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9 | 9 | // `name` returns the name of a specified `Variable`. |
10 | 10 | // |
11 | 11 | // `lookup` retrieves the value of `Variable` in the environment. |
12 | | - |
13 | | -#include <datadog/environment_registry.h> |
14 | | -#include <datadog/expected.h> |
15 | 12 | #include <datadog/optional.h> |
16 | 13 | #include <datadog/string_view.h> |
17 | 14 |
|
18 | | -#include <cstdint> |
19 | | -#include <cstdlib> |
| 15 | +#include <string> |
20 | 16 |
|
21 | 17 | namespace datadog { |
22 | 18 | namespace tracing { |
23 | 19 | namespace environment { |
24 | 20 |
|
25 | | -enum class VariableType { |
26 | | - STRING, |
27 | | - BOOLEAN, |
28 | | - INT, |
29 | | - DECIMAL, |
30 | | - ARRAY, |
31 | | - MAP, |
32 | | -}; |
33 | | - |
34 | | -struct VariableSpec { |
35 | | - StringView name; |
36 | | - VariableType type; |
37 | | -}; |
38 | | - |
39 | | -#define VARIABLE_ENUM_VALUE(DATA, NAME, TYPE, DEFAULT_VALUE) NAME, |
40 | | - |
41 | | -enum Variable { DD_ENVIRONMENT_VARIABLES(VARIABLE_ENUM_VALUE, ~) }; |
| 21 | +// Central registry for supported environment variables. |
| 22 | +// All configurations must be registered here. |
| 23 | +// |
| 24 | +// This registry is the single source of truth for: |
| 25 | +// - env variable name allowlist (`include/datadog/environment.h`) |
| 26 | +// - generated metadata (`metadata/supported-configurations.json`) |
| 27 | +// |
| 28 | +// Each entry has: |
| 29 | +// - NAME: environment variable symbol (e.g. DD_SERVICE) |
| 30 | +// - TYPE: STRING | BOOLEAN | INT | DECIMAL | ARRAY | MAP |
| 31 | +// - DEFAULT: literal default value or a marker token |
| 32 | +// |
| 33 | +// Marker tokens: |
| 34 | +// - ENV_DEFAULT_RESOLVED_IN_CODE("...description...") |
| 35 | +// The runtime default is resolved in C++ configuration finalization |
| 36 | +// logic. The description is emitted as the "default" field in |
| 37 | +// metadata/supported-configurations.json. |
| 38 | +#define DD_LIST_ENVIRONMENT_VARIABLES(MACRO) \ |
| 39 | + MACRO(DD_AGENT_HOST, STRING, "localhost") \ |
| 40 | + MACRO(DD_ENV, STRING, "") \ |
| 41 | + MACRO(DD_INSTRUMENTATION_TELEMETRY_ENABLED, BOOLEAN, true) \ |
| 42 | + MACRO(DD_PROPAGATION_STYLE_EXTRACT, ARRAY, "datadog,tracecontext,baggage") \ |
| 43 | + MACRO(DD_PROPAGATION_STYLE_INJECT, ARRAY, "datadog,tracecontext,baggage") \ |
| 44 | + MACRO(DD_REMOTE_CONFIGURATION_ENABLED, BOOLEAN, true) \ |
| 45 | + MACRO(DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS, DECIMAL, 5.0) \ |
| 46 | + MACRO(DD_SERVICE, STRING, \ |
| 47 | + ENV_DEFAULT_RESOLVED_IN_CODE("Defaults to process name when unset.")) \ |
| 48 | + MACRO(DD_SPAN_SAMPLING_RULES, ARRAY, "[]") \ |
| 49 | + MACRO(DD_SPAN_SAMPLING_RULES_FILE, STRING, "") \ |
| 50 | + MACRO(DD_TRACE_PROPAGATION_STYLE_EXTRACT, ARRAY, \ |
| 51 | + "datadog,tracecontext,baggage") \ |
| 52 | + MACRO(DD_TRACE_PROPAGATION_STYLE_INJECT, ARRAY, \ |
| 53 | + "datadog,tracecontext,baggage") \ |
| 54 | + MACRO(DD_TRACE_PROPAGATION_STYLE, ARRAY, "datadog,tracecontext,baggage") \ |
| 55 | + MACRO(DD_TAGS, MAP, "") \ |
| 56 | + MACRO(DD_TRACE_AGENT_PORT, INT, 8126) \ |
| 57 | + MACRO(DD_TRACE_AGENT_URL, STRING, \ |
| 58 | + ENV_DEFAULT_RESOLVED_IN_CODE( \ |
| 59 | + "If unset, built from DD_AGENT_HOST and DD_TRACE_AGENT_PORT, " \ |
| 60 | + "then defaults to http://localhost:8126.")) \ |
