4.5 KiB
go-ceph - Go bindings for Ceph APIs
Installation
go get github.com/ceph/go-ceph
The native RADOS library and development headers are expected to be installed.
On debian systems (apt):
libcephfs-dev librbd-dev librados-dev
On rpm based systems (dnf, yum, etc):
libcephfs-devel librbd-devel librados-devel
go-ceph tries to support different Ceph versions. However some functions might
only be available in recent versions, and others can be deprecated. In order to
work with non-current versions of Ceph, it is required to pass build-tags to on
the go commandline. A tag with the named Ceph release will enable/disable
certain features of the go-ceph packages, and prevent warnings or compile
problems. E.g. build against libcephfs/librados/librbd from Mimic, or run go test against Limunous, use:
go build -tags mimic ....
go test -tags luminous ....
Documentation
Detailed documentation is available at https://pkg.go.dev/github.com/ceph/go-ceph.
Connecting to a cluster
Connect to a Ceph cluster using a configuration file located in the default search paths.
conn, _ := rados.NewConn()
conn.ReadDefaultConfigFile()
conn.Connect()
A connection can be shutdown by calling the Shutdown method on the
connection object (e.g. conn.Shutdown()). There are also other methods for
configuring the connection. Specific configuration options can be set:
conn.SetConfigOption("log_file", "/dev/null")
and command line options can also be used using the ParseCmdLineArgs method.
args := []string{ "--mon-host", "1.1.1.1" }
err := conn.ParseCmdLineArgs(args)
For other configuration options see the full documentation.
Object I/O
Object in RADOS can be written to and read from with through an interface very similar to a standard file I/O interface:
// open a pool handle
ioctx, err := conn.OpenIOContext("mypool")
// write some data
bytesIn := []byte("input data")
err = ioctx.Write("obj", bytesIn, 0)
// read the data back out
bytesOut := make([]byte, len(bytesIn))
_, err := ioctx.Read("obj", bytesOut, 0)
if !bytes.Equal(bytesIn, bytesOut) {
fmt.Println("Output is not input!")
}
Pool maintenance
The list of pools in a cluster can be retreived using the ListPools method
on the connection object. On a new cluster the following code snippet:
pools, _ := conn.ListPools()
fmt.Println(pools)
will produce the output [data metadata rbd], along with any other pools that
might exist in your cluster. Pools can also be created and destroyed. The
following creates a new, empty pool with default settings.
conn.MakePool("new_pool")
Deleting a pool is also easy. Call DeletePool(name string) on a connection object to
delete a pool with the given name. The following will delete the pool named
new_pool and remove all of the pool's data.
conn.DeletePool("new_pool")
Development
docker run --rm -it --net=host \
--device /dev/fuse --cap-add SYS_ADMIN --security-opt apparmor:unconfined \
-v ${PWD}:/go/src/github.com/ceph/go-ceph:z \
-v /home/nwatkins/src/ceph/build:/home/nwatkins/src/ceph/build:z \
-e CEPH_CONF=/home/nwatkins/src/ceph/build/ceph.conf \
ceph-golang
Run against a vstart.sh cluster without installing Ceph:
export CGO_CPPFLAGS="-I/ceph/src/include"
export CGO_LDFLAGS="-L/ceph/build/lib"
go build
Contributing
Contributions are welcome & greatly appreciated, every little bit helps. Make code changes via Github pull requests:
- Fork the repo and create a topic branch for every feature/fix. Avoid making changes directly on master branch.
- All incoming features should be accompanied with tests.
- Make sure that you run
go fmtbefore submitting a change set. Alternatively the Makefile has a flag for this, so you can callmake fmtas well. - The integration tests can be run in a docker container, for this run:
make test-docker
Interactive "Office Hours"
The maintenance team plans to be available regularly for questions, comments, pings, etc for about an hour twice a week. The current schedule is:
- 2:00pm EDT (currently 18:00 UTC) Mondays
- 9:00am EDT (currently 13:00 UTC) Thursdays
We will use the #ceph-devel IRC channel