shotover 0.7.2

Shotover API for building custom transforms
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
use crate::frame::Frame;
use crate::frame::MessageType;
use crate::frame::ValkeyFrame;
use crate::message::{MessageIdMap, Messages};
use crate::transforms::DownChainProtocol;
use crate::transforms::TransformContextBuilder;
use crate::transforms::TransformContextConfig;
use crate::transforms::UpChainProtocol;
use crate::transforms::{ChainState, Transform, TransformBuilder, TransformConfig};
use anyhow::{Context, Result, anyhow, bail};
use async_trait::async_trait;
use bytes::{BufMut, Bytes, BytesMut};
use serde::Deserialize;
use serde::Serialize;

#[derive(Serialize, Deserialize, Debug)]
#[serde(deny_unknown_fields)]
pub struct ValkeyClusterPortsRewriteConfig {
    pub new_port: u16,
}

const NAME: &str = "ValkeyClusterPortsRewrite";
#[typetag::serde(name = "ValkeyClusterPortsRewrite")]
#[async_trait(?Send)]
impl TransformConfig for ValkeyClusterPortsRewriteConfig {
    async fn get_builder(
        &self,
        _transform_context: TransformContextConfig,
    ) -> Result<Box<dyn TransformBuilder>> {
        Ok(Box::new(ValkeyClusterPortsRewrite::new(self.new_port)))
    }

    fn up_chain_protocol(&self) -> UpChainProtocol {
        UpChainProtocol::MustBeOneOf(vec![MessageType::Valkey])
    }

    fn down_chain_protocol(&self) -> DownChainProtocol {
        DownChainProtocol::SameAsUpChain
    }
}

impl TransformBuilder for ValkeyClusterPortsRewrite {
    fn build(&self, _transform_context: TransformContextBuilder) -> Box<dyn Transform> {
        Box::new(self.clone())
    }

    fn get_name(&self) -> &'static str {
        NAME
    }
}

#[derive(Clone)]
pub struct ValkeyClusterPortsRewrite {
    new_port: u16,
    request_type: MessageIdMap<RequestType>,
}

#[derive(Clone)]
enum RequestType {
    ClusterSlot,
    ClusterNodes,
}

impl ValkeyClusterPortsRewrite {
    pub fn new(new_port: u16) -> Self {
        ValkeyClusterPortsRewrite {
            new_port,
            request_type: MessageIdMap::default(),
        }
    }
}

#[async_trait]
impl Transform for ValkeyClusterPortsRewrite {
    fn get_name(&self) -> &'static str {
        NAME
    }

    async fn transform<'shorter, 'longer: 'shorter>(
        &mut self,
        chain_state: &'shorter mut ChainState<'longer>,
    ) -> Result<Messages> {
        for message in chain_state.requests.iter_mut() {
            let message_id = message.id();
            if let Some(frame) = message.frame() {
                if is_cluster_slots(frame) {
                    self.request_type
                        .insert(message_id, RequestType::ClusterSlot);
                }

                if is_cluster_nodes(frame) {
                    self.request_type
                        .insert(message_id, RequestType::ClusterNodes);
                }
            }
        }

        let mut responses = chain_state.call_next_transform().await?;

        for response in &mut responses {
            if let Some(request_id) = response.request_id() {
                match self.request_type.remove(&request_id) {
                    // Rewrite the ports in the cluster slots responses
                    Some(RequestType::ClusterSlot) => {
                        if let Some(frame) = response.frame() {
                            rewrite_port_slot(frame, self.new_port)
                                .context("failed to rewrite CLUSTER SLOTS port")?;
                            response.invalidate_cache();
                        }
                    }
                    // Rewrite the ports in the cluster nodes responses
                    Some(RequestType::ClusterNodes) => {
                        if let Some(frame) = response.frame() {
                            rewrite_port_node(frame, self.new_port)
                                .context("failed to rewrite CLUSTER NODES port")?;
                            response.invalidate_cache();
                        }
                    }
                    None => {}
                }
            }
        }

