search

kevinjqiu / coredns-dockerdiscovery

Docker Discovery Plugin for CoreDNS
Apache License 2.0
61 stars 29 forks source link

Logs mention containers registered. dig still fails to return records for them. #40

Open jmdots opened 4 months ago

jmdots commented 4 months ago

Could you help me figure out where I went wrong?

(base) josh@monolith-1:~$ dig @127.0.0.1 -p 15353 caddy.docker

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @127.0.0.1 -p 15353 caddy.docker
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 34602
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;caddy.docker.          IN  A

;; AUTHORITY SECTION:
.           599 IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2024052602 1800 900 604800 86400

;; Query time: 95 msec
;; SERVER: 127.0.0.1#15353(127.0.0.1) (UDP)
;; WHEN: Sun May 26 17:22:32 EDT 2024
;; MSG SIZE  rcvd: 116

(base) josh@monolith-1:~$ dig @127.0.0.1 -p 15353 caddy.docker.loc

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @127.0.0.1 -p 15353 caddy.docker.loc
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 835
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;caddy.docker.loc.      IN  A

;; AUTHORITY SECTION:
.           599 IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2024052602 1800 900 604800 86400

;; Query time: 91 msec
;; SERVER: 127.0.0.1#15353(127.0.0.1) (UDP)
;; WHEN: Sun May 26 17:22:56 EDT 2024
;; MSG SIZE  rcvd: 120

(base) josh@monolith-1:~$ dig @127.0.0.1 -p 15353 caddy.docker-host.loc

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @127.0.0.1 -p 15353 caddy.docker-host.loc
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 53881
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;caddy.docker-host.loc.     IN  A

;; AUTHORITY SECTION:
.           599 IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2024052602 1800 900 604800 86400

;; Query time: 99 msec
;; SERVER: 127.0.0.1#15353(127.0.0.1) (UDP)
;; WHEN: Sun May 26 17:23:14 EDT 2024
;; MSG SIZE  rcvd: 125

