====== Developer Playgrounds ======

Developer playground machines are used for developing Ceph.

All machines have [[services:cephfs]] mounts for accessing the teuthology, scratch, and postfile file systems. It is encouraged to use these machines to view teuthology logs as they will be significantly faster than the [[services:teuthology|teuthology VM]], which is often memory/CPU starved.

===== Machines ====

^ Name                                             ^ Notes            ^
| [[hardware:senta|senta01.front.sepia.ceph.com]]  | General purpose (currently unavailable) |
| [[hardware:senta|senta02.front.sepia.ceph.com]]  | General purpose  |
| [[hardware:senta|senta03.front.sepia.ceph.com]]  | General purpose  |
| [[hardware:vossi|vossi01.front.sepia.ceph.com]]  | General purpose  |
| [[hardware:vossi|vossi04.front.sepia.ceph.com]]  | CephFS Team      |
| [[hardware:vossi|vossi06.front.sepia.ceph.com]]  | RADOS Team       |
| [[hardware:folio|folio02.front.sepia.ceph.com]]  | General purpose  |
| [[hardware:folio|folio13.front.sepia.ceph.com]]  | General purpose  |

==== Playing Nice ====

Developer playgrounds should be able to build the ''main'' branch. It is okay to use ''./install-deps.sh'' top-level script from the ceph source tree to update dependencies. Do not run that script from an older release of Ceph as it may break other developer's work. If you need to build an older release, lock a throwaway node like [[hardware:smithi]] and build there. Or, use a container to do the build/testing!

Using the developer machines to look at teuthology QA artifacts is encouraged. Try to avoid using a text editor to look at large (1GB+) debug logs as this can be RAM intensive/disruptive. Instead, prefer ''less'' or use ''tail -c xM | $EDITOR -'' to look at portions of the log in a text editor.

Many of the developer playground nodes have extra disks for testing Ceph. It's okay to use these for ''vstart'' clusters but it may be more flexible to build LVM volumes on top of these devices so others may use them too.

==== MOTD ====

Please use this MOTD for these playground machines:

<code>
*******************************************************************************

                                Welcome!

      This machine is a Ceph Developer Playground for shared use.  Please
          see the following wiki document for guidelines and a list of
                              available machines.

             https://wiki.sepia.ceph.com/doku.php?id=devplayground

                           Create support tickets at:

                     https://tracker.ceph.com/projects/lab

                                    Thanks!

*******************************************************************************
</code>


==== Configuring CephFS Mounts ====

The following ansible playbook can be run to setup CephFS mounts on a new developer playground machines:

<code>
---
- name: Configure Ceph Client and Mounts
  hosts: all
  become: true
  vars:
    admin_node: "reesi003.front.sepia.ceph.com"
    ceph_conf_path: "/etc/ceph/ceph.conf"
    keyring_path: "/etc/ceph/client.sepian.keyring"
    secret_path: "/etc/ceph/client.sepian.secret"
    mounts:
      - { path: "/teuthology", fstype: "ceph", src: "/teuthology-archive", mds_namespace: "teuthology", opts: "_netdev,ro" }
      - { path: "/scratch", fstype: "ceph", src: "/", mds_namespace: "scratch", opts: "_netdev" }
      - { path: "/postfile", fstype: "ceph", src: "/", mds_namespace: "postfile", opts: "_netdev,ro" }

  tasks:
    - name: "1. Gather Ceph configuration using raw commands"
      delegate_to: "{{ admin_node }}"
      block:
        - name: "▶️ Generate minimal ceph.conf (raw)"
          ansible.builtin.raw: >
            env CEPH_KEYRING=/etc/ceph/client.sepian.keyring ceph --id sepian config generate-minimal-conf
          register: ceph_conf_content
          changed_when: false

        - name: "▶️ Fetch Ceph keyring (raw)"
          ansible.builtin.raw: >
            cat {{ keyring_path }}
          register: keyring_content
          changed_when: false

        - name: "▶️ Generate client secret (raw)"
          ansible.builtin.raw: >
            ceph-authtool {{ keyring_path }} -n client.sepian -p
          register: secret_content
          changed_when: false

        - name: "▶️ Get Ceph monitor list (raw)"
          ansible.builtin.raw: >
            env CEPH_KEYRING=/etc/ceph/client.sepian.keyring ceph --id sepian mon dump --format json 2>/dev/null | jq -r '[.mons[] | .public_addrs.addrvec[] | select(.type=="v1").addr] | join(",")'
          register: mon_hosts
          changed_when: false

    - name: "2. Configure Ceph client files"
      block:
        - name: "▶️ Ensure /etc/ceph directory exists"
          ansible.builtin.file:
            path: "/etc/ceph"
            state: directory
            mode: '0755'

