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membphis pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
new 216debe feat: support priority in SRV record (#3845)
216debe is described below
commit 216debe22354af8f0bf8691d1bd8f15cd4af12c9
Author: 罗泽轩 <spacewander...@gmail.com>
AuthorDate: Tue Mar 23 20:05:23 2021 +0800
feat: support priority in SRV record (#3845)
---
apisix/discovery/dns.lua | 4 ++++
docs/en/latest/discovery/dns.md | 15 ++++++++-------
t/coredns/db.test.local | 3 +++
t/discovery/dns/sanity.t | 19 +++++++++++++++++++
4 files changed, 34 insertions(+), 7 deletions(-)
diff --git a/apisix/discovery/dns.lua b/apisix/discovery/dns.lua
index 64ffe1d..e599cf6 100644
--- a/apisix/discovery/dns.lua
+++ b/apisix/discovery/dns.lua
@@ -53,6 +53,10 @@ function _M.nodes(service_name)
for i, r in ipairs(records) do
if r.address then
nodes[i] = {host = r.address, weight = r.weight or 1, port =
r.port or port}
+ if r.priority then
+ -- for SRV record, nodes with lower priority are chosen first
+ nodes[i].priority = -r.priority
+ end
end
end
diff --git a/docs/en/latest/discovery/dns.md b/docs/en/latest/discovery/dns.md
index 0fd7977..4bb5461 100644
--- a/docs/en/latest/discovery/dns.md
+++ b/docs/en/latest/discovery/dns.md
@@ -92,8 +92,10 @@ Assumed you have the SRV record like this:
A 300 IN A 1.1.1.1
B 300 IN A 1.1.1.2
B 300 IN A 1.1.1.3
-srv 86400 IN SRV 10 60 1980 A
-srv 86400 IN SRV 10 20 1981 B
+
+; name TTL type priority weight port
+srv 86400 IN SRV 10 60 1980 A
+srv 86400 IN SRV 20 20 1981 B
```
Upstream configuration like:
@@ -114,14 +116,15 @@ is the same as:
"id": 1,
"type": "roundrobin",
"nodes": [
- {"host": "1.1.1.1", "port": 1980, "weight": 60},
- {"host": "1.1.1.2", "port": 1981, "weight": 10},
- {"host": "1.1.1.3", "port": 1981, "weight": 10}
+ {"host": "1.1.1.1", "port": 1980, "weight": 60, "priority": -10},
+ {"host": "1.1.1.2", "port": 1981, "weight": 10, "priority": -20},
+ {"host": "1.1.1.3", "port": 1981, "weight": 10, "priority": -20}
]
}
```
Note that two records of domain B split the weight evenly.
+For SRV record, nodes with lower priority are chosen first, so the final
priority is negative.
As for 0 weight SRV record, the [RFC
2782](https://www.ietf.org/rfc/rfc2782.txt) says:
@@ -133,5 +136,3 @@ being selected.
We treat weight 0 record has a weight of 1 so the node "have a very small
chance of
being selected", which is also the common way to treat this type of record.
-
-TODO: support priority.
diff --git a/t/coredns/db.test.local b/t/coredns/db.test.local
index e4bb2fa..27296bf 100644
--- a/t/coredns/db.test.local
+++ b/t/coredns/db.test.local
@@ -42,3 +42,6 @@ zero-weight.srv 86400 IN SRV 10 0 1980 B
split-weight.srv 86400 IN SRV 10 100 1980 A
split-weight.srv 86400 IN SRV 10 0 1980 C
+
+priority.srv 86400 IN SRV 10 60 1979 A
+priority.srv 86400 IN SRV 20 60 1980 B
diff --git a/t/discovery/dns/sanity.t b/t/discovery/dns/sanity.t
index 89b67a1..753b9bb 100644
--- a/t/discovery/dns/sanity.t
+++ b/t/discovery/dns/sanity.t
@@ -266,3 +266,22 @@ qr/upstream nodes: \{[^}]+\}/
qr/upstream nodes: \{(,?"127.0.0.(1:1980":200|3:1980":1|4:1980":1)){3}\}/
--- response_body
hello world
+
+
+
+=== TEST 13: SRV (priority)
+--- apisix_yaml
+upstreams:
+ - service_name: "priority.srv.test.local"
+ discovery_type: dns
+ type: roundrobin
+ id: 1
+--- response_body
+hello world
+--- error_log
+connect() failed
+--- grep_error_log eval
+qr/proxy request to \S+/
+--- grep_error_log_out
+proxy request to 127.0.0.1:1979
+proxy request to 127.0.0.2:1980
