{"record":{"id":"67c5660928355e8f","repo":"firecracker-microvm/firecracker","slug":"mmds-error-metadata-provided-not-valid-json","errorCode":null,"errorMessage":"MMDS error: metadata provided not valid json","messagePattern":"MMDS error: metadata provided not valid json","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/vmm/src/resources.rs","lineNumber":216,"sourceCode":"            resources.set_block_device(drive_config)?;\n        }\n\n        for net_config in vmm_config.network_interfaces.into_iter() {\n            resources.build_net_device(net_config)?;\n        }\n\n        if let Some(vsock_config) = vmm_config.vsock {\n            resources.set_vsock_device(vsock_config)?;\n        }\n\n        if let Some(balloon_config) = vmm_config.balloon {\n            resources.set_balloon_device(balloon_config)?;\n        }\n\n        // Init the data store from file, if present.\n        if let Some(data) = metadata_json {\n            resources.locked_mmds_or_default()?.put_data(\n                serde_json::from_str(data).expect(\"MMDS error: metadata provided not valid json\"),\n            )?;\n            info!(\"Successfully added metadata to mmds from file\");\n        }\n\n        if let Some(mmds_config) = vmm_config.mmds_config {\n            resources.set_mmds_config(mmds_config, &instance_info.id)?;\n        }\n\n        if let Some(entropy_device_config) = vmm_config.entropy {\n            resources.build_entropy_device(entropy_device_config)?;\n        }\n\n        for pmem_config in vmm_config.pmem_devices.into_iter() {\n            resources.build_pmem_device(pmem_config)?;\n        }\n\n        if let Some(serial_cfg) = vmm_config.serial_config {\n            resources.serial_out_path = serial_cfg.serial_out_path;","sourceCodeStart":198,"sourceCodeEnd":234,"githubUrl":"https://github.com/firecracker-microvm/firecracker/blob/a5a45f68b862689efa31ea0847695c108d872121/src/vmm/src/resources.rs#L198-L234","documentation":"Error \"MMDS error: metadata provided not valid json\" thrown in firecracker-microvm/firecracker.","triggerScenarios":"Thrown at src/vmm/src/resources.rs:216 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Validate the MMDS metadata as well-formed JSON before sending the PUT/PATCH request.","Check for truncated request bodies and encoding issues in the metadata payload."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"a5a45f68b862689efa31ea0847695c108d872121","analyzedAt":"2026-08-19T05:27:02.517Z","contentChangedAt":"2026-08-19T05:27:02.517Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}