我正在尝试使用docker-compose连接go和postgres容器。
这是我的docker-compose.yml：
version: '2'
services:
postgres:
image: postgres
ports:
- "5432"
environment:
- POSTGRES_PASSWORD=postgres
server:
build: ./server
command: gin
volumes:
- ./server:/go/src/app
ports:
- "8080:3000"
起初我尝试使用docker-compose.yml中的links命令，但这并没有在服务器容器中创建任何env变量，所以这让我很困惑。 （它应该创建SOMETHINGSOMETHING_PORT_5432_TCP_ADDR和SOMETHINGSOMETHING_5432_TCP_PORT，不是吗？）
然后我读到某处我可以使用http://postgres作为主持人，所以我尝试了。所以现在这就是我的main.go的样子（注意：我正在使用Gorp代替“ORM”）：
func main() {
dbinfo := fmt.Sprintf("user=%s password=%s host=%s dbname=%s sslmode=disable",
"postgres",
os.Getenv("DB_ENV_POSTGRES_PASSWORD"),
"http://postgres",
DB_NAME,
)
db, err := sql.Open("postgres", dbinfo)
checkErr(err, "sql.Open failed")
// construct a gorp DbMap
dbmap := &gorp.DbMap{Db: db, Dialect: gorp.PostgresDialect{}}
// add a table, setting the table name to 'posts' and
// specifying that the Id property is an auto incrementing PK
dbmap.AddTableWithName(Todo{}, "todos").SetKeys(true, "Id")
// create the table. in a production system you'd generally
// use a migration tool, or create the tables via scripts
err = dbmap.CreateTablesIfNotExists()
checkErr(err, "Create tables failed")
http.HandleFunc("/", handler)
http.ListenAndServe(":3001", nil)
}
以下是docker-compose的详细日志（我在端口5432上拒绝连接）：
←[36mserver_1 |←[0m [gin] listening on port 3000
←[33mpostgres_1 |←[0m The files belonging to this database system will be owned by user "postgres".
←[33mpostgres_1 |←[0m This user must also own the server process.
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m The database cluster will be initialized with locale "en_US.utf8".
←[33mpostgres_1 |←[0m The default database encoding has accordingly been set to "UTF8".
←[33mpostgres_1 |←[0m The default text search configuration will be set to "english".
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m Data page checksums are disabled.
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m fixing permissions on existing directory /var/lib/postgresql/data ... ok
←[33mpostgres_1 |←[0m creating subdirectories ... ok
←[33mpostgres_1 |←[0m selecting default max_connections ... 100
←[33mpostgres_1 |←[0m selecting default shared_buffers ... 128MB
←[33mpostgres_1 |←[0m selecting dynamic shared memory implementation ... posix
←[33mpostgres_1 |←[0m creating configuration files ... ok
←[33mpostgres_1 |←[0m creating template1 database in /var/lib/postgresql/data/base/1 ... ok
←[33mpostgres_1 |←[0m initializing pg_authid ... ok
←[33mpostgres_1 |←[0m initializing dependencies ... ok
←[33mpostgres_1 |←[0m creating system views ... ok
←[33mpostgres_1 |←[0m loading system objects' descriptions ... ok
←[33mpostgres_1 |←[0m creating collations ... ok
←[33mpostgres_1 |←[0m creating conversions ... ok
←[33mpostgres_1 |←[0m creating dictionaries ... ok
←[33mpostgres_1 |←[0m setting privileges on built-in objects ... ok
←[33mpostgres_1 |←[0m creating information schema ... ok
←[33mpostgres_1 |←[0m loading PL/pgSQL server-side language ... ok
←[33mpostgres_1 |←[0m vacuuming database template1 ... ok
←[33mpostgres_1 |←[0m copying template1 to template0 ... ok
←[33mpostgres_1 |←[0m copying template1 to postgres ... ok
←[33mpostgres_1 |←[0m syncing data to disk ... ok
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m WARNING: enabling "trust" authentication for local connections
←[33mpostgres_1 |←[0m You can change this by editing pg_hba.conf or using the option -A, or
←[33mpostgres_1 |←[0m --auth-local and --auth-host, the next time you run initdb.
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m Success. You can now start the database server using:
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m pg_ctl -D /var/lib/postgresql/data -l logfile start
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m waiting for server to start....LOG: database system was shut down at 2016-08-19 18:31:55 UTC
←[33mpostgres_1 |←[0m LOG: MultiXact member wraparound protections are now enabled
←[33mpostgres_1 |←[0m LOG: database system is ready to accept connections
←[33mpostgres_1 |←[0m LOG: autovacuum launcher started
←[33mpostgres_1 |←[0m done
←[33mpostgres_1 |←[0m server started
←[33mpostgres_1 |←[0m ALTER ROLE
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m /docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m LOG: received fast shutdown request
←[33mpostgres_1 |←[0m LOG: aborting any active transactions
←[33mpostgres_1 |←[0m LOG: autovacuum launcher shutting down
←[33mpostgres_1 |←[0m LOG: shutting down
←[33mpostgres_1 |←[0m waiting for server to shut down....LOG: database system is shut down
←[33mpostgres_1 |←[0m done
←[33mpostgres_1 |←[0m server stopped
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m PostgreSQL init process complete; ready for start up.
←[33mpostgres_1 |←[0m
←[33mpostgres_1 |←[0m LOG: database system was shut down at 2016-08-19 18:31:57 UTC
←[33mpostgres_1 |←[0m LOG: MultiXact member wraparound protections are now enabled
←[33mpostgres_1 |←[0m LOG: database system is ready to accept connections
←[33mpostgres_1 |←[0m LOG: autovacuum launcher started
←[36mserver_1 |←[0m 2016/08/19 18:32:05 Create tables failed dial tcp [::1]:5432: getsockopt: connection refused
←[36mserver_1 |←[0m 2016/08/19 18:32:05 http: proxy error: dial tcp [::1]:3001: getsockopt: connection refused
←[36mserver_1 |←[0m 2016/08/19 18:32:05 Create tables failed dial tcp [::1]:5432: getsockopt: connection refused
←[36mserver_1 |←[0m 2016/08/19 18:32:05 http: proxy error: dial tcp [::1]:3001: getsockopt: connection refused
所以我的问题是如何让这些能够彼此交谈以及我在这里做错了什么？
答案 0 :(得分：5)
这是一个码头网络问题。你可以阅读更多关于它的信息here. Docker dns完成了所有艰苦的工作，因此您可以通过撰写文件中给出的名称访问每个容器。
Posgres网址通常像
一样postgresql://user:password@ip:port/database
所以对你来说，就像是。
db, err := sql.Open("postgres", "postgresql://user:password@postgres/mydatabase)
请注意，如果postgres位于标准端口（5432）上，则不需要该端口。
答案 1 :(得分：1)
事实证明，因为我实际上并没有链接容器，所以os.Getenv（“DB_ENV_POSTGRES_PASSWORD”）正在生成一个空字符串。在docker-compose.yml中为服务器容器添加了一个带密码的环境变量，现在我可以连接到我的数据库了。