Price oracle (#11)

* update services

aqua-examples/price-oracle/air-scripts/get_crypto_prices.get_price.air

@@ -0,0 +1,61 @@
+(xor
+ (seq
+  (seq
+   (seq
+    (seq
+     (seq
+      (seq
+       (seq
+        (seq
+         (seq
+          (call %init_peer_id% ("getDataSrv" "-relay-") [] -relay-)
+          (call %init_peer_id% ("getDataSrv" "coin") [] coin)
+         )
+         (call %init_peer_id% ("getDataSrv" "currency") [] currency)
+        )
+        (call %init_peer_id% ("getDataSrv" "node") [] node)
+       )
+       (call %init_peer_id% ("getDataSrv" "pg_sid") [] pg_sid)
+      )
+      (call %init_peer_id% ("getDataSrv" "mean_sid") [] mean_sid)
+     )
+     (call -relay- ("op" "noop") [])
+    )
+    (xor
+     (seq
+      (seq
+       (seq
+        (seq
+         (seq
+          (seq
+           (seq
+            (call node ("op" "string_to_b58") [node] k)
+            (call node ("peer" "timestamp_ms") [] ts_ms0)
+           )
+           (call node (pg_sid "price_getter") [coin currency ts_ms0] res0)
+          )
+          (call node ("op" "identity") [res0.$.result!] $prices)
+         )
+         (call node ("peer" "timestamp_ms") [] ts_ms1)
+        )
+        (call node (pg_sid "price_getter") [coin currency ts_ms1] res1)
+       )
+       (call node ("op" "identity") [res1.$.result!] $prices)
+      )
+      (call node (mean_sid "mean") [$prices] result)
+     )
+     (seq
+      (call -relay- ("op" "noop") [])
+      (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 1])
+     )
+    )
+   )
+   (call -relay- ("op" "noop") [])
+  )
+  (xor
+   (call %init_peer_id% ("callbackSrv" "response") [result])
+   (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 2])
+  )
+ )
+ (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 3])
+)

aqua-examples/price-oracle/air-scripts/get_crypto_prices.get_prices_par.air

@@ -0,0 +1,47 @@
+(xor
+ (seq
+  (seq
+   (seq
+    (seq
+     (call %init_peer_id% ("getDataSrv" "-relay-") [] -relay-)
+     (call %init_peer_id% ("getDataSrv" "payload") [] payload)
+    )
+    (call %init_peer_id% ("getDataSrv" "ns_pairs") [] ns_pairs)
+   )
+   (fold ns_pairs p
+    (par
+     (seq
+      (seq
+       (call -relay- ("op" "noop") [])
+       (xor
+        (seq
+         (call p.$.node! ("op" "string_to_b58") [p.$.node!] k)
+         (fold payload d
+          (seq
+           (seq
+            (call p.$.node! ("peer" "timestamp_ms") [] ts_ms)
+            (call p.$.node! (p.$.service_id! "price_getter") [d.$.coin! d.$.currency! ts_ms] $prices)
+           )
+           (next d)
+          )
+         )
+        )
+        (seq
+         (call -relay- ("op" "noop") [])
+         (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 1])
+        )
+       )
+      )
+      (call %init_peer_id% ("op" "noop") [])
+     )
+     (next p)
+    )
+   )
+  )
+  (xor
+   (call %init_peer_id% ("callbackSrv" "response") [$prices])
+   (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 2])
+  )
+ )
+ (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 3])
+)

aqua-examples/price-oracle/air-scripts/get_crypto_prices.get_prices_par_2.air

@@ -0,0 +1,39 @@
+(xor
+ (seq
+  (seq
+   (seq
+    (call %init_peer_id% ("getDataSrv" "-relay-") [] -relay-)
+    (call %init_peer_id% ("getDataSrv" "payload") [] payload)
+   )
+   (fold payload p
+    (par
+     (seq
+      (seq
+       (call -relay- ("op" "noop") [])
+       (xor
+        (seq
+         (seq
+          (call p.$.node! ("op" "string_to_b58") [p.$.node!] k)
+          (call p.$.node! ("peer" "timestamp_ms") [] ts_ms)
+         )
+         (call p.$.node! (p.$.service_id! "price_getter") [p.$.coin! p.$.currency! ts_ms] $prices)
+        )
+        (seq
+         (call -relay- ("op" "noop") [])
+         (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 1])
+        )
+       )
+      )
+      (call %init_peer_id% ("op" "noop") [])
+     )
+     (next p)
+    )
+   )
+  )
+  (xor
+   (call %init_peer_id% ("callbackSrv" "response") [$prices])
+   (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 2])
+  )
+ )
+ (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 3])
+)

