Ucloud » History » Version 3
Ahmed Bilal, 07/01/2019 02:03 PM
| 1 | 1 | Ahmed Bilal | h1. ucloud (To Be Continued) |
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| 2 | |||
| 3 | h2. ucloud-api |
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| 4 | |||
| 5 | Outside world (indirect) communication with the internal systems. |
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| 6 | |||
| 7 | Its responsibilities are |
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| 8 | * Create VM *(Done)* POST _/vm/create_ |
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| 9 | <pre><code class="javascript"> |
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| 10 | { |
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| 11 | "name": "username", |
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| 12 | "realm": "user_realm", |
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| 13 | "seed": "user_seed", |
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| 14 | "specs": { |
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| 15 | "cpu": 16, |
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| 16 | "ram": 256, |
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| 17 | 2 | Ahmed Bilal | "hdd": 2000, |
| 18 | "ssd": 256 |
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| 19 | 1 | Ahmed Bilal | } |
| 20 | } |
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| 21 | </code></pre> |
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| 22 | |||
| 23 | * Delete VM *(Done)* POST _/vm/delete_ |
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| 24 | <pre><code class="javascript"> |
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| 25 | { |
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| 26 | "name": "username", |
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| 27 | "realm": "user_realm", |
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| 28 | "seed": "user_seed", |
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| 29 | "vmid": "id_of_virtual_machine" |
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| 30 | } |
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| 31 | </code></pre> |
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| 32 | |||
| 33 | * Status VM *(Done)* GET _/vm/status_ |
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| 34 | <pre><code class="javascript"> |
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| 35 | { |
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| 36 | "id": "id_of_virtual_machine" |
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| 37 | } |
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| 38 | </code></pre> |
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| 39 | |||
| 40 | * Create new network |
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| 41 | * Attach network to VM |
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| 42 | * Detach network from VM |
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| 43 | * Delete network |
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| 44 | |||
| 45 | h2. ucloud-scheduler |
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| 46 | |||
| 47 | It schedules/reschedules VM that are created using ucloud-api. How does it schedules? It does by watching any changes under the _/v1/vm/_ prefix. Basically, it deals with two ETCD entries |
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| 48 | |||
| 49 | 1. Virtual Machines Entries that looks like |
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| 50 | <pre><code class="javascript"> |
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| 51 | /v1/vm/1 |
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| 52 | { |
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| 53 | "owner": "ahmedbilal-admin", |
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| 54 | "specs": { |
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| 55 | "cpu": 20, |
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| 56 | "ram": 2, |
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| 57 | "hdd": 10, |
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| 58 | 3 | Ahmed Bilal | "ssd": 10 |
| 59 | 1 | Ahmed Bilal | }, |
| 60 | "hostname": "", |
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| 61 | "status": "REQUESTED_NEW" |
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| 62 | } |
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| 63 | </code></pre> |
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| 64 | 2. Hosts Entries that look like |
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| 65 | <pre><code class="javascript"> |
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| 66 | /v1/host/1 |
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| 67 | { |
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| 68 | "cpu": 32, |
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| 69 | "ram": 128, |
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| 70 | "hdd": 1024, |
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| 71 | 3 | Ahmed Bilal | "ssd": 0 |
| 72 | 1 | Ahmed Bilal | "status": "UP" |
| 73 | } |
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| 74 | </code></pre> |
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| 75 | |||
| 76 | It loop through list of host entries found under _/v1/host/_ and check whether we can run the incoming VM on that host. if we can, then it (ucloud-scheduler) sets the hostname key of incoming VM to that host. Suppose, our scheduler decides that we can run the earlier shown VM _/v1/vm/1_ on _/v1/host/1_. Then, our updated entry would look like |
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| 77 | |||
| 78 | <pre><code class="javascript"> |
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| 79 | /v1/vm/1 |
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| 80 | { |
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| 81 | "owner": "ahmedbilal-admin", |
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| 82 | "specs": { |
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| 83 | "cpu": 20, |
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| 84 | "ram": 2, |
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| 85 | "hdd": 10, |
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| 86 | 3 | Ahmed Bilal | "ssd": 10 |
| 87 | 1 | Ahmed Bilal | }, |
| 88 | "hostname": "/v1/host/1", |
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| 89 | "status": "REQUESTED_NEW" |
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| 90 | } |
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| 91 | </code></pre> |
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| 92 | |||
| 93 | *Note* the hostname key/value pair. |
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| 94 | |||
| 95 | h2. ucloud-vm |
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| 96 | It is responsible for creating (running) / deleting (stopping) / monitoring virtual machines |
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| 97 | |||
| 98 | It watches the _/v1/vm/_ prefix for any changes like (Virtual Machines with status like *SCHEDULED_DEPLOY* or *REQUEST_DELETE*. |
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| 99 | |||
| 100 | On, *SCHEDULED_DEPLOY* it creates the VM and run it. On, *REQUEST_DELETE* it stops the VM. |
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| 101 | |||
| 102 | It is also responsible for monitoring VM statues i.e whether they are RUNNING or KILLED (in action). If a VM is killed we put that in log file, notify system administrator and restart it. |