(base) josh@monolith-1:~$ docker logs coredns 
[docker] start
.:15353 on 0.0.0.0
CoreDNS-1.11.3
linux/amd64, go1.21.10, 621ffde53-dirty
[docker] Add entry of container coredns (0ea7cd62cf0a). IP: 172.17.0.4
[docker] Add entry of container caddy (1171c37a5aa8). IP: 172.17.0.2
[docker] Add entry of container postgres (d5c42b170e49). IP: 172.18.0.4
[docker] Add entry of container namecheap-ddns-updater (88dfeb04f838). IP: 172.17.0.3
[docker] Add entry of container element (71102d723743). IP: 172.18.0.2
[INFO] 172.17.0.1:54709 - 34602 "A IN caddy.docker. udp 53 false 1232" NXDOMAIN qr,rd,ra 116 0.095756145s
[INFO] 172.17.0.1:41537 - 835 "A IN caddy.docker.loc. udp 57 false 1232" NXDOMAIN qr,rd,ra 120 0.091373966s
[INFO] 172.17.0.1:60327 - 53881 "A IN caddy.docker-host.loc. udp 62 false 1232" NXDOMAIN qr,rd,ra 125 0.099162413s
(base) josh@monolith-1:~$ docker ps
CONTAINER ID   IMAGE                         COMMAND                  CREATED         STATUS         PORTS                                                         NAMES
0ea7cd62cf0a   custom-coredns:latest         "/coredns/coredns -c…"   2 minutes ago   Up 2 minutes   0.0.0.0:15353->15353/udp                                      coredns
1171c37a5aa8   custom-caddy:latest           "caddy run --config …"   20 hours ago    Up 10 hours    0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp, 443/udp, 2019/tcp   caddy
d5c42b170e49   postgres:14                   "docker-entrypoint.s…"   20 hours ago    Up 10 hours    5432/tcp                                                      postgres
88dfeb04f838   namecheap-ddns-updater        "bash -c 'while :; d…"   20 hours ago    Up 10 hours                                                                  namecheap-ddns-updater
71102d723743   vectorim/element-web:latest   "/docker-entrypoint.…"   28 hours ago    Up 10 hours    80/tcp                                                        element
(base) josh@monolith-1:~$ 
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ docker logs coredns -f
[docker] start
.:15353 on 0.0.0.0
CoreDNS-1.11.3
linux/amd64, go1.21.10, 621ffde53-dirty
[docker] Add entry of container coredns (0ea7cd62cf0a). IP: 172.17.0.4
[docker] Add entry of container caddy (1171c37a5aa8). IP: 172.17.0.2
[docker] Add entry of container postgres (d5c42b170e49). IP: 172.18.0.4
[docker] Add entry of container namecheap-ddns-updater (88dfeb04f838). IP: 172.17.0.3
[docker] Add entry of container element (71102d723743). IP: 172.18.0.2
[INFO] 172.17.0.1:54709 - 34602 "A IN caddy.docker. udp 53 false 1232" NXDOMAIN qr,rd,ra 116 0.095756145s
[INFO] 172.17.0.1:41537 - 835 "A IN caddy.docker.loc. udp 57 false 1232" NXDOMAIN qr,rd,ra 120 0.091373966s
[INFO] 172.17.0.1:60327 - 53881 "A IN caddy.docker-host.loc. udp 62 false 1232" NXDOMAIN qr,rd,ra 125 0.099162413s
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ docker logs coredns -f
[docker] start
.:15353 on 0.0.0.0
CoreDNS-1.11.3
linux/amd64, go1.21.10, 621ffde53-dirty
[docker] Add entry of container coredns (0ea7cd62cf0a). IP: 172.17.0.4
[docker] Add entry of container caddy (1171c37a5aa8). IP: 172.17.0.2
[docker] Add entry of container postgres (d5c42b170e49). IP: 172.18.0.4
[docker] Add entry of container namecheap-ddns-updater (88dfeb04f838). IP: 172.17.0.3
[docker] Add entry of container element (71102d723743). IP: 172.18.0.2
[INFO] 172.17.0.1:54709 - 34602 "A IN caddy.docker. udp 53 false 1232" NXDOMAIN qr,rd,ra 116 0.095756145s
[INFO] 172.17.0.1:41537 - 835 "A IN caddy.docker.loc. udp 57 false 1232" NXDOMAIN qr,rd,ra 120 0.091373966s
[INFO] 172.17.0.1:60327 - 53881 "A IN caddy.docker-host.loc. udp 62 false 1232" NXDOMAIN qr,rd,ra 125 0.099162413s
^C
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ cat var/coredns-build/
Corefile    Dockerfile  
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ cat var/coredns-build/Corefile 
.:15353 {
    bind 0.0.0.0
    docker unix:///var/run/docker.sock {
        ttl 30
        domain docker.loc
        hostname_domain docker-host.loc
    }
    log
    errors
    forward . 8.8.8.8 8.8.4.4
}
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ cat var/coredns-build/Dockerfile 
# Stage 1: Build CoreDNS with Docker plugin
FROM golang:1.21-alpine AS build

# Install necessary build tools
RUN apk add --no-cache git make

# Set up working directory
WORKDIR /go/src/github.com/coredns/coredns

# Clone the CoreDNS repository
RUN git clone https://github.com/coredns/coredns.git .

# Add the Docker plugin to plugin.cfg
RUN echo "docker:github.com/kevinjqiu/coredns-dockerdiscovery" >> plugin.cfg

# Ensure no duplicate entries in plugin.cfg
RUN cat plugin.cfg | uniq > plugin.cfg.tmp && mv plugin.cfg.tmp plugin.cfg

# Fetch Go modules
RUN go mod tidy

# Build CoreDNS
RUN make

# Stage 2: Create the final image
FROM alpine:latest

# Set up working directory
WORKDIR /coredns

# Copy the built CoreDNS binary
COPY --from=build /go/src/github.com/coredns/coredns/coredns /coredns/coredns

# Copy the Corefile
COPY Corefile /coredns/Corefile

# Expose DNS ports
EXPOSE 15353/udp

# Command to run CoreDNS
CMD ["/coredns/coredns", "-conf", "/coredns/Corefile"]
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$

Edit: 

