consync

consync

consync is a tool to help sync or diff Consul key/value data across multiple datacenters.

Please note that consync is in early development and does not have full test coverage yet. It seems to be working correctly but until tests are implemented completely use with caution!

Installation

consync uses glide to handle dependencies, so be sure to have that installed first. Once you have glide installed, install the dependencies required to build consync by typing:

$ glide install

Note: If you have a problem installing packages from gopkg.in when installing dependencies, see gopkg #50 for more information and a workaround.

After the dependencies have been installed, consync can be built and installed using:

$ go install

This will put the consync binary in $GOPATH/bin so you can use it as a normal command if you have that directory on your execution path.

Usage

One thing to note with consync is that the URLs it expects on the command line are not the same as the URLs used if you were to connect to the Consul REST API. consync URLs only require the path from the beginning of the key/value path instead of the full REST path. For example, if you want to see the difference between / on one server and /my/path on another you would use something like http://10.10.10.10:8500/ for the "from" and http://10.10.10.11:8500/my/path for the "to".

Displaying Differences

consync provides a diff command to display the differences between two paths in Consul. These paths can be in the same data center at different paths, different data centers at the same path or even different data centers at different paths.

By default a diff will only show a diff of the keys in the specified directory. To perform a diff on both keys and directories, provide the --recursive (or -r) parameter.

For example, to view the difference between the same path for two data centers in the same cluster, you could do:

$ consync diff \
    -f http://consul.host/app/settings --from-dc dc1 --from-token b3e...9a2 \
    -t http://consul.host/app/settings --to-dc dc2 --to-token b3e...9a2

Syncing Changes

consync also provides a sync command to modify a target path to match a source path. This includes adding any new keys, updating any modified keys and removing any keys that exist in the target but not in the source. This command functions similar to the diff command as far as the parameters you can provide but it also includes an additional --execute (or -e) parameter. If the execute parameter is not provided, consync will only display the changes it would make instead of actually applying them. This is to make sure changes aren't accidentally applied to a target.

By default syncing will only sync keys in the specified directory. To sync keys and directories, provide the --recursive (or -r) parameter.

An example of using the sync command is as follows:

$ consync sync \
    -f http://consul.host/app/settings --from-dc dc1 --from-token b3e...9a2 \
    -t http://consul.host/app/settings --to-dc dc2 --to-token b3e...9a2 \
    --execute