bug: failed to use etcd service name as etcd endpoint

[zhaobu]

Issue description

使用官方的docker-compos文件,下面这一部分

......
  apisix:
    image: apache/apisix:2.11.0-alpine
    restart: always
    volumes:
      - ./apisix_log:/usr/local/apisix/logs
      - ./apisix_conf/config.yaml:/usr/local/apisix/conf/config.yaml:ro
    depends_on:
      - etcd
    ##network_mode: host
    ports:
      - "9080:9080/tcp"
      - "9091:9091/tcp"
      - "9443:9443/tcp"
      - "9092:9092/tcp"
    networks:
      apisix:

  etcd:
    image: bitnami/etcd:3.4.15
    restart: always
    volumes:
      - etcd_data:/bitnami/etcd
    environment:
      ETCD_ENABLE_V2: "true"
      ALLOW_NONE_AUTHENTICATION: "yes"
      ETCD_ADVERTISE_CLIENT_URLS: "http://0.0.0.0:2379"
      ETCD_LISTEN_CLIENT_URLS: "http://0.0.0.0:2379"
    ports:
      - "2379:2379/tcp"
    networks:
      apisix:
......

此时对应的apisix镜像的配置文件etcd部分是这样的

......
etcd:
  host:                           # it's possible to define multiple etcd hosts addresses of the same etcd cluster.
    - "http://etcd:2379"     # multiple etcd address
  prefix: "/apisix"               # apisix configurations prefix
  timeout: 30                     # 30 seconds
......

这是官方的默认配置是没有问题的.

如果把其中的etcd的部分改成下面这样

  mf_etcd:
    image: bitnami/etcd:3.4.15
    container_name: mf_etcd
    restart: always
    volumes:
      - etcd_data:/bitnami/etcd
    environment:
      ETCD_ENABLE_V2: "true"
      ALLOW_NONE_AUTHENTICATION: "yes"
      ETCD_ADVERTISE_CLIENT_URLS: "http://0.0.0.0:2379"
      ETCD_LISTEN_CLIENT_URLS: "http://0.0.0.0:2379"
    ports:
      - "2379:2379/tcp"
    networks:
      apisix:

此时对应的etcd配置应当修改为如下

......
etcd:
  host:                           # it's possible to define multiple etcd hosts addresses of the same etcd cluster.
    - "http://mf_etcd:2379"     # multiple etcd address
  prefix: "/apisix"               # apisix configurations prefix
  timeout: 30                     # 30 seconds
......

