swift/doc/source/development_saio.rst

SAIO - Swift All In One

Note

This guide assumes an existing Linux server. A physical machine or VM will work. We recommend configuring it with at least 2GB of memory and 40GB of storage space. We recommend using a VM in order to isolate Swift and its dependencies from other projects you may be working on.

Instructions for setting up a development VM

This section documents setting up a virtual machine for doing Swift development. The virtual machine will emulate running a four node Swift cluster. To begin:

• Get a linux system server image, this guide will cover:
  • Ubuntu 14.04, 16.04 LTS
  • Fedora/CentOS
  • OpenSuse
• Create guest virtual machine from the image.

What's in a <your-user-name>

Much of the configuration described in this guide requires escalated administrator (root) privileges; however, we assume that administrator logs in as an unprivileged user and can use sudo to run privileged commands.

Swift processes also run under a separate user and group, set by configuration option, and referenced as <your-user-name>:<your-group-name>. The default user is swift, which may not exist on your system. These instructions are intended to allow a developer to use his/her username for <your-user-name>:<your-group-name>.

Installing dependencies

• On apt based systems:

  sudo apt-get update
  sudo apt-get install curl gcc memcached rsync sqlite3 xfsprogs \
                       git-core libffi-dev python-setuptools \
                       liberasurecode-dev libssl-dev
  sudo apt-get install python-coverage python-dev python-nose \
                       python-xattr python-eventlet \
                       python-greenlet python-pastedeploy \
                       python-netifaces python-pip python-dnspython \
                       python-mock

• On yum based systems:

  sudo yum update
  sudo yum install curl gcc memcached rsync sqlite xfsprogs git-core \
                   libffi-devel xinetd liberasurecode-devel \
                   openssl-devel python-setuptools \
                   python-coverage python-devel python-nose \
                   pyxattr python-eventlet \
                   python-greenlet python-paste-deploy \
                   python-netifaces python-pip python-dns \
                   python-mock

• On OpenSuse:

  sudo zypper install curl gcc memcached rsync sqlite3 xfsprogs git-core \
                      libffi-devel liberasurecode-devel python2-setuptools \
                      libopenssl-devel
  sudo zypper install python2-coverage python-devel python2-nose \
                      python-xattr python-eventlet python2-greenlet \
                      python2-netifaces python2-pip python2-dnspython \
                      python2-mock

Note

This installs necessary system dependencies and most of the python dependencies. Later in the process setuptools/distribute or pip will install and/or upgrade packages.

Next, choose either partition-section or loopback-section.

Using a partition for storage

If you are going to use a separate partition for Swift data, be sure to add another device when creating the VM, and follow these instructions:

1. Set up a single partition:

   sudo fdisk /dev/sdb
   sudo mkfs.xfs /dev/sdb1

2. Edit /etc/fstab and add:

   /dev/sdb1 /mnt/sdb1 xfs noatime,nodiratime,logbufs=8 0 0

3. Create the mount point and the individualized links:

   sudo mkdir /mnt/sdb1
   sudo mount /mnt/sdb1
   sudo mkdir /mnt/sdb1/1 /mnt/sdb1/2 /mnt/sdb1/3 /mnt/sdb1/4
   sudo chown ${USER}:${USER} /mnt/sdb1/*
   sudo mkdir /srv
   for x in {1..4}; do sudo ln -s /mnt/sdb1/$x /srv/$x; done
   sudo mkdir -p /srv/1/node/sdb1 /srv/1/node/sdb5 \
                 /srv/2/node/sdb2 /srv/2/node/sdb6 \
                 /srv/3/node/sdb3 /srv/3/node/sdb7 \
                 /srv/4/node/sdb4 /srv/4/node/sdb8 \
                 /var/run/swift
   sudo chown -R ${USER}:${USER} /var/run/swift
   # **Make sure to include the trailing slash after /srv/$x/**
   for x in {1..4}; do sudo chown -R ${USER}:${USER} /srv/$x/; done

   Note

   For OpenSuse users, a user's primary group is users, so you have 2 options:

   • Change ${USER}:${USER} to ${USER}:users in all references of this guide; or

   • Create a group for your username and add yourself to it:

     sudo groupadd ${USER} && sudo gpasswd -a ${USER} ${USER}

   Note

   We create the mount points and mount the storage disk under /mnt/sdb1. This disk will contain one directory per simulated swift node, each owned by the current swift user.

   We then create symlinks to these directories under /srv. If the disk sdb is unmounted, files will not be written under /srv/*, because the symbolic link destination /mnt/sdb1/* will not exist. This prevents disk sync operations from writing to the root partition in the event a drive is unmounted.

