[KeyVault] KeyVault Round 4 Commands

[tjprescott]

Closes #885.

This PR updates the secret set command and adds the secret download and certificate download commands. With this, the entire KeyVault data plane functionality should be exposed.

Plan to defer merging this until #1059 is merged.

[tjprescott]

secret set

Arguments
    --name -n    [Required]: Name of the secret.
    --vault-name [Required]: Name of the key vault.
    --description          : Description of the secret contents (i.e. password, connection string,
                             etc).
    --disabled             : Create secret in disabled state.
    --expires              : Expiration UTC datetime  (Y-m-d'T'H:M'Z').
    --not-before           : Key not usable before the provided UTC datetime  (Y-m-d'T'H:M'Z').
    --tags                 : Space separated tags in 'key[=value]' format. Use "" to clear existing
                             tags.

Content Source Arguments
    --encoding -e          : Source file encoding. The value is saved as a tag (file-encoding=<val>)
                             and used during download to automtically encode the resulting file.
                             Allowed values: ascii, base64, hex, utf-16be, utf-16le, utf-8.
                             Default: utf-8.
    --file -f              : Source file for secret. Use in conjunction with '--encoding'.
    --value                : Plain text secret value. Cannot be used with '--file' or '--encoding'.

secret download

Command
    az keyvault secret download: Download a secret from a KeyVault.

Arguments
    --file -f    [Required]: File to receive the secret contents.
    --name -n    [Required]: Name of the secret.
    --vault-name [Required]: Name of the key vault.
    --encoding -e          : Encoding of the destination file. By default, will look for the 'file-
                             encoding' tag on the secret. Otherwise will assume 'utf-8'.  Allowed
                             values: ascii, base64, hex, utf-16be, utf-16le, utf-8.
    --version -v           : The secret version. If omitted, uses the latest version.

certificate download

Command
    az keyvault certificate download: Download a certificate from a KeyVault.

Arguments
    --file -f    [Required]: File to receive the binary certificate contents.
    --name -n    [Required]: Name of the certificate.
    --vault-name [Required]: Name of the key vault.
    --encoding -e          : How to store base64 certificate contents in file.  Allowed values:
                             binary, string.  Default: binary.
    --version -v           : The certificate version. If omitted, uses the latest version.

[derekbekoe]

Looks good overall. Added a few comments..

[derekbekoe]

looks like this is unused?

[derekbekoe]

Consider checking for a directory as well as you can't write to a file_path if it's actually a directory.

if os.path.isfile(file_path) or os.path.isdir(file_path):
...

https://docs.python.org/2/library/os.path.html#os.path.isdir

Then, the error message would have "File or directory already exists".

Just showing you can't have a file and directory with the same name.

Dereks-MacBook-Pro-2:atest debekoe$ ls -la
total 0
drwxr-xr-x   2 debekoe  staff    68 Nov 11 13:42 .
drwxr-xr-x+ 63 debekoe  staff  2142 Nov 11 13:42 ..
Dereks-MacBook-Pro-2:atest debekoe$ mkdir a_directory
Dereks-MacBook-Pro-2:atest debekoe$ ls -la
total 0
drwxr-xr-x   3 debekoe  staff   102 Nov 11 13:42 .
drwxr-xr-x+ 63 debekoe  staff  2142 Nov 11 13:42 ..
drwxr-xr-x   2 debekoe  staff    68 Nov 11 13:42 a_directory
Dereks-MacBook-Pro-2:atest debekoe$ echo 'helloworld' > a_directory
-bash: a_directory: Is a directory
Dereks-MacBook-Pro-2:atest debekoe$ echo $?
1
Dereks-MacBook-Pro-2:atest debekoe$ 

[derekbekoe]

Same here

[derekbekoe]

You catch the exception which is fine but should you then raise CLIError after you remove the file?
Otherwise I think the command would return an exit code of 0 and it'd look like it downloaded fine.

[derekbekoe]

Same here.

[derekbekoe]

nit: i.e. or e.g.?

[derekbekoe]

I'm thinking e.g. as you're listing examples.

[tjprescott]

@derekbekoe fixed up your issues.