此时就会启动报错

Environment

bash-5.1# apisix version
/usr/local/openresty/luajit/bin/luajit ./apisix/cli/apisix.lua version
2.11.0
bash-5.1# uname -a
Linux b2c3fc362a79 5.10.60.1-microsoft-standard-WSL2 apache/apisix#1 SMP Wed Aug 25 23:20:18 UTC 2021 x86_64 Linux
bash-5.1# nginx -V
nginx version: openresty/1.19.3.2
built by gcc 9.3.0 (Alpine 9.3.0) 
built with OpenSSL 1.1.1g  21 Apr 2020
TLS SNI support enabled
configure arguments: --prefix=/usr/local/openresty/nginx --with-cc-opt='-O2 -DAPISIX_BASE_VER=1.19.3.2.2 -DNGX_LUA_ABORT_AT_PANIC -I/usr/local/openresty/zlib/include -I/usr/local/openresty/pcre/include -I/usr/local/openresty/openssl111/include' --add-module=../ngx_devel_kit-0.3.1 --add-module=../echo-nginx-module-0.62 --add-module=../xss-nginx-module-0.06 --add-module=../ngx_coolkit-0.2 --add-module=../set-misc-nginx-module-0.32 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.08 --add-module=../srcache-nginx-module-0.32 --add-module=../ngx_lua-0.10.19 --add-module=../ngx_lua_upstream-0.07 --add-module=../headers-more-nginx-module-0.33 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.19 --add-module=../redis2-nginx-module-0.15 --add-module=../redis-nginx-module-0.3.7 --add-module=../ngx_stream_lua-0.0.9 --with-ld-opt='-Wl,-rpath,/usr/local/openresty/luajit/lib -Wl,-rpath,/usr/local/openresty/wasmtime-c-api/lib -L/usr/local/openresty/zlib/lib -L/usr/local/openresty/pcre/lib -L/usr/local/openresty/openssl111/lib -Wl,-rpath,/usr/local/openresty/zlib/lib:/usr/local/openresty/pcre/lib:/usr/local/openresty/openssl111/lib' --add-module=/tmp/tmp.Po19j8606M/openresty-1.19.3.2/../mod_dubbo --add-module=/tmp/tmp.Po19j8606M/openresty-1.19.3.2/../ngx_multi_upstream_module --add-module=/tmp/tmp.Po19j8606M/openresty-1.19.3.2/../apisix-nginx-module --add-module=/tmp/tmp.Po19j8606M/openresty-1.19.3.2/../wasm-nginx-module --add-module=/tmp/tmp.Po19j8606M/openresty-1.19.3.2/../lua-var-nginx-module --with-poll_module --with-pcre-jit --with-stream --with-stream_ssl_module --with-stream_ssl_preread_module --with-http_v2_module --without-mail_pop3_module --without-mail_imap_module --without-mail_smtp_module --with-http_stub_status_module --with-http_realip_module --with-http_addition_module --with-http_auth_request_module --with-http_secure_link_module --with-http_random_index_module --with-http_gzip_static_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-threads --with-compat --with-stream --with-http_ssl_module
bash-5.1# curl http://127.0.0.1:9092/v1/server_info
{"hostname":"b2c3fc362a79","boot_time":1641116153,"id":"b3949f69-8817-47c0-895e-25387a09adc6","up_time":383,"last_report_time":1641116512,"etcd_version":"3.5.0","version":"2.11.0"}

Steps to reproduce

1. 修改etcd 的label为mf_etcd,container_name为mf_etcd
2. 修改apisix的有关etcd部分的配置文件如下

etcd:
  host:                           # it's possible to define multiple etcd hosts addresses of the same etcd cluster.
    - "http://mf_etcd:2379"     # multiple etcd address
  prefix: "/apisix"               # apisix configurations prefix
  timeout: 30                     # 30 seconds

Actual result

不能通过etcd的label名初始化

Error log

WARNING: using fixed Admin API token has security risk.
Please modify "admin_key" in conf/config.yaml .

/usr/local/openresty/luajit/bin/luajit ./apisix/cli/apisix.lua init_etcd
Warning! Request etcd endpoint 'http://etcd:2379/version' error, host or service not provided, or not known, retry time=1
request etcd endpoint 'http://etcd:2379/version' error, host or service not provided, or not known
all etcd nodes are unavailable
Warning! Request etcd endpoint 'http://etcd:2379/version' error, host or service not provided, or not known, retry time=2
/usr/local/openresty/luajit/bin/luajit ./apisix/cli/apisix.lua init

WARNING: using fixed Admin API token has security risk.
Please modify "admin_key" in conf/config.yaml .

/usr/local/openresty/luajit/bin/luajit ./apisix/cli/apisix.lua init_etcd
nginx: [error] init_by_lua error: /usr/local/apisix/apisix/core/config_etcd.lua:787: attempt to concatenate local 'err' (a nil value)
stack traceback:
/usr/local/apisix/apisix/core/config_etcd.lua:787: in function 'init'
/usr/local/apisix/apisix/init.lua:84: in function 'http_init'
init_by_lua:9: in main chunk

Expected result

用docker-compose的label名或者容器的container都能正确启动. 其他容器一般都能这样

[tzssangglass]

Duplicate of #115?

[zhaobu]

Duplicate of apache/apisix-docker#115?