| 61 | + MACRO(DD_TRACE_DEBUG, BOOLEAN, false) \ |
| 62 | + MACRO(DD_TRACE_ENABLED, BOOLEAN, true) \ |
| 63 | + MACRO(DD_TRACE_RATE_LIMIT, DECIMAL, 100.0) \ |
| 64 | + MACRO(DD_TRACE_REPORT_HOSTNAME, BOOLEAN, false) \ |
| 65 | + MACRO(DD_TRACE_SAMPLE_RATE, DECIMAL, 1.0) \ |
| 66 | + MACRO(DD_TRACE_SAMPLING_RULES, ARRAY, "[]") \ |
| 67 | + MACRO(DD_TRACE_STARTUP_LOGS, BOOLEAN, true) \ |
| 68 | + MACRO(DD_TRACE_TAGS_PROPAGATION_MAX_LENGTH, INT, 512) \ |
| 69 | + MACRO(DD_VERSION, STRING, "") \ |
| 70 | + MACRO(DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED, BOOLEAN, true) \ |
| 71 | + MACRO(DD_TELEMETRY_HEARTBEAT_INTERVAL, DECIMAL, 10) \ |
| 72 | + MACRO(DD_TELEMETRY_METRICS_ENABLED, BOOLEAN, true) \ |
| 73 | + MACRO(DD_TELEMETRY_METRICS_INTERVAL_SECONDS, DECIMAL, 60) \ |
| 74 | + MACRO(DD_TELEMETRY_DEBUG, BOOLEAN, false) \ |
| 75 | + MACRO(DD_TRACE_BAGGAGE_MAX_ITEMS, INT, 64) \ |
| 76 | + MACRO(DD_TRACE_BAGGAGE_MAX_BYTES, INT, 8192) \ |
| 77 | + MACRO(DD_TELEMETRY_LOG_COLLECTION_ENABLED, BOOLEAN, true) \ |
| 78 | + MACRO(DD_INSTRUMENTATION_INSTALL_ID, STRING, "") \ |
| 79 | + MACRO(DD_INSTRUMENTATION_INSTALL_TYPE, STRING, "") \ |
| 80 | + MACRO(DD_INSTRUMENTATION_INSTALL_TIME, STRING, "") \ |
| 81 | + MACRO(DD_APM_TRACING_ENABLED, BOOLEAN, true) \ |
| 82 | + MACRO(DD_TRACE_RESOURCE_RENAMING_ENABLED, BOOLEAN, false) \ |
| 83 | + MACRO(DD_TRACE_RESOURCE_RENAMING_ALWAYS_SIMPLIFIED_ENDPOINT, BOOLEAN, false) \ |
| 84 | + MACRO(DD_EXTERNAL_ENV, STRING, "") |
| 85 | + |
| 86 | +#define ENV_DEFAULT_RESOLVED_IN_CODE(X) X |
| 87 | +#define WITH_COMMA(ARG, TYPE, DEFAULT_VALUE) ARG, |
| 88 | + |
| 89 | +enum Variable { DD_LIST_ENVIRONMENT_VARIABLES(WITH_COMMA) }; |
42 | 90 |
|
43 | 91 | // Quoting a macro argument requires this two-step. |
44 | 92 | #define QUOTED_IMPL(ARG) #ARG |
45 | 93 | #define QUOTED(ARG) QUOTED_IMPL(ARG) |
46 | 94 |
|
47 | | -#define VARIABLE_SPEC_WITH_COMMA(DATA, NAME, TYPE, DEFAULT_VALUE) \ |
48 | | - VariableSpec{StringView{QUOTED(NAME)}, VariableType::TYPE}, |
49 | | - |
50 | | -inline const VariableSpec variable_specs[] = { |
51 | | - DD_ENVIRONMENT_VARIABLES(VARIABLE_SPEC_WITH_COMMA, ~)}; |
52 | | - |
53 | | -template <VariableType type> |
54 | | -struct LookupResultByType; |
55 | | - |
56 | | -template <> |
57 | | -struct LookupResultByType<VariableType::STRING> { |
58 | | - using type = Optional<StringView>; |
59 | | -}; |
60 | | - |
61 | | -template <> |
62 | | -struct LookupResultByType<VariableType::BOOLEAN> { |
63 | | - using type = Optional<bool>; |
64 | | -}; |
65 | | - |
66 | | -template <> |
67 | | -struct LookupResultByType<VariableType::INT> { |
68 | | - using type = Expected<Optional<std::uint64_t>>; |
69 | | -}; |
| 95 | +#define QUOTED_WITH_COMMA(ARG, TYPE, DEFAULT_VALUE) \ |
| 96 | + WITH_COMMA(QUOTED(ARG), TYPE, DEFAULT_VALUE) |
70 | 97 |
|
71 | | -template <> |
72 | | -struct LookupResultByType<VariableType::DECIMAL> { |
73 | | - using type = Expected<Optional<double>>; |
74 | | -}; |
| 98 | +inline const char *const variable_names[] = { |
| 99 | + DD_LIST_ENVIRONMENT_VARIABLES(QUOTED_WITH_COMMA)}; |
75 | 100 |
|
76 | | -template <> |
77 | | -struct LookupResultByType<VariableType::ARRAY> { |
78 | | - using type = Optional<StringView>; |
79 | | -}; |
80 | | - |
81 | | -template <> |
82 | | -struct LookupResultByType<VariableType::MAP> { |
