Problem scenario
Sometimes you try to start a Docker container but there is a problem.  For example you try:
docker start <containerID
But you receive this: “Error response from daemon: Cannot start container <containerID: failed to create endpoint <nameon network bridge: ip tables failed: iptables –wait -t nat -A DOCKER -p tcp -d 0/0 –dport 80 -j DNAT –to-destination x.x.x.x:80 ! -i docker0: iptables: No chain/target/match by that name.”
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Solution
cd /var/lib/docker/network/files/
ls -lh /tmp/forposterity
mkdir /tmp/backupdir
mv /var/lib/docker/network/files/ /tmp/backupdir
systemctl restart docker #change this command depending on your distribution and version of Linux to restart Docker services

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Continue reading “How Do You Troubleshoot the Docker problem “Error response from daemon: Cannot start container”?”

Problem Scenario
Sometimes the “docker save” command does not work as you would expect.  You run the command on a Docker host, but it does not work.  You might even try the -o flag or the –output=/tmp/destinationFileName.tar option.  But the response may be an surprising error “Cowardly refusing to save to a terminal. Use the -o flag or redirect.”  You want to copy a Docker image from one machine to another computer but problems get in your way. 

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Goal: You want two Docker containers to use the same file share on the Docker server from time to time.  

Problem/Error blocking goal:  In a Docker container, when you try to change directories to a directory that is on the Docker host (e.g., the docker container was created with the –volume flag), and you get an error “bash: cd <directoryname> permission denied,” you have to run two commands to fix it. 

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Continue reading “Having Two Docker Containers Share A Directory on the Host”

Normally you can enter a Docker container with this command:
docker exec -it <containerIDbash
It is possible you receive an error that says ‘exec “bash”: executable file not found in $PATH’
The root cause could be related to insufficient disk space on the Docker host.  Delete files or otherwise make room (e.g., add disk space).  Then stop the container with this command: docker stop <containerID
Finally,

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