd v2.0.
+The config version 2 used in containerd 1.x is still supported and automatically
+converted to the config version 3.
+
+For the further information, see [`../PLUGINS.md`](../PLUGINS.md).
+
 ## Basic configuration
 ### Cgroup Driver
 While containerd and Kubernetes use the legacy `cgroupfs` driver for managing cgroups by default,
@@ -16,6 +28,13 @@ it is recommended to use the `systemd` driver on systemd-based hosts for complia
 [the "single-writer" rule](https://systemd.io/CGROUP_DELEGATION/) of cgroups.
 
 To configure containerd to use the `systemd` driver, set the following option in `/etc/containerd/config.toml`:
++ In containerd 2.x
+```toml
+version = 3
+[plugins.'io.containerd.cri.v1.runtime'.containerd.runtimes.runc.options]
+  SystemdCgroup = true
+```
++ In containerd 1.x
 ```toml
 version = 2
 [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
@@ -51,6 +70,13 @@ kubeadm users should also see [the kubeadm documentation](https://kubernetes.io/
 ### Snapshotter
 
 The default snapshotter is set to `overlayfs` (akin to Docker's `overlay2` storage driver):
++ In containerd 2.x
+```toml
+version = 3
+[plugins.'io.containerd.cri.v1.images']
+  snapshotter = "overlayfs"
+```
++ In containerd 1.x
 ```toml
 version = 2
 [plugins."io.containerd.grpc.v1.cri".containerd]
@@ -62,6 +88,25 @@ See [here](https://github.com/containerd/containerd/blob/main/docs/snapshotters)
 ### Runtime classes
 
 The following example registers custom runtimes into containerd:
++ In containerd 2.x
+```toml
+version = 3
+[plugins."io.containerd.cri.v1.runtime".containerd]
+  default_runtime_name = "crun"
+  [plugins."io.containerd.cri.v1.runtime".containerd.runtimes]
+    # crun: https://github.com/containers/crun
+    [plugins."io.containerd.cri.v1.runtime".containerd.runtimes.crun]
+      runtime_type = "io.containerd.runc.v2"
+      [plugins."io.containerd.cri.v1.runtime".containerd.runtimes.crun.options]
+        BinaryName = "/usr/local/bin/crun"
+    # gVisor: https://gvisor.dev/
+    [plugins."io.containerd.cri.v1.runtime".containerd.runtimes.gvisor]
+      runtime_type = "io.containerd.runsc.v1"
+    # Kata Containers: https://katacontainers.io/
+    [plugins."io.containerd.cri.v1.runtime".containerd.runtimes.kata]
+      runtime_type = "io.containerd.kata.v2"
+```
++ In containerd 1.x
 ```toml
 version = 2
 [plugins."io.containerd.grpc.v1.cri".containerd]
@@ -116,14 +161,128 @@ See also [the Kubernetes documentation](https://kubernetes.io/docs/concepts/cont
 
 ## Full configuration
 The explanation and default value of each configuration item are as follows:
++ In containerd 2.x
 <details>
 
 <p>
 
