CODEWITHSUNDEEP
dockeralpine-linux
thewire247
thewire247

Reputation: 805

Building docker image, inside an alpine linux container

We are using docker containers running alpine linux as build agents in bamboo. As part of the build plan a docker image needs to be created.

Our build agent has docker installed, however we are getting errors as the docker daemon isn't running. Starting the daemon with

/usr/local/bin/dockerd

gives the following:

INFO[0000] libcontainerd: new containerd process, pid: 640 
ERRO[0001] 'overlay' is not supported over overlayfs    
INFO[0001] Graph migration to content-addressability took 0.00 seconds 
INFO[0001] Loading containers: start.                   
WARN[0001] Running modprobe bridge br_netfilter failed with message: modprobe: can't change directory to '/lib/modules': No such file or directory
, error: exit status 1 
WARN[0001] Running modprobe nf_nat failed with message: `modprobe: can't change directory to '/lib/modules': No such file or directory`, error: exit status 1 
WARN[0001] Running modprobe xt_conntrack failed with message: `modprobe: can't change directory to '/lib/modules': No such file or directory`, error: exit status 1 
Error starting daemon: Error initializing network controller: error obtaining controller instance: failed to create NAT chain: Iptables not found

To try and get round this I've installed iptables. Now when I try to run the docker daemon I get:

INFO[0000] libcontainerd: new containerd process, pid: 705 
ERRO[0001] 'overlay' is not supported over overlayfs    
INFO[0001] Graph migration to content-addressability took 0.00 seconds 
INFO[0001] Loading containers: start.                   
WARN[0001] Running modprobe bridge br_netfilter failed with message: modprobe: can't change directory to '/lib/modules': No such file or directory
, error: exit status 1 
WARN[0001] Running modprobe nf_nat failed with message: `modprobe: can't change directory to '/lib/modules': No such file or directory`, error: exit status 1 
WARN[0001] Running modprobe xt_conntrack failed with message: `modprobe: can't change directory to '/lib/modules': No such file or directory`, error: exit status 1 
Error starting daemon: Error initializing network controller: error obtaining controller instance: failed to create NAT chain: iptables failed: iptables -t nat -N DOCKER: iptables v1.6.0: can't initialize iptables table `nat': Permission denied (you must be root)
Perhaps iptables or your kernel needs to be upgraded.
 (exit status 3)

I'm a little stuck on where to go now as sudo isn't a thing on alpine.

Upvotes: 1

Views: 4175

Answers (1)

Scott Rankin
Scott Rankin

Reputation: 443

Running the Docker daemon inside the Docker container is generally a dodgy prospect. We have this exact same requirement, and we solve it by mounting /var/run/docker.sock from the Docker host into the Docker container:

docker run -v /var/run/docker.sock:/var/run/docker.sock --privileged

That way the docker command inside the build agent container is actually talking to the Docker daemon on the host, not inside the container. Works really well for us.

Upvotes: 2

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