How to fix Error response from daemon: invalid CPU shares in Docker

# Valid values
docker run --cpu-shares 512 myimage    # Valid: integer >= 2
docker run --cpu-shares 1024 myimage   # Valid: default value
docker run --cpu-shares 2048 myimage   # Valid: higher than default
docker run -c 0 myimage                # Valid: 0 defaults to 1024

# Invalid values that cause the error
docker run --cpu-shares 1 myimage      # Invalid: must be >= 2
docker run --cpu-shares 0.5 myimage    # Invalid: float not allowed
docker run --cpu-shares "high" myimage # Invalid: must be numeric

# Change from invalid value
docker run --cpu-shares 1 -d nginx

# To valid value (minimum is 2)
docker run --cpu-shares 2 -d nginx

# Or use a standard proportion value
docker run --cpu-shares 512 -d nginx   # Half of default
docker run --cpu-shares 1024 -d nginx  # Default (same as omitting)
docker run --cpu-shares 2048 -d nginx  # Double the default

# docker-compose.yml
version: "3.9"
services:
  web:
    image: nginx
    cpu_shares: 512  # Valid: integer value

  worker:
    image: myworker
    cpu_shares: 1024  # Valid: default weight

# This can cause issues if CPU_SHARES is read as a string
services:
  web:
    cpu_shares: ${CPU_SHARES}  # May be parsed as string

services:
  web:
    cpu_shares: ${CPU_SHARES:-1024}  # Default to 1024 if not set

# .env
CPU_SHARES=512

# Check current container settings
docker inspect --format '{{.HostConfig.CpuShares}}' container_name

# Update to a valid value
docker update --cpu-shares 512 container_name

# Verify the change
docker inspect --format '{{.HostConfig.CpuShares}}' container_name

#!/bin/bash
# Ensure the value is an integer
CPU_SHARES=${CPU_SHARES:-1024}

# Validate before using
if [[ ! "$CPU_SHARES" =~ ^[0-9]+$ ]] || [ "$CPU_SHARES" -eq 1 ]; then
    echo "Invalid CPU_SHARES value, using default 1024"
    CPU_SHARES=1024
fi

docker run --cpu-shares "$CPU_SHARES" -d myimage

# GitHub Actions example
- name: Run container
  run: |
    docker run --cpu-shares ${{ vars.CPU_SHARES || '1024' }} -d myimage

import docker
client = docker.from_env()

# Ensure integer type
cpu_shares = int(os.environ.get('CPU_SHARES', 1024))
if cpu_shares < 2:
    cpu_shares = 1024

container = client.containers.run(
    'myimage',
    cpu_shares=cpu_shares,
    detach=True
)

# Check cgroup driver
docker info | grep -i cgroup

# Expected output for cgroup v1 or v2
Cgroup Driver: cgroupfs
# or
Cgroup Driver: systemd

# WSL users may see warnings like:
# WARNING: No cpu shares support

# Alternative: use --cpus for hard limits
docker run --cpus 0.5 -d myimage  # Limit to half a CPU