Notice

This document is for a development version of Ceph.

Developer Guide (Quick)

This guide will describe how to build and test Ceph for development.

Development

The run-make-check.sh script will install Ceph dependencies, compile everything in debug mode and run a number of tests to verify the result behaves as expected.

./run-make-check.sh

Optionally if you want to work on a specific component of Ceph, install the dependencies and build Ceph in debug mode with required cmake flags.

Example:

./install-deps.sh
./do_cmake.sh -DWITH_MANPAGE=OFF -DWITH_BABELTRACE=OFF -DWITH_MGR_DASHBOARD_FRONTEND=OFF

You can also turn off building of some core components that are not relevant to your development:

./do_cmake.sh ... -DWITH_RBD=OFF -DWITH_KRBD=OFF -DWITH_RADOSGW=OFF

Finally, build ceph:

cmake --build build [--target <target>...]

Omit --target... if you want to do a full build.

Running a development deployment

Ceph contains a script called vstart.sh (see also Deploying a development cluster) which allows developers to quickly test their code using a simple deployment on your development system. Once the build finishes successfully, start the ceph deployment using the following command:

cd build
../src/vstart.sh -d -n

You can also configure vstart.sh to use only one monitor and one metadata server by using the following:

env MON=1 MDS=1 ../src/vstart.sh -d -n -x

Most logs from the cluster can be found in build/out.

The system creates two pools on startup: cephfs_data_a and cephfs_metadata_a. Let’s get some stats on the current pools:

$ bin/ceph osd pool stats
*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***
pool cephfs_data_a id 1
  nothing is going on

pool cephfs_metadata_a id 2
  nothing is going on

$ bin/ceph osd pool stats cephfs_data_a
*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***
pool cephfs_data_a id 1
  nothing is going on

$ bin/rados df
POOL_NAME         USED OBJECTS CLONES COPIES MISSING_ON_PRIMARY UNFOUND DEGRADED RD_OPS RD WR_OPS WR
cephfs_data_a        0       0      0      0                  0       0        0      0  0      0    0
cephfs_metadata_a 2246      21      0     63                  0       0        0      0  0     42 8192

total_objects    21
total_used       244G
total_space      1180G

Make a pool and run some benchmarks against it:

bin/ceph osd pool create mypool
bin/rados -p mypool bench 10 write -b 123

Place a file into the new pool:

bin/rados -p mypool put objectone <somefile>
bin/rados -p mypool put objecttwo <anotherfile>

List the objects in the pool:

bin/rados -p mypool ls

Once you are done, type the following to stop the development ceph deployment:

../src/stop.sh

Resetting your vstart environment

The vstart script creates out/ and dev/ directories which contain the cluster’s state. If you want to quickly reset your environment, you might do something like this:

../src/stop.sh
rm -rf out dev
env MDS=1 MON=1 OSD=3 ../src/vstart.sh -n -d

Running a RadosGW development environment

Set the RGW environment variable when running vstart.sh to enable the RadosGW.

cd build
RGW=1 ../src/vstart.sh -d -n -x

You can now use the swift python client to communicate with the RadosGW.

swift -A http://localhost:8000/auth -U test:tester -K testing list
swift -A http://localhost:8000/auth -U test:tester -K testing upload mycontainer ceph
swift -A http://localhost:8000/auth -U test:tester -K testing list

Run unit tests

The tests are located in src/tests. To run them type:

(cd build && ninja check)