 ```toml
-# Use config version 2 to enable new configuration fields.
+# containerd has several configuration versions:
-# Config file is parsed as version 1 by default.
+# - Version 3 (Recommended for containerd 2.x): Introduced in containerd 2.0.
-# Version 2 uses long plugin names, i.e. "io.containerd.grpc.v1.cri" vs "cri".
+#   Several plugin IDs have changed in this version.
+# - Version 2 (Recommended for containerd 1.x): Introduced in containerd 1.3.
+#   Still supported in containerd v2.x.
+#   Plugin IDs are changed to have prefixes like "io.containerd.".
+# - Version 1 (Default): Introduced in containerd 1.0. Removed in containerd 2.0.
+version = 3
+
+[plugins]
+  [plugins.'io.containerd.cri.v1.images']
+    snapshotter = 'overlayfs'
+    disable_snapshot_annotations = true
+    discard_unpacked_layers = false
+    max_concurrent_downloads = 3
+    image_pull_progress_timeout = '5m0s'
+    image_pull_with_sync_fs = false
+    stats_collect_period = 10
+
+    [plugins.'io.containerd.cri.v1.images'.pinned_images]
+      sandbox = 'registry.k8s.io/pause:3.10'
+
+    [plugins.'io.containerd.cri.v1.images'.registry]
+      config_path = ''
+
+    [plugins.'io.containerd.cri.v1.images'.image_decryption]
+      key_model = 'node'
+
+  [plugins.'io.containerd.cri.v1.runtime']
+    enable_selinux = false
+    selinux_category_range = 1024
+    max_container_log_line_size = 16384
+    disable_cgroup = false
+    disable_apparmor = false
+    restrict_oom_score_adj = false
+    disable_proc_mount = false
+    unset_seccomp_profile = ''
+    tolerate_missing_hugetlb_controller = true
+    disable_hugetlb_controller = true
+    device_ownership_from_security_context = false
+    ignore_image_defined_volumes = false
+    netns_mounts_under_state_dir = false
+    enable_unprivileged_ports = true
+    enable_unprivileged_icmp = true
+    enable_cdi = true
+    cdi_spec_dirs = ['/etc/cdi', '/var/run/cdi']
+    drain_exec_sync_io_timeout = '0s'
+    ignore_deprecation_warnings = []
+
+    [plugins.'io.containerd.cri.v1.runtime'.containerd]
+      default_runtime_name = 'runc'
+      ignore_blockio_not_enabled_errors = false
+      ignore_rdt_not_enabled_errors = false
+
+      [plugins.'io.containerd.cri.v1.runtime'.containerd.runtimes]
+        [plugins.'io.containerd.cri.v1.runtime'.containerd.runtimes.runc]
+          runtime_type = 'io.containerd.runc.v2'
+          runtime_path = ''
+          pod_annotations = []
+          container_annotations = []
+          privileged_without_host_devices = false
+          privileged_without_host_devices_all_devices_allowed = false
+          base_runtime_spec = ''
+          cni_conf_dir = ''
+          cni_max_conf_num = 0
+          snapshotter = ''
+          sandboxer = 'podsandbox'
+          io_type = ''
+
+          [plugins.'io.containerd.cri.v1.runtime'.containerd.runtimes.runc.options]
+            BinaryName = ''
+            CriuImagePath = ''
+            CriuWorkPath = ''
+            IoGid = 0
+            IoUid = 0
+            NoNewKeyring = false
+            Root = ''
+            ShimCgroup = ''
+
+    [plugins.'io.containerd.cri.v1.runtime'.cni]
+      bin_dir = '/opt/cni/bin'
+      conf_dir = '/etc/cni/net.d'
+      max_conf_num = 1
+      setup_serially = false
+      conf_template = ''
+      ip_pref = ''
+      use_internal_loopback = false
+
+  [plugins.'io.containerd.grpc.v1.cri']
+    disable_tcp_service = true
+    stream_server_address = '127.0.0.1'
+    stream_server_port = '0'
+    stream_idle_timeout = '4h0m0s'
+    enable_tls_streaming = false
+
+    [plugins.'io.containerd.grpc.v1.cri'.x509_key_pair_streaming]
+      tls_cert_file = ''
+      tls_key_file = ''
+```
+
+</p>
+</details>
+
++ In containerd 1.x
+<details>
+
+<p>
+
+```toml
+# containerd has several configuration versions:
+# - Version 3 (Recommended for containerd 2.x): Introduced in containerd 2.0.
+#   Several plugin IDs have changed in this version.
+# - Version 2 (Recommended for containerd 1.x): Introduced in containerd 1.3.
+#   Still supported in containerd v2.x.
+#   Plugin IDs are changed to have prefixes like "io.containerd.".
+# - Version 1 (Default): Introduced in containerd 1.0. Removed in containerd 2.0.
 version = 2
 
 # The 'plugins."io.containerd.grpc.v1.cri"' table contains all of the server options.

docs/cri/registry.md

@@ -5,16 +5,16 @@ This document describes the method to configure the image registry for `containe
 > **_NOTE:_** registry.mirrors and registry.configs as previously described in this document
 > have been DEPRECATED. As described in [the cri config](./config.md#registry-configuration) you
 > should now use the following configuration
-+ Before containerd 2.0
++ In containerd 2.x
-```toml
-[plugins."io.containerd.grpc.v1.cri".registry]
-   config_path = "/etc/containerd/certs.d"
-```
-+ In containerd 2.0
 ```toml
 [plugins."io.containerd.cri.v1.images".registry]
    config_path = "/etc/containerd/certs.d"
 ```
++ In containerd 1.x
+```toml
+[plugins."io.containerd.grpc.v1.cri".registry]
+   config_path = "/etc/containerd/certs.d"
+```
 
