How to fix Error: No such container: mycontainer in Docker

First, check if your container exists at all. Use the '-a' flag to see both running and stopped containers:

docker ps -a

Look through the output for your container. The NAMES column shows the container name, and CONTAINER ID shows the ID. If you don't see your container, it has been removed and needs to be recreated.

To avoid typos, copy the container identifier directly from the 'docker ps -a' output:

# Get full container ID (no truncation)
docker ps -a --no-trunc

# Filter by partial name if you know it
docker ps -a | grep myapp

Copy the value from the NAMES or CONTAINER ID column and paste it into your command. Container IDs can be shortened to the first few characters (e.g., 'a1b2c3') as long as they're unique.

If your container doesn't exist, create it with a memorable name using the '--name' flag:

docker run --name mycontainer -d nginx:latest

This is much better than letting Docker assign random names like 'hungry_tesla' or 'clever_banach'. You can then reference it reliably:

docker stop mycontainer
docker start mycontainer
docker exec -it mycontainer bash

A common mistake is confusing image names with container names:

# This creates a container from the 'nginx' IMAGE
docker run nginx

# 'nginx' is the IMAGE name, not the container name
# Docker assigns a random container name like 'eloquent_keller'

# This will FAIL - 'nginx' is not a container name
docker stop nginx  # Error: No such container: nginx

# You need to use the actual container name or ID
docker ps -a  # Find the real name/ID
docker stop eloquent_keller  # Use the actual container name

Always use '--name' when creating containers to avoid this confusion.

Containers launched with '--rm' are automatically deleted after they exit:

# This container will be removed after it stops
docker run --rm --name tempcontainer busybox echo "Hello"

# After the command completes, the container is gone
docker start tempcontainer  # Error: No such container

If you need to keep the container for debugging or restart later, don't use the '--rm' flag. Remove it manually when you're done:

docker run --name mycontainer busybox echo "Hello"
docker ps -a  # Container still exists in 'Exited' state
docker start mycontainer  # Works fine
docker rm mycontainer  # Remove when done

If you're using Docker contexts to manage remote Docker hosts, ensure you're connected to the correct context:

# List available contexts
docker context ls

# Check current context
docker context show

# Switch to the correct context
docker context use my-remote-host

# Now list containers in that context
docker ps -a

Containers exist on specific Docker hosts, so switching contexts changes which containers you can see.