op-node: Persist synchroniser state

[ajsutton]

Description

Adds a --rpc.admin-state CLI option to specify a file to persist config changes made via the RPC Admin APIs to. Currently that's just whether the sequencer is started or stopped.

• The file is only created when the first change is made via RPC
• If the file doesn't exist, the other CLI args determine if the sequencer starts or not (--sequencer.stopped in particular)
• If the file does exist and is valid, the persisted value overrides the --sequencer.stopped option
• If the file exists and is invalid, op-node will refuse to start
• If writing the file fails, the admin API call will report an error and the sequencer state will be unchanged

The state is persisted as a JSON file so that we can extend it with additional options in the future if need be. The code for persistence has been kept simple and takes advantage of there only being one value currently - it can be refactored to be more complex and merge multiple values in the future if needed.

The file is written with maximal safety - updates are first written to a temp file, fsync'd and then renamed into place.

Tests

Unit tests added around the persistence code. Manual testing for the actual CLI interactions. Will investigate cli tests or e2e tests for this in a follow up PR.

Metadata

• https://linear.app/optimism/issue/CLI-4094/persistence-for-zdd-flags

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Latest commit: 189ae1e

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[codecov]

Codecov Report

Merging #6105 (4163278) into develop (4d7798f) will increase coverage by 0.29%.
The diff coverage is 31.29%.

❗ Current head 4163278 differs from pull request most recent head 189ae1e. Consider uploading reports for the commit 189ae1e to get more accurate results

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #6105      +/-   ##
===========================================
+ Coverage    44.48%   44.78%   +0.29%     
===========================================
  Files          443      307     -136     
  Lines        29058    23540    -5518     
  Branches       691        0     -691     
===========================================
- Hits         12926    10542    -2384     
+ Misses       15084    12019    -3065     
+ Partials      1048      979      -69     

Flag	Coverage Δ
bedrock-go-tests	44.78% <31.29%> (+1.12%)	⬆️
cannon-go-tests	?
common-ts-tests	?
contracts-bedrock-tests	?
core-utils-tests	?
fault-detector-tests	?
sdk-tests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
op-node/flags/flags.go	62.50% <ø> (ø)
op-node/node/config.go	0.00% <0.00%> (ø)
op-node/node/node.go	0.64% <0.00%> (ø)
op-node/rollup/driver/driver.go	0.00% <0.00%> (ø)
op-node/rollup/driver/state.go	0.00% <0.00%> (ø)
op-node/service.go	9.09% <0.00%> (-0.84%)	⬇️
op-node/sources/rollupclient.go	0.00% <0.00%> (ø)
op-node/node/config_persistence.go	55.40% <55.40%> (ø)

... and 148 files with indirect coverage changes

[mergify]

Hey @ajsutton! This PR has merge conflicts. Please fix them before continuing review.

[ajsutton]

@protolambda I've added some e2e tests in here. I was going to do it as a follow up but in implementing them I discovered that having the loading of persisted config mixed in with CLI option parsing made it impossible to test since the e2e tests don't do the CLI parsing. So I've moved it to a method on Config. Happy to accept suggestions for better approaches...

[mergify]

This PR has been added to the merge queue, and will be merged soon.

[mergify]

This PR is next in line to be merged, and will be merged as soon as checks pass.

[mergify]

This PR is next in line to be merged, and will be merged as soon as checks pass.