aqua-examples/price-oracle/air-scripts/get_crypto_prices.get_prices_seq.air

@@ -0,0 +1,47 @@
+(xor
+ (seq
+  (seq
+   (seq
+    (seq
+     (call %init_peer_id% ("getDataSrv" "-relay-") [] -relay-)
+     (call %init_peer_id% ("getDataSrv" "payloads") [] payloads)
+    )
+    (call %init_peer_id% ("getDataSrv" "ns_pairs") [] ns_pairs)
+   )
+   (fold ns_pairs p
+    (seq
+     (seq
+      (seq
+       (call -relay- ("op" "noop") [])
+       (xor
+        (seq
+         (call p.$.node! ("op" "string_to_b58") [p.$.node!] k)
+         (fold payloads d
+          (seq
+           (seq
+            (call p.$.node! ("peer" "timestamp_ms") [] ts_ms)
+            (call p.$.node! (p.$.service_id! "price_getter") [d.$.coin! d.$.currency! ts_ms] $prices)
+           )
+           (next d)
+          )
+         )
+        )
+        (seq
+         (call -relay- ("op" "noop") [])
+         (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 1])
+        )
+       )
+      )
+      (call -relay- ("op" "noop") [])
+     )
+     (next p)
+    )
+   )
+  )
+  (xor
+   (call %init_peer_id% ("callbackSrv" "response") [$prices])
+   (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 2])
+  )
+ )
+ (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 3])
+)

