Disable DNS-backed key-value store

I'm disabling the key-value store because no one was using it.

There are other reasons, too:

- The removal of the `etcd` library dropped the executable size by over
  half from 17MB to 7MB
- I didn't want users who've deployed it internally to be "surprised" by
  unexpected key-value features
- Key-value-over-DNS has a seamy side to it: "data exfiltration". I know
  there are legitimate uses for it, but I've come to believe that a
  Key-value-over-HTTP solution is preferable because it's not only more
  legitimate but also because it eliminates the DNS caching problem.

docs/DEVELOPER.md

@@ -60,18 +60,7 @@ dig @$DNS_SERVER_IP txt ip.sslip.io +short | tr -d '"'
 echo 127.0.0.1
 dig @$DNS_SERVER_IP txt version.status.sslip.io +short | grep $VERSION
 echo "\"$VERSION\""
-dig @$DNS_SERVER_IP my-key.k-v.io txt +short # returns nothing
 echo " ===" # separator because the results are too similar
-dig @$DNS_SERVER_IP put.MyValue.my-key.k-v.io txt +short
-echo "\"MyValue\""
-echo " ===" # separator because the results are too similar
-dig @$DNS_SERVER_IP MY-KEY.k-v.io txt +short
-echo "\"MyValue\""
-echo " ===" # separator because the results are too similar
-dig @$DNS_SERVER_IP delete.my-key.k-v.io txt +short
-echo
-echo " ===" # separator because the results are too similar
-dig @$DNS_SERVER_IP my-key.k-v.io txt +short # returns nothing
 dig @$DNS_SERVER_IP 1.0.0.127.in-addr.arpa ptr +short
 echo "127-0-0-1.sslip.io."
 dig @$DNS_SERVER_IP metrics.status.sslip.io txt +short | grep '"Queries: '

k8s/document_root_k-v.io/index.html

@@ -36,6 +36,8 @@
   <main role="main" class="container">
     <div class="starter-template">
       <h1>k-v.io</h1>
+      <p>k-v.io is under construction. I've dismantled the DNS-backed key-value store—no one was using it. Stay
+      tuned.</p><!--
       <p>A DNS-based Key-Value Store. <a href="https://ci.nono.io/teams/main/pipelines/sslip.io"><img alt="badge" src=
       "https://ci.nono.io/api/v1/teams/main/pipelines/sslip.io/badge"></a></p>
       <h2>Quick Start</h2>
@@ -115,6 +117,8 @@
         </li>
       </ul>
     </div>
+    -->
+    </div>
   </main><!-- /.container -->
   <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity=
   "sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>

src/sslip.io-dns-server/default.json

@@ -21,14 +21,6 @@
         "TXTSslipIoSPF"
       ]
     },
-    "k-v.io.": {
-      "A": [
-        "104.155.144.4"
-      ]
-    },
-    "_acme-challenge.k-v.io.": {
-      "TXT": []
-    },
     "ns.sslip.io.": {
       "A": [
         "52.0.56.137",

src/sslip.io-dns-server/go.mod

@@ -1,33 +1,22 @@
 module xip
 
-go 1.19
+go 1.20
 
 require (
 	github.com/onsi/ginkgo/v2 v2.8.4
 	github.com/onsi/gomega v1.27.2
-	go.etcd.io/etcd/client/v3 v3.5.7
 	golang.org/x/net v0.7.0
 )
 
 require (
-	github.com/coreos/go-semver v0.3.1 // indirect
-	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
-	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/google/pprof v0.0.0-20230228050547-1710fef4ab10 // indirect
-	go.etcd.io/etcd/api/v3 v3.5.7 // indirect
+	github.com/stretchr/testify v1.8.0 // indirect
-	go.etcd.io/etcd/client/pkg/v3 v3.5.7 // indirect
-	go.uber.org/atomic v1.10.0 // indirect
-	go.uber.org/multierr v1.9.0 // indirect
-	go.uber.org/zap v1.24.0 // indirect
 	golang.org/x/sys v0.5.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
 	golang.org/x/tools v0.6.0 // indirect
-	google.golang.org/genproto v0.0.0-20230227214838-9b19f0bdc514 // indirect
-	google.golang.org/grpc v1.53.0 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

