8d71771391
This change repivots the plan/apply commands slightly. This is largely in preparation for performing deletes and updates of existing environments. The old way was slightly confusing and made things appear more "magical" than they actually are. Namely, different things are needed for different kinds of deployment operations, and trying to present them each underneath a single pair of CLI commands just leads to weird modality and options. The new way is to offer three commands: create, update, and delete. Each does what it says on the tin: create provisions a new environment, update makes resource updates to an existing one, and delete tears down an existing one entirely. The arguments are what make this interesting: create demands a MuPackage to evaluate (producing the new desired state snapshot), update takes *both* an existing snapshot file plus a MuPackage to evaluate (producing the new desired state snapshot to diff against the existing one), and delete merely takes an existing snapshot file and no MuPackage, since all it must do is tear down an existing known environment. Replacing the plan functionality is the --dry-run (-n) flag that may be passed to any of the above commands. This will print out the plan without actually performing any opterations. All commands produce serializable resource files in the MuGL file format, and attempt to do smart things with respect to backups, etc., to support the intended "Git-oriented" workflow of the pure CLI dev experience. |
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|---|---|---|
| cmd | ||
| docs | ||
| examples | ||
| lib | ||
| pkg | ||
| sdk | ||
| tools/mujs | ||
| .gitignore | ||
| .gitmodules | ||
| glide.lock | ||
| glide.yaml | ||
| main.go | ||
| Makefile | ||
| README.md | ||
Mu
Mu is a framework and toolset for creating reusable stacks of services.
If you are learning about Mu for the first time, please see the overview document.
Architecture
Prerequisites
Mu is written in Go and uses Glide for dependency management. They must be installed:
If you wish to use the optional lint make target, you'll also need to install Golint:
go get -u github.com/golang/lint/golint
Building and Testing
To build Mu, first clone it into a standard Go workspace:
$ mkdir -p $GOPATH/src/github.com/marapongo
$ git clone git@github.com:marapongo/mu $GOPATH/src/github.com/marapongo/mu
A good default value for GOPATH is ~/go.
Mu needs to know where to look for its runtime, library, etc. By default, it will look in /usr/local/mu, however you
can override this with the MUPATH variable. Normally it's easiest just to create a symlink:
$ ln -s $GOPATH/src/github.com/marapongo/mu /usr/local/mu
There is one additional build-time dependency, golint, which can be installed using:
$ go get -u github.com/golang/lint/golint
And placed on your path by:
$ export PATH=$PATH:$GOPATH/bin
At this point you should be able to build and run tests from the root directory:
$ cd $GOPATH/src/github.com/marapongo/mu
$ glide update
$ make
This installs the mu binary into $GOPATH/bin, which may now be run provided make exited successfully.
Compilers
The Mu compilers are built and tested independently from the Mu tool and runtime written in Go. Please see the respective pages for details on this process for each compiler:
Debugging
The Mu tools have extensive logging built in. In fact, we encourage liberal logging in new code, and addding new logging when debugging problems. This helps to ensure future debugging endeavors benefit from your sleuthing.
All logging is done using Google's Glog library. It is relatively barebones, and adds basic leveled logging, stack dumping, and other capabilities beyond what Go's built-in logging routines offer.
The Mu command line has two flags that control this logging and that can come in handy when debugging problems. The
--logtostderr flag spews directly to stderr, rather than the default of logging to files in your temp directory. And
the --verbose=n flag (-v=n for short) sets the logging level to n. Anything greater than 3 is reserved for
debug-level logging, greater than 5 is going to be quite verbose, and anything beyond 7 is extremely noisy.
For example, the command
$ mu compile blueprint.yaml --logtostderr -v=5
is a pretty standard starting point during debugging that will show a fairly comprehensive trace log of a compilation.