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 [e-mail]",
    "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.