aqua-examples/price-oracle/aqua-scripts/builtin.aqua

@@ -0,0 +1,217 @@
+-- Default public interface of Fluence nodes
+
+alias Field : []string
+alias Argument : []string
+alias Bytes : []u8
+alias PeerId : string
+alias Pairs : [][]string
+alias Base58String : string
+
+-- There are two types of dependencies: named and by-hash. 
+-- name:foobar      – specifies dependency by module name, points to a module with import name 'foobar'
+-- hash:04dc884...  – specifies dependency by module hash
+-- By-hash dependencies are preffered since they are deteremenistic 
+-- while by-name dependency can yield different modules at different points in time
+alias Dependency : string
+
+data Service:
+    id: string
+    blueprint_id: string
+    owner_id: string
+
+data FunctionSignature:
+    arguments: []Argument
+    name: string
+    output_types: []string
+
+data RecordType:
+    fields: []Field
+    id: u64
+    name: string
+
+data Interface:
+    function_signatures: []FunctionSignature
+    record_types: []RecordType
+
+data Info:
+    external_addresses: []string
+
+data ModuleConfig:
+    name: string
+
+data Module:
+    name: string
+    hash: string
+    config: ModuleConfig
+
+data AddBlueprint:
+    name: string
+    dependencies: []Dependency
+
+data Blueprint:
+    id: string
+    name: string
+    dependencies: []Dependency
+
+data ScriptInfo:
+    id: string
+    src: string
+    failures: u32
+    interval: string
+    owner: string
+
+data Contact:
+    peer_id: string
+    addresses: []string
+
+service Op("op"):
+    -- does nothing
+    noop()
+    -- returns length of the passed array
+    array_length(array: []string) -> u32
+    -- takes any number of arguments and wraps them into a single array
+    array(a: string, b: ?string, c: ?string, d: ?string) -> []string
+    -- takes any number of arrays and flattens them by concatenating
+    concat(a: []string, b: ?[]string, c: ?[]string, d: ?[]string) -> []string
+    -- takes a single argument and returns it back
+    identity(s: ?string) -> ?string
+    string_to_b58(s: string) -> Base58String
+    string_from_b58(b: Base58String) -> string
+    bytes_to_b58(bs: []u8) -> Base58String
+    bytes_from_b58(b: Base58String) -> []u8
+    -- Applies SHA256 to the given string
+    -- Argument: s - string to apply sha256 to (hash is applied to utf8 bytes of s)
+    -- Returns: returns sha256 multihash encoded as base58
+    sha256_string(s: string) -> Base58String
+
+service Peer("peer"):
+    -- Checks if there is a direct connection to the peer identified by a given PeerId
+    -- Argument: PeerId – id of the peer to check if there's a connection with
+    -- Returns: bool - true if connected to the peer, false otherwise
+    is_connected(peer: PeerId) -> bool
+
+    -- Initiates a connection to the specified peer
+    -- Arguments:
+    --  id - id of the target peer
+    --  multiaddrs – an array of target peer's addresses
+    -- Returns: bool - true if connection was successful
+    connect(id: PeerId, multiaddrs: ?[]string) -> bool
+    -- Resolves the contact of a peer via Kademlia
+    -- Argument: PeerId – id of the target peer
+    -- Returns: Contact - true if connection was successful
+    get_contact(peer: PeerId) -> Contact
+
+    -- Get information about the peer
+    identify() -> Info
+
+    -- Get Unix timestamp in milliseconds
+    timestamp_ms() -> u64
+
+    -- Get Unix timestamp in seconds
+    timestamp_sec() -> u64
+
+service Kademlia("kad"):
+    -- Instructs node to return the locally-known nodes
+    -- in the Kademlia neighborhood for a given key
+    -- Arguments:
+    --  key – base58 string
+    --  already_hashed – default false; if set to true, key is considered to be a SHA256 multihash
+    --  count – default 20; limits number of returned nodes
+    neighborhood(key: Base58String, already_hashed: ?bool, count: ?u32) -> []PeerId
+    -- Merges given lists and sorts them by distance to target
+    -- Arguments:
+    --  target – base58 string; result is sorted by XOR distance to target
+    --  left – list of base58 strings
+    --  right – list of base58 strings
+    --  count – how many items to return, unlimited by default
+    -- Returns: list of base58 strings sorted by distance to target; list will contain at most count elements
+    merge(target: Base58String, left: []string, right: []string, count: ?u32) -> []string
+
+service Srv("srv"):
+    -- Used to create a service on a certain node
+    -- Arguments:
+    --  blueprint_id – ID of the blueprint that has been added to the node specified in the service call by the dist add_blueprint service.
+    -- Returns: service_id – the service ID of the created service.
+    create(blueprint_id: string) -> string
+
+    -- Used to remove a service from a certain node
+    -- Arguments:
+    --  service_id – ID of the service to remove
+    remove(service_id: string)
+
+    -- Returns a list of services running on a peer
+    list() -> []Service
+
+    -- Adds an alias on service, so, service could be called
+    -- not only by service_id but by alias as well.
+    -- Arguments:
+    --  alias - settable service name
+    --  service_id – ID of the service whose interface you want to name.
+    add_alias(alias: string, service_id: string)
+
+    -- Resolves given alias to a service id
+    -- If there's no such alias, throws an error
+    -- Returns: service id associated with the given alias
+    resolve_alias(alias: string) -> string
+
+    -- Retrieves the functional interface of a service running
+    -- on the node specified in the service call
+    -- Argument: service_id – ID of the service whose interface you want to retrieve.
+    get_interface(service_id: string) -> Interface
+
+service Dist("dist"):
+    -- Constructs a ModuleConfig structure
+    -- Arguments:
+    --  module_name        - import name of the module
+    --  mem_pages_count    - Maximum memory size accessible by a module in Wasm pages (64 Kb)
+    --  logger_enabled     - Defines whether Marine should provide a special host log_utf8_string function for this module
+    --  preopened_files    - Files available for this module. Module can access only files from this list
+    --  envs               - environment variables available for this module
+    --  mapped_dirs        - Directory mapping, e.g. [["/sites", "./web/data"]] so all 
+    --                       reads & writes to /sites will actually to go ./web/data
+    --  mounted_binaries   - Mapping of host binaries available to call from module, 
+    --                       e.g. [["curl", "/usr/bin/curl"]] will allow module to 
+    --                       call /usr/bin/curl binary as function 'curl'
+    --  logging_mask       - Binary mask to enable & disable logging targets. Targets are
+    --                       configured in WasmLoggerBuilder::with_target_map
+    --  mem_pages_count    - Maximum memory size accessible by a module in Wasm pages (64 Kb)
+    make_module_config(name: string, mem_pages_count: ?u32, logger_enabled: ?bool, preopened_files: ?[]string, envs: ?Pairs, mapped_dirs: ?Pairs, mounted_binaries: ?Pairs, logging_mask: ?i32) -> ModuleConfig
+
+    -- Used to add modules to the node specified in the service call
+    -- Arguments:
+    --  bytes – a base64 string containing the .wasm module to add.
+    --  config – module info
+    --  Returns: blake3 hash of the module
+    add_module(wasm_b56_content: Bytes, conf: ModuleConfig) -> string
+
+    -- Get a list of modules available on the node
+    list_modules() -> []Module
+
+    -- Get the interface of a module
+    get_interface(module_id: string) -> Interface
+
+    -- Creates Blueprint structure from from blueprint name and dependencies (modules)
+    make_blueprint(name: string, dependencies: []Dependency) -> AddBlueprint
+    -- Add a blueprint to the node
+    add_blueprint(blueprint: AddBlueprint) -> string
+
+    -- Used to get the blueprints available on the node specified in the service call.
+    -- A blueprint is an object of the following structure
+    list_blueprints() -> []Blueprint
+
+service Script("script"):
+    -- Adds the given script to a node
+    -- Arguments:
+    --  air_script - raw AIR script without any undefined variables
+    --  interval   - if not set, script will be ran only once
+    --               if set, script will be ran once in the interval 
+    --               (NOTE: actual interval may vary by up to 3 seconds)
+    -- TODO: change interval to ?u64 when node API is updated
+    add(air_script: string, interval: ?string) -> string
+
+    -- Removes recurring script from a node. Only a creator of the script can delete it
+    remove(script_id: string) -> bool
+
+    -- Returns a list of existing scripts on the node.
+    -- Each object in the list is of the following structure
+    list() -> ScriptInfo