我看了一下,好像你给的这个issues里面说的已经pr合并了,我遇到的应该是新的问题.我是昨天才开始用apisix的,也许是姿势不对? 不过貌似只有apisix才会遇到这个问题,

[tzssangglass]

Warning! Request etcd endpoint 'http://etcd:2379/version' error,

see this, It could be

apisix-docker/example/apisix_conf/config.yaml

Line 24 in 5d3c4c6

- "http://etcd:2379" # multiple etcd address

has not been changed

[pkking]

seems like the resty-etcd use a regular to check the etcd url, and the rule will reject the char -

https://github.com/api7/lua-resty-etcd/blob/f75f4c551b048e00233df38ab725b46218b35de9/lib/resty/etcd/v3.lua#L240

    for _, host in ipairs(http_hosts) do
        local m, err = re_match(host,
            [=[([^\/]+):\/\/([\da-zA-Z.-]+|\[[\da-fA-F:]+\]):?(\d+)?$]=], "jo")
        if not m then
            return nil, "invalid http host: " .. host .. ", err: " .. (err or "not matched")
        end

maybe try with mf-etcd instead

[tokers]

seems like the resty-etcd use a regular to check the etcd url, and the rule will reject the char -

https://github.com/api7/lua-resty-etcd/blob/f75f4c551b048e00233df38ab725b46218b35de9/lib/resty/etcd/v3.lua#L240

    for _, host in ipairs(http_hosts) do
        local m, err = re_match(host,
            [=[([^\/]+):\/\/([\da-zA-Z.-]+|\[[\da-fA-F:]+\]):?(\d+)?$]=], "jo")
        if not m then
            return nil, "invalid http host: " .. host .. ", err: " .. (err or "not matched")
        end

maybe try with mf-etcd instead

Oh, yes, and actually _ is not a valid char in the domain.

[leslie-tsang]

seems like the resty-etcd use a regular to check the etcd url, and the rule will reject the char -
https://github.com/api7/lua-resty-etcd/blob/f75f4c551b048e00233df38ab725b46218b35de9/lib/resty/etcd/v3.lua#L240

    for _, host in ipairs(http_hosts) do
        local m, err = re_match(host,
            [=[([^\/]+):\/\/([\da-zA-Z.-]+|\[[\da-fA-F:]+\]):?(\d+)?$]=], "jo")
        if not m then
            return nil, "invalid http host: " .. host .. ", err: " .. (err or "not matched")
        end

maybe try with mf-etcd instead

Oh, yes, and actually _ is not a valid char in the domain.

Cool, After reading of RFC1123 and RFC952, I'm wondering if we should use it as a DNS domain or Host ?

RFC-1123

The DNS itself places only one restriction on the particular labels
that can be used to identify resource records.  That one restriction
relates to the length of the label and the full name.  The length of
any one label is limited to between 1 and 63 octets.  A full domain
name is limited to 255 octets (including the separators).  The zero
length full name is defined as representing the root of the DNS tree,
and is typically written and displayed as ".".  Those restrictions
aside, any binary string whatever can be used as the label of any
resource record.  Similarly, any binary string can serve as the value
of any record that includes a domain name as some or all of its value
(SOA, NS, MX, PTR, CNAME, and any others that may be added).
Implementations of the DNS protocols must not place any restrictions
on the labels that can be used.  In particular, DNS servers must not
refuse to serve a zone because it contains labels that might not be
acceptable to some DNS client programs.  A DNS server may be
configurable to issue warnings when loading, or even to refuse to
load, a primary zone containing labels that might be considered
questionable, however this should not happen by default.

RFC-952 define

 B. Lexical grammar

    <entry-field> ::= <entry-text> [<cr><lf> <blank> <entry-field>]
    <entry-text>  ::= <print-char> *<text>
    <blank> ::= <space-or-tab> [<blank>]
    <keyword> ::= NET | GATEWAY | HOST | DOMAIN
    <hname> ::= <name>*["."<name>]
    <name>  ::= <let>[*[<let-or-digit-or-hyphen>]<let-or-digit>]

If we use it as an hostname, we should avoid _ in the config.

[leslie-tsang]

After reading lua-resty-etcd test case , I think the answer is clear, let's use it as a Host.

@juzhiyuan Consider solved. Feel free to reopen it if needed.