Summary:
This allows limiting the memory available to documents in the sandbox when gvisor is used. If memory limit is exceeded, we offer to open doc in recovery mode. Recovery mode is tweaked to open docs with tables in "ondemand" mode, which will generally take less memory and allow for deleting rows.
The limit is on the size of the virtual address space available to the sandbox (`RLIMIT_AS`), which in practice appears to function as one would want, and is the only practical option. There is a documented `RLIMIT_RSS` limit to `specifies the limit (in bytes) of the process's resident set (the number of virtual pages resident in RAM)` but this is no longer enforced by the kernel (neither the host nor gvisor).
When the sandbox runs out of memory, there are many ways it can fail. This diff catches all the ones I saw, but there could be more.
Test Plan: added tests
Reviewers: alexmojaki
Reviewed By: alexmojaki
Subscribers: alexmojaki
Differential Revision: https://phab.getgrist.com/D3398
Summary:
This adds support for gvisor sandboxing in core. When Grist is run outside of a container, regular gvisor can be used (if on linux), and will run in rootless mode. When Grist is run inside a container, docker's default policy is insufficient for running gvisor, so a fork of gvisor is used that has less defence-in-depth but can run without privileges.
Sandboxing is automatically turned on in the Grist core container. It is not turned on automatically when built from source, since it is operating-system dependent.
This diff may break a complex method of testing Grist with gvisor on macs that I may have been the only person using. If anyone complains I'll find time on a mac to fix it :)
This diff includes a small "easter egg" to force document loads, primarily intended for developer use.
Test Plan: existing tests pass; checked that core and saas docker builds function
Reviewers: alexmojaki
Reviewed By: alexmojaki
Subscribers: alexmojaki
Differential Revision: https://phab.getgrist.com/D3333