aqua-examples/price-oracle/aqua-scripts/get_crypto_prices.aqua

@@ -0,0 +1,49 @@
+-- import "@fluencelabs/aqua-lib/builtin.aqua"
+import "builtin.aqua"
+
+data Result:
+  result: f64
+  success: bool
+  error_msg: string
+
+service PriceGetterService:
+  price_getter(coin: string, currency: string, timestamp_ms: u64) -> Result
+
+service MeanService:
+  mean(data: []f64) -> Result
+
+service F64Op("op"):
+    identity(x:f64) -> f64
+
+data Payload:
+    coin: string
+    currency: string
+
+data NodeServicePair:
+    node: string
+    service_id: string
+
+-- func get_price(coin: string, currency: string, node: string, service_id: string, logError:string, string -> ()) -> Result:
+func get_price(coin: string, currency: string, node: string, pg_sid: string, mean_sid: string) -> Result:
+    prices: *f64
+    on node:
+        k <- Op.string_to_b58(node)
+        
+        PriceGetterService pg_sid
+        MeanService mean_sid
+
+        ts_ms0 <- Peer.timestamp_ms()
+        res0 <- PriceGetterService.price_getter(coin, currency, ts_ms0)
+        -- if price.success:
+        prices <- F64Op.identity(res0.result)
+
+        ts_ms1 <- Peer.timestamp_ms()
+        res1 <- PriceGetterService.price_getter(coin, currency, ts_ms1)
+        -- if price.success:
+        prices <- F64Op.identity(res1.result)
+
+        result <- MeanService.mean(prices)
+        -- else:
+             --    logError("price_getter: ", price.error_msg)
+    <- result
+

aqua-examples/price-oracle/configs/Config.toml

@@ -0,0 +1,19 @@
+modules_dir = "artifacts/"
+
+[[module]]
+    name = "curl_adapter"
+    logger_enabled = false
+    mem_pages_count = 1
+
+    [module.mounted_binaries]
+    curl = "/usr/bin/curl"
+
+[[module]]
+    name = "price_getter_service"
+    logger_enabled = false
+    mem_pages_count = 1
+
+[[module]]
+    name = "mean_service"
+    logger_enabled = false
+    mem_pages_count = 1