src/sslip.io-dns-server/go.sum

@@ -1,8 +1,3 @@
-github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
-github.com/coreos/go-semver v0.3.1 h1:yi21YpKnrx1gt5R+la8n5WgS0kCrsPp33dmEyHReZr4=
-github.com/coreos/go-semver v0.3.1/go.mod h1:irMmmIw/7yzSRPWryHsK7EYSg09caPQL03VsM8rvUec=
-github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
-github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -10,87 +5,40 @@ github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
 github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 h1:p104kn46Q8WdvHunIJ9dAyjPVtrBPhSr3KT2yUst43I=
 github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg7847qk6SyHyPtNmDHnmrv/HOrqktSC+C9fM+CJOE=
-github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
-github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
-github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw=
-github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/pprof v0.0.0-20230228050547-1710fef4ab10 h1:CqYfpuYIjnlNxM3msdyPRKabhXZWbKjf3Q8BWROFBso=
 github.com/google/pprof v0.0.0-20230228050547-1710fef4ab10/go.mod h1:79YE0hCXdHag9sBkw2o+N/YnZtTkXi0UT9Nnixa5eYk=
-github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
-github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/onsi/ginkgo/v2 v2.8.4 h1:gf5mIQ8cLFieruNLAdgijHF1PYfLphKm2dxxcUtcqK0=
 github.com/onsi/ginkgo/v2 v2.8.4/go.mod h1:427dEDQZkDKsBvCjc2A/ZPefhKxsTTrsQegMlayL730=
 github.com/onsi/gomega v1.27.2 h1:SKU0CXeKE/WVgIV1T61kSa3+IRE8Ekrv9rdXDwwTqnY=
 github.com/onsi/gomega v1.27.2/go.mod h1:5mR3phAHpkAVIDkHEUBY6HGVsU+cpcEscrGPB4oPlZI=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
-github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-go.etcd.io/etcd/api/v3 v3.5.7 h1:sbcmosSVesNrWOJ58ZQFitHMdncusIifYcrBfwrlJSY=
-go.etcd.io/etcd/api/v3 v3.5.7/go.mod h1:9qew1gCdDDLu+VwmeG+iFpL+QlpHTo7iubavdVDgCAA=
-go.etcd.io/etcd/client/pkg/v3 v3.5.7 h1:y3kf5Gbp4e4q7egZdn5T7W9TSHUvkClN6u+Rq9mEOmg=
-go.etcd.io/etcd/client/pkg/v3 v3.5.7/go.mod h1:o0Abi1MK86iad3YrWhgUsbGx1pmTS+hrORWc2CamuhY=
-go.etcd.io/etcd/client/v3 v3.5.7 h1:u/OhpiuCgYY8awOHlhIhmGIGpxfBU/GZBUP3m/3/Iz4=
-go.etcd.io/etcd/client/v3 v3.5.7/go.mod h1:sOWmj9DZUMyAngS7QQwCyAXXAL6WhgTOPLNS/NabQgw=
-go.uber.org/atomic v1.10.0 h1:9qC72Qh0+3MqyJbAn8YU5xVq1frD8bn3JtD2oXtafVQ=
-go.uber.org/atomic v1.10.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
-go.uber.org/goleak v1.1.11 h1:wy28qYRKZgnJTxGxvye5/wgWr1EKjmUDGYox5mGlRlI=
-go.uber.org/multierr v1.9.0 h1:7fIwc/ZtS0q++VgcfqFDxSBZVv/Xo49/SYnDFupUwlI=
-go.uber.org/multierr v1.9.0/go.mod h1:X2jQV1h+kxSjClGpnseKVIxpmcjrj7MNnI0bnlfKTVQ=
-go.uber.org/zap v1.24.0 h1:FiJd5l1UOLj0wCgbSE0rwwXHzEdAZS6hiiSnxJN/D60=
-go.uber.org/zap v1.24.0/go.mod h1:2kMP+WWQ8aoFoedH3T2sq6iJ2yDWpHbP0f6MQbS9Gkg=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.7.0 h1:rJrUqqhjsgNp7KqAIc25s9pZnjU7TUcSY7HcVZjdn1g=
 golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.7.0 h1:4BRB4x83lYWy72KwLD/qYDuTu7q9PjSagHvijDw7cLo=
 golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.0.0-20200619180055-7c47624df98f/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
-golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
 golang.org/x/tools v0.6.0 h1:BOw41kyTf3PuCW1pVQf8+Cyg8pMlkYB1oo9iJ6D/lKM=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/genproto v0.0.0-20230227214838-9b19f0bdc514 h1:rtNKfB++wz5mtDY2t5C8TXlU5y52ojSu7tZo0z7u8eQ=
-google.golang.org/genproto v0.0.0-20230227214838-9b19f0bdc514/go.mod h1:TvhZT5f700eVlTNwND1xoEZQeWTB2RY/65kplwl/bFA=
-google.golang.org/grpc v1.53.0 h1:LAv2ds7cmFV/XTS3XG1NneeENYrXGmorPxsBbptIjNc=
-google.golang.org/grpc v1.53.0/go.mod h1:OnIrk0ipVdj4N5d9IUoFUx72/VlD7+jUsHwZgwSMQpw=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
 google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

src/sslip.io-dns-server/integration_metrics_test.go

@@ -123,30 +123,6 @@ var _ = Describe("IntegrationMetrics", func() {
 			actualMetrics = digAndGetMetrics("@localhost version.status.sslip.io txt +short -p "+strconv.Itoa(port), port)
 			Expect(expectedMetrics.MostlyEquals(actualMetrics)).To(BeTrue())
 
