Tuftool - accept relative dates

[tjkirch]

0df8d11 tuftool: allow for relative date arguments like 'in 7 days'
81c6a71 tuftool: disable clippy use_self lint for clearer identifiers
dd6cc7a tuftool: fix typo that put snapshot version/expires into timestamp

---

Fixes #213

Testing done:

New usage message for root expire:

$ cargo run -- root expire --help
tuftool-root-expire 0.1.0
Set the expiration time for root.json

USAGE:
    tuftool root expire <path> <time>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

ARGS:
    <path>    Path to root.json
    <time>    Expiration of root; can be in full RFC 3339 format, or something like 'in 7 days'

And for create:

tuftool-create 0.1.0
Create a TUF repository

USAGE:
    tuftool create [FLAGS] [OPTIONS] <indir> <outdir> --root <root> --snapshot-expires <snapshot-expires> --snapshot-version <snapshot-version> --targets-expires <targets-expires> --targets-version <targets-version> --timestamp-expires <timestamp-expires> --timestamp-version <timestamp-version>

FLAGS:
    -c, --copy        Copy files into `outdir` instead of symlinking them
    -f, --follow      Follow symbolic links in `indir`
    -H, --hardlink    Hardlink files into `outdir` instead of symlinking them
    -h, --help        Prints help information
    -V, --version     Prints version information

OPTIONS:
    -j, --jobs <jobs>                              Number of target hashing threads to run (default: number of cores)
    -k, --key <keys>...                            Key files to sign with
    -r, --root <root>                              Path to root.json file for the repository
        --snapshot-expires <snapshot-expires>
            Expiration of snapshot.json file; can be in full RFC 3339 format, or something like 'in 7 days'

        --snapshot-version <snapshot-version>      Version of snapshot.json file
        --targets-expires <targets-expires>
            Expiration of targets.json file; can be in full RFC 3339 format, or something like 'in 7 days'

        --targets-version <targets-version>        Version of targets.json file
        --timestamp-expires <timestamp-expires>
            Expiration of timestamp.json file; can be in full RFC 3339 format, or something like 'in 7 days'

        --timestamp-version <timestamp-version>    Version of timestamp.json file

ARGS:
    <indir>     Directory of targets
    <outdir>    Repository output directory

Root expire accepts relative:

$ cargo run -- root expire root.json 'in 52 weeks'

$ grep expire root.json
    "expires": "2020-10-19T17:07:33Z",

Create accepts relative:

$ cargo run -- create ./src ./outdir --root root.json --snapshot-expires 'in 2 days' --snapshot-version 42 --targets-expires 'in 1 hour' --targets-version 42 --timestamp-expires 'in 6 weeks' --timestamp-version 42
cargo run -- create ./src ./outdir --root root.json --snapshot-expires   42    6.64s user 1.11s system 102% cpu 7.596 total
 
$ grep expire outdir/metadata/*
grep: outdir/metadata/1.root.json: No such file or directory
outdir/metadata/42.snapshot.json:    "expires": "2019-10-23T17:13:42.305040769Z",
outdir/metadata/42.targets.json:    "expires": "2019-10-21T18:13:42.305052425Z",
outdir/metadata/timestamp.json:    "expires": "2019-12-02T17:13:42.305061253Z",

$ date --rfc-3339=seconds -u
2019-10-21 17:13:49+00:00

You can also see that the timestamp expiration is correct now; before, it showed the same as the snapshot expiration.

RFC 3339 format also works:

$ cargo run -- root expire root.json '2019-10-21T19:13:49+00:00'
$ grep expire root.json
    "expires": "2019-10-21T19:13:49Z",

Or with Z:

$ cargo run -- root expire root.json '2019-10-21T19:13:49Z'
$ grep expire root.json
    "expires": "2019-10-21T19:13:49Z",

[iliana]

🎉 🚣‍♀️

[sam-aws]

Well, OK then