Imports github.com/mattermost/mattermost-server/mlog github.com/mattermost/mattermost-server/model github.com/mattermost/mattermost-server/services/configservice github.com/mattermost/mattermost-server/services/httpservice willnorris.com/go/imageproxy Standard library imports encoding/hex errors io io/ioutil net/http net/url strings sync time crypto/sha1 crypto/hmac net/http/httptest