Code review comment for lp:~thumper/juju-core/system-ssh-key

https://codereview.appspot.com/43730044/diff/1/environs/cloudinit/cloudinit.go
File environs/cloudinit/cloudinit.go (right):

https://codereview.appspot.com/43730044/diff/1/environs/cloudinit/cloudinit.go#newcode262
environs/cloudinit/cloudinit.go:262: identityFile :=
ssh.SystemIdentityFilename(cfg.DataDir)
See comment on ssh.SystemIdentityFilename: the path here should be
obtained with path.Join, not filepath.Join. If you expose
ssh.SystemIdentity, you can just use cfg.dataFile(ssh.SystemIdentity)
here.

https://codereview.appspot.com/43730044/diff/1/provider/common/bootstrap.go
File provider/common/bootstrap.go (right):

https://codereview.appspot.com/43730044/diff/1/provider/common/bootstrap.go#newcode90
provider/common/bootstrap.go:90: func GenerateSystemSSHKey(env
environs.Environ) (privateKey string, err error) {
Doc comment please. Please mention that the function records the public
key in the environment config.

https://codereview.appspot.com/43730044/diff/1/provider/common/bootstrap.go#newcode90
provider/common/bootstrap.go:90: func GenerateSystemSSHKey(env
environs.Environ) (privateKey string, err error) {
Can you please add a test for this function in bootstrap_test.go, to
make sure the public key is added to the environment's config?

https://codereview.appspot.com/43730044/diff/1/provider/common/bootstrap.go#newcode95
provider/common/bootstrap.go:95: return "", fmt.Errorf("failed to create
system key: %v", err)
I'm told the errors should be worded like "creating system key", so it
ends up as
error: creating system key: <thing>

(I've traditionally done it the same way as you have here, mind.)

https://codereview.appspot.com/43730044/diff/1/utils/ssh/generate.go
File utils/ssh/generate.go (right):

https://codereview.appspot.com/43730044/diff/1/utils/ssh/generate.go#newcode19
utils/ssh/generate.go:19: func GenerateKey(comment string) (private,
public string, err error) {
Doc comment please. What are the properties of the keys? It's RSA,
2048-bits, unencrypted (i.e. no passphrase), with the private key
encoded as PEM and the public key encoded in authorized_keys format. I
think it'd be good to spell all of that out.

https://codereview.appspot.com/43730044/diff/1/utils/ssh/systemidentity.go
File utils/ssh/systemidentity.go (right):

https://codereview.appspot.com/43730044/diff/1/utils/ssh/systemidentity.go#newcode15
utils/ssh/systemidentity.go:15: func WriteSystemIdentity(dataDir string,
privateKey string) error {
This seems a bit too high-level for the utils/ssh package. It probably
ought to go in environs/ssh, as a "system identity" is a Juju-level
concept rather than an SSH-level one.

I'm probably being a bit too anal though, so I won't insist.

https://codereview.appspot.com/43730044/diff/1/utils/ssh/systemidentity.go#newcode28
utils/ssh/systemidentity.go:28: return filepath.Join(dataDir,
systemIdentity)
Using filepath.Join isn't correct in the case of bootstrapping from
Windows. I'd say just expose the systemIdentity constant, and use the
appropriate path/filepath.Join depending on the context.

https://codereview.appspot.com/43730044/