(base) josh@monolith-1:~$ dig @127.0.0.1 -p 15353 caddy

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @127.0.0.1 -p 15353 caddy
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 52825
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;caddy.             IN  A

;; Query time: 0 msec
;; SERVER: 127.0.0.1#15353(127.0.0.1) (UDP)
;; WHEN: Sun May 26 17:26:56 EDT 2024
;; MSG SIZE  rcvd: 34

(base) josh@monolith-1:~$

Second edit, to show me folllowing readme verbatim (--hostname)

(base) josh@monolith-1:~$ docker run -d --name my-alpine --hostname alpine alpine sleep 1000
Unable to find image 'alpine:latest' locally
latest: Pulling from library/alpine
d25f557d7f31: Already exists 
Digest: sha256:77726ef6b57ddf65bb551896826ec38bc3e53f75cdde31354fbffb4f25238ebd
Status: Downloaded newer image for alpine:latest
288dcc77b7f64dd5972402d42969864f197290244f918c915bfb0491443dcf5e
(base) josh@monolith-1:~$ docker ps
CONTAINER ID   IMAGE                         COMMAND                  CREATED         STATUS         PORTS                                                         NAMES
288dcc77b7f6   alpine                        "sleep 1000"             5 seconds ago   Up 4 seconds                                                                 my-alpine
0ea7cd62cf0a   custom-coredns:latest         "/coredns/coredns -c…"   8 minutes ago   Up 8 minutes   0.0.0.0:15353->15353/udp                                      coredns
1171c37a5aa8   custom-caddy:latest           "caddy run --config …"   20 hours ago    Up 10 hours    0.0.0.0:80->80/tcp, 0.0.0.0:443->443/tcp, 443/udp, 2019/tcp   caddy
d5c42b170e49   postgres:14                   "docker-entrypoint.s…"   20 hours ago    Up 10 hours    5432/tcp                                                      postgres
88dfeb04f838   namecheap-ddns-updater        "bash -c 'while :; d…"   20 hours ago    Up 10 hours                                                                  namecheap-ddns-updater
71102d723743   vectorim/element-web:latest   "/docker-entrypoint.…"   28 hours ago    Up 10 hours    80/tcp                                                        element
(base) josh@monolith-1:~$ 78c2a06ef2a9b63df857b7985468f7310bba0d9ea4d0d2629343aff4fd171861^C
(base) josh@monolith-1:~$ dig @localhost -p 15353 my-alpine.docker.loc

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @localhost -p 15353 my-alpine.docker.loc
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 30514
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;my-alpine.docker.loc.      IN  A

;; AUTHORITY SECTION:
.           599 IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2024052602 1800 900 604800 86400

;; Query time: 35 msec
;; SERVER: 127.0.0.1#15353(localhost) (UDP)
;; WHEN: Sun May 26 17:30:42 EDT 2024
;; MSG SIZE  rcvd: 124

(base) josh@monolith-1:~$ 
(base) josh@monolith-1:~$ dig @localhost -p 15353 alpine.docker-host.loc

; <<>> DiG 9.18.18-0ubuntu0.22.04.2-Ubuntu <<>> @localhost -p 15353 alpine.docker-host.loc
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 2258
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;alpine.docker-host.loc.        IN  A

;; AUTHORITY SECTION:
.           599 IN  SOA a.root-servers.net. nstld.verisign-grs.com. 2024052602 1800 900 604800 86400

;; Query time: 91 msec
;; SERVER: 127.0.0.1#15353(localhost) (UDP)
;; WHEN: Sun May 26 17:32:55 EDT 2024
;; MSG SIZE  rcvd: 126

(base) josh@monolith-1:~$

Another edit to show what network the containers are on:

(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$ ./containers_vs_networks.sh 
CONTAINER ID  NAME                    NETWORK NAMES
fd2e5d7eed97  postgres                bridge
0ea7cd62cf0a  coredns                 bridge
1171c37a5aa8  caddy                   bridge
88dfeb04f838  namecheap-ddns-updater  bridge
e434dcd864b4  synapse                 bridge,matrix_net
71102d723743  element                 bridge,matrix_net
(base) josh@monolith-1:~/src/jmdots-ansible/common/docker$