aqua-examples/price-oracle/configs/curl_adapter_cfg.json

@@ -0,0 +1,8 @@
+{
+    "name": "curl_adapter",
+    "mountedBinaries": {
+        "curl": "/usr/bin/curl"
+    },
+    "mem_page_count": 1,
+    "logger_enabled": false
+}

aqua-examples/price-oracle/configs/mean_service_cfg.json

@@ -0,0 +1,5 @@
+{
+    "name": "mean_service",
+    "mem_page_count": 1,
+    "logger_enabled": false
+}

aqua-examples/price-oracle/configs/price_getter_service_cfg.json

@@ -0,0 +1,5 @@
+{
+    "name": "price_getter_service",
+    "mem_page_count": 1,
+    "logger_enabled": false
+}

aqua-examples/price-oracle/curl_adapter/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "curl_adapter"
+version = "0.1.0"
+authors = ["Fluence Labs"]
+edition = "2018"
+publish = false
+
+[[bin]]
+path = "src/main.rs"
+name = "curl_adapter"
+
+[dependencies]
+marine-rs-sdk = "0.6.11"
+log = "0.4.8"

aqua-examples/price-oracle/curl_adapter/src/main.rs

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2021 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#![allow(improper_ctypes)]
+
+use marine_rs_sdk::marine;
+use marine_rs_sdk::module_manifest;
+
+use marine_rs_sdk::MountedBinaryResult;
+
+module_manifest!();
+
+pub fn main() {}
+
+#[marine]
+pub fn curl_request(cmd: Vec<String>) -> MountedBinaryResult {
+    curl(cmd)
+}
+
+#[marine]
+#[link(wasm_import_module = "host")]
+extern "C" {
+    fn curl(cmd: Vec<String>) -> MountedBinaryResult;
+}

aqua-examples/price-oracle/data/deployed_services.json

@@ -0,0 +1,16 @@
+[
+    {
+        "service": "price_getter",
+        "deployed": [
+            "12D3KooWCMr9mU894i8JXAFqpgoFtx6qnV1LFPSfVc3Y34N4h4LS",
+            "c315073d-4311-4db3-be57-8f154f032d28"
+        ]
+    },
+    {
+        "service": "mean",
+        "deployed": [
+            "12D3KooWCMr9mU894i8JXAFqpgoFtx6qnV1LFPSfVc3Y34N4h4LS",
+            "dd47389f-25d9-4870-a2a9-909359e73580"
+        ]
+    }
+]

aqua-examples/price-oracle/mean_service/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "price_getter_service"
+version = "0.1.0"
+authors = ["boneyard93501 <4523011+boneyard93501@users.noreply.github.com>"]
+edition = "2018"
+description = "price-getter-service, a Marine wasi module"
+license = "Apache-2.0"
+
+[[bin]]
+name = "mean_service"
+path = "src/main.rs"
+
+[dependencies]
+marine-rs-sdk = "0.6.11"
+log = "0.4.14"
+
+[dev-dependencies]
+marine-rs-sdk-test = "0.1.11"
+
+[dev]
+[profile.release]
+opt-level = "s"

aqua-examples/price-oracle/mean_service/src/main.rs

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2021 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+use marine_rs_sdk::{marine, module_manifest};
+
+module_manifest!();
+
+fn main() {}
+
+#[marine]
+pub struct Result {
+    pub result: f64,
+    pub success: bool,
+    pub error_msg: String,
+}
+
+#[marine]
+pub fn mean(data: Vec<f64>) -> Result {
+    match calc_mean(data.iter()) {
+        Some(res) => Result {
+            result: res,
+            success: true,
+            error_msg: "".to_string(),
+        },
+        None => Result {
+            result: -1f64,
+            success: false,
+            error_msg: "Failure to calculate mean. Check your inputs.".to_string(),
+        },
+    }
+}
+
+fn calc_mean<'a>(data: impl ExactSizeIterator<Item = &'a f64>) -> Option<f64> {
+    let n = data.len() as u64;
+    if n < 1 {
+        return None;
+    }
+    let res = (data.sum::<f64>() / n as f64) as f64;
+    let res = format!("{:.2}", res).parse::<f64>().unwrap();
+    Some(res)
+}

