Add Azure Linux support to MongoDB/YCSB workload (declarative SupportedLinuxDistributions filtering)

[moprashant]

Summary

Adds Azure Linux 3 (Mariner) support to the MongoDB/YCSB workload, which previously ran on Ubuntu only. Also fixes two product bugs in MongoDBServerExecutor that prevented the server from starting on any RPM-based distribution, and adds a reusable SupportedLinuxDistributions parameter to VirtualClientComponent.

Note for reviewers: this is one of two alternative implementations. The companion PR (mongodb-azurelinux-runtime-detection) achieves the same outcome by detecting the package manager at runtime inside the shell steps. Only one should be merged — they conflict in PERF-MONGODB-YCSB.json. Both share the identical C# fixes. This PR is the more declarative option: each distro's install steps are visible in the profile, at the cost of a longer dependency list and a new framework-level parameter.

Product fixes (MongoDBServerExecutor.cs)

These are genuine bugs, not Azure-Linux-specific workarounds:

1. Hardcoded mongodb service account. The data directory was chowned to a hardcoded mongodb user. RPM packages create the account as mongod, so mongod could not write to its own dbPath and failed to start. Now resolved at runtime per package family (mongodb on Debian/Ubuntu, mongod on RPM).

2. MongoDB port never opened on the local firewall. Ubuntu's default iptables INPUT policy is ACCEPT, so this was silently unnecessary there. Azure Linux defaults to DROP, so the client could never reach the server. InitializeAsync now opens the port via the existing IFirewallManager.

Framework change (VirtualClientComponent.cs)

Adds a SupportedLinuxDistributions parameter allowing any component to declare which Linux distributions it applies to. Components whose distribution doesn't match are skipped. Matching is case-insensitive, whitespace-tolerant, comma-delimited, and honours upstream/downstream distro relationships.

This is generally reusable beyond MongoDB, but note it expands the framework surface area — reviewers may prefer the companion PR if that isn't desirable.

Profile changes (PERF-MONGODB-YCSB.json)

• Dependency steps carry explicit SupportedLinuxDistributions values (Debian,Ubuntu vs AzureLinux), so the install path for each distro is declared rather than inferred.
• Adds lshw and gnupg2, which Ubuntu images preinstall but Azure Linux does not.
• Adds -p mongodb.upsert=true to the Read_Latest and Short_Range_Scan scenarios (see below).

Fixes pre-existing duplicate-key insert failures

Read_Latest (workloadd) and Short_Range_Scan (workloade) both perform 5% run-phase inserts. YCSB seeds both insert sequences at recordcount, so whichever runs second collides on every insert:

E11000 duplicate key error collection: ycsb.usertable index: _id_

The error count matched INSERT-FAILED-Operations exactly (3445/3445). This is pre-existing on main and reproduces identically on Ubuntu — it is not introduced or caused by Azure Linux. mongodb.upsert=true is the documented remedy for a partially loaded data set.

Behavioural note: colliding inserts now become updates, so INSERT latency is measured where it previously reported 0 successful ops. RecordCount, metric names, the operation mix, and scenario names are unchanged.

Testing

Unit tests (new):

• MongoDBServerExecutorTests: ..._ResolvesTheMongoDBServiceUserForThePlatform, ..._OpensTheMongoDBPortOnTheLocalFirewall
• VirtualClientComponentTests: 12 cases covering empty/undefined parameters, delimited parsing, case and whitespace tolerance, downstream-distro matching, non-Linux platforms, and interaction with SupportedPlatforms

92/92 MongoDB tests and 12/12 SupportedLinuxDistributions tests pass against current main.

End-to-end, two-VM client/server (Standard_D8s_v5):

Distro	Result
Ubuntu 24.04	Exit Code 0 — 7/7 scenarios, 0 failed operations
Azure Linux 3	Exit Code 0 — 7/7 scenarios (validated prior to the upsert change; see below)

Distro filtering was verified directly on Ubuntu: all three AzureLinux-only steps executed 0 times and dnf was invoked 0 times.

Ubuntu regression risk was explicitly exercised, not just reasoned about: the firewall rule was flushed before the Ubuntu run so the new code path genuinely executed, and it completed without throwing. Measured data-directory ownership confirmed mongodb on Ubuntu and mongod on Azure Linux.

Known gap

The Azure Linux end-to-end run for this branch predates the mongodb.upsert change. The upsert change is byte-identical to the companion PR, which was validated end-to-end on Azure Linux with it applied — but for full transparency, this exact combination was not re-run here.

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[moprashant]

Alternative implementation of the same feature: #783 (runtime package-manager detection, keeps the profile scenario list identical to \main). These two PRs conflict in \PERF-MONGODB-YCSB.json\ — only one should be merged. Happy to close whichever the team doesn't prefer.

[moprashant]

Added one commit here: the AzureLinux line in website/docs/workloads/mongodb/mongodb-profiles.md.

That was the only change in #783 not already covered by this PR. The profile metadata already declared "SupportedOperatingSystems": "AzureLinux,Ubuntu", but the docs page still listed Ubuntu only, so the two had drifted. #783 is now closed in favour of this PR.

The diff is a single added line:

 * **Supported Operating Systems**
+  * AzureLinux
   * Ubuntu

Bryan DeYoung (@brdeyo) apologies -- pushing this dismissed your approval. Could I get a re-approve when you have a moment? All 5 checks are green, and no code changed since you reviewed.

[moprashant]

This PR is now fully ready to merge — all blockers are cleared:

• reviewDecision: APPROVED (Bryan DeYoung (@brdeyo) — thank you for re-approving after the docs commit)
• mergeStateStatus: CLEAN
• mergeable: MERGEABLE
• All 5 checks green: CodeQL, Document Website Build Check, PR build + test (Linux), Pull request build + test, license/cla

I refreshed the branch against main (it had fallen behind) and CI re-ran clean on the merged result.

Could a maintainer with write access please squash-merge this? I only have pull permission, so both mergePullRequest and enablePullRequestAutoMerge are denied for my account.