-			// TXT put.value.key.k-v.io updates .Queries, .AnsweredQueries, .AnsweredTXTPutKvQueries
-			expectedMetrics.Queries++
-			expectedMetrics.AnsweredQueries++
-			expectedMetrics.AnsweredTXTPutKvQueries++
-			expectedMetrics = bumpExpectedToAccountForMetricsQuery(expectedMetrics)
-			actualMetrics = digAndGetMetrics("@localhost put.value.key.k-v.io txt +short -p "+strconv.Itoa(port), port)
-			Expect(expectedMetrics.MostlyEquals(actualMetrics)).To(BeTrue())
-
-			// TXT key.k-v.io updates .Queries, .AnsweredQueries, .AnsweredTXTGetKvQueries
-			expectedMetrics.Queries++
-			expectedMetrics.AnsweredQueries++
-			expectedMetrics.AnsweredTXTGetKvQueries++
-			expectedMetrics = bumpExpectedToAccountForMetricsQuery(expectedMetrics)
-			actualMetrics = digAndGetMetrics("@localhost key.k-v.io txt +short -p "+strconv.Itoa(port), port)
-			Expect(expectedMetrics.MostlyEquals(actualMetrics)).To(BeTrue())
-
-			// TXT delete.key.k-v.io updates .Queries, .AnsweredTXTDelKvQueries
-			// It doesn't count as an "answered" query because it returns no record
-			expectedMetrics.Queries++
-			expectedMetrics.AnsweredTXTDelKvQueries++
-			expectedMetrics = bumpExpectedToAccountForMetricsQuery(expectedMetrics)
-			actualMetrics = digAndGetMetrics("@localhost delete.key.k-v.io txt +short -p "+strconv.Itoa(port), port)
-			Expect(expectedMetrics.MostlyEquals(actualMetrics)).To(BeTrue())
-
 			// PTR version.sslip.io updates .Queries, .AnsweredQueries, .AnsweredPTRQueriesIPv4
 			expectedMetrics.Queries++
 			expectedMetrics.AnsweredQueries++
@@ -203,7 +179,6 @@ func getMetrics(port int) (m xip.Metrics) {
 	var junk string
 	_, err = fmt.Sscanf(string(stdout),
 		"\"Uptime: %d\"\n"+
-			"\"KV Store: %s\n"+ // %s "swallows" the double-quote at the end
 			"\"Blocklist: %s %s %s\n"+
 			"\"Queries: %d (%s\n"+ // %s "swallows" the `/s"` at the end
 			"\"Answered Queries: %d (%s\n"+ // %s "swallows" the `/s"` at the end
@@ -211,12 +186,10 @@ func getMetrics(port int) (m xip.Metrics) {
 			"\"AAAA: %d\"\n"+
 			"\"TXT Source: %d\"\n"+
 			"\"TXT Version: %d\"\n"+
-			"\"TXT KV GET/PUT/DEL: %d/%d/%d\"\n"+
 			"\"PTR IPv4/IPv6: %d/%d\"\n"+
 			"\"NS DNS-01: %d\"\n"+
 			"\"Blocked: %d\"\n",
 		&uptime,
-		&junk,
 		&junk, &junk, &junk,
 		&m.Queries, &junk,
 		&m.AnsweredQueries, &junk,
@@ -224,7 +197,6 @@ func getMetrics(port int) (m xip.Metrics) {
 		&m.AnsweredAAAAQueries,
 		&m.AnsweredTXTSrcIPQueries,
 		&m.AnsweredTXTVersionQueries,
-		&m.AnsweredTXTGetKvQueries, &m.AnsweredTXTPutKvQueries, &m.AnsweredTXTDelKvQueries,
 		&m.AnsweredPTRQueriesIPv4, &m.AnsweredPTRQueriesIPv6,
 		&m.AnsweredNSDNS01ChallengeQueries,
 		&m.AnsweredBlockedQueries,

