Why does Docker say it can't execute 'bash"?

Question

I'm using Docker on MacOSX (with Boot2Docker).

I can run images from Docker Hub.

However, when I try to run one of my own images like this:

docker run -P mylocalimage 

or

docker run -P mylocalimage bin/a3-write-back 

or

... 

I get:

docker "env: can't execute 'bash': No such file or directory" 

I guess that it can't find a bash binary to execute in the container, but why?

The base image is errordeveloper/oracle-jdk

Thanks for any help.

Ashley.

[{     "Architecture": "amd64",     "Author": "ABC [email protected]",     "Checksum": "tarsum.dev+sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",     "Comment": "",     "Config": {         "AttachStderr": false,         "AttachStdin": false,         "AttachStdout": false,         "Cmd": [],         "CpuShares": 0,         "Cpuset": "",         "Domainname": "",         "Entrypoint": [             "bin/a3-write-back"         ],         "Env": [             "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/jdk1.8.0_25/bin",             "JAVA_HOME=/usr/jdk1.8.0_25"         ],         "ExposedPorts": null,         "Hostname": "5bf0de3d0926",         "Image": "abd65ce243a5b015bb49f3e958103a5cc0c5f14938df4e480ded25f3ecf878e7",         "MacAddress": "",         "Memory": 0,         "MemorySwap": 0,         "NetworkDisabled": false,         "OnBuild": [],         "OpenStdin": false,         "PortSpecs": null,         "StdinOnce": false,         "Tty": false,         "User": "daemon",         "Volumes": null,         "WorkingDir": "/opt/docker"     },     "Container": "987d2279b6e42195fe8e732c0637798926db6cfaeab93fcc25a3f10dac73f111",     "ContainerConfig": {         "AttachStderr": false,         "AttachStdin": false,         "AttachStdout": false,         "Cmd": [             "/bin/sh",             "-c",             "#(nop) CMD []"         ],         "CpuShares": 0,         "Cpuset": "",         "Domainname": "",         "Entrypoint": [             "bin/a3-write-back"         ],         "Env": [             "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/jdk1.8.0_25/bin",             "JAVA_HOME=/usr/jdk1.8.0_25"         ],         "ExposedPorts": null,         "Hostname": "5bf0de3d0926",         "Image": "abd65ce243a5b015bb49f3e958103a5cc0c5f14938df4e480ded25f3ecf878e7",         "MacAddress": "",         "Memory": 0,         "MemorySwap": 0,         "NetworkDisabled": false,         "OnBuild": [],         "OpenStdin": false,         "PortSpecs": null,         "StdinOnce": false,         "Tty": false,         "User": "daemon",         "Volumes": null,         "WorkingDir": "/opt/docker"     },     "Created": "2015-01-13T05:25:38.467586784Z",     "DockerVersion": "1.4.1",     "Id": "ddbd5d3f52cc5fd41605c95e4525cd2f3e0808a3741b3f8d77f46f0661945f7b",     "Os": "linux",     "Parent": "abd65ce243a5b015bb49f3e958103a5cc0c5f14938df4e480ded25f3ecf878e7",     "Size": 0,     "VirtualSize": 390826666 } ] 

Answer 1

Your image is based on busybox, which doesn't have a bash shell. It does have a shell at /bin/sh.

So this doesn't work:

$ docker run -it busybox bash exec: "bash": executable file not found in $PATH2015/01/15 11:09:08 Error response from daemon:  Cannot start container a5074af2f81f8cc1eb0076f4ec9ada5f87be1440006f54a9b06ab701fc60176a: exec:   "bash": executable file not found in $PATH 

But this does:

$ docker run -it busybox /bin/sh / # 

There may be further complications due to your entrypoint script, but you can always override that.

Answer 2

This won't work if your image has a defined ENTRYPOINT. For these cases use: ' docker run -it --entrypoint /bin/bash '