        Ok(responses)
    }
}

/// Rewrites the ports of a response to a CLUSTER SLOTS message to `new_port`
fn rewrite_port_slot(frame: &mut Frame, new_port: u16) -> Result<()> {
    if let Frame::Valkey(ValkeyFrame::Array(array)) = frame {
        for elem in array.iter_mut() {
            if let ValkeyFrame::Array(slot) = elem {
                for (index, mut frame) in slot.iter_mut().enumerate() {
                    match (index, &mut frame) {
                        (0..=1, _) => {}
                        (_, ValkeyFrame::Array(target)) => match target.as_mut_slice() {
                            [ValkeyFrame::BulkString(_ip), ValkeyFrame::Integer(port), ..] => {
                                *port = new_port.into();
                            }
                            _ => bail!(
                                "expected slot to start with bulkstring followed by integer, but was something else"
                            ),
                        },
                        _ => bail!("non array value in slot map"),
                    }
                }
            };
        }
    }
    Ok(())
}

/// Get a mutable reference to the CSV string inside a response to CLUSTER NODES or REPLICAS
fn get_buffer(frame: &mut Frame) -> Option<&mut Bytes> {
    // CLUSTER NODES
    if let Frame::Valkey(ValkeyFrame::BulkString(buf)) = frame {
        return Some(buf);
    }

    // CLUSTER REPLICAS
    if let Frame::Valkey(ValkeyFrame::Array(array)) = frame {
        for item in array.iter_mut() {
            if let ValkeyFrame::BulkString(buf) = item {
                return Some(buf);
            }
        }
    }

    None
}

/// Rewrites the ports of a response to a CLUSTER NODES message to `new_port`
fn rewrite_port_node(frame: &mut Frame, new_port: u16) -> Result<()> {
    if let Some(buf) = get_buffer(frame) {
        let mut bytes_writer = BytesMut::new().writer();

        {
            let read_cursor = std::io::Cursor::new(&buf);

            let mut reader = csv::ReaderBuilder::new()
                .delimiter(b' ')
                .has_headers(false)
                .flexible(true) // flexible because the last fields is an arbitrary number of tokens
                .from_reader(read_cursor);

            let mut writer = csv::WriterBuilder::new()
                .delimiter(b' ')
                .flexible(true)
                .from_writer(&mut bytes_writer);

            for result in reader.records() {
                let record = result?;
                let mut record_iter = record.into_iter();

                // Write the id field
                let id = record_iter
                    .next()
                    .ok_or_else(|| anyhow!("CLUSTER NODES response missing id field"))?;
                writer.write_field(id)?;

                // Modify and rewrite the port field
                let ip = record_iter
                    .next()
                    .ok_or_else(|| anyhow!("CLUSTER NODES response missing address field"))?;

                let split = ip.split([':', '@']).collect::<Vec<&str>>();

                if split.len() < 3 {
                    bail!("IP address not in valid format: {ip}");
                }
                let new_ip = format!("{}:{}@{}", split[0], new_port, split[2]);

                writer.write_field(&*new_ip)?;

                // Write the last of the record
                writer.write_record(record_iter)?;
            }
            writer.flush()?;
        }

        *buf = bytes_writer.into_inner().freeze();
    }

    Ok(())
}

/// Determines if the supplied Valkey Frame is a `CLUSTER NODES` request
/// or `CLUSTER REPLICAS` which returns the same response as `CLUSTER NODES`
fn is_cluster_nodes(frame: &Frame) -> bool {
    if let Frame::Valkey(ValkeyFrame::Array(array)) = frame {
        match array.as_slice() {
            [
                ValkeyFrame::BulkString(one),
                ValkeyFrame::BulkString(two),
                ..,
            ] => {
                one.eq_ignore_ascii_case(b"CLUSTER")
                    && (two.eq_ignore_ascii_case(b"NODES") || two.eq_ignore_ascii_case(b"REPLICAS"))
            }
            [..] => false,
        }
    } else {
        false
    }
}

/// Determines if the supplied Valkey Frame is a `CLUSTER SLOTS` request
fn is_cluster_slots(frame: &Frame) -> bool {
    if let Frame::Valkey(ValkeyFrame::Array(array)) = frame {
        match array.as_slice() {
            [
                ValkeyFrame::BulkString(one),
                ValkeyFrame::BulkString(two),
                ..,
            ] => one.eq_ignore_ascii_case(b"CLUSTER") && two.eq_ignore_ascii_case(b"SLOTS"),
            [..] => false,
        }
    } else {
        false
    }
}

