Taken from $GOROOT/src/pkg/net/http/chunked needed to write https responses to client. Package goproxy provides a customizable HTTP proxy, supporting hijacking HTTPS connection. The intent of the proxy, is to be usable with reasonable amount of traffic yet, customizable and programable. The proxy itself is simply an `net/http` handler. Typical usage is Adding a header to each request: For printing the content type of all incoming responses Note the use of `ctx.Req` here. The `ctx` holds `Req` and `Resp`. `Resp` can be nil if not available. To print the content type of all responses from a certain url, we'll add a "middleware" before: To invalide responses based on headers for example, you can: We close the body of the original repsonse, and return a new 403 response with a short message. You can catch traffic going through the proxy selectively, and write it to a HAR formatted file with this code: You then "curl http://localhost:8888/har" to provoke a file flush to "/tmp/file.har". Example use cases: 1. https://github.com/abourget/goproxy/tree/master/examples/goproxy-avgsize To measure the average size of an Html served in your site. One can ask all the QA team to access the website by a proxy, and the proxy will measure the average size of all text/html responses from your host. 2. [not yet implemented] All requests to your web servers should be directed through the proxy, when the proxy will detect html pieces sent as a response to AJAX request, it'll send a warning email. 3. https://github.com/abourget/goproxy/blob/master/examples/goproxy-httpdump/ Generate a real traffic to your website by real users using through proxy. Record the traffic, and try it again for more real load testing. 4. https://github.com/abourget/goproxy/tree/master/examples/goproxy-no-reddit-at-worktime Will allow browsing to reddit.com between 8:00am and 17:00pm 5. https://github.com/abourget/goproxy/tree/master/examples/goproxy-jquery-version Will warn if multiple versions of jquery are used in the same domain. 6. https://github.com/abourget/goproxy/blob/master/examples/goproxy-upside-down-ternet/ Modifies image files in an HTTP response via goproxy's image extension found in ext/.
Taken from $GOROOT/src/pkg/net/http/chunked needed to write https responses to client. Package goproxy provides a customizable HTTP proxy, supporting hijacking HTTPS connection. The intent of the proxy, is to be usable with reasonable amount of traffic yet, customizable and programmable. The proxy itself is simply an `net/http` handler. Typical usage is Adding a header to each request For printing the content type of all incoming responses note that we used the ProxyCtx context variable here. It contains the request and the response (Req and Resp, Resp is nil if unavailable) of this specific client interaction with the proxy. To print the content type of all responses from a certain url, we'll add a ReqCondition to the OnResponse function: We can write the condition ourselves, conditions can be set on request and on response Caution! If you give a RespCondition to the OnRequest function, you'll get a run time panic! It doesn't make sense to read the response, if you still haven't got it! Finally, we have convenience function to throw a quick response we close the body of the original response, and return a new 403 response with a short message. Example use cases: 1. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-avgsize To measure the average size of an Html served in your site. One can ask all the QA team to access the website by a proxy, and the proxy will measure the average size of all text/html responses from your host. 2. [not yet implemented] All requests to your web servers should be directed through the proxy, when the proxy will detect html pieces sent as a response to AJAX request, it'll send a warning email. 3. https://github.com/elazarl/goproxy/blob/master/examples/goproxy-httpdump/ Generate a real traffic to your website by real users using through proxy. Record the traffic, and try it again for more real load testing. 4. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-no-reddit-at-worktime Will allow browsing to reddit.com between 8:00am and 17:00pm 5. https://github.com/elazarl/goproxy/tree/master/examples/goproxy-jquery-version Will warn if multiple versions of jquery are used in the same domain. 6. https://github.com/elazarl/goproxy/blob/master/examples/goproxy-upside-down-ternet/ Modifies image files in an HTTP response via goproxy's image extension found in ext/.
Command grok provides standalone server terminating https and proxying requests in plain http over reverse ssh tunnels. Its main use-case is the same as of the ngrok tool from <https://ngrok.com>. Command grok listens https and ssh endpoints. On ssh connections it's looking for "tcpip-forward" request (RFC 4254, Section 7.1), once received, it establishes reverse proxy for domain derived from public key of the client. When receiving request over https, grok inspects request domain name, if matching active tunnel is found, request is proxied over found tunnel as plain HTTP/1.1 request. Certificates for matched domains are automatically obtained from https://letsencrypt.org authority as required. Domains are either derived from public key md5 fingerprint: hash.base.tld (where base.tld domain is set with -domain flag) or defined per-key in authorized_keys file as key option specification in form of domain=name.tld: Once set, developer may then connect to this service with ssh client setting up reverse port forwarding (i.e. to localhost:8080): Note the notation for -R used by ssh: When connecting to grok only host:hostport pair is significant, since they specify where ssh client will connect on forwarded connection, the first port can be set to arbitrary value and is ignored by the server.
