Summary: Adds new TraceProgram object to pxtrace which accepts a BPFtrace program and selectors to specify deployment restrictions as key value arguments. Also modifies the probe_fn argument to pxtrace.UpsertTracepoint to accept a single TraceProgram object or a list of them, extracting selectors and populating TracepointDeployment as required, so that the query broker can register tracepoints with agents that match those selectors.

Example usage

import pxtrace
import px

before_518_trace_program = pxtrace.TraceProgram(
  program="""$0""",
  max_kernel='5.18',
)
after_519_trace_program = pxtrace.TraceProgram(
  program="""$1""",
  min_kernel='5.19',
)

table_name = 'tcp_drop_table'
pxtrace.UpsertTracepoint('tcp_drop_tracer',
                          table_name,
                          [before_518_trace_program, after_519_trace_program],
                          pxtrace.kprobe(),
                          '10m')
)pxl";

Related issues: #1582. Closes #1659.

Type of change: /kind feature

Test Plan: Tested all existing targets, added compiler tests to src/carnot/planner/logical_planner_test.cc and src/carnot/planner/probes/probes_test.cc, and skaffolded changes to a cluster, verifying expected behavior and interoperability with selectors introduced in PR #1686.

Known issues

• Two or more programs on one PEM: If selectors are specified such that two or more bpftrace programs are deployed to a PEM as part of a single TracepointDeployment, stirling throws an error stirling.cc:511 error::Internal("Only one Tracepoint is currently supported.");. This is an existing limitation, which is a little more exposed as a result of the selector feature introduced in this PR. To mitigate this, we could add documentation, improve the error message, and/or have just one of the bpftrace programs in the TracepointDeployment run.
• Schemas differ: If the schemas of two bpftrace programs passed to one pxtrace.UpsertTracepoint call differ, only one of the schemas will be used to the create the output table (currently the first one that is processed). When the program whose schema differs tries to push a record to the table, we get the error source_connector.cc:64] Failed to push data. Message = Table_id ## doesn't exist. The user has to manually create another table/make another call to UpsertTracepoint if they want to deploy bpftrace programs with different schemas.