src/sslip.io-dns-server/integration_test.go

@@ -58,10 +58,6 @@ var _ = Describe("sslip.io-dns-server", func() {
 				Eventually(string(digSession.Out.Contents())).Should(MatchRegexp(digResults))
 				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(serverLogMessage))
 			},
-			Entry("A (customized) for k-v.io",
-				"@localhost k-v.io +short",
-				`\A104.155.144.4\n\z`,
-				`TypeA k-v.io. \? 104.155.144.4\n`),
 			Entry("A (customized) for sslip.io",
 				"@localhost sslip.io +short",
 				`\A78.46.204.247\n\z`,
@@ -131,26 +127,6 @@ var _ = Describe("sslip.io-dns-server", func() {
 				"@127.0.0.1 example.com txt +short",
 				`\A\z`,
 				`TypeTXT example.com. \? nil, SOA example.com. briancunnie.gmail.com. 2022112600 900 900 1800 180\n`),
-			Entry(`getting a non-existent value: TXT for non-existent.k-v.io"`,
-				"@127.0.0.1 non-existent.k-v.io txt +short",
-				`\A\z`,
-				`TypeTXT non-existent.k-v.io. \? nil, SOA non-existent.k-v.io. briancunnie.gmail.com. 2022112600 900 900 1800 180\n`),
-			Entry(`putting a value: TXT for put.MyValue.MY-KEY.k-v.io"`,
-				"@127.0.0.1 put.MyValue.MY-KEY.k-v.io txt +short",
-				`"MyValue"`,
-				`TypeTXT put.MyValue.MY-KEY.k-v.io. \? \["MyValue"\]`),
-			Entry(`deleting a value: TXT for delete.my-key.k-v.io"`,
-				"@127.0.0.1 delete.my-key.k-v.io txt +short",
-				`\A\z`,
-				`TypeTXT delete.my-key.k-v.io. \? nil, SOA delete.my-key.k-v.io. briancunnie.gmail.com. 2022112600 900 900 1800 180\n`),
-			Entry(`setting a TXT for _acme-challenge.k-v.io appears to work (spoiler: it doesn't)'"`,
-				"@127.0.0.1 put.sneaky-boy._acme-challenge.k-v.io txt +short",
-				`sneaky-boy`,
-				`TypeTXT put.sneaky-boy._acme-challenge.k-v.io. \? \["sneaky-boy"\]`),
-			Entry(`get a TXT for _acme-challenge.k-v.io is blocked to foil Let's Encrypt ACME DNS-01 challenge"`,
-				"@127.0.0.1 _acme-challenge.k-v.io txt +short",
-				`Please don't try to procure a k-v.io cert via DNS-01 challenge`,
-				`TypeTXT _acme-challenge.k-v.io. \? \["Please don't try to procure a k-v.io cert via DNS-01 challenge"\]`),
 			Entry(`get a PTR for 1.0.168.192.in-addr.arpa returns 192-168-0-1.sslip.io`,
 				"@127.0.0.1 1.0.168.192.in-addr.arpa ptr +short",
 				`\A192-168-0-1.sslip.io.\n\z`,
@@ -267,79 +243,6 @@ var _ = Describe("sslip.io-dns-server", func() {
 				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT sslip.io. \? \["protonmail-verification=ce0ca3f5010aa7a2cf8bcc693778338ffde73e26"\], \["v=spf1 include:_spf.protonmail.ch mx ~all"\]\n`))
 			})
 		})
-		When(`a TXT record for a host under the "k-v.io" domain is queried`, func() {
-			It(`the PUT has a three-minute TTL`, func() {
-				digArgs = "@localhost put.a.a.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				Eventually(string(digSession.Out.Contents())).Should(MatchRegexp(`put.a.a.k-v.io.		180	IN	TXT	"a"`))
-				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT put.a.a.k-v.io. \? \["a"\]`))
-			})
-			It(`the GET has a three-minute TTL`, func() {
-				// create (PUT) the key
-				digArgs = "@localhost put.a.b.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				// retrieve (GET) the key
-				digArgs = "@localhost b.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				Eventually(string(digSession.Out.Contents()), 3).Should(MatchRegexp(`b.k-v.io.		180	IN	TXT	"a"`))
-				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT b.k-v.io. \? \["a"\]`))
-			})
-			It(`the DELETE returns no records so that value cached in downstream DNS servers expires more quickly`, func() {
-				// create (PUT) the key
-				digArgs = "@localhost put.a.c.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				// DELETE the key
-				digArgs = "@localhost delete.c.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT delete.c.k-v.io. \? nil, SOA delete.c.k-v.io. briancunnie.gmail.com. 2022112600 900 900 1800 180`))
-			})
-			It(`the DELETE on a non-existent key behaves the same as the DELETE on an existing key`, func() {
-				// DELETE the key (make sure it's gone)
-				digArgs = "@localhost delete.d.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				// DELETE again to test the non-existent behavior
-				digArgs = "@localhost delete.d.k-v.io txt -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT delete.d.k-v.io. \? nil, SOA delete.d.k-v.io. briancunnie.gmail.com. 2022112600 900 900 1800 180`))
-			})
-			It(`setting a TXT for _acme-challenge.subdomain-key.k-v.io doesn't expose DNS-01 vulnerability`, func() {
-				// set (PUT) the key
-				digArgs = "@localhost put.baffled-boy._acme-challenge.subdomain-key.k-v.io txt +short -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				// GET the key
-				digArgs = "@localhost get.subdomain-key.k-v.io txt +short -p " + strconv.Itoa(port)
-				digCmd = exec.Command("dig", strings.Split(digArgs, " ")...)
-				digSession, err = Start(digCmd, GinkgoWriter, GinkgoWriter)
-				Expect(err).ToNot(HaveOccurred())
-				Eventually(digSession, 1).Should(Exit(0))
-				Eventually(string(digSession.Out.Contents()), 3).Should(MatchRegexp(`"baffled-boy._acme-challenge"`))
-				Eventually(string(serverSession.Err.Contents())).Should(MatchRegexp(`TypeTXT get.subdomain-key.k-v.io. \? \["baffled-boy._acme-challenge"\]`))
-			})
-		})
 		When(`a record for an "_acme-challenge" domain is queried`, func() {
 			When(`it's an NS record`, func() {
 				It(`returns the NS record of the query with the "_acme-challenge." stripped`, func() {

src/sslip.io-dns-server/main.go

@@ -15,13 +15,11 @@ import (
 
 func main() {
 	var wg sync.WaitGroup
-	var etcdEndpoint = flag.String("etcdHost", "localhost:2379", "etcd client endpoint; falls back to builtin key-value store if unable to connect")
 	var blocklistURL = flag.String("blocklistURL", "https://raw.githubusercontent.com/cunnie/sslip.io/main/etc/blocklist.txt", `URL containing a list of "forbidden" names/CIDRs`)
 	var nameservers = flag.String("nameservers", "ns-aws.sslip.io.,ns-azure.sslip.io.,ns-gce.sslip.io.", "comma-separated list of nameservers")
 	var addresses = flag.String("addresses",
 		"sslip.io=78.46.204.247,"+
 			"sslip.io=2a01:4f8:c17:b8f::2,"+
-			"k-v.io=104.155.144.4,"+
 			"ns.sslip.io=52.0.56.137,"+
 			"ns.sslip.io=52.187.42.158,"+
 			"ns.sslip.io=104.155.144.4,"+
@@ -34,10 +32,10 @@ func main() {
 	var quiet = flag.Bool("quiet", false, "suppresses logging of each DNS response")
 	flag.Parse()
 	log.Printf("%s version %s starting", os.Args[0], xip.VersionSemantic)
-	log.Printf("etcd endpoint: %s, blocklist URL: %s, name servers: %s, bind port: %d, quiet: %t",
+	log.Printf("blocklist URL: %s, name servers: %s, bind port: %d, quiet: %t",
-		*etcdEndpoint, *blocklistURL, *nameservers, *bindPort, *quiet)
+		*blocklistURL, *nameservers, *bindPort, *quiet)
 