4. Next, skip to common-dev-section.

Using a loopback device for storage

If you want to use a loopback device instead of another partition, follow these instructions:

1. Create the file for the loopback device:

   sudo mkdir /srv
   sudo truncate -s 1GB /srv/swift-disk
   sudo mkfs.xfs /srv/swift-disk

   Modify size specified in the truncate command to make a larger or smaller partition as needed.

2. Edit /etc/fstab and add:

   /srv/swift-disk /mnt/sdb1 xfs loop,noatime,nodiratime,logbufs=8 0 0

3. Create the mount point and the individualized links:

   sudo mkdir /mnt/sdb1
   sudo mount /mnt/sdb1
   sudo mkdir /mnt/sdb1/1 /mnt/sdb1/2 /mnt/sdb1/3 /mnt/sdb1/4
   sudo chown ${USER}:${USER} /mnt/sdb1/*
   for x in {1..4}; do sudo ln -s /mnt/sdb1/$x /srv/$x; done
   sudo mkdir -p /srv/1/node/sdb1 /srv/1/node/sdb5 \
                 /srv/2/node/sdb2 /srv/2/node/sdb6 \
                 /srv/3/node/sdb3 /srv/3/node/sdb7 \
                 /srv/4/node/sdb4 /srv/4/node/sdb8 \
                 /var/run/swift
   sudo chown -R ${USER}:${USER} /var/run/swift
   # **Make sure to include the trailing slash after /srv/$x/**
   for x in {1..4}; do sudo chown -R ${USER}:${USER} /srv/$x/; done

   Note

   For OpenSuse users, a user's primary group is users, so you have 2 options:

   • Change ${USER}:${USER} to ${USER}:users in all references of this guide; or

   • Create a group for your username and add yourself to it:

     sudo groupadd ${USER} && sudo gpasswd -a ${USER} ${USER}

   Note

   We create the mount points and mount the loopback file under /mnt/sdb1. This file will contain one directory per simulated swift node, each owned by the current swift user.

   We then create symlinks to these directories under /srv. If the loopback file is unmounted, files will not be written under /srv/*, because the symbolic link destination /mnt/sdb1/* will not exist. This prevents disk sync operations from writing to the root partition in the event a drive is unmounted.

Common Post-Device Setup

Add the following lines to /etc/rc.local (before the exit 0):

mkdir -p /var/cache/swift /var/cache/swift2 /var/cache/swift3 /var/cache/swift4
chown <your-user-name>:<your-group-name> /var/cache/swift*
mkdir -p /var/run/swift
chown <your-user-name>:<your-group-name> /var/run/swift

Note that on some systems you might have to create /etc/rc.local.

On Fedora 19 or later, you need to place these in /etc/rc.d/rc.local.

On OpenSuse you need to place these in /etc/init.d/boot.local.

Creating an XFS tmp dir

Tests require having an XFS directory available in /tmp or in the TMPDIR environment variable. To set up /tmp with an XFS filesystem, do the following:

cd ~
truncate -s 1GB xfs_file  # create 1GB fil for XFS in your home directory
mkfs.xfs xfs_file
sudo mount -o loop,noatime,nodiratime xfs_file /tmp
sudo chmod -R 1777 /tmp

To persist this, edit and add the following to /etc/fstab:

/home/<your-user-name>/xfs_file /tmp xfs rw,noatime,nodiratime,attr2,inode64,noquota 0 0

Getting the code

1. Check out the python-swiftclient repo:

   cd $HOME; git clone https://github.com/openstack/python-swiftclient.git

2. Build a development installation of python-swiftclient:

   cd $HOME/python-swiftclient; sudo python setup.py develop; cd -

   Ubuntu 12.04 users need to install python-swiftclient's dependencies before the installation of python-swiftclient. This is due to a bug in an older version of setup tools:

   cd $HOME/python-swiftclient; sudo pip install -r requirements.txt; sudo python setup.py develop; cd -

3. Check out the swift repo:

   git clone https://github.com/openstack/swift.git

4. Build a development installation of swift:

   cd $HOME/swift; sudo pip install --no-binary cryptography -r requirements.txt; sudo python setup.py develop; cd -

   Note

   Due to a difference in how libssl.so is named in OpenSuse vs. other Linux distros the wheel/binary won't work; thus we use --no-binary cryptography to build cryptography locally.