aqua-examples/price-oracle/price_getter_service/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "price_getter_service"
+version = "0.1.0"
+authors = ["boneyard93501 <4523011+boneyard93501@users.noreply.github.com>"]
+edition = "2018"
+description = "price-getter-service, a Marine wasi module"
+license = "Apache-2.0"
+
+[[bin]]
+name = "price_getter_service"
+path = "src/main.rs"
+
+[dependencies]
+marine-rs-sdk = "0.6.11"
+log = "0.4.14"
+picorand = "0.1.1"
+fstrings = "0.2.3"
+hex = "0.4.3"
+serde_json = "1.0.57"
+
+[dev-dependencies]
+marine-rs-sdk-test = "0.1.11"
+
+[dev]
+[profile.release]
+opt-level = "s"

aqua-examples/price-oracle/price_getter_service/src/main.rs

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2021 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use hex;
+use marine_rs_sdk::{marine, module_manifest, MountedBinaryResult};
+use picorand::{PicoRandGenerate, WyRand, RNG};
+use serde_json;
+
+#[macro_use]
+extern crate fstrings;
+
+module_manifest!();
+
+pub fn main() {}
+
+#[marine]
+pub struct Result {
+    pub result: f64,
+    pub success: bool,
+    pub error_msg: String,
+}
+
+#[marine]
+pub fn price_getter(coin: String, currency: String, timestamp_ms: u64) -> Result {
+    let url =
+        f!("https://api.coingecko.com/api/v3/simple/price?ids={coin}&vs_currencies={currency}");
+    let curl_cmd = vec![
+        "-X".to_string(),
+        "GET".to_string(),
+        "-H".to_string(),
+        "Accept: application/json".to_string(),
+        url,
+    ];
+    let response = curl_request(curl_cmd);
+    let result = String::from_utf8(response.stdout);
+
+    match result {
+        Ok(res) => {
+            let json_res = serde_json::from_str(&res.clone());
+            if json_res.is_err() {
+                return Result {
+                    result: -1f64,
+                    success: false,
+                    error_msg: "Failure to complete call".to_string(),
+                };
+            }
+            let json_res: serde_json::Value = json_res.unwrap();
+            let value = json_res[coin.to_lowercase()][currency.to_lowercase()].as_f64();
+            if value.is_none() {
+                return Result {
+                    result: -1f64,
+                    success: false,
+                    error_msg:
+                        "No price value from source available. Check your coin and currency values."
+                            .to_string(),
+                };
+            }
+
+            let value: f64 = value.unwrap();
+
+            let mut rng = RNG::<WyRand, u16>::new(timestamp_ms);
+            let multiplier = rng.generate_range(5, 20) as f64;
+            let rnd_value = value * (1f64 + multiplier / 100f64);
+            Result {
+                result: format!("{:.2}", rnd_value).parse::<f64>().unwrap(),
+                success: true,
+                error_msg: "".to_string(),
+            }
+        }
+        Err(_) => Result {
+            result: -1f64,
+            success: false,
+            error_msg: String::from_utf8(response.stderr).unwrap(),
+        },
+    }
+}
+
+#[marine]
+#[link(wasm_import_module = "curl_adapter")]
+extern "C" {
+    pub fn curl_request(cmd: Vec<String>) -> MountedBinaryResult;
+}

aqua-examples/price-oracle/scripts/build.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash -o errexit -o nounset -o pipefail
+
+mkdir -p artifacts
+
+cd curl_adapter
+cargo update --aggressive
+marine build --release
+cd ..
+
+cd price_getter_service
+cargo update --aggressive
+marine build --release
+cd ..
+
+cd mean_service
+cargo update --aggressive
+marine build --release
+cd ..
+
+rm -f artifacts/*.wasm
+
+cp curl_adapter/target/wasm32-wasi/release/curl_adapter.wasm artifacts/
+cp price_getter_service/target/wasm32-wasi/release/price_getter_service.wasm artifacts/
+cp mean_service/target/wasm32-wasi/release/mean_service.wasm artifacts/