-	x, logmessages := xip.NewXip(*etcdEndpoint, *blocklistURL, strings.Split(*nameservers, ","), strings.Split(*addresses, ","))
+	x, logmessages := xip.NewXip(*blocklistURL, strings.Split(*nameservers, ","), strings.Split(*addresses, ","))
 	for _, logmessage := range logmessages {
 		log.Println(logmessage)
 	}

src/sslip.io-dns-server/xip/xip.go

@@ -5,7 +5,6 @@ package xip
 
 import (
 	"bufio"
-	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -14,29 +13,18 @@ import (
 	"net/http"
 	"net/netip"
 	"os"
-	"reflect"
 	"regexp"
 	"strconv"
 	"strings"
 	"time"
 
-	clientv3 "go.etcd.io/etcd/client/v3"
 	"golang.org/x/net/dns/dnsmessage"
 )
 
 //go:generate go run github.com/maxbrunsfeld/counterfeiter/v6 -generate
 
-//counterfeiter:generate . V3client
-type V3client interface {
-	Get(context.Context, string, ...clientv3.OpOption) (*clientv3.GetResponse, error)
-	Put(context.Context, string, string, ...clientv3.OpOption) (*clientv3.PutResponse, error)
-	Delete(context.Context, string, ...clientv3.OpOption) (*clientv3.DeleteResponse, error)
-	Close() error
-}
-
 // Xip is meant to be a singleton that holds global state for the DNS server
 type Xip struct {
-	Etcd                        V3client                // etcd client for `k-v.io`
 	DnsAmplificationAttackDelay chan struct{}           // for throttling metrics.status.sslip.io
 	Metrics                     Metrics                 // DNS server metrics
 	BlocklistStrings            []string                // list of blacklisted strings that shouldn't appear in public hostnames
@@ -54,9 +42,6 @@ type Metrics struct {
 	AnsweredAAAAQueries             int
 	AnsweredTXTSrcIPQueries         int
 	AnsweredTXTVersionQueries       int
-	AnsweredTXTGetKvQueries         int
-	AnsweredTXTPutKvQueries         int
-	AnsweredTXTDelKvQueries         int
 	AnsweredNSDNS01ChallengeQueries int
 	AnsweredBlockedQueries          int
 	AnsweredPTRQueriesIPv4          int
@@ -88,12 +73,6 @@ type DomainCustomization struct {
 // DNS hostnames are technically case-insensitive
 type DomainCustomizations map[string]DomainCustomization
 
-// KvCustomizations is a lookup table for custom TXT records
-// e.g. KvCustomizations["my-key"] = []dnsmessage.TXTResource{ TXT: { "my-value" } }
-// The key should NOT include ".k-v.io."
-// It's used when there's no etcd server running
-type KvCustomizations map[string][]dnsmessage.TXTResource
-
 // There's nothing like global variables to make my heart pound with joy.
 // Some of these are global because they are, in essence, constants which
 // I don't want to waste time recreating with every function call.
@@ -105,7 +84,6 @@ var (
 	ipv4ReverseRE    = regexp.MustCompile(`^(.*)\.in-addr\.arpa\.$`)
 	ipv6ReverseRE    = regexp.MustCompile(`^(([[:xdigit:]]\.){32})ip6\.arpa\.`)
 	dns01ChallengeRE = regexp.MustCompile(`(?i)_acme-challenge\.`) // (?i) → non-capturing case insensitive
-	kvRE             = regexp.MustCompile(`\.k-v\.io\.$`)
 
 	mbox, _  = dnsmessage.NewName("briancunnie.gmail.com.")
 	mx1, _   = dnsmessage.NewName("mail.protonmail.ch.")
@@ -120,15 +98,6 @@ var (
 
 	MetricsBufferSize = 200 // big enough to run our tests, and small enough to prevent DNS amplification attacks
 
-	// etcdContextTimeout — the duration (context) that we wait for etcd to get back to us
-	// - etcd queries on the nameserver take as long as 482 milliseconds on the "slow" server, 247 on the "fast"
-	// - round-trip time from my house in San Francisco to ns-azure in Singapore is 190 milliseconds
-	// - time between queries with `dig` on my macOS Monterey is 5000 milliseconds, three queries before giving up
-	// - quadruple the headroom for queries 4 x 482 = 1928, should still leave enough room to get answer back
-	//   within the 5000 milliseconds
-	etcdContextTimeout = 1928 * time.Millisecond
-
-	TxtKvCustomizations = KvCustomizations{}
 	Customizations = DomainCustomizations{
 		"sslip.io.": {
 			MX: []dnsmessage.MXResource{
@@ -143,12 +112,6 @@ var (
 			},
 			TXT: TXTSslipIoSPF,
 		},
-		// don't let people procure *.k-v.io TLS certs via ACME DNS-01 challenge
-		"_acme-challenge.k-v.io.": {
-			TXT: func(_ *Xip, _ net.IP) ([]dnsmessage.TXTResource, error) {
-				return []dnsmessage.TXTResource{{TXT: []string{"Please don't try to procure a k-v.io cert via DNS-01 challenge"}}}, nil
-			},
-		},
 		// nameserver addresses; we get queries for those every once in a while
 		// CNAMEs for sslip.io for DKIM signing
 		"protonmail._domainkey.sslip.io.": {
@@ -201,19 +164,8 @@ type Response struct {
 }
 