Package gosnowflake is a pure Go Snowflake driver for the database/sql package. Clients can use the database/sql package directly. For example: Use Open to create a database handle with connection parameters: The Go Snowflake Driver supports the following connection syntaxes (or data source name formats): where all parameters must be escaped or use `Config` and `DSN` to construct a DSN string. The following example opens a database handle with the Snowflake account myaccount where the username is jsmith, password is mypassword, database is mydb, schema is testschema, and warehouse is mywh: The following connection parameters are supported: account <string>: Specifies the name of your Snowflake account, where string is the name assigned to your account by Snowflake. In the URL you received from Snowflake, your account name is the first segment in the domain (e.g. abc123 in https://abc123.snowflakecomputing.com). This parameter is optional if your account is specified after the @ character. If you are not on us-west-2 region or AWS deployment, then append the region after the account name, e.g. “<account>.<region>”. If you are not on AWS deployment, then append not only the region, but also the platform, e.g., “<account>.<region>.<platform>”. Account, region, and platform should be separated by a period (“.”), as shown above. If you are using a global url, then append connection group and "global", e.g., "account-<connection_group>.global". Account and connection group are separated by a dash ("-"), as shown above. region <string>: DEPRECATED. You may specify a region, such as “eu-central-1”, with this parameter. However, since this parameter is deprecated, it is best to specify the region as part of the account parameter. For details, see the description of the account parameter. database: Specifies the database to use by default in the client session (can be changed after login). schema: Specifies the database schema to use by default in the client session (can be changed after login). warehouse: Specifies the virtual warehouse to use by default for queries, loading, etc. in the client session (can be changed after login). role: Specifies the role to use by default for accessing Snowflake objects in the client session (can be changed after login). passcode: Specifies the passcode provided by Duo when using MFA for login. passcodeInPassword: false by default. Set to true if the MFA passcode is embedded in the login password. Appends the MFA passcode to the end of the password. loginTimeout: Specifies the timeout, in seconds, for login. The default is 60 seconds. The login request gives up after the timeout length if the HTTP response is success. authenticator: Specifies the authenticator to use for authenticating user credentials: To use the internal Snowflake authenticator, specify snowflake (Default). To authenticate through Okta, specify https://<okta_account_name>.okta.com (URL prefix for Okta). To authenticate using your IDP via a browser, specify externalbrowser. To authenticate via OAuth, specify oauth and provide an OAuth Access Token (see the token parameter below). application: Identifies your application to Snowflake Support. insecureMode: false by default. Set to true to bypass the Online Certificate Status Protocol (OCSP) certificate revocation check. IMPORTANT: Change the default value for testing or emergency situations only. token: a token that can be used to authenticate. Should be used in conjunction with the "oauth" authenticator. client_session_keep_alive: Set to true have a heartbeat in the background every hour to keep the connection alive such that the connection session will never expire. Care should be taken in using this option as it opens up the access forever as long as the process is alive. ocspFailOpen: true by default. Set to false to make OCSP check fail closed mode. validateDefaultParameters: true by default. Set to false to disable checks on existence and privileges check for Database, Schema, Warehouse and Role when setting up the connection All other parameters are taken as session parameters. For example, TIMESTAMP_OUTPUT_FORMAT session parameter can be set by adding: The Go Snowflake Driver honors the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY for the forward proxy setting. NO_PROXY specifies which hostname endings should be allowed to bypass the proxy server, e.g. :code:`no_proxy=.amazonaws.com` means that AWS S3 access does not need to go through the proxy. NO_PROXY does not support wildcards. Each value specified should be one of the following: The end of a hostname (or a complete hostname), for example: ".amazonaws.com" or "xy12345.snowflakecomputing.com". An IP address, for example "192.196.1.15". If more than one value is specified, values should be separated by commas, for example: By default, the driver's builtin logger is NOP; no output is generated. This is intentional for those applications that use the same set of logger parameters not to conflict with glog, which is incorporated in the driver logging framework. In order to enable debug logging for the driver, add a build tag sfdebug to the go tool command lines, for example: For tests, run the test command with the tag along with glog parameters. For example, the following command will generate all acitivty logs in the standard error. Likewise, if you build your application with the tag, you may specify the same set of glog parameters. To get the logs for a specific