Configuration Files

The Docker command line stores its configuration files in a directory called
.docker within your HOME directory. Docker manages most of the files in
.docker and you should not modify them. However, you can modify the
.docker/config.json file to control certain aspects of how the docker
command behaves.

Currently, you can modify the docker command behavior using environment variables or command-line options. You can also use options within config.json to modify that same behavior. When using these mechanisms, you must keep in mind the order of precedence among them. Command line options override environment variables and environment variables override properties you specify in a config.json file.

The config.json file stores a JSON encoding of a single HttpHeaders
property. The property specifies a set of headers to include in all
messages sent from the Docker client to the daemon. Docker does not try to
interpret or understand these header; it simply puts them into the messages.
Docker does not allow these headers to change any headings it sets for itself.

Following is a sample config.json file:

{
  "HttpHeaders: {
    "MyHeader": "MyValue"
  }
}

@moxiegirl ok - picked up your edits with just a minor tweak to the start of the 2nd paragraph. See if you're ok with that.

oh I also changed "headings" to "headers" in the last para.

@duglin Looks like you created an incomplete email address after changing it from @gmail.com

Not sure it's a problem here, just noting it, just in case :)

Not sure how I managed to do that but I fixed it. thanks!

On Apr 20, 2015, at 3:56 PM, Sebastiaan van Stijn notifications@github.com wrote:

In registry/config_file_test.go #12009 (comment):

+func TestOldJson(t *testing.T) {

• if runtime.GOOS == "windows" {

•   return
  

• }

• tmpHome, _ := ioutil.TempDir("", "config-test")
• defer os.RemoveAll(tmpHome)

• homeKey := homedir.Key()
• homeVal := homedir.Get()

• defer func() { os.Setenv(homeKey, homeVal) }()
• os.Setenv(homeKey, tmpHome)

• fn := filepath.Join(tmpHome, OLD_CONFIGFILE)
• js := {"https://index.docker.io/v1/":{"auth":"am9lam9lOmhlbGxv","email":"@example.com"}}
  @duglin https://github.com/duglin Looks like you created an incomplete email address after changing it from @gmail.com

Not sure it's a problem here, just noting it, just in case :)

—
Reply to this email directly or view it on GitHub https://github.com/docker/docker/pull/12009/files#r28722782.

Copy-pasta-slippo 😄 👍

Argh was still testing this fix when the merge came in. This permission causes problems and needs to be 0700.

ok - I can easily change that. But I'm curious, why do you need +x ?

Without the x bit traversing will still throw a permission, writing to "~/.docker/config.json" failed and even attempting to touch is not allowed.

$ ls -ld ~/.docker
drw-------. 2 derek derek 4096 Apr 20 12:18 /home/derek/.docker
$ touch ~/.docker/config.json
touch: cannot touch ‘/home/derek/.docker/config.json’: Permission denied

That's what I would have expected. However, if you look at this branch: https://github.com/duglin/docker/tree/TweakConfigPerms
I added a testcase to have Save() create the dir and when I left the code at 0600 it still worked - even was able to read the new config file. Is the next test wrong?

could it be because the test is running as root? dunno if it is or not, just speculating.