 // NewXip follows convention for constructors: https://go.dev/doc/effective_go#allocation_new
-func NewXip(etcdEndpoint, blocklistURL string, nameservers []string, addresses []string) (x *Xip, logmessages []string) {
+func NewXip(blocklistURL string, nameservers []string, addresses []string) (x *Xip, logmessages []string) {
-	var err error
 	x = &Xip{Metrics: Metrics{Start: time.Now()}}
-	// connect to `etcd`; if there's an error, set etcdCli to `nil` and that to
-	// determine whether to use a local key-value store instead
-	x.Etcd, err = clientv3New(etcdEndpoint)
-	if err != nil {
-		logmessages = append(logmessages, fmt.Sprintf("failed to connect to etcd at %s, using local key-value store instead: %s", etcdEndpoint, err.Error()))
-	} else {
-		logmessages = append(logmessages, fmt.Sprintf("Successfully connected to etcd at %s", etcdEndpoint))
-	}
-	// don't `defer etcdCli.Close()`: "The Client has internal state (watchers and leases), so
-	// Clients should be reused instead of created as needed"
 
 	// Download the blocklist
 	logmessages = append(logmessages, x.downloadBlockList(blocklistURL))
@@ -819,7 +771,7 @@ func (x *Xip) NSResources(fqdnString string) []dnsmessage.NSResource {
 	return x.NameServers
 }
 
-// TXTResources returns TXT records from Customizations or KvCustomizations
+// TXTResources returns TXT records from Customizations
 func (x *Xip) TXTResources(fqdn string, ip net.IP) ([]dnsmessage.TXTResource, error) {
 	if domain, ok := Customizations[strings.ToLower(fqdn)]; ok {
 		// Customizations[strings.ToLower(fqdn)] returns a _function_,
@@ -828,9 +780,6 @@ func (x *Xip) TXTResources(fqdn string, ip net.IP) ([]dnsmessage.TXTResource, er
 			return domain.TXT(x, ip)
 		}
 	}
-	if kvRE.MatchString(fqdn) {
-		return x.kvTXTResources(fqdn)
-	}
 	return nil, nil
 }
 
@@ -938,11 +887,6 @@ func TXTMetrics(x *Xip, _ net.IP) (txtResources []dnsmessage.TXTResource, err er
 	var metrics []string
 	uptime := time.Since(x.Metrics.Start)
 	metrics = append(metrics, fmt.Sprintf("Uptime: %.0f", uptime.Seconds()))
-	keyValueStore := "etcd"
-	if x.isEtcdNil() {
-		keyValueStore = "builtin"
-	}
-	metrics = append(metrics, "KV Store: "+keyValueStore)
 	metrics = append(metrics, fmt.Sprintf("Blocklist: %s %d,%d",
 		x.BlocklistUpdated.Format("2006-01-02 15:04:05-07"),
 		len(x.BlocklistStrings),
@@ -953,7 +897,6 @@ func TXTMetrics(x *Xip, _ net.IP) (txtResources []dnsmessage.TXTResource, err er
 	metrics = append(metrics, fmt.Sprintf("AAAA: %d", x.Metrics.AnsweredAAAAQueries))
 	metrics = append(metrics, fmt.Sprintf("TXT Source: %d", x.Metrics.AnsweredTXTSrcIPQueries))
 	metrics = append(metrics, fmt.Sprintf("TXT Version: %d", x.Metrics.AnsweredTXTVersionQueries))
-	metrics = append(metrics, fmt.Sprintf("TXT KV GET/PUT/DEL: %d/%d/%d", x.Metrics.AnsweredTXTGetKvQueries, x.Metrics.AnsweredTXTPutKvQueries, x.Metrics.AnsweredTXTDelKvQueries))
 	metrics = append(metrics, fmt.Sprintf("PTR IPv4/IPv6: %d/%d", x.Metrics.AnsweredPTRQueriesIPv4, x.Metrics.AnsweredPTRQueriesIPv6))
 	metrics = append(metrics, fmt.Sprintf("NS DNS-01: %d", x.Metrics.AnsweredNSDNS01ChallengeQueries))
 	metrics = append(metrics, fmt.Sprintf("Blocked: %d", x.Metrics.AnsweredBlockedQueries))
@@ -963,106 +906,6 @@ func TXTMetrics(x *Xip, _ net.IP) (txtResources []dnsmessage.TXTResource, err er
 	return txtResources, nil
 }
 