module, use the -vmodule option. For example, to retrieve the driver.go and connection.go module logs: Note: If your request retrieves no logs, call db.Close() or glog.flush() to flush the glog buffer. Note: The logger may be changed in the future for better logging. Currently if the applications use the same parameters as glog, you cannot collect both application and driver logs at the same time. From 0.5.0, a signal handling responsibility has moved to the applications. If you want to cancel a query/command by Ctrl+C, add a os.Interrupt trap in context to execute methods that can take the context parameter, e.g., QueryContext, ExecContext. See cmd/selectmany.go for the full example. Queries return SQL column type information in the ColumnType type. The DatabaseTypeName method returns the following strings representing Snowflake data types: Go's database/sql package limits Go's data types to the following for binding and fetching: Fetching data isn't an issue since the database data type is provided along with the data so the Go Snowflake Driver can translate Snowflake data types to Go native data types. When the client binds data to send to the server, however, the driver cannot determine the date/timestamp data types to associate with binding parameters. For example: To resolve this issue, a binding parameter flag is introduced that associates any subsequent time.Time type to the DATE, TIME, TIMESTAMP_LTZ, TIMESTAMP_NTZ or BINARY data type. The above example could be rewritten as follows: The driver fetches TIMESTAMP_TZ (timestamp with time zone) data using the offset-based Location types, which represent a collection of time offsets in use in a geographical area, such as CET (Central European Time) or UTC (Coordinated Universal Time). The offset-based Location data is generated and cached when a Go Snowflake Driver application starts, and if the given offset is not in the cache, it is generated dynamically. Currently, Snowflake doesn't support the name-based Location types, e.g., America/Los_Angeles. For more information about Location types, see the Go documentation for https://golang.org/pkg/time/#Location. Internally, this feature leverages the []byte data type. As a result, BINARY data cannot be bound without the binding parameter flag. In the following example, sf is an alias for the gosnowflake package: The driver directly downloads a result set from the cloud storage if the size is large. It is required to shift workloads from the Snowflake database to the clients for scale. The download takes place by goroutine named "Chunk Downloader" asynchronously so that the driver can fetch the next result set while the application can consume the current result set. The application may change the number of result set chunk downloader if required. Note this doesn't help reduce memory footprint by itself. Consider Custom JSON Decoder. Experimental: Custom JSON Decoder for parsing Result Set The application may have the driver use a custom JSON decoder that incrementally parses the result set as follows. This option will reduce the memory footprint to half or even quarter, but it can significantly degrade the performance depending on the environment. The test cases running on Travis Ubuntu box show five times less memory footprint while four times slower. Be cautious when using the option. (Private Preview) JWT authentication ** Not recommended for production use until GA Now JWT token is supported when compiling with a golang version of 1.10 or higher. Binary compiled with lower version of golang would return an error at runtime when users try to use JWT authentication feature. To enable this feature, one can construct DSN with fields "authenticator=SNOWFLAKE_JWT&privateKey=<your_private_key>", or using Config structure specifying: The <your_private_key> should be a base64 URL encoded PKCS8 rsa private key string. One way to encode a byte slice to URL base 64 URL format is through base64.URLEncoding.EncodeToString() function. On the server side, one can alter the public key with the SQL command: The <your_public_key> should be a base64 Standard encoded PKI public key string. One way to encode a byte slice to base 64 Standard format is through base64.StdEncoding.EncodeToString() function. To generate the valid key pair, one can do the following command on the shell script: GET and PUT operations are unsupported.
Package gotojs offers a library for exposing go-interfaces as Javascript proxy objects. Therefore gotojs assembles a JS engine which creates proxy objects as JS code and forwards the calls to them via JSON encoded HTTP Ajax requests. This allows web developers to easily write HTML5 based application using jQuery,YUI and other simalar frameworks without explictily dealing with ajax calls and RESTful server APIs but using a transparent RPC service. This service includes the follwing features: - Injection of Objects (like a session or http context) - Automatic include of external and internal libaries while the engine is loaded. - Routing to internal fileserver that serves static content like images and html files.
Package httpcache provides a http.RoundTripper implementation that works as a mostly RFC-compliant cache for http responses. It is only suitable for use as a 'private' cache (i.e. for a web-browser or an API-client and not for a shared proxy).
Package httpproxyfailover provides a means to construct a fault-tolerant HTTP proxy out of multiple somewhat unreliable HTTP proxies.