use afero when possible

Use afero when possible to allow for fs flexibitily (in tests or other instances).

fixes #39

Signed-off-by: bryanl <bryanliles@gmail.com>

Proposal: Modular components and cleaner environments

In summary:
* Introduce the concept of _targets_, easily allowing an environment to
  target specific components.
* Add optional hierarchy structure to components, for grouping and
  reusability.
* Allow environments to operate on multiple _destinations_.
* Consolidate shared environment metadata and configuration files.

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Upgrade to client-go version 5

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

design proposal: ksonnet lib simple constructors

Add remove component functionality

Introduce `ks component rm <component>`. This functionality will:

1. Delete the component file from components/. This is determined by the
component file name. If there exists two files with the same name but
different file  extensions, we will error out.

2. Remove component references. This currently implies removing all
component referenes in the component/params.libsonnet file and the
environment-specific params.libsonnet files.

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

pruning vendor from dep conversion

Signed-off-by: bryanl <bryanliles@gmail.com>

Signed-off-by: bryanl <bryanliles@gmail.com>

Versions retrospective and fixes

The versioning retrospectiv chronicles our failure to correctly
implement versioning semantics for many parts of the ksonnet experience.

Signed-off-by: Alex Clemmer <clemmer.alexander@gmail.com>

Dependencies in a ksonnet application are installed from collections of
packages called registries. In order to be precise about which packages
an app depends on, and where they are from, we have an API that
specifies each of these nouns.

Unfortunately, we never hooked up code to verify the versions of these
specifications as we deserialize them.

This commit will correct that.

Signed-off-by: Alex Clemmer <clemmer.alexander@gmail.com>

ksonnet makes extensive use of semantic versioning for many things,
including API schemas. To aid this, we introduce a dependency on
`blang/semver` v3.5.1, and `pkg/errors` as a helper.

Signed-off-by: Alex Clemmer <clemmer.alexander@gmail.com>

Construct apimachinery version

Using `Version()` as a string leaves a preprocessed version tag in the
ksonnet version. Construct a new version using the `Major` and `Minor`
fields. Adds short SHA1 from k8s.io/apimachinery as well. SHA1 is pulled
from `dep status`.

Re: #250

Signed-off-by: bryanl <bryanliles@gmail.com>

Signed-off-by: bryanl <bryanliles@gmail.com>

Implement explicit env metadata

Removing realpath

Darwin operating systems does not ship with `realpath` so using another working variation

Signed-off-by: Kris Nova <knova@heptio.com>

convert from govendor to dep

Partially implements the proposal
[here](https://github.com/ksonnet/ksonnet/blob/master/design/proposals/explicit-environment-metadata.md

)

Fixes #222

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Add env. metadata proposal link to README

And format file to be consistent with other proposals.

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Design proposal: explicit environment metadata

Design: propose improvements to the "fresh clone" story

Signed-off-by: Alex Clemmer <clemmer.alexander@gmail.com>

Signed-off-by: Alex Clemmer <clemmer.alexander@gmail.com>

Proposal for explicit environment metadata; allowing environment
metadata (such as namespace, server URI) to be reference-able at the
component and prototype manifest level.

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Clarify error message for duplicate packages on install

Consider the scenario where the user has two registries 'incubator', and
'incubatorXYZ' pointing to the same repository.

It might be confusing why running `ks pkg install incubatorXYZ/mysql`
fails if they ran `ks pkg install incubator/mysql` previously.

This is a small change to help users resolve that scenario by passing
the `--name` flag on install.

Signed-off-by: Jessica Yuen <im.jessicayuen@gmail.com>

Signed-off-by: bryanl <bryanliles@gmail.com>

Signed-off-by: bryanl <bryanliles@gmail.com>

Signed-off-by: Joe Beda <joe.github@bedafamily.com>

Signed-off-by: Joe Beda <joe.github@bedafamily.com>