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Docker环境变量问题

Docker环境变量问题,比如,在Docker Hub上下载了一个nginx镜像,现在要把我自己的配置文件用上去,看到说可以有三种方式:
1、用环境变量传递配置。
2、用数据卷,把配置文件放到数据卷中。
3、修改镜像,保存为新的镜像。

现在,我想采用第1种方法,文档中关于环境变量的内容如下:

可是怎么配置,仍然有点不清楚。

黄舟黄舟2758 天前815

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  • PHP中文网

    PHP中文网2017-04-24 09:12:12

    谁告诉你环境变量可以用于传输配置文件了…
    可以用环境变量的意思是,有些软件既能识别环境变量中提供的配置,又能识别文件形式的配置,不过,很不幸,Nginx不在此列。

    以wget为例,当设定HTTP代理时,可以选用以下任一方式:

    • 在配置文件中加一行http_proxy = http://example.com/xxx

    • 将系统环境变量$http_proxy设定为http://example.com/xxx

    两种方法的作用是相同的。

    当然,你可以在Docker容器里写一个Shell脚本,根据环境变量来修改配置文件的内容,但这就是另一个话题了。Github上有不少实现类似功能的工具,如Tiller。

    补充一个资料:How Should I Get Application Configuration into my Docker Containers?

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  • 天蓬老师

    天蓬老师2017-04-24 09:12:12

    哦,在启动容器的时候要带参数,比如:
    ./docker run --detach --name wordpress --net wordnet --publish 80:80 --env WORDPRESS_DB_HOST=mysql --env WORDPRESS_DB_PASSWORD=xxxxxxxx wordpress:4.4

    当然在容器启动命令里要处理带进来的参数:

    cat /entrypoint.sh

    #!/bin/bash
    set -e
    
    if [[ "" == apache2* ]] || [ "" == php-fpm ]; then
        if [ -n "$MYSQL_PORT_3306_TCP" ]; then
            if [ -z "$WORDPRESS_DB_HOST" ]; then
                WORDPRESS_DB_HOST='mysql'
            else
                echo >&2 'warning: both WORDPRESS_DB_HOST and MYSQL_PORT_3306_TCP found'
                echo >&2 "  Connecting to WORDPRESS_DB_HOST ($WORDPRESS_DB_HOST)"
                echo >&2 '  instead of the linked mysql container'
            fi
        fi
    
        if [ -z "$WORDPRESS_DB_HOST" ]; then
            echo >&2 'error: missing WORDPRESS_DB_HOST and MYSQL_PORT_3306_TCP environment variables'
            echo >&2 '  Did you forget to --link some_mysql_container:mysql or set an external db'
            echo >&2 '  with -e WORDPRESS_DB_HOST=hostname:port?'
            exit 1
        fi
    
        # if we're linked to MySQL and thus have credentials already, let's use them
        : ${WORDPRESS_DB_USER:=${MYSQL_ENV_MYSQL_USER:-root}}
        if [ "$WORDPRESS_DB_USER" = 'root' ]; then
            : ${WORDPRESS_DB_PASSWORD:=$MYSQL_ENV_MYSQL_ROOT_PASSWORD}
        fi
        : ${WORDPRESS_DB_PASSWORD:=$MYSQL_ENV_MYSQL_PASSWORD}
        : ${WORDPRESS_DB_NAME:=${MYSQL_ENV_MYSQL_DATABASE:-wordpress}}
    
        if [ -z "$WORDPRESS_DB_PASSWORD" ]; then
            echo >&2 'error: missing required WORDPRESS_DB_PASSWORD environment variable'
            echo >&2 '  Did you forget to -e WORDPRESS_DB_PASSWORD=... ?'
            echo >&2
            echo >&2 '  (Also of interest might be WORDPRESS_DB_USER and WORDPRESS_DB_NAME.)'
            exit 1
        fi
    
        if ! [ -e index.php -a -e wp-includes/version.php ]; then
            echo >&2 "WordPress not found in $(pwd) - copying now..."
            if [ "$(ls -A)" ]; then
                echo >&2 "WARNING: $(pwd) is not empty - press Ctrl+C now if this is an error!"
                ( set -x; ls -A; sleep 10 )
            fi
            tar cf - --one-file-system -C /usr/src/wordpress . | tar xf -
            echo >&2 "Complete! WordPress has been successfully copied to $(pwd)"
            if [ ! -e .htaccess ]; then
                # NOTE: The "Indexes" option is disabled in the php:apache base image
                cat > .htaccess <<-'EOF'
                    # BEGIN WordPress
                    <IfModule mod_rewrite.c>
                    RewriteEngine On
                    RewriteBase /
                    RewriteRule ^index\.php$ - [L]
                    RewriteCond %{REQUEST_FILENAME} !-f
                    RewriteCond %{REQUEST_FILENAME} !-d
                    RewriteRule . /index.php [L]
                    </IfModule>
                    # END WordPress
                EOF
                chown www-data:www-data .htaccess
            fi
        fi
    