-// when TXT for "k-v.io" is queried, return the key-value pair
-func (x *Xip) kvTXTResources(fqdn string) ([]dnsmessage.TXTResource, error) {
-	// "labels" => official RFC 1035 term
-	// k-v.io. => ["k-v", "io"] are labels
-	var (
-		verb  string // i.e. "get", "put", "delete"
-		key   string // e.g. "my-key" as in "my-key.k-v.io"
-		value string // e.g. "my-value" as in "put.my-value.my-key.k-v.io"
-	)
-	labels := strings.Split(fqdn, ".")
-	labels = labels[:len(labels)-3] // strip ".k-v.io"
-	// key is always present, always first subdomain of "k-v.io"
-	key = strings.ToLower(labels[len(labels)-1])
-	switch {
-	case len(labels) == 1:
-		verb = "get" // default action if only key, not verb, is not present
-	case len(labels) == 2:
-		verb = strings.ToLower(labels[0]) // verb, if present, is leftmost, "put.value.key.k-v.io"
-	case len(labels) > 2:
-		verb = strings.ToLower(labels[0])
-		// concatenate multiple labels to create value, especially useful for version numbers
-		value = strings.Join(labels[1:len(labels)-1], ".") // e.g. "put.94.0.2.firefox-version.k-v.io"
-	}
-	// prepare to query etcd:
-	switch verb {
-	case "get":
-		return x.getKv(key)
-	case "put":
-		if len(labels) == 2 {
-			return []dnsmessage.TXTResource{{[]string{"422: missing a value: put.value.key.k-v.io"}}}, nil
-		}
-		return x.putKv(key, value)
-	case "delete":
-		return x.deleteKv(key)
-	}
-	return []dnsmessage.TXTResource{{[]string{"422: valid verbs are get, put, delete"}}}, nil
-}
-
-func (x *Xip) getKv(key string) ([]dnsmessage.TXTResource, error) {
-	if x.isEtcdNil() {
-		if txtRecord, ok := TxtKvCustomizations[key]; ok {
-			x.Metrics.AnsweredTXTGetKvQueries++
-			return txtRecord, nil
-		}
-		return nil, nil
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), etcdContextTimeout)
-	defer cancel()
-	resp, err := x.Etcd.Get(ctx, key)
-	if err != nil {
-		return nil, fmt.Errorf(`couldn't GET "%s": %w`, key, err)
-	}
-	if len(resp.Kvs) > 0 {
-		x.Metrics.AnsweredTXTGetKvQueries++
-		return []dnsmessage.TXTResource{{[]string{string(resp.Kvs[0].Value)}}}, nil
-	}
-	return []dnsmessage.TXTResource{}, nil
-}
-
-func (x *Xip) putKv(key, value string) ([]dnsmessage.TXTResource, error) {
-	if len(value) > 63 { // too-long TXT records can be used in DNS amplification attacks; Truncate!
-		value = value[:63]
-	}
-	if x.isEtcdNil() {
-		TxtKvCustomizations[key] = []dnsmessage.TXTResource{
-			{
-				[]string{value},
-			},
-		}
-		x.Metrics.AnsweredTXTPutKvQueries++
-		return TxtKvCustomizations[key], nil
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), etcdContextTimeout)
-	defer cancel()
-	_, err := x.Etcd.Put(ctx, key, value)
-	if err != nil {
-		return nil, fmt.Errorf("couldn't PUT (%s: %s): %w", key, value, err)
-	}
-	x.Metrics.AnsweredTXTPutKvQueries++
-	return []dnsmessage.TXTResource{{[]string{value}}}, nil
-}
-
-func (x *Xip) deleteKv(key string) ([]dnsmessage.TXTResource, error) {
-	if x.isEtcdNil() {
-		if _, ok := TxtKvCustomizations[key]; ok {
-			x.Metrics.AnsweredTXTDelKvQueries++
-			delete(TxtKvCustomizations, key)
-		}
-		return nil, nil
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), etcdContextTimeout)
-	defer cancel()
-	_, err := x.Etcd.Delete(ctx, key)
-	if err != nil {
-		return nil, fmt.Errorf("couldn't DELETE (key %s): %w", key, err)
-	}
-	x.Metrics.AnsweredTXTDelKvQueries++
-	return nil, nil
-}
-
 // soaLogMessage returns an easy-to-read string for logging SOA Answers/Authorities
 func soaLogMessage(soaResource dnsmessage.SOAResource) string {
 	return soaResource.NS.String() + " " +
@@ -1082,9 +925,6 @@ func (a Metrics) MostlyEquals(b Metrics) bool {
 		a.AnsweredAAAAQueries == b.AnsweredAAAAQueries &&
 		a.AnsweredTXTSrcIPQueries == b.AnsweredTXTSrcIPQueries &&
 		a.AnsweredTXTVersionQueries == b.AnsweredTXTVersionQueries &&
-		a.AnsweredTXTGetKvQueries == b.AnsweredTXTGetKvQueries &&
-		a.AnsweredTXTPutKvQueries == b.AnsweredTXTPutKvQueries &&
-		a.AnsweredTXTDelKvQueries == b.AnsweredTXTDelKvQueries &&
 		a.AnsweredPTRQueriesIPv4 == b.AnsweredPTRQueriesIPv4 &&
 		a.AnsweredPTRQueriesIPv6 == b.AnsweredPTRQueriesIPv6 &&
 		a.AnsweredNSDNS01ChallengeQueries == b.AnsweredNSDNS01ChallengeQueries &&
@@ -1161,15 +1001,6 @@ func ReadBlocklist(blocklist io.Reader) (stringBlocklists []string, cidrBlocklis
 	return stringBlocklists, cidrBlocklists, nil
 }
 
-func (x *Xip) isEtcdNil() bool {
-	// comparing interfaces to nil are tricky: interfaces contain both a type
-	// and a value, and although the value is nil the type isn't, so we need the following
-	if x.Etcd == nil || reflect.ValueOf(x.Etcd).IsNil() {
-		return true
-	}
-	return false
-}
-
 func (x *Xip) blocklist(hostname string) bool {
 	aResources := NameToA(hostname)
 	aaaaResources := NameToAAAA(hostname)
@@ -1322,25 +1153,3 @@ func (x *Xip) nameToAAAAwithBlocklist(q dnsmessage.Question, response Response,
 	}
 	return response, logMessage + strings.Join(logMessages, ", "), nil
 }
-
-// clientv3New attempts to connect to local etcd and retrieve a key to make
-// sure the connection works. If for any reason it fails it returns nil +
-// error
-func clientv3New(etcdEndpoint string) (*clientv3.Client, error) {
-	etcdEndpoints := []string{etcdEndpoint}
-	etcdCli, err := clientv3.New(clientv3.Config{
-		Endpoints:   etcdEndpoints,
-		DialTimeout: 250 * time.Millisecond,
-	})
-	if err != nil {
-		return nil, err
-	}
-	// Let's do a query to determine if etcd is really, truly there
-	ctx, cancel := context.WithTimeout(context.Background(), etcdContextTimeout)
-	defer cancel()
-	_, err = etcdCli.Get(ctx, "some-silly-key, doesn't matter if it exists")
-	if err != nil {
-		return nil, err
-	}
-	return etcdCli, nil
-}

src/sslip.io-dns-server/xip/xip_test.go

@@ -5,12 +5,10 @@ import (
 	"math/rand"
 	"net"
 	"strings"
-	"time"
 	"xip/xip"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
-	clientv3 "go.etcd.io/etcd/client/v3"
 	"golang.org/x/net/dns/dnsmessage"
 )
 