 ## Configure Registry Credentials
 
@@ -26,20 +26,7 @@ This document describes the method to configure the image registry for `containe
 To configure a credential for a specific registry, create/modify the
 `/etc/containerd/config.toml` as follows:
 
-+ Before containerd 2.0
++ In containerd 2.x
-```toml
-# explicitly use v2 config format
-version = 2
-
-# The registry host has to be a domain name or IP. Port number is also
-# needed if the default HTTPS or HTTP port is not used.
-[plugins."io.containerd.grpc.v1.cri".registry.configs."gcr.io".auth]
-  username = ""
-  password = ""
-  auth = ""
-  identitytoken = ""
-```
-+ In containerd 2.0
 ```toml
 # explicitly use v3 config format
 version = 3
@@ -52,6 +39,19 @@ version = 3
   auth = ""
   identitytoken = ""
 ```
++ In containerd 1.x
+```toml
+# explicitly use v2 config format
+version = 2
+
+# The registry host has to be a domain name or IP. Port number is also
+# needed if the default HTTPS or HTTP port is not used.
+[plugins."io.containerd.grpc.v1.cri".registry.configs."gcr.io".auth]
+  username = ""
+  password = ""
+  auth = ""
+  identitytoken = ""
+```
 
 The meaning of each field is the same with the corresponding field in `.docker/config.json`.
 
@@ -95,22 +95,7 @@ Now that you know you can access your GCR from your terminal, it is now time to
 Edit the containerd config (default location is at `/etc/containerd/config.toml`)
 to add your JSON key for `gcr.io` domain image pull
 requests:
-+ Before containerd 2.0
++ In containerd 2.x
-```toml
-version = 2
-
-[plugins."io.containerd.grpc.v1.cri".registry]
-  [plugins."io.containerd.grpc.v1.cri".registry.mirrors]
-    [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
-      endpoint = ["https://registry-1.docker.io"]
-    [plugins."io.containerd.grpc.v1.cri".registry.mirrors."gcr.io"]
-      endpoint = ["https://gcr.io"]
-  [plugins."io.containerd.grpc.v1.cri".registry.configs]
-    [plugins."io.containerd.grpc.v1.cri".registry.configs."gcr.io".auth]
-      username = "_json_key"
-      password = 'paste output from jq'
-```
-+ In containerd 2.0
 ```toml
 version = 3
 
@@ -125,6 +110,21 @@ version = 3
       username = "_json_key"
       password = 'paste output from jq'
 ```
++ In containerd 1.x
+```toml
+version = 2
+
+[plugins."io.containerd.grpc.v1.cri".registry]
+  [plugins."io.containerd.grpc.v1.cri".registry.mirrors]
+    [plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
+      endpoint = ["https://registry-1.docker.io"]
+    [plugins."io.containerd.grpc.v1.cri".registry.mirrors."gcr.io"]
+      endpoint = ["https://gcr.io"]
+  [plugins."io.containerd.grpc.v1.cri".registry.configs]
+    [plugins."io.containerd.grpc.v1.cri".registry.configs."gcr.io".auth]
+      username = "_json_key"
+      password = 'paste output from jq'
+```
 
 > Note: `username` of `_json_key` signifies that JSON key authentication will be used.
 

docs/hosts.md

@@ -33,20 +33,20 @@ been **DEPRECATED**._ You should now point your registry `config_path` to the pa
 `hosts.toml` files are located.
 
 Modify your `config.toml` (default location: `/etc/containerd/config.toml`) as follows:
-+ Before containerd 2.0
++ In containerd 2.x
-```toml
-version = 2
-
-[plugins."io.containerd.grpc.v1.cri".registry]
-   config_path = "/etc/containerd/certs.d"
-```
-+ In containerd 2.0
 ```
 version = 3
 
 [plugins."io.containerd.cri.v1.images".registry]
    config_path = "/etc/containerd/certs.d"
 ```
++ In containerd 1.x
+```toml
+version = 2
+
+[plugins."io.containerd.grpc.v1.cri".registry]
+   config_path = "/etc/containerd/certs.d"
+```
 
 ## Support for Docker's Certificate File Pattern