我正在尝试使用docker和Golang设置并连接到Cassandra单节点实例,但它无法正常工作。
我可以找到解决golang gocql
包和Cassandra之间连接问题的最接近的信息:Cassandra cqlsh - connection refused,但是有许多不同的upvote答案,没有明确指出哪个是首选。这也是一个受保护的问题(没有“我的toos”),所以很多社区成员似乎都遇到了麻烦。
这个问题应该略有不同,因为它使用的是Docker,我尝试了大多数(如果不是所有与上面相关的解决方案)。
version: "3"
services:
cassandra00:
restart: always
image: cassandra:latest
volumes:
- ./db/casdata:/var/lib/cassandra
ports:
- 7000:7000
- 7001:7001
- 7199:7199
- 9042:9042
- 9160:9160
environment:
- CASSANDRA_RPC_ADDRESS=127.0.0.1
- CASSANDRA_BROADCAST_ADDRESS=127.0.0.1
- CASSANDRA_LISTEN_ADDRESS=127.0.0.1
- CASSANDRA_START_RPC=true
db:
restart: always
build: ./db
environment:
POSTGRES_USER: patientplatypus
POSTGRES_PASSWORD: SUPERSECRETFAKEPASSD00T
POSTGRES_DB: zennify
expose:
- "5432"
ports:
- 5432:5432
volumes:
- ./db/pgdata:/var/lib/postgresql/data
app:
restart: always
build:
context: .
dockerfile: Dockerfile
command: bash -c 'while !</dev/tcp/db/5432; do sleep 10; done; realize start --run'
# command: bash -c 'while !</dev/tcp/db/5432; do sleep 10; done; go run main.go'
ports:
- 8000:8000
depends_on:
- db
- cassandra00
links:
- db
- cassandra00
volumes:
- ./:/go/src/github.com/patientplatypus/webserver/
不可否认,我对于我应该在环境部分传递给Cassandra的听力地址有点不稳定,所以我只是通过了'home':
- CASSANDRA_RPC_ADDRESS=127.0.0.1
- CASSANDRA_BROADCAST_ADDRESS=127.0.0.1
- CASSANDRA_LISTEN_ADDRESS=127.0.0.1
如果您尝试通过0.0.0.0
,则会收到以下错误:
cassandra00_1 | Exception (org.apache.cassandra.exceptions.ConfigurationException) encountered during startup: listen_address cannot be a wildcard address (0.0.0.0)!
cassandra00_1 | listen_address cannot be a wildcard address (0.0.0.0)!
cassandra00_1 | ERROR [main] 2018-09-10 21:50:44,530 CassandraDaemon.java:708 - Exception encountered during startup: listen_address cannot be a wildcard address (0.0.0.0)!
总的来说,我认为我正在为Cassandra(afaict)获得正确的启动程序,因为我的终端输出Cassandra正常启动并正在侦听相应的端口:
cassandra00_1 | INFO [main] 2018-09-10 22:06:28,920 StorageService.java:1446 - JOINING: Finish joining ring
cassandra00_1 | INFO [main] 2018-09-10 22:06:29,179 StorageService.java:2289 - Node /127.0.0.1 state jump to NORMAL
cassandra00_1 | INFO [main] 2018-09-10 22:06:29,607 NativeTransportService.java:70 - Netty using native Epoll event loop
cassandra00_1 | INFO [main] 2018-09-10 22:06:29,750 Server.java:155 - Using Netty Version: [netty-buffer=netty-buffer-4.0.44.Final.452812a, netty-codec=netty-codec-4.0.44.Final.452812a, netty-codec-haproxy=netty-codec-haproxy-4.0.44.Final.452812a, netty-codec-http=netty-codec-http-4.0.44.Final.452812a, netty-codec-socks=netty-codec-socks-4.0.44.Final.452812a, netty-common=netty-common-4.0.44.Final.452812a, netty-handler=netty-handler-4.0.44.Final.452812a, netty-tcnative=netty-tcnative-1.1.33.Fork26.142ecbb, netty-transport=netty-transport-4.0.44.Final.452812a, netty-transport-native-epoll=netty-transport-native-epoll-4.0.44.Final.452812a, netty-transport-rxtx=netty-transport-rxtx-4.0.44.Final.452812a, netty-transport-sctp=netty-transport-sctp-4.0.44.Final.452812a, netty-transport-udt=netty-transport-udt-4.0.44.Final.452812a]
cassandra00_1 | INFO [main] 2018-09-10 22:06:29,754 Server.java:156 - Starting listening for CQL clients on /127.0.0.1:9042 (unencrypted)...
cassandra00_1 | INFO [main] 2018-09-10 22:06:29,990 ThriftServer.java:116 - Binding thrift service to /127.0.0.1:9160
在我的golang代码中,我有以下被调用的包(简化为显示相关部分):
package data
import(
"fmt"
"github.com/gocql/gocql"
)
func create_userinfo_table() {
<...>
fmt.Println("replicating table in cassandra")
cluster := gocql.NewCluster("localhost") //<---error here!
cluster.ProtoVersion = 4
<...>
}
这导致我的终端出现以下错误:
app_1 | [21:52:38][WEBSERVER] : 2018/09/10
21:52:38 gocql: unable to dial control conn 127.0.0.1:
dial tcp 127.0.0.1:9042: connect: connection refused
app_1 | [21:52:38][WEBSERVER] : 2018/09/10
21:52:38 gocql: unable to dial control conn ::1:
dial tcp [::1]:9042: connect: cannot assign requested address
app_1 | [21:52:38][WEBSERVER] : 2018/09/10
21:52:38 Could not connect to cassandra cluster: gocql:
unable to create session: control: unable to connect to initial hosts:
dial tcp [::1]:9042: connect: cannot assign requested address
我在连接地址上尝试了几种变体
cluster := gocql.NewCluster("localhost")
cluster := gocql.NewCluster("127.0.0.1")
cluster := gocql.NewCluster("127.0.0.1:9042")
cluster := gocql.NewCluster("127.0.0.1:9160")
例如,这些似乎是候选人,但没有运气。
有谁知道我做错了什么?
根据docker-compose文档使用服务名称cassandra00
作为主机名https://docs.docker.com/compose/compose-file/#links
链接服务的容器可以在与别名相同的主机名上访问,如果未指定别名,则可以访问服务名称。
每个CASSANDRA_LISTEN_ADDRESS
保留auto
envvar未设置(或通过https://docs.docker.com/samples/library/cassandra/)
默认值为auto,它将cassandra.yaml中的listen_address选项设置为容器启动时的IP地址。此默认值适用于大多数用例。