83 | | - using type = Optional<StringView>; |
84 | | -}; |
85 | | - |
86 | | -template <Variable variable> |
87 | | -struct VariableTraits; |
88 | | - |
89 | | -#define VARIABLE_TRAITS_VALUE(DATA, NAME, TYPE, DEFAULT_VALUE) \ |
90 | | - template <> \ |
91 | | - struct VariableTraits<NAME> { \ |
92 | | - static constexpr VariableType variable_type = VariableType::TYPE; \ |
93 | | - static constexpr const char *name() { return QUOTED(NAME); } \ |
94 | | - using lookup_result = typename LookupResultByType<variable_type>::type; \ |
95 | | - }; |
96 | | - |
97 | | -DD_ENVIRONMENT_VARIABLES(VARIABLE_TRAITS_VALUE, ~) |
98 | | - |
99 | | -template <Variable variable> |
100 | | -using LookupResult = typename VariableTraits<variable>::lookup_result; |
101 | | - |
102 | | -namespace detail { |
103 | | -template <VariableType> |
104 | | -inline constexpr bool unsupported_variable_type_v = false; |
105 | | - |
106 | | -template <Variable variable> |
107 | | -Optional<StringView> lookup_raw() { |
108 | | - const char *value = std::getenv(VariableTraits<variable>::name()); |
109 | | - if (!value) { |
110 | | - return nullopt; |
111 | | - } |
112 | | - return StringView{value}; |
113 | | -} |
114 | | - |
115 | | -Optional<bool> lookup_bool_from_raw(Optional<StringView> value); |
116 | | -Expected<Optional<std::uint64_t>> lookup_uint64_from_raw( |
117 | | - Optional<StringView> value); |
118 | | -Expected<Optional<double>> lookup_double_from_raw(Optional<StringView> value); |
119 | | -} // namespace detail |
120 | | - |
121 | | -template <Variable variable> |
122 | | -LookupResult<variable> lookup() { |
123 | | - constexpr VariableType type = VariableTraits<variable>::variable_type; |
124 | | - const auto raw = detail::lookup_raw<variable>(); |
125 | | - if constexpr (type == VariableType::STRING || type == VariableType::ARRAY || |
126 | | - type == VariableType::MAP) { |
127 | | - return raw; |
128 | | - } else if constexpr (type == VariableType::BOOLEAN) { |
129 | | - return detail::lookup_bool_from_raw(raw); |
130 | | - } else if constexpr (type == VariableType::INT) { |
131 | | - return detail::lookup_uint64_from_raw(raw); |
132 | | - } else if constexpr (type == VariableType::DECIMAL) { |
133 | | - return detail::lookup_double_from_raw(raw); |
134 | | - } else { |
135 | | - static_assert(detail::unsupported_variable_type_v<type>, |
136 | | - "Unsupported environment variable type"); |
137 | | - } |
138 | | -} |
139 | | - |
140 | | -#undef VARIABLE_SPEC_WITH_COMMA |
141 | | -#undef VARIABLE_TRAITS_VALUE |
142 | 101 | #undef QUOTED |
143 | 102 | #undef QUOTED_IMPL |
144 | | -#undef VARIABLE_ENUM_VALUE |
145 | | - |
146 | | -// Return the metadata for the specified environment `variable`. |
147 | | -const VariableSpec &spec(Variable variable); |
| 103 | +#undef WITH_COMMA |
| 104 | +#undef ENV_DEFAULT_RESOLVED_IN_CODE |
148 | 105 |
|
149 | 106 | // Return the name of the specified environment `variable`. |
150 | 107 | StringView name(Variable variable); |
151 | 108 |
|
| 109 | +// Return the value of the specified environment `variable`, or return |
| 110 | +// `nullopt` if that variable is not set in the environment. |
| 111 | +Optional<StringView> lookup(Variable variable); |
| 112 | + |
152 | 113 | std::string to_json(); |
153 | 114 |
|
154 | 115 | } // namespace environment |
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