   Fedora 19 or later users might have to perform the following if development installation of swift fails:

   sudo pip install -U xattr

5. Install swift's test dependencies:

   cd $HOME/swift; sudo pip install -r test-requirements.txt

Setting up rsync

1. Create /etc/rsyncd.conf:

   sudo cp $HOME/swift/doc/saio/rsyncd.conf /etc/
   sudo sed -i "s/<your-user-name>/${USER}/" /etc/rsyncd.conf

   Here is the default rsyncd.conf file contents maintained in the repo that is copied and fixed up above:

   /../saio/rsyncd.conf

2. On Ubuntu, edit the following line in /etc/default/rsync:

   RSYNC_ENABLE=true

   On Fedora, edit the following line in /etc/xinetd.d/rsync:

   disable = no

   One might have to create the above files to perform the edits.

   On OpenSuse, nothing needs to happen here.

3. On platforms with SELinux in Enforcing mode, either set to Permissive:

   sudo setenforce Permissive

   Or just allow rsync full access:

   sudo setsebool -P rsync_full_access 1

4. Start the rsync daemon

   • On Ubuntu 14.04, run:

     sudo service rsync restart

   • On Ubuntu 16.04, run:

     sudo systemctl enable rsync
     sudo systemctl start rsync

   • On Fedora, run:

     sudo systemctl restart xinetd.service
     sudo systemctl enable rsyncd.service
     sudo systemctl start rsyncd.service

   • On OpenSuse, run:

     sudo systemctl enable rsyncd.service
     sudo systemctl start rsyncd.service

   • On other xinetd based systems simply run:

     sudo service xinetd restart

5. Verify rsync is accepting connections for all servers:

   rsync rsync://pub@localhost/

   You should see the following output from the above command:

   account6012
   account6022
   account6032
   account6042
   container6011
   container6021
   container6031
   container6041
   object6010
   object6020
   object6030
   object6040

Starting memcached

On non-Ubuntu distros you need to ensure memcached is running:

sudo service memcached start
sudo chkconfig memcached on

or:

sudo systemctl enable memcached.service
sudo systemctl start memcached.service

The tempauth middleware stores tokens in memcached. If memcached is not running, tokens cannot be validated, and accessing Swift becomes impossible.

Optional: Setting up rsyslog for individual logging

1. Install the swift rsyslogd configuration:

   sudo cp $HOME/swift/doc/saio/rsyslog.d/10-swift.conf /etc/rsyslog.d/

   Note: OpenSuse may have the systemd logger installed, so if you want this to work, you need to install rsyslog:

   sudo zypper install rsyslog
   sudo systemctl start rsyslog.service
   sudo systemctl enable rsyslog.service

   Be sure to review that conf file to determine if you want all the logs in one file vs. all the logs separated out, and if you want hourly logs for stats processing. For convenience, we provide its default contents below:

   /../saio/rsyslog.d/10-swift.conf

2. Edit /etc/rsyslog.conf and make the following change (usually in the "GLOBAL DIRECTIVES" section):

   $PrivDropToGroup adm

3. If using hourly logs (see above) perform:

   sudo mkdir -p /var/log/swift/hourly

   Otherwise perform:

   sudo mkdir -p /var/log/swift

4. Setup the logging directory and start syslog:

   • On Ubuntu:

     sudo chown -R syslog.adm /var/log/swift
     sudo chmod -R g+w /var/log/swift
     sudo service rsyslog restart

   • On Fedora and OpenSuse:

     sudo chown -R root:adm /var/log/swift
     sudo chmod -R g+w /var/log/swift
     sudo systemctl restart rsyslog.service

Configuring each node

After performing the following steps, be sure to verify that Swift has access to resulting configuration files (sample configuration files are provided with all defaults in line-by-line comments).

1. Optionally remove an existing swift directory:

   sudo rm -rf /etc/swift

2. Populate the /etc/swift directory itself:

   cd $HOME/swift/doc; sudo cp -r saio/swift /etc/swift; cd -
   sudo chown -R ${USER}:${USER} /etc/swift

3. Update <your-user-name> references in the Swift config files:

   find /etc/swift/ -name \*.conf | xargs sudo sed -i "s/<your-user-name>/${USER}/"

The contents of the configuration files provided by executing the above commands are as follows:

