Obtaining software updates from neighboring hosts in a virtualized computing system

1. A method of generating software installation bundles (SIBs) in a cluster of a virtualized computing system, the method comprising:

receiving, at a host from a neighboring host in the cluster, a request to download the SIBs;

obtaining, at the host, image metadata describing a running image of a hypervisor executing on the host;

identifying, from the image metadata, a plurality of SIBs used to install the running image on the host;

obtaining, from storage on the host, payloads referenced in the image metadata for the SIBs;

recreating the SIBs from the payloads; and

storing the recreated SIBs for access by the neighboring host.

2. The method of claim 1 , further comprising:

obtaining, at the host from the image metadata, SIB descriptors and SIB signatures for the plurality of SIBs;

wherein the SIBs are recreated from the SIB descriptors, the SIB signatures, and the payloads.

3. The method of claim 1 , further comprising:

verifying, by the host, checksums of the SIBs as recreated against checksums for the SIBs as stored in the image metadata.

4. The method of claim 1 , further comprising:

downloading, by the neighboring host from the host, the SIBs as recreated; and

executing an upgrade of another hypervisor executing in the neighboring host using the SIBs as recreated.

5. The method of claim 4 , further comprising:

determining, by the neighboring host, a list of required SIBs to satisfy a desired software specification;

identifying, by the neighboring host, the host in the cluster from which to obtain the SIBs.

6. The method of claim 5 , wherein the neighboring host receives a list of hosts having the host from a lifecycle manager.

7. The method of claim 5 , wherein the neighboring host determines the host autonomously.

8. A non-transitory computer readable medium comprising instructions to be executed in a computing device to cause the computing device to carry out a method of generating software installation bundles (SIBs) in a cluster of a virtualized computing system, the method comprising:

receiving, at a host from a neighboring host in the cluster, a request to download the SIBs;

obtaining, at the host, image metadata describing a running image of a hypervisor executing on the host;

identifying, from the image metadata, a plurality of SIBs used to install the running image on the host;

obtaining, from storage on the host, payloads referenced in the image metadata for the SIBs;

recreating the SIBs from the payloads; and

storing the recreated SIBs for access by the neighboring host.

9. The non-transitory computer readable medium of claim 8 , further comprising:

obtaining, at the host from the image metadata, SIB descriptors and SIB signatures for the plurality of SIBs;

wherein the SIBs are recreated from the SIB descriptors, the SIB signatures, and the payloads.

10. The non-transitory computer readable medium of claim 8 , further comprising:

verifying, by the host, checksums of the SIBs as recreated against checksums for the SIBs as stored in the image metadata.

11. The non-transitory computer readable medium of claim 8 , further comprising:

downloading, by the neighboring host from the host, the SIBs as recreated; and

executing an upgrade of another hypervisor executing in the neighboring host using the SIBs as recreated.

12. The non-transitory computer readable medium of claim 11 , further comprising:

determining, by the neighboring host, a list of required SIBs to satisfy a desired software specification;

identifying, by the neighboring host, the host in the cluster from which to obtain the SIBs.

13. The non-transitory computer readable medium of claim 12 , wherein the neighboring host receives a list of hosts having the host from a lifecycle manager.

14. The non-transitory computer readable medium of claim 13 , wherein the neighboring host determines the host autonomously.

15. A virtualized computing system having a cluster comprising hosts connected to a network, the virtualized computing system comprising:

a host having a hardware platform that includes a central processing unit (CPU) and a system memory; and

a neighboring host to the host;

the hardware platform of the host configured to execute software to:

receive, from the neighboring host, a request to download software installation bundles (SIBs);

obtain image metadata describing a running image of a hypervisor executing on the host;

identify, from the image metadata, a plurality of SIBs used to install the running image on the host;

obtain, from storage on the host, payloads referenced in the image metadata for the SIBs;

recreate the SIBs from the payloads; and

store the recreated SIBs for access by the neighboring host.

16. The virtualized computing system of claim 15 , wherein the host is configured to obtain, from the image metadata, SIB descriptors and SIB signatures for the plurality of SIBs, and wherein the SIBs are recreated from the SIB descriptors, the SIB signatures, and the payloads.

17. The virtualized computing system of claim 15 , wherein the host is configured to verify checksums of the SIBs as recreated against checksums for the SIBs as stored in the image metadata.

18. The virtualized computing system of claim 15 , wherein the neighboring host is configured to:

download, from the host, the SIBs as recreated; and

execute an upgrade of another hypervisor executing in the neighboring host using the SIBs as recreated.

19. The virtualized computing system of claim 18 , wherein the neighboring host is configured to:

determine a list of required SIBs to satisfy a desired software specification; and

identify the host in the cluster from which to obtain the SIBs.

20. The virtualized computing system of claim 19 , wherein the neighboring host receives a list of hosts having the host from a lifecycle manager.