        - name: "▶️ Deploy ceph.conf"
          ansible.builtin.copy:
            content: "{{ ceph_conf_content.stdout }}"
            dest: "{{ ceph_conf_path }}"
            mode: '0644'

        - name: "▶️ Deploy client keyring"
          ansible.builtin.copy:
            content: "{{ keyring_content.stdout }}"
            dest: "{{ keyring_path }}"
            mode: '0644'

        - name: "▶️ Deploy client secret file (for other tools)"
          ansible.builtin.copy:
            content: "{{ secret_content.stdout }}"
            dest: "{{ secret_path }}"
            mode: '0600'

    - name: "3. Set up CephFS mounts"
      block:
        - name: "▶️ Unmount filesystems if they currently exist"
          ansible.posix.mount:
            path: "{{ item.path }}"
            state: unmounted
          loop: "{{ mounts }}"

        - name: "▶️ Create mount point directories"
          ansible.builtin.file:
            path: "{{ item.path }}"
            state: directory
            mode: '000'
          loop: "{{ mounts }}"

        - name: "▶️ Set immutable attribute on mount points"
          ansible.builtin.file:
            path: "{{ item.path }}"
            attr: +i
          register: immutable_file
          changed_when: "'i' not in immutable_file.diff.before.attributes"
          loop: "{{ mounts }}"

        - name: "▶️ Configure CephFS mounts in /etc/fstab"
          ansible.posix.mount:
            path: "{{ item.path }}"
            src: "{{ mon_hosts.stdout | trim }}:{{ item.src }}"
            fstype: "{{ item.fstype }}"
            opts: "name=sepian,secret={{ secret_content.stdout | trim }},mds_namespace={{ item.mds_namespace }},{{ item.opts }}"
            state: mounted
            dump: 2
            passno: 2
          loop: "{{ mounts }}"
          notify: Reload Systemd

        - name: "▶️ Create symlink for /a -> /teuthology"
          ansible.builtin.file:
            src: "/teuthology"
            dest: "/a"
            state: link
            force: true

    - name: "Force handlers to run before mounting"
      ansible.builtin.meta: flush_handlers

  handlers:
    - name: Reload Systemd
      listen: Reload Systemd
      ansible.builtin.systemd:
        daemon_reload: true
</code>
==== Teuthology scheduling ====

Configure the dev playground node to schedule jobs:

<code>
sudo tee /etc/teuthology.yaml <<EOF
default_machine_type: smithi
queue_host: teuthology.front.sepia.ceph.com
queue_port: 11300
active_machine_types:
  - smithi
EOF
</code>

Note: killing a run is (generally) still necessary on [[services:teuthology|teuthology VM]]. This is because teuthology-kill requires killing the test processes running there.
==== Configuring LVM volumes using spare disks ====

When setting up a fresh Developer Playground machine, configure an LVM VolumeGroup for use by users. Volumes can be provisioned for a build directory, OSD block device, or anything else needed.

Note: no redundancy is configured below (i.e. RAID). If a disk is lost, all volumes will be affected.

<code>
sudo pvcreate /dev/$DISK
</code>

Do this for every disk. This is an ad-hoc process because all nodes are different. Also, some disks may have been used in the past so they will need wiped first:

<code>
sudo wipefs -a /dev/$DISK
</code>

Once all disks are added as physical volumes, it's then possible to add to a VolumeGroup:

<code>
sudo vgcreate DevPlayground $DISKS
</code>

Finally make a volume for yourself:

<code>
sudo lvcreate -L 256G DevPlayground -n $(whoami)-build
sudo mkfs.xfs /dev/DevPlayground/$(whoami)-build
mkdir $HOME/build
chmod 000 $HOME/build
sudo chattr +i $HOME/build
echo "/dev/DevPlayground/$(whoami)-build $HOME/build xfs defaults 1 1" | sudo tee -a /etc/fstab
sudo systemctl daemon-reload
sudo mount $HOME/build
</code>

and some OSD block devices:

<code>
for i in `seq 0 8`; do sudo lvcreate -L 16G DevPlayground -n $(whoami)-osd.$i ; done
</code>

Make those OSDs owned by you:

<code>
printf 'ENV{DM_VG_NAME}=="DevPlayground" ENV{DM_LV_NAME}=="%s-*" OWNER="%s" GROUP="users"\n' $(whoami) $(whoami) | sudo tee -a /etc/udev/rules.d/99-lvmowner.rules
sudo udevadm control --reload-rules
sudo udevadm trigger
</code>

Then you can use those devices with vstart.sh:

<code>
wipefs -a /dev/DevPlayground/$(whoami)-osd.*
shred -v -n 0 -z -s 16M /dev/DevPlayground/$(whoami)-osd.*
env OSD=8 ~/ceph/src/vstart.sh \
    --bluestore-devs $(echo /dev/DevPlayground/$(whoami)-osd.* | tr ' ' ',')
</code>

Feel free to make any other volumes that you require.