        # TODO handle WordPress upgrades magically in the same way, but only if wp-includes/version.php's $wp_version is less than /usr/src/wordpress/wp-includes/version.php's $wp_version
    
        # version 4.4.1 decided to switch to windows line endings, that breaks our seds and awks
        # https://github.com/docker-library/wordpress/issues/116
        # https://github.com/WordPress/WordPress/commit/1acedc542fba2482bab88ec70d4bea4b997a92e4
        sed -ri 's/\r\n|\r/\n/g' wp-config*
    
        if [ ! -e wp-config.php ]; then
            awk '/^\/\*.*stop editing.*\*\/$/ && c == 0 { c = 1; system("cat") } { print }' wp-config-sample.php > wp-config.php <<'EOPHP'
    // If we're behind a proxy server and using HTTPS, we need to alert Wordpress of that fact
    // see also http://codex.wordpress.org/Administration_Over_SSL#Using_a_Reverse_Proxy
    if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
        $_SERVER['HTTPS'] = 'on';
    }
    
    EOPHP
            chown www-data:www-data wp-config.php
        fi
    
        # see http://stackoverflow.com/a/2705678/433558
        sed_escape_lhs() {
            echo "$@" | sed 's/[]\/$*.^|[]/\&/g'
        }
        sed_escape_rhs() {
            echo "$@" | sed 's/[\/&]/\&/g'
        }
        php_escape() {
            php -r 'var_export(('') $argv[1]);' ""
        }
        set_config() {
            key=""
            value=""
            var_type="${3:-string}"
            start="(['\"])$(sed_escape_lhs "$key")\s*,"
            end="\);"
            if [ "${key:0:1}" = '$' ]; then
                start="^(\s*)$(sed_escape_lhs "$key")\s*="
                end=";"
            fi
            sed -ri "s/($start\s*).*($end)$/$(sed_escape_rhs "$(php_escape "$value" "$var_type")")/" wp-config.php
        }
    
        set_config 'DB_HOST' "$WORDPRESS_DB_HOST"
        set_config 'DB_USER' "$WORDPRESS_DB_USER"
        set_config 'DB_PASSWORD' "$WORDPRESS_DB_PASSWORD"
        set_config 'DB_NAME' "$WORDPRESS_DB_NAME"
    
        # allow any of these "Authentication Unique Keys and Salts." to be specified via
        # environment variables with a "WORDPRESS_" prefix (ie, "WORDPRESS_AUTH_KEY")
        UNIQUES=(
            AUTH_KEY
            SECURE_AUTH_KEY
            LOGGED_IN_KEY
            NONCE_KEY
            AUTH_SALT
            SECURE_AUTH_SALT
            LOGGED_IN_SALT
            NONCE_SALT
        )
        for unique in "${UNIQUES[@]}"; do
            eval unique_value=$WORDPRESS_$unique
            if [ "$unique_value" ]; then
                set_config "$unique" "$unique_value"
            else
                # if not specified, let's generate a random value
                current_set="$(sed -rn "s/define\((([\'\"])$unique\s*,\s*)(['\"])(.*)\);//p" wp-config.php)"
                if [ "$current_set" = 'put your unique phrase here' ]; then
                    set_config "$unique" "$(head -c1M /dev/urandom | sha1sum | cut -d' ' -f1)"
                fi
            fi
        done
    
        if [ "$WORDPRESS_TABLE_PREFIX" ]; then
            set_config '$table_prefix' "$WORDPRESS_TABLE_PREFIX"
        fi
    
        if [ "$WORDPRESS_DEBUG" ]; then
            set_config 'WP_DEBUG' 1 boolean
        fi
    
        TERM=dumb php -- "$WORDPRESS_DB_HOST" "$WORDPRESS_DB_USER" "$WORDPRESS_DB_PASSWORD" "$WORDPRESS_DB_NAME" <<'EOPHP'
    <?php
    // database might not exist, so let's try creating it (just to be safe)
    
    $stderr = fopen('php://stderr', 'w');
    
    list($host, $port) = explode(':', $argv[1], 2);
    
    $maxTries = 10;
    do {
        $mysql = new mysqli($host, $argv[2], $argv[3], '', (int)$port);
        if ($mysql->connect_error) {
            fwrite($stderr, "\n" . 'MySQL Connection Error: (' . $mysql->connect_errno . ') ' . $mysql->connect_error . "\n");
            --$maxTries;
            if ($maxTries <= 0) {
                exit(1);
            }
            sleep(3);
        }
    } while ($mysql->connect_error);
    
    if (!$mysql->query('CREATE DATABASE IF NOT EXISTS `' . $mysql->real_escape_string($argv[4]) . '`')) {
        fwrite($stderr, "\n" . 'MySQL "CREATE DATABASE" Error: ' . $mysql->error . "\n");
        $mysql->close();
        exit(1);
    }
    
    $mysql->close();
    EOPHP
    fi
    
    exec "$@"

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