#[cfg(test)]
mod test {
    use super::*;
    use crate::codec::Direction;
    use crate::codec::valkey::ValkeyDecoder;
    use crate::transforms::valkey::sink_cluster::parse_slots;
    use pretty_assertions::assert_eq;
    use tokio_util::codec::Decoder;

    #[test]
    fn test_is_cluster_slots() {
        let combos = [
            (b"cluster", b"slots"),
            (b"CLUSTER", b"SLOTS"),
            (b"cluster", b"SLOTS"),
            (b"CLUSTER", b"slots"),
        ];

        for combo in combos {
            let frame = Frame::Valkey(ValkeyFrame::Array(vec![
                ValkeyFrame::BulkString(Bytes::from_static(combo.0)),
                ValkeyFrame::BulkString(Bytes::from_static(combo.1)),
            ]));
            assert!(is_cluster_slots(&frame));
        }

        let frame = Frame::Valkey(ValkeyFrame::Array(vec![
            ValkeyFrame::BulkString(Bytes::from_static(b"GET")),
            ValkeyFrame::BulkString(Bytes::from_static(b"key1")),
        ]));

        assert!(!is_cluster_slots(&frame));
    }

    #[test]
    fn test_is_cluster_nodes() {
        let combos = [
            //nodes
            (b"cluster", b"nodes" as &[u8]),
            (b"CLUSTER", b"NODES" as &[u8]),
            (b"cluster", b"NODES" as &[u8]),
            (b"CLUSTER", b"nodes" as &[u8]),
            // replicas
            (b"cluster", b"replicas" as &[u8]),
            (b"CLUSTER", b"REPLICAS" as &[u8]),
            (b"cluster", b"replicas" as &[u8]),
            (b"CLUSTER", b"replicas" as &[u8]),
        ];

        for combo in combos {
            let frame = Frame::Valkey(ValkeyFrame::Array(vec![
                ValkeyFrame::BulkString(Bytes::from_static(combo.0)),
                ValkeyFrame::BulkString(Bytes::from_static(combo.1)),
            ]));
            assert!(is_cluster_nodes(&frame));
        }

        let frame = Frame::Valkey(ValkeyFrame::Array(vec![
            ValkeyFrame::BulkString(Bytes::from_static(b"GET")),
            ValkeyFrame::BulkString(Bytes::from_static(b"key1")),
        ]));

        assert!(!is_cluster_nodes(&frame));
    }

    #[test]
    fn test_rewrite_port_slots() {
        let slots_pcap: &[u8] = b"*3\r\n*4\r\n:10923\r\n:16383\r\n*3\r\n$12\r\n192.168.80.6\r\n:6379\r\n$40\r\n3a7c357ed75d2aa01fca1e14ef3735a2b2b8ffac\r\n*3\r\n$12\r\n192.168.80.3\r\n:6379\r\n$40\r\n77c01b0ddd8668fff05e3f6a8aaf5f3ccd454a79\r\n*4\r\n:5461\r\n:10922\r\n*3\r\n$12\r\n192.168.80.5\r\n:6379\r\n$40\r\n969c6215d064e68593d384541ceeb57e9520dbed\r\n*3\r\n$12\r\n192.168.80.2\r\n:6379\r\n$40\r\n3929f69990a75be7b2d49594c57fe620862e6fd6\r\n*4\r\n:0\r\n:5460\r\n*3\r\n$12\r\n192.168.80.7\r\n:6379\r\n$40\r\n15d52a65d1fc7a53e34bf9193415aa39136882b2\r\n*3\r\n$12\r\n192.168.80.4\r\n:6379\r\n$40\r\ncd023916a3528fae7e606a10d8289a665d6c47b0\r\n";
        let mut codec = ValkeyDecoder::new(None, Direction::Sink);
        let mut message = codec
            .decode(&mut slots_pcap.into())
            .unwrap()
            .unwrap()
            .pop()
            .unwrap();

