drt: add date to roachtest_ops.log entries

[vidit-bhat]

Previously, roachtest_ops.log entries show the current timestamp in hh:mm:ss without the timezone. This makes correlating logs quite tricky. This patch add date and timezone to the logs.

Fixes: #125304
Release note: None

[cockroach-teamcity]

This change is 

[renatolabs]

How do the log entries look like? I wonder if we should just change roachprod's defaults to include Ldate, as that would likely be useful for roachtest as well.

[vidit-bhat]

How do the log entries look like? I wonder if we should just change roachprod's defaults to include Ldate, as that would likely be useful for roachtest as well.

How do the log entries look like? I wonder if we should just change roachprod's defaults to include Ldate, as that would likely be useful for roachtest as well.

Something like

2024/06/10 15:48:58 run.go:554: more than one operation found for filter node-kill, randomly selected node-kill/sigterm/drain=false to run
2024/06/10 15:48:58 main.go:198: operation status: checking if operation node-kill/sigterm/drain=false dependencies are met
2024/06/10 15:48:58 main.go:198: operation status: skipping dependency check
2024/06/10 15:48:58 main.go:198: operation status: running operation node-kill/sigterm/drain=false with run id 1883723429829256626
2024/06/10 15:48:58 node_kill.go:51: operation status: killing node 3  with signal 15
2024/06/10 15:48:58 cluster.go:2420: running cmd `pkill -15 -f cockroach\ start` on nodes [:3]; details in run_154858.582585000_n3_pkill-15-f-cockroach.log
run_154858.582585000_n3_pkill-15-f-cockroach: 15:48:58 cluster.go:2421: > pkill -15 -f cockroach\ start
run_154858.582585000_n3_pkill-15-f-cockroach: 15:48:58 cluster.go:2439: > result: <ok>
2024/06/10 15:48:58 node_kill.go:51: operation status: sent signal 15 to node 3 , waiting for process to exit
2024/06/10 15:48:58 cluster.go:2420: running cmd `pgrep -f cockroach\ start` on nodes [:3]; details in run_154858.617996000_n3_pgrep-f-cockroach-st.log

We don't see the timestamp but it's UTC by default I think. I thought of adding LDate in defaults but then wasn't sure if we'd want to have the date everywhere.

[renatolabs]

@cockroachdb/test-eng anyone opposed to adding Ldate to roachprod's default log flags? This issue has definitely come up before when investigating failures in the weekly test suite. I personally think it's a good default, but let me know if I'm missing something.

[vidit-bhat]

I'll make the changes

[vidit-bhat]

bors r+

[craig]

Build succeeded:

• examples_orms
• windows_build
• unit_tests
• docker_image_amd64
• acceptance
• macos_amd64_build
• check_generated_code
• macos_arm64_build
• linux_amd64_fips_build
• local_roachtest_fips
• lint
• linux_amd64_build
• linux_arm64_build
• local_roachtest