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Use python openstacksdk to create and prepare VM in nectar with user data and task script

Owned by Tiancheng Lan
Last updated: 17 May 2023
6 min read

  1. configure connection to nectar server

  2. write and pack the user data

    1. write the user data in a .fcc file

      variant: fcos version: 1.4.0 passwd: # set user and group for operate on NFS groups: - name: Q4646RW gid: 544646 users: - name: core groups: - Q4646RW # core, adm, wheel, sudo, systemd-journal storage: # write content into file files: # disable auto updates by config - path: /etc/zincati/config.d/90-disable-auto-updates.toml contents: inline: | [updates] enabled = false systemd: units: # disabling zincati service only works in fcos 36-20220522.2.1 upwards - name: zincati.service enabled: false # mount NFS onto VM - name: var-mnt-data-Q4646.mount contents: | [Unit] Description = /var/mnt/data/Q4646 After=network-online.target Wants=network-online.target [Mount] What = 10.255.122.28:/gpfs/general02/pool9200/Q4646/Q4646 Where = /var/mnt/data/Q4646 Type=nfs Options= rw,hard,nfsvers=3,nosuid,nodev,noresvport TimeoutSec=5 [Install] WantedBy=multi-user.target - name: var-mnt-data-Q4646.automount enabled: true contents: | [Unit] Description=/var/mnt/data/Q4646 [Automount] Where=/var/mnt/data/Q4646 TimeoutIdleSec=0 [Install] WantedBy=multi-user.target

    2. generate ign user data file from fcc. docker installed required.

      # fcc file location: C:\Users\uqtlan\fcos.fcc docker run --rm -i -v C:\Users\uqtlan:/var/opt -w /var/opt \ quay.io/coreos/fcct:v0.18.0 --pretty --strict --output fcos.ign fcos.fcc

  3. specify the parameters for the VM

    1. name: name of the instance. drone_pdal_translate

    2. port: network port suffix for mounting NFS.
      "-test(-prod)" for port nfs-port-02-test(nfs-port-02-prod)

    3. image: image for the instance.
      tern-fedora-core-38 for running podman directly

    4. nets: list of network names. ["qld"]

    5. security_groups: list of security group names. ["default", "ssh_public"]

    6. availability_zone: availability zone for the VM. QRISCloud

    7. key: name of the keypair for the vm. ansible

    8. flavor: name of the flavor for creating VM. r3.large

    9. user_data: read from ign file as string and base64-encode it

  4. create VM in python by openstacksdk (and push the instance id and ip to xcom)

    conn = openstack.connect(**auth) # user_data needs to be base64 encoded with open(user_data_file, 'r') as file: user_data_raw = file.read() user_data = base64.b64encode(user_data_raw.encode("utf-8")).decode('utf-8') # check whether security groups exist security_groups = [] for security_group in security_groups_list: sg = conn.network.find_security_group(security_group) if sg: log.info('adding security group {}:{}'.format(sg.name,sg.id)) security_groups.append({"name":sg.name}) else: raise Exception('security group {} not found'.format(security_group)) # check whether image exists im = conn.image.find_image(image) if im: log.info('using image {}:{}'.format(image,im.id)) else: raise Exception('image {} not found'.format(image)) # check whether flavor exists fl = conn.compute.find_flavor(flavor) if fl: log.info('using flavor {}:{}'.format(flavor,fl.id)) else: raise Exception('flavor {} not found'.format(flavor)) # find an available port port = None for num in range(1,6): suf = port_suf _port = conn.network.find_port(f"nfs-port-{num:02}{suf}") if _port and not _port.device_id: port = _port print(f'using port {port.name}:{port.id}') break if not port: log.warn("no available port for NFS. using direct mounting instead, which might cause error.") # nics = [{'uuid': some_net.id},{'port': port.id}] nics = [] if port: log.info('appending port {}:{}'.format(port.name,port.id)) nics.append({'port': port.id}) for net_name in nets: # check whether network exists net = conn.network.find_network(net_name) if net: log.info('appending network {}:{}'.format(net_name,net.id)) nics.append({'uuid': net.id}) else: log.warn('net {} not found'.format(net)) conn.compute.create_server(name = name, image_id = im.id, flavor_id = fl.id, security_groups = security_groups, availability_zone = availability_zone, key_name = key, networks = nics, user_data = user_data ) log.info("Sleeping for 5s after create command") time.sleep(5) try: check_instance = conn.compute.find_server(name) while check_instance.status != 'ACTIVE' and check_instance.status != 'ERROR': log.info("Building instance... please wait...") time.sleep(30) check_instance = conn.compute.get_server(check_instance.id) except: raise Exception("Error building instance {}. Probably a nectar outage.".format(check_instance.name)) if check_instance.status == 'ERROR': raise Exception("Error building instance {}. Please check OpenStack logs: {}".format(check_instance.name,check_instance.fault)) log.info("VM running... status=" + conn.compute.get_server(check_instance.id).status) log.info("Instance {}:{} created and running".format(check_instance.name, check_instance.id)) # wait a bit for VM building up time.sleep(30) # push instance id and ip address kwargs["task_instance"].xcom_push(key = "instance-id", value = check_instance.id) kwargs["task_instance"].xcom_push( key="private-ip", value = check_instance.addresses['qld'][0]["addr"] )

     

  5. upload taskscripts. skip this step if taskscript is written in user data

    1. grant write permission of the directory for uploading taskscripts.

    2. upload taskscript

    3. run taskscript with VM

  6. delete vm after use

 

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