        rewrite_port_slot(message.frame().unwrap(), 6380).unwrap();

        let slots_frames = match message.frame().unwrap() {
            Frame::Valkey(ValkeyFrame::Array(frames)) => frames,
            frame => panic!("bad input: {frame:?}"),
        };

        let slots = parse_slots(slots_frames).unwrap();

        let nodes = vec![
            "192.168.80.2:6380",
            "192.168.80.3:6380",
            "192.168.80.4:6380",
            "192.168.80.5:6380",
            "192.168.80.6:6380",
            "192.168.80.7:6380",
        ]
        .into_iter()
        .map(String::from)
        .collect();

        let masters = vec![
            (5460u16, "192.168.80.7:6380".to_string()),
            (10922u16, "192.168.80.5:6380".to_string()),
            (16383u16, "192.168.80.6:6380".to_string()),
        ];

        let replicas = vec![
            (5460u16, "192.168.80.4:6380".to_string()),
            (10922u16, "192.168.80.2:6380".to_string()),
            (16383u16, "192.168.80.3:6380".to_string()),
        ];

        assert_eq!(slots.nodes, nodes);
        assert_eq!(slots.masters.into_iter().collect::<Vec<_>>(), masters);
        assert_eq!(slots.replicas.into_iter().collect::<Vec<_>>(), replicas);
    }

    #[test]
    fn test_rewrite_port_nodes() {
        let bulk_string = b"b5657714579550445f271ff65e47f3d39a36806c :0@0 slave,noaddr 95566d2da3382ea88f549ab5766db9a6f4fbc44b 1634273478445 1634273478445 1 disconnected
95566d2da3382ea88f549ab5766db9a6f4fbc44b :0@0 master,noaddr - 1634273478445 1634273478445 1 disconnected 0-5460
c852007a1c3b726534e6866456c1f2002fc442d9 172.31.0.6:6379@16379 myself,master - 0 1634273501000 3 connected 10923-16383
847c2efa4f5dcbca969f30a903ee54c5deb285f6 172.31.0.5:6379@16379 slave 2ee0e46acaec3fcb09fdff3ced0c267ffa2b78d3 0 1634273501428 2 connected
2ee0e46acaec3fcb09fdff3ced0c267ffa2b78d3 :0@0 master,noaddr - 1634273478446 1634273478446 2 disconnected 5461-10922
f9553ea7fc23905476efec1f949b4b3e41a44103 :0@0 slave,noaddr c852007a1c3b726534e6866456c1f2002fc442d9 1634273478445 1634273478445 3 disconnected
";

        // bulk_string with port numbers replaced
        let expected_string = b"b5657714579550445f271ff65e47f3d39a36806c :1234@0 slave,noaddr 95566d2da3382ea88f549ab5766db9a6f4fbc44b 1634273478445 1634273478445 1 disconnected
95566d2da3382ea88f549ab5766db9a6f4fbc44b :1234@0 master,noaddr - 1634273478445 1634273478445 1 disconnected 0-5460
c852007a1c3b726534e6866456c1f2002fc442d9 172.31.0.6:1234@16379 myself,master - 0 1634273501000 3 connected 10923-16383
847c2efa4f5dcbca969f30a903ee54c5deb285f6 172.31.0.5:1234@16379 slave 2ee0e46acaec3fcb09fdff3ced0c267ffa2b78d3 0 1634273501428 2 connected
2ee0e46acaec3fcb09fdff3ced0c267ffa2b78d3 :1234@0 master,noaddr - 1634273478446 1634273478446 2 disconnected 5461-10922
f9553ea7fc23905476efec1f949b4b3e41a44103 :1234@0 slave,noaddr c852007a1c3b726534e6866456c1f2002fc442d9 1634273478445 1634273478445 3 disconnected
";

        let mut raw_frame = Frame::Valkey(ValkeyFrame::BulkString(Bytes::from_static(bulk_string)));
        rewrite_port_node(&mut raw_frame, 1234).unwrap();

        assert_eq!(
            raw_frame,
            Frame::Valkey(ValkeyFrame::BulkString(Bytes::from_static(expected_string)))
        );
    }
}