Cri File System Tools Install ^hot^ May 2026

CRI (Container Runtime Interface) filesystem tools — Installation & quick guide

This guide assumes you want common CRI filesystem tools used for inspecting and managing container images and runtimes on Linux (cri-o, containerd, crictl, runc, nerdctl, skopeo, umoci). It provides installation steps, basic usage examples, and troubleshooting notes.

8) ctr (containerd client) — basic usage

  • List images: sudo ctr images list
  • Pull image: sudo ctr images pull docker.io/library/alpine:latest
  • Create/run container (advanced): use namespaces and tasks. For example: 
    sudo ctr run --rm -t docker.io/library/alpine:latest mytest /bin/sh

Write-Up: Installing CRI File System Tools

When working with Kubernetes, the term "CRI" refers to the Container Runtime Interface. Users generally search for "CRI file system tools" for one of two reasons:

  1. Management: They need crictl (from the cri-tools repo) to inspect containers and pods via the command line.
  2. Runtime: They need cri-dockerd to allow Kubernetes to communicate with the Docker Engine.

This guide covers the installation of both on Linux systems (the standard OS for Kubernetes nodes). cri file system tools install

Step 2: Clone and Build CriFS

git clone https://github.com/containers/crifs.git
cd crifs
make
sudo make install

Step 4: Verify Installation and Filesystem Access

crictl pods
crictl ps
crictl exec -it <container-id> df -h

If crictl exec fails (e.g., due to distroless images), use:

crictl inspect <container-id> | grep -A 5 "mounts"

Step 2: Build and Install cri-dockerd

Since package availability for cri-dockerd varies wildly between distros, building from source is often the most consistent method. List images: sudo ctr images list Pull image:

# Clone the repository
git clone https://github.com/Mirantis/cri-dockerd.git
cd cri-dockerd

7) umoci — install & example


Install:


    

  1. Download binary or via package manager (if available).
    2. 

  2. Example: repack an OCI layout

    umoci unpack --image mylayout:latest /tmp/rootfs
umoci repack --image mylayout:latest /tmp/rootfs

    

    3. 



Use cases:


    

  • Modify image filesystems, re-signing, working with OCI layouts.
    • 





Step 1: Identify the Container Runtime


Run on a Kubernetes node:


ps aux | grep -E "containerd|dockerd|crio"



Or use crictl (if already installed):


crictl info | grep runtime