@@ -81,7 +79,7 @@ var _ = Describe("Xip", func() {
 
 	Describe("NSResources()", func() {
 		When("we use the default nameservers", func() {
-			var x, _ = xip.NewXip("localhost:2379", "file:///", []string{"ns-aws.sslip.io.", "ns-azure.sslip.io.", "ns-gce.sslip.io."}, []string{})
+			var x, _ = xip.NewXip("file:///", []string{"ns-aws.sslip.io.", "ns-azure.sslip.io.", "ns-gce.sslip.io."}, []string{})
 			It("returns the name servers", func() {
 				randomDomain := random8ByteString() + ".com."
 				ns := x.NSResources(randomDomain)
@@ -113,7 +111,7 @@ var _ = Describe("Xip", func() {
 			})
 		})
 		When("we override the default nameservers", func() {
-			var x, _ = xip.NewXip("localhost:2379", "file:///", []string{"mickey", "minn.ie.", "goo.fy"}, []string{})
+			var x, _ = xip.NewXip("file:///", []string{"mickey", "minn.ie.", "goo.fy"}, []string{})
 			It("returns the configured servers", func() {
 				randomDomain := random8ByteString() + ".com."
 				ns := x.NSResources(randomDomain)
@@ -178,69 +176,6 @@ var _ = Describe("Xip", func() {
 				Expect(len(txts)).To(Equal(0))
 			})
 		})
-		When(`the domain "k-v.io is queried"`, Ordered, func() {
-			txtTests := func() {
-				DescribeTable(`the domain "k-v.io" is queried for TXT records`,
-					func(fqdn string, txts []string) {
-						txtResources, err := x.TXTResources(fqdn, nil)
-						Expect(err).ToNot(HaveOccurred())
-						Expect(len(txtResources)).To(Equal(len(txts)))
-						for i, txtResource := range txtResources {
-							Expect(len(txtResource.TXT)).To(Equal(1)) // each TXT record has 1 & only 1 string
-							Expect(txtResource.TXT[0]).To(Equal(txts[i]))
-						}
-					},
-					// simple tests: get, put, delete with single label value
-					Entry("no arguments → empty array", "k-v.io.", []string{}),
-					Entry("putting a value → that value", "PUT.MyValue.my-key.k-v.io.", []string{"MyValue"}),
-					Entry("getting that value → that value", "my-key.k-v.io.", []string{"MyValue"}),
-					Entry("getting that value with an UPPERCASE key → that value", "MY-KEY.k-v.io.", []string{"MyValue"}),
-					Entry("explicitly getting that value → that value", "GeT.my-key.k-v.io.", []string{"MyValue"}),
-					Entry("deleting that value → empty array", "DelETe.my-key.k-v.io.", []string{}),
-					Entry("getting that deleted value → empty array", "my-key.k-v.io.", []string{}),
-					// errors
-					Entry("getting a non-existent key → empty array", "nonexistent.k-v.io.", []string{}),
-					Entry("putting but skipping the value → error txt", "put.my-key.k-v.io.", []string{"422: missing a value: put.value.key.k-v.io"}),
-					Entry("deleting a non-existent key → silently succeeds", "delete.non-existent.k-v.io.", []string{}),
-					Entry("using a garbage verb → error txt", "post.my-key.k-v.io.", []string{"422: valid verbs are get, put, delete"}),
-					// others
-					Entry("putting a multi-label value", "put.96.0.4664.55.chrome-version.k-v.io.", []string{"96.0.4664.55"}),
-					Entry("putting a super-long multi-label value to use in a DNS amplification attack gets truncated to 63 characters",
-						"put"+
-							".IReturnedAndSawUnderTheSunThatTheRaceIsNotToTheSwiftNotThe"+
-							".BattleToTheStrongNeitherYetBreadToTheWiseNorYetRichesToMenOf"+
-							".amplify.k-v.io.",
-						[]string{"IReturnedAndSawUnderTheSunThatTheRaceIsNotToTheSwiftNotThe.Batt"},
-					),
-				)
-
-			}
-			When("there's no etcd, just local, in-memory key-value", func() {
-				txtTests()
-			})
-			etcdURI := "localhost:2379"
-			// make sure there's an etcd listening before we run our tests
-			conn, err := net.DialTimeout("tcp", etcdURI, 250*time.Millisecond)
-			if err == nil {
-				err = conn.Close()
-				Expect(err).ToNot(HaveOccurred())
-				When(`etcd is backing the kv store`, func() {
-					BeforeEach(func() {
-						etcdCli, err := clientv3.New(clientv3.Config{
-							Endpoints:   []string{etcdURI},
-							DialTimeout: 250 * time.Millisecond,
-						})
-						Expect(err).ToNot(HaveOccurred())
-						x.Etcd = etcdCli
-					})
-					AfterEach(func() {
-						err = x.Etcd.Close()
-						Expect(err).ToNot(HaveOccurred())
-					})
-					txtTests()
-				})
-			}
-		})
 	})
 
 	Describe("NameToA()", func() {