如何推送关联容器的Docker镜像？拉取镜像后容器不显示求助

Hey there! Let's break down what's going on here and get your Postgres container up and running locally. First, a quick key distinction you might be missing: Docker images are just templates, while containers are running (or stopped) instances created from those templates. Pulling/loading the image to your local machine doesn't automatically recreate the container—you'll need to explicitly start a new container from the imported image.

Here's a step-by-step troubleshooting guide:

1. Verify the Migrated Image is Present Locally #

First, confirm that the Postgres image was successfully loaded to your local Docker environment. Run this command:

docker images

Look for your Postgres image in the output—check the repository name, tag, and image ID to make sure it matches what you exported from the VM.

2. Understand the Difference Between save/load vs export/import #

• docker save + docker load: This preserves the full image, including all layers, tags, and metadata. This is the preferred method for migrating images.
• docker export + docker import: This creates a flattened image from a running/stopped container, which loses metadata like the original image tag, entrypoint, and environment variables. If you used this method, your imported image might not behave like the original.

If you used export/import, try re-migrating the image using save/load instead:

# On the VM: Save the image to a tar file
docker save -o postgres-image.tar your-postgres-image:tag

# Copy the tar file to your local machine, then load it
docker load -i postgres-image.tar

3. Recreate the Container from the Loaded Image #

Once the image is confirmed to be local, you need to start a container using the same configuration (or adjusted for your local setup) as the VM's container. First, on the VM, get the original container's startup details with:

docker inspect <vm-container-name-or-id> | grep -A 20 "Cmd\|Env\|Mounts\|Ports"

This will show you critical info like environment variables (e.g., POSTGRES_PASSWORD), port mappings, volume mounts, and the command used to start the container.

Then, on your local machine, run a new container using that info. Here's a typical example for Postgres:

docker run -d \
  --name local-postgres \
  -p 5432:5432 \
  -e POSTGRES_PASSWORD=your-vm-postgres-password \
  -v /path/on/local/machine/postgres-data:/var/lib/postgresql/data \
  your-postgres-image:tag

• -d: Runs the container in detached mode (background)
• --name: Gives your container a readable name
• -p: Maps your local port 5432 to the container's port 5432
• -e: Sets environment variables (match what was in the VM container)
• -v: Mounts a local directory to persist Postgres data (optional but recommended)

4. Check if the Container is Running #

After running the docker run command, check if the container exists and is running:

# View running containers
docker ps

# View all containers (including stopped ones)
docker ps -a

If the container appears in docker ps -a but not docker ps, it likely started and immediately exited. Check the logs to debug:

docker logs local-postgres

Common issues here include missing environment variables (like POSTGRES_PASSWORD) or permission issues with volume mounts.

5. Double-Check for Typos or Mismatches #

• Make sure you're using the correct image name and tag in the docker run command (match what's in docker images).
• If you're using volume mounts, ensure the local directory exists and has the right permissions.

内容的提问来源于stack exchange，提问作者Prabhjot Singh