1. /etc/swift/swift.conf

   /../saio/swift/swift.conf

2. /etc/swift/proxy-server.conf

   /../saio/swift/proxy-server.conf

3. /etc/swift/object-expirer.conf

   /../saio/swift/object-expirer.conf

4. /etc/swift/container-reconciler.conf

   /../saio/swift/container-reconciler.conf

5. /etc/swift/container-sync-realms.conf

   /../saio/swift/container-sync-realms.conf

6. /etc/swift/account-server/1.conf

   /../saio/swift/account-server/1.conf

7. /etc/swift/container-server/1.conf

   /../saio/swift/container-server/1.conf

8. /etc/swift/object-server/1.conf

   /../saio/swift/object-server/1.conf

9. /etc/swift/account-server/2.conf

   /../saio/swift/account-server/2.conf

10. /etc/swift/container-server/2.conf

    /../saio/swift/container-server/2.conf

11. /etc/swift/object-server/2.conf

    /../saio/swift/object-server/2.conf

12. /etc/swift/account-server/3.conf

    /../saio/swift/account-server/3.conf

13. /etc/swift/container-server/3.conf

    /../saio/swift/container-server/3.conf

14. /etc/swift/object-server/3.conf

    /../saio/swift/object-server/3.conf

15. /etc/swift/account-server/4.conf

    /../saio/swift/account-server/4.conf

16. /etc/swift/container-server/4.conf

    /../saio/swift/container-server/4.conf

17. /etc/swift/object-server/4.conf

    /../saio/swift/object-server/4.conf

Setting up scripts for running Swift

1. Copy the SAIO scripts for resetting the environment:

   mkdir -p $HOME/bin
   cd $HOME/swift/doc; cp saio/bin/* $HOME/bin; cd -
   chmod +x $HOME/bin/*

2. Edit the $HOME/bin/resetswift script

   The template resetswift script looks like the following:

   /../saio/bin/resetswift

   If you are using a loopback device add an environment var to substitute /dev/sdb1 with /srv/swift-disk:

   echo "export SAIO_BLOCK_DEVICE=/srv/swift-disk" >> $HOME/.bashrc

   If you did not set up rsyslog for individual logging, remove the find /var/log/swift... line:

   sed -i "/find \/var\/log\/swift/d" $HOME/bin/resetswift

3. Install the sample configuration file for running tests:

   cp $HOME/swift/test/sample.conf /etc/swift/test.conf

   The template test.conf looks like the following:

   /../../test/sample.conf

4. Add an environment variable for running tests below:

   echo "export SWIFT_TEST_CONFIG_FILE=/etc/swift/test.conf" >> $HOME/.bashrc

5. Be sure that your PATH includes the bin directory:

   echo "export PATH=${PATH}:$HOME/bin" >> $HOME/.bashrc

6. Source the above environment variables into your current environment:

   . $HOME/.bashrc

7. Construct the initial rings using the provided script:

   remakerings

   The remakerings script looks like the following:

   /../saio/bin/remakerings

   You can expect the output from this command to produce the following. Note that 3 object rings are created in order to test storage policies and EC in the SAIO environment. The EC ring is the only one with all 8 devices. There are also two replication rings, one for 3x replication and another for 2x replication, but those rings only use 4 devices:

   Device d0r1z1-127.0.0.1:6010R127.0.0.1:6010/sdb1_"" with 1.0 weight got id 0
   Device d1r1z2-127.0.0.2:6020R127.0.0.2:6020/sdb2_"" with 1.0 weight got id 1
   Device d2r1z3-127.0.0.3:6030R127.0.0.3:6030/sdb3_"" with 1.0 weight got id 2
   Device d3r1z4-127.0.0.4:6040R127.0.0.4:6040/sdb4_"" with 1.0 weight got id 3
   Reassigned 3072 (300.00%) partitions. Balance is now 0.00.  Dispersion is now 0.00
   Device d0r1z1-127.0.0.1:6010R127.0.0.1:6010/sdb1_"" with 1.0 weight got id 0
   Device d1r1z2-127.0.0.2:6020R127.0.0.2:6020/sdb2_"" with 1.0 weight got id 1
   Device d2r1z3-127.0.0.3:6030R127.0.0.3:6030/sdb3_"" with 1.0 weight got id 2
   Device d3r1z4-127.0.0.4:6040R127.0.0.4:6040/sdb4_"" with 1.0 weight got id 3
   Reassigned 2048 (200.00%) partitions. Balance is now 0.00.  Dispersion is now 0.00
   Device d0r1z1-127.0.0.1:6010R127.0.0.1:6010/sdb1_"" with 1.0 weight got id 0
   Device d1r1z1-127.0.0.1:6010R127.0.0.1:6010/sdb5_"" with 1.0 weight got id 1
   Device d2r1z2-127.0.0.2:6020R127.0.0.2:6020/sdb2_"" with 1.0 weight got id 2
   Device d3r1z2-127.0.0.2:6020R127.0.0.2:6020/sdb6_"" with 1.0 weight got id 3
   Device d4r1z3-127.0.0.3:6030R127.0.0.3:6030/sdb3_"" with 1.0 weight got id 4
   Device d5r1z3-127.0.0.3:6030R127.0.0.3:6030/sdb7_"" with 1.0 weight got id 5
   Device d6r1z4-127.0.0.4:6040R127.0.0.4:6040/sdb4_"" with 1.0 weight got id 6
   Device d7r1z4-127.0.0.4:6040R127.0.0.4:6040/sdb8_"" with 1.0 weight got id 7
   Reassigned 6144 (600.00%) partitions. Balance is now 0.00.  Dispersion is now 0.00
   Device d0r1z1-127.0.0.1:6011R127.0.0.1:6011/sdb1_"" with 1.0 weight got id 0
   Device d1r1z2-127.0.0.2:6021R127.0.0.2:6021/sdb2_"" with 1.0 weight got id 1
   Device d2r1z3-127.0.0.3:6031R127.0.0.3:6031/sdb3_"" with 1.0 weight got id 2
   Device d3r1z4-127.0.0.4:6041R127.0.0.4:6041/sdb4_"" with 1.0 weight got id 3
   Reassigned 3072 (300.00%) partitions. Balance is now 0.00.  Dispersion is now 0.00
   Device d0r1z1-127.0.0.1:6012R127.0.0.1:6012/sdb1_"" with 1.0 weight got id 0
   Device d1r1z2-127.0.0.2:6022R127.0.0.2:6022/sdb2_"" with 1.0 weight got id 1
   Device d2r1z3-127.0.0.3:6032R127.0.0.3:6032/sdb3_"" with 1.0 weight got id 2
   Device d3r1z4-127.0.0.4:6042R127.0.0.4:6042/sdb4_"" with 1.0 weight got id 3
   Reassigned 3072 (300.00%) partitions. Balance is now 0.00.  Dispersion is now 0.00

8. Read more about Storage Policies and your SAIO policies_saio

9. Verify the unit tests run:

   $HOME/swift/.unittests

   Note that the unit tests do not require any swift daemons running.

10. Start the "main" Swift daemon processes (proxy, account, container, and object):

    startmain

    (The "Unable to increase file descriptor limit. Running as non-root?" warnings are expected and ok.)

    The startmain script looks like the following:

    /../saio/bin/startmain

11. Get an X-Storage-Url and X-Auth-Token:

    curl -v -H 'X-Storage-User: test:tester' -H 'X-Storage-Pass: testing' http://127.0.0.1:8080/auth/v1.0

12. Check that you can GET account:

    curl -v -H 'X-Auth-Token: <token-from-x-auth-token-above>' <url-from-x-storage-url-above>

13. Check that swift command provided by the python-swiftclient package works:

    swift -A http://127.0.0.1:8080/auth/v1.0 -U test:tester -K testing stat

14. Verify the functional tests run:

    $HOME/swift/.functests

    (Note: functional tests will first delete everything in the configured accounts.)

15. Verify the probe tests run:

    $HOME/swift/.probetests

    (Note: probe tests will reset your environment as they call resetswift for each test.)

Debugging Issues

If all doesn't go as planned, and tests fail, or you can't auth, or something doesn't work, here are some good starting places to look for issues:

1. Everything is logged using system facilities -- usually in /var/log/syslog, but possibly in /var/log/messages on e.g. Fedora -- so that is a good first place to look for errors (most likely python tracebacks).
2. Make sure all of the server processes are running. For the base functionality, the Proxy, Account, Container, and Object servers should be running.
3. If one of the servers are not running, and no errors are logged to syslog, it may be useful to try to start the server manually, for example: swift-object-server /etc/swift/object-server/1.conf will start the object server. If there are problems not showing up in syslog, then you will likely see the traceback on startup.
4. If you need to, you can turn off syslog for unit tests. This can be useful for environments where /dev/log is unavailable, or which cannot rate limit (unit tests generate a lot of logs very quickly). Open the file SWIFT_TEST_CONFIG_FILE points to, and change the value of fake_syslog to True.
5. If you encounter a 401 Unauthorized when following Step 12 where you check that you can GET account, use sudo service memcached status and check if memcache is running. If memcache is not running, start it using sudo service memcached start. Once memcache is running, rerun GET account.

Known Issues

Listed here are some "gotcha's" that you may run into when using or testing your SAIO:

1. fallocate_reserve - in most cases a SAIO doesn't have a very large XFS partition so having fallocate enabled and fallocate_reserve set can cause issues, specifically when trying to run the functional tests. For this reason fallocate has been turned off on the object-servers in the SAIO. If you want to play with the fallocate_reserve settings then know that functional tests will fail unless you change the max_file_size constraint to something more reasonable then the default (5G). Ideally you'd make it 